A Primer for Understanding the 

Principles and Practices of Disaster 

Surveillance in the United States

National Center for Environmental Health

Division of Environmental Hazards and Health Effects
Suggested Citation: 

Centers for Disease Control and Prevention (CDC). A Primer for Understanding the Principles and Practices of 

Disaster Surveillance in the United States: First edition. Atlanta (GA): CDC; 2016.

For additional information or to obtain copies, please contact:

CDC’s Health Studies Branch at 4770 Buford Highway, MS F-60, Chamblee, GA 30341

Phone: +1 770-488-3410 Fax: +1 770-488-3450

You can electronically download this document from CDC’s, Division of Environmental Hazards and Health Effects, Health Studies 

Branch Website at http://www.cdc.gov/nceh/hsb/disaster/default.htm. 
Contents

Acknowledgements............................................................................................................................................................................ii

Introduction...........................................................................................................................................................................................1

Disaster Epidemiology......................................................................................................................................................................3

Purpose of Disaster Surveillance.................................................................................................................................................4

Understanding Surveillance...........................................................................................................................................................5

Types of Surveillance........................................................................................................................................................................5

Disaster Data Types...........................................................................................................................................................................8

Surveillance During a Disaster......................................................................................................................................................9

Planning for Surveillance................................................................................................................................................................9

Define Objectives...............................................................................................................................................................................9

Select Variables to Collect............................................................................................................................................................10

Determine Data Sources...............................................................................................................................................................11

Develop a Data Analysis Approach...........................................................................................................................................15

Frequencies.......................................................................................................................................................................................16

Monitoring Anomalies...................................................................................................................................................................17

Plan for Report Generation and Results Dissemination..................................................................................................19

Challenges of Surveillance in Disasters...................................................................................................................................20

Key Considerations in Conducting Surveillance..................................................................................................................24

Conclusion............................................................................................................................................................................................28

Glossary.................................................................................................................................................................................................29

Links.........................................................................................................................................................................................................30

References.............................................................................................................................................................................................31

 i
Acknowledgements

Acknowledgements

The first edition of the Primer for Understanding the Principles and Practices of Disaster Surveillance in 

the United States was developed by the Centers for Disease Control and Prevention, National Center for 

Environmental Health, Division of Environmental Hazards and Health Effects, Health Studies Branch (HSB). 

HSB acknowledges the following individuals for their collaboration and commitment in the development of 

the primer: 

Primary Authors:

Nicole Nakata, MPH; Amy Schnall, MPH; Amy Wolkin, DrPH; Rebecca Noe, MN, MPH; Sherry Burrer, DVM, 

MPH; and Tesfaye Bayleyegn, MD

Critical Reviewers:

We want to acknowledge the members of the Council of State and Territorial Epidemiologists Disaster 

Epidemiology Subcommittee who provided review and feedback on the primer. Special thanks to Ashley 

Conley, Nicole Cook, Miguel Cruz, Kenneth Dufault, Millicent Eidson, Svetlana Smorodinsky, and David Zane. 

 

Disclaimer

The findings and conclusions in this report are those of the authors and do not necessarily represent the 

official position of the Centers for Disease Control and Prevention.

ii
Introduction

Disasters can significantly affect human health 

and seriously disrupt the functioning of society. 

They cause widespread human, material, or 

environmental losses that exceed local capacity 

to respond, and call for external assistance.1

 These 

events can be categorized as natural, humaninduced, and complex. Natural events include 

tornadoes and earthquakes, human-induced include 

accidental chemical spills and terrorist events, and 

complex include famine and war. Disasters can 

severely impact a community’s well-being though 

major infrastructure damage and severe financial 

losses, straining local health care and emergency 

response capabilities and severely affecting health 

and the environment.2,3 Health risks include 

illness, physical injury, potential disease outbreaks, 

exacerbation of chronic illness, mental health issues, 

and death.4

Epidemiology plays an integral role in disaster 

preparedness, response, and recovery activities. 

During disasters, public health surveillance can 

provide useful information for targeted and 

effective public health response.5-10 However, 

according to a study by the Disaster Epidemiology 

Subcommittee of the Council of State and Territorial 

Epidemiologists (CSTE), the range of disaster 

surveillance activities conducted across U.S. states 

differ significantly.9

 States varied in whether they 

had performed disaster surveillance in the past 10 

years, had included surveillance in their jurisdiction’s 

response plan, and had used exercises to test their 

surveillance systems. Those that had conducted 

disaster surveillance activities reported the need 

for flexible disaster surveillance response plans, key 

partnerships established, and staff trained and ready 

to support surveillance activities before an event.9 

This primer was developed to provide introductory 

information on the purpose, importance, and 

methods for approaching disaster surveillance in the 

U.S.

 1
The audience for this primer is public health 

departments at state, local, tribal, and territorial 

levels. This document outlines how health 

departments can approach public health 

surveillance during a disaster and reviews principles 

and practices of disaster surveillance. It provides 

key concepts and challenges to consider when 

conducting disaster surveillance, but does not give 

step-by-step guidance. 

The principles and practices described in this 

document can be useful for developing surveillance 

systems for disasters if existing systems do not exist, 

or for leveraging or modifying existing systems for 

disaster situations. 

2
Disaster Epidemiology

To mitigate adverse health effects and reduce future 

impacts from disasters, public health officials must 

respond with appropriate public health actions. 

Those might include conducting epidemiological 

studies or program development and 

implementation throughout the disaster life cycle 

(i.e., preparedness, response, recovery, mitigation). 

Timely and accurate information is required so that 

actions from policy decisions during the mitigation 

and preparedness phases, to resource allocation 

during the response phase and long-term assistance 

in the recovery phase is appropriate and effective. 

Disaster epidemiology plays a major role 

throughout the disaster life cycle in providing 

needed information. In simple terms, disaster 

epidemiology is the use of epidemiology to 

investigate the short- and long-term health effects of 

disasters and to predict the health consequences of 

future disasters.11

Disaster surveillance is a tool in disaster 

epidemiology that

•	 provides ongoing, systematic collection, analysis, 

and interpretation of injuries, illnesses, and 

deaths for use in planning, implementation, and 

evaluation of public health practice;

•	 enables public health to track and identify 

morbidity and mortality linked to an event; and 

•	 provides insight into future disasters.12-14

Information collected from any surveillance system 

must serve to facilitate action, and therefore must 

be communicated to emergency managers, policy 

makers, public health staff, program leaders, and 

the public. Information can also be used to drive 

public health actions, target response activities, 

provide situational awareness, direct public 

communications, and address rumors.5-10,14,15

Surveillance can be invaluable in understanding 

the totality of the disaster’s human health impacts. 

Surveillance systems provide data on health events 

resulting from the disaster that are analyzed to 

characterize those events by person, place, and 

time. This information helps to identify where public 

health problems are, who is affected, and where and 

how they are affected.16,17

Information collected from any surveillance system 

must serve to facilitate action.

 3
Purpose of Disaster Surveillance

When disasters occur, many questions will need 

to be answered. These include what public health 

problems are occurring, where and why they 

are occurring, who is impacted, and which are 

causing the greatest public health problems. 

Disaster surveillance is an effective way to address 

these questions. It provides public health staff 

and other decision makers with actionable health 

information.15 Disaster surveillance helps to

•	 define and detect outbreaks and health problems 

early on;

•	 determine when, where, and how injuries, illnesses, 

and deaths occur;

•	 prepare for and prevent ongoing adverse health 

effects; 

•	 estimate the magnitude of a health problem;

•	 identify at-risk groups or geographic areas;

•	 demonstrate the need for public health 

intervention or resources;

•	 inform and monitor the effectiveness of response 

and relief efforts; and

•	 assist with planning for future disasters and 

recommend ways to decrease the consequences of 

future disasters.14

For many conditions, surveillance is used to 

monitor and track morbidity (i.e., illness or disease) 

and mortality (i.e., fatalities) in a population or 

subset of a population, such as first responders.18

Surveillance can track morbidity and mortality 

from communicable diseases such as norovirus and 

waterborne diseases, and chronic diseases such 

as diabetes and chronic obstructive pulmonary 

disease (COPD). Surveillance also might track injuries 

from carbon monoxide (CO) exposure, falls, and 

other causes; health consequences of exposure to 

chemicals and environmental contaminants; and 

behavioral and mental health issues. 

Without surveillance data, decision makers’ 

actions might not address the most urgent needs 

of the affected population. When implementing 

a disaster surveillance system, keep in mind 

that information must be promptly dispersed to 

health and government officials and emergency 

managers who are in a position to take action 

based on data-driven recommendations. This is the 

primary purpose of disaster surveillance: to provide 

timely, accurate, and relevant information to drive 

decisions and interventions during a disaster.12,19-22 

Surveillance also helps plan for future disasters. 

As issues are resolved and needs arise, continued 

disaster surveillance allows responders to track and 

redefine public health problems and priorities as 

the disaster progresses and moves to new phases.12

Finally, disaster surveillance serves to highlight areas 

for future research and training, which will help 

jurisdictions better prepare for disasters.23

Disaster surveillance helps to identify disasterrelated health problems; provides information to 

prevent or reduce injury, illness, or death; and helps 

guide prevention strategies for future disasters.

4
Understanding Surveillance

Types of Surveillance

Passive Surveillance

Traditionally, surveillance systems are classified as 

passive or active. Passive surveillance is the regular 

reporting of disease data by health institutions to 

health authorities. In a passive surveillance system, 

there is no active search for cases, rather it involves 

passive notification by the health care facilities or 

practitioners.24 For example, hospitals, clinics, public 

health facilities, laboratories, and other sources 

report pre-determined notifiable diseases to state 

health departments due to legal state mandates.25

This is the basis of notifiable disease surveillance in 

the U.S. The National Notifiable Disease Surveillance 

System (NNDSS) collects information on selected 

infectious and non-infectious diseases and 

conditions, such as salmonellosis, West Nile virus, 

and carbon monoxide (CO) poisoning that can be 

used as a data source during disasters.26

Passive systems are useful beause they

•	 are relatively inexpensive, 

•	 are cost-effective to implement, 

•	 have a low data collection burden, and

•	 provide important information for monitoring a 

population’s health. 

Often data requested from passive systems are 

minimal. If a large area needs to be covered, passive 

surveillance may be used as a relatively inexpensive 

strategy. For example, following a widespread 

disaster, passive surveillance may be used to monitor 

vaccine-preventable disease occurrence, such as 

tetanus. However, because passive surveillance 

depends on health officials and procedures in 

different institutions to provide data, the quality 

and timeliness of those data are difficult to control.7 

Reporting can be slow, variable, or incomplete if the 

responsible health officials do not report regularly. 

Slow and irregular reporting are concerns in disaster 

situations where timely information is needed. These 

issues with passive systems might be compounded 

if the health care infrastructure is damaged or 

destroyed.27 

Active Surveillance

Active surveillance uses designated staff 

members to regularly contact heath care providers, 

laboratories, hospitals, the population, and others 

to seek information about health conditions. Active 

surveillance is often more sensitive and may collect 

information that is more detailed than passive 

system data since staff can search or request for 

specific information about cases.25

During disasters, epidemiologists may use active 

surveillance systems in addition to passive 

surveillance. After Hurricane Andrew, for example, 

the Louisiana Office of Public Health, in coordination 

with emergency departments, public utility 

personnel, and coroners, used active surveillance to 

facilitate health impact and outcome reporting in 

the affected areas.28

Active surveillance is commonly used in disaster 

situations where tents, temporary shelters, mobile 

clinics, or other venues are established for shortterm medical care by response agencies such as 

Active systems are useful because they

•	 can complement regular reporting functions 

disrupted by the disaster;

•	 can be used in non-traditional settings, such 

as evacuation centers and temporary shelters, 

providing more flexibility than regular reporting 

mechanisms;

•	 can be targeted to determine the needs of 

special populations or identify groups, more at 

risk for adverse health events; and

•	 often provide more complete information than 

passive surveillance. 

 5
the American Red Cross and the military.7 Whether 

you use active, passive, or a combination of both is 

determined by the specific disaster situation and 

available resources. 

Although active surveillance provides the 

most accurate and timely information, it is also 

expensive and labor intensive. Resource scarcity 

in disaster settings and the cost of running active 

surveillance might limit its use to short periods 

and the investigation of specific health concerns.27

Differences in format, methods of data collection, 

and reporting across sources also make it difficult to 

aggregate this information unless the surveillance 

system uses mechanisms such as standardized 

questionnaires to diminish such differences. 

Sentinel Surveillance 

Sentinel surveillance is an active or passive 

surveillance system that collects data from a 

limited number of recruited participants or 

providers to report on specific health events.29 The 

selected sample of reporting sources may serve to 

estimate trends in the larger affected population.7

Sentinel surveillance providers may include clinics, 

hospitals, other health care facilities, laboratories, 

or physicians. Providers included in the sentinel 

surveillance system report all cases of the conditions 

of interest. 

Sentinel systems are useful because they 

•	 monitor trends effectively,

•	 overcomes issues of underreporting,

•	 monitor a greater number of conditions,27

•	 are less costly than other methods,7 and

•	 are flexible and can be scaled up by recruiting 

additional surveillance sites.

Sentinel surveillance can be established to 

supplement an existing surveillance system. 

After the 2010 earthquake in Haiti, national and 

international agencies collaborated to form the 

National Sentinel Site Surveillance System to 

monitor disease trends, detect outbreaks, and 

characterize the affected population to target 

relief efforts to areas of need.30 Over the course of 3 

months, 51 selected hospital and clinic surveillance 

sites provided daily telephone or email reports for 25 

specified conditions. During that time the sentinel 

system did not pick up any anomalies, but was used 

as proof to dispel rumors about disease clusters and 

outbreaks.30

Although sentinel surveillance can be extremely 

useful for detecting large public health problems, 

it might not capture rare events, such as the early 

emergence of a new disease, which might occur 

in areas not covered in the sentinel surveillance 

system.7 The sentinel sites selected also might not be 

representative of the larger disaster-affected area, 

depending on how the sample is selected. 

Syndromic Surveillance

Syndromic surveillance is an active or passive 

system that uses case definitions or syndromes 

based on a group of signs and symptoms, primary 

complaints or presumptive diagnoses, or other 

characteristics of the disease, rather than specific 

clinical or laboratory diagnostic criteria. Data can 

be gathered from traditional surveillance sources, 

such as emergency rooms and physicians, or from 

non-traditional sources such as nurse hotlines 

and pharmacies.31 Each source included in the 

syndromic surveillance system reports any case 

matching the syndromes being monitored to the 

appropriate health authority. This process can be 

automated for quicker turnaround of information. 

In instances where the health infrastructure is 

maintained but increased timeliness is important, 

syndromic surveillance can supplement existing 

active or passive systems. In these situations, adding 

or monitoring specific syndromes, such as fever 

6
and shortness of breath, in an existing surveillance 

system may ensure that you capture essential 

data.3 However, syndromic surveillance is often less 

specific and can be subject to misclassification. 

It might identify more people than actually have 

the condition of interest and might result in more 

complex data analyses and handling. For example, 

if a jurisdiction is interested in monitoring flu-like 

syndromes following a snowstorm, the number of 

true positives of influenza may be a much smaller 

number than the number of cases flagged by the 

syndromic surveillance system and would require 

additional data, such as laboratory confirmation, to 

monitor influenza trends.

Syndromic systems are useful because they 

•	 are timely, providing early information and 

situational awareness, sometimes in near 

real time; 

•	 do not require health care practitioners to 

make diagnoses, which can be time consuming 

and difficult;

•	 do not require laboratory confirmation; and

•	 can detect outbreaks early on.

Syndromic surveillance is particularly useful in the 

early stages of a disaster if routine surveillance 

has been disrupted or has not been established. 

Flexibility and timely reporting are ideal. It can be 

used many ways, including situations where health 

effects are widespread, as in wildfires or hurricanes. 

It can be used to rule out an illness outbreak after 

a disaster or to detect and monitor health impacts 

that affect only a few individuals.8 In 2001, after the 

World Trade Center attacks, syndromic surveillance 

was established in New York to help quickly 

identifying potential outbreaks or illnesses that 

could be linked to a bioterrorist event.25 Syndromic 

surveillance provides early identification of potential 

morbidity and mortality because the system can 

identify potential cases from doctor or emergency 

department visits before a person’s condition 

is officially diagnosed.11 In areas particularly 

devastated by a disaster, syndromic surveillance 

provides an earlier indication of unusual increases in 

illnesses, injury, or death to shape early intervention 

efforts.

CDC’s National Syndromic Surveillance Program 

(NSSP) BioSense Platform is a public health 

surveillance system that increases the ability of 

health officials at local, state, and national levels to 

efficiently, rapidly, and collaboratively monitor and 

respond to harmful health effects of exposure to 

disease or hazardous conditions. The Platform gives 

users access to the data and technology to conduct 

syndromic surveillance to track health issues and 

rapidly share information with others in the system. 

After the 2010 Deepwater Horizon Gulf oil spill, state 

and local jurisdictions coordinated with CDC and 

other federal agencies to use the BioSense Platform 

to monitor 21 conditions. The monitoring produced 

daily situational awareness reports for affected state 

and local responders.32 Another example, in 2007 

CDC personnel monitored data received by the 

Biossense Platform for evidence of health effects 

possibly related to wildfires in San Diego County, CA. 

Visits for diagnoses and chief complaints of asthma 

were all increased during the monitoring period.33

More information about the BioSense Platform 

and NSSP is available at http://www.cdc.gov/nssp/

biosense/index.html. 

 7
Surveillance during a Disaster

Disasater Data Types

Disaster surveillance is often defined by data types: 

morbidity and mortality. 

•	 Morbidity is the state of being ill, diseased, or 

injured or the incidence or prevalence of illness or 

injury in a population.18

•	 Mortality is the incidence of death in a 

population.18 It is an important indicator of the 

gravity of a disaster. 

Detecting outbreaks of infectious disease such 

as gastrointestinal and respiratory illness after a 

disaster is crucial, especially when populations are 

displaced and sheltering in large groups. However, 

data collected after Hurricane Katrina and other 

major disasters show that health events in disasters 

are not limited to infectious diseases. Chronic illness, 

injury, and mental health outcomes can worsen and 

often play a larger role than communicable disease.17

Therefore, surveillance systems need to monitor 

morbidity and mortality related to non-infectious 

conditions such as chronic disease, mental health 

issues, CO poisoning, and injury, especially focusing 

on at-risk populations (e.g., young children, pregnant 

women, elderly).17

Morbidity Surveillance

Disaster-related morbidity surveillance helps 

inform decisions about allocating resources, 

targeting interventions to meet specific needs, 

triggering public health response, and planning for 

future disasters.34 Morbidity surveillance collects 

information on 

•	 incidence rate, 

•	 prevalence rate, and 

•	 stratified rates (e.g., by age, sex, geographic 

location).

Mortality Surveillance 

The mortality (death) rate helps to measure the 

impact of a disaster on a population.19 It can assist in 

determining the magnitude of event-related health 

effects, evaluating prevention policy effectiveness, 

and identifying preventable disaster-related deaths.6 

Important mortality-related data to collect include

•	 demographic characteristics, 

•	 time and location of death, and 

•	 cause and manner of death. 

8
Surveillance During a Disaster

During a disaster, data collection conditions are 

often chaotic and unpredictable. Surveillance is time 

and resource intensive, so use the most efficient 

method of reaching your objectives.35

The preferred approach is to use preexisting 

surveillance data for baseline information and 

modify established epidemiologic surveillance 

systems for disaster settings. In the U.S., many 

existing public health infectious disease surveillance 

systems can be used or modified for use during a 

disaster. Many states also have systems to monitor 

non-infectious diseases and injuries, which might be 

beneficial.15 Examples of existing state surveillance 

systems include NCDETECT in North Carolina, 

ESSENCE in Florida, and SPARCS in New York.36-38

A supplemental or ad hoc surveillance system will 

be useful 

•	 if the area lacks a preexisting surveillance 

infrastructure, or

•	 in circumstances where populations are 

displaced and temporary health care facilities 

are established. 

Planning for Surveillance

Sometimes a surveillance system has not been 

created. Other times the existing surveillance 

systems are insufficient or have been compromised 

because the health infrastructure is severely 

damaged. In such situations, you might need to 

conduct supplemental surveillance, create a new 

system, or modify one that is available.7 

Whether you plan to use an existing surveillance 

system and supplement it as needed or you need 

to create a new system or modify an existing one, 

careful planning is important and should be done 

in the preparedness phase of the disaster cycle.21

Determining priority conditions or indicators to 

monitor will help to ready jurisdictions to rapidly 

conduct disaster surveillance.17 Although no one 

approach fits all situations, key steps to help you 

develop a disaster surveillance system include the 

following:

•	 Define objectives

•	 Select variables for data collection 

•	 Determine data sources 

•	 Develop a data analysis approach

•	 Plan for report generation and results 

dissemination

Disaster surveillance is a fluid process. Outcomes 

from previous or current surveillance activities 

might affect the surveillance objectives and data 

collection, analysis, and dissemination.39 As with all 

disaster activities, surveillance should be flexible 

and adaptable and integrate lessons learned from 

previous experiences. Knowing how to adapt 

existing systems to your needs can help facilitate 

your disaster surveillance activities.

Define Objectives

Set clearly defined objectives for your system in 

the preparedness phase. A surveillance system 

may be more likely to collect the information you 

need to answer your questions if you create strong 

objectives early on. Failing to create clear objectives 

may result in collecting unnecessary information, 

wasting time and resources. The objectives describe 

how the surveillance information will be used to 

inform public health actions. 

Potentially useful objectives of a disaster surveillance 

system include the following:

•	 Monitoring the affected population’s health for a 

defined time period

•	 Estimating the magnitude of a health problem

•	 Tracking disease trends for early detection and 

outbreak control

•	 Identifying priority health needs, both immediate 

and long-term

 9
•	 Identifying causes of event-related injury and 

illness

•	 Tracking the geographic distribution of morbidity 

and mortality

•	 Focusing resources on groups that might be more 

vulnerable to disaster-related impacts and other 

disproportionately affected populations

•	 Evaluating public health actions and interventions

•	 Identifying research needs and evaluating control 

strategies5,19

Additionally, when defining your objectives, you 

should plan for which phase of a disaster you will 

implement surveillance and how your objectives 

may change as you shift from one phase to another. 

In the response phase, for example, the main priority 

of surveillance is to reduce morbidity and mortality 

rates. In contrast, an objective in the recovery phase 

may be to evaluate program interventions.19

After establishing the objectives, use them to 

limit your data collection and sites to the simplest 

possible solution that will meet the objectives. 

Consider data quantity versus timeliness and 

simplicity. You do not want to burden or overwhelm 

staff, therefore, collecting only the information that 

is absolutely needed is important.

Select Variables to Collect

After you have developed your objectives, you will 

need to select variables for data collection and 

establish case definitions. A case definition is a set 

of standard criteria for classifying whether a person 

has a particular disease, syndrome, or other health 

condition. Case definitions must be simple, clearly 

defined, understandable, and practical for use in a 

disaster setting. Generally, case definitions include 

criteria for person, place, and time.27

During a disaster, time and resource constraints 

often will limit your case definitions to 

•	 simple clinical signs and symptoms, and

•	 a few common conditions.19

For disaster surveillance, case definition criteria 

might differ from clinical criteria when diagnosing an 

illness, disease, or other health condition. You might 

be dependent on initial impressions, chief complaint, 

or a broad category of signs and symptoms (e.g., 

nausea, diarrhea, skin irritation, conjunctivitis) 

rather than laboratory results, discharge diagnosis, 

or other confirmatory information.5,25 You might 

need to make a trade-off between degree of 

certainty in diagnosis and timeliness of reporting. 

Common clinical signs and symptoms could include 

fever alone or in combination with sore throat or 

cough.40 Disaster surveillance often also includes 

noncommunicable conditions such as burns, 

chemical exposures, CO poisoning, physical trauma, 

and adverse mental health effects. 

When developing case definitions, consider both

•	 direct health effects — caused by the disaster’s 

actual, physical forces, or essential elements (e.g., 

flooding from a hurricane or flying debris in a 

tornado), and

•	 indirect health effects — caused by unsafe 

or unhealthy conditions that develop from the 

effects of the disaster or events that occur from 

anticipating the disaster (e.g., motor vehicle 

accidents during mandatory evacuation).41

Without case definitions that account for both the 

direct and indirect effects of a disaster, surveillance 

data may be incomplete or may not accurately 

capture the health needs of the affected population. 

The information you collect will be limited by 

your available human and financial resources. The 

conditions and determinants under surveillance 

should not affect the system’s ability to operate 

10
throughout the extent of the disaster.14 Remember 

to set your objectives and priorities for case 

definitions based on those considerations. 

To aid with timeliness and standardization, you 

ight use established case definitions such as 

hose established by NNDSS (http://wwwn.cdc.

ov/nndss/conditions/). 

m

t

g

Determine Data Sources

Before creating a new form to collect data, try to 

find out what existing data sources are available.

Whether you are using or modifying an existing 

surveillance system or creating a supplemental 

or active surveillance system, the objectives and 

type of surveillance system will help determine 

the data source(s). Consider identifying existing 

potential data sources and establishing working 

relationships with partners during the preparedness 

phase. For example, if you are interested in mortality 

surveillance it would be helpful to reach out to your 

partners in vital statistics, funeral directors, medical 

examiners and coroners, and mass fatality staff 

to see their electronic death registration system 

(EDRS) capabilities. Additionally, nongovernmental 

organizations (e.g., American Red Cross) and federal 

agencies (e.g., FEMA) may be collecting mortality 

information that could supplement your existing 

efforts. 

Many sources for morbidity and mortality data are 

available. These include national and state-based 

reportable disease systems, electronic or paper 

hospital records, census data on vulnerability 

and health predictors, disease registries, and 

health surveys (e.g., National Health and Nutrition 

Examination Survey, Behavioral Risk Factor 

Surveillance System).15,17

Health Care Facilities

Hospital and other health care facility data can 

provide a look at morbidity and mortality for certain 

conditions that are attributed to a disaster to 

determine increases due to the event. Hospitals in 

the U.S. currently use the International Classification 

of Diseases, 10th revision, Clinical Modification 

(ICD-10-CM) codes to classify diseases and health 

issues. The ICD alpha numeric codes allow for 

morbidity and mortality data to be systematically 

classified, compiled, and compared.42 This coding 

enables searches for disaster-related ICD codes (e.g., 

X37 for cataclysmic storm, T58 for toxic effects of 

carbon monoxide) to gather morbidity and mortality 

surveillance data. 

The ICD-10 site can be accessed at 

https://www.cms.gov/Medicare/Coding/icd10/.

In the U.S., many hospitals and health care providers 

use electronic information systems, which are a 

potential source for large amounts of data. Electronic 

health records and exchanges are valuable data 

sources that can help address baseline and logistical 

constraints on data collection.15,43, 44

When electronic systems are not available, paper 

forms can be used to collect morbidity and mortality 

data. Using pre-created, validated, and standardized 

collection instruments is ideal in disaster situations. 

They save time and resources and may allow for 

cross-jurisdictional standardization for comparison 

and data aggregation.11 Abbreviated forms can 

be used if summary or less-detailed information 

is sufficient or when the burden of collecting 

detailed, individual information is substantial. CDC 

has developed multiple, ready-to-use templates 

for morbidity and mortality surveillance forms. You 

can use these templates to supplement existing 

surveillance, temporarily replace a system, or create 

an ad hoc surveillance system (e.g., in a shelter 

where no system previously existed).

You can access these surveillance templates on 

the CDC Emergency Preparedness and Response 

website (http://emergency.cdc.gov/disasters/

surveillance/).

 11
During a disaster, the Red Cross, if deployed, 

captures aggregate morbidity data, from their 

shelters onto a report form. Public health working 

with local chapters of Red Cross can develop 

information sharing protocols for such events. 

Although using existing data sources and forms is 

preferred, you may need to create new surveillance 

forms for some disaster circumstances (e.g., severe 

health care infrastructure disruption, persons 

seeking care outside typical acute care settings) or 

when no forms or existing data sources are available 

to meet your surveillance objectives.17

Ideally, surveillance forms will be developed, tested, 

and distributed before a disaster. However, you 

might need to modify them depending on factors 

such as disaster type, available resources, and 

surveillance site. The forms should be easy to use 

and only collect the most essential information to 

simplify data entry. 

Vital Statistics

Vital statistics (i.e., death records) are the gold 

standard for mortality surveillance. They provide 

data on demographic characteristics, geographic 

location, and cause of death. However, death record 

data can take months to obtain and might be of 

limited use in the response phase. Electronic death 

registration systems (EDRS) have been established 

in 38 of the 57 vital statistics jurisdictions in the U.S. 

EDRS allow for electronic filing of death certificates 

anywhere that has Internet access. They provide 

timely data in a more standardized manner that 

can be shared across jurisdictions and with federal 

agencies.45 

To facilitate inter-jurisdictional data exchange, the 

National Association for Public Health Statistics 

and Information Systems developed the State and 

Territorial Exchange of Vital Events (STEVE) system. 

Jurisdictions and federal agencies can use this 

messaging application to electronically exchange 

vital event data such as death certificates.45 

Electronic recording and sharing of death data can 

potentially provide a useful, timely, and streamlined 

source of baseline and event specific mortality 

surveillance data collected from various agencies 

and jurisdictions (e.g., Red Cross, Federal Emergency 

Management Agency [FEMA], state emergency 

operation centers). 

You will face various challenges in using EDRS for 

disaster-related mortality surveillance. Some of these 

include a lack of standardized cause of death entry 

and coding, missing data on disaster-relatedness 

in a death entry, and limitations on the search 

capabilities within the system. Timely reporting 

and high quality information on cause of death and 

injury are required for EDRS to be beneficial in a 

disaster.46 When collecting morbidity and mortality 

data, it helps to have the death certificate flagged as 

disaster-related so the record can be retrieved and 

tracked. It also helps to work with your local medical 

examiners or coroners during the preparedness 

phase to enlist their aid in the identification and 

reporting of all disaster-related deaths. CDC’s 

“Reference Guide for Certification of Deaths in the 

Event of a Disaster” has information to help you with 

in this process. 

Poison Centers

Poison centers (PCs) are a useful source of 

information on chemical exposures and poisonings 

related to disasters. PCs can provide background 

data and situational awareness by helping to 

monitor and detect outbreaks and trends and track 

disaster-related exposures, among other activities.43 

A network of 55 regional PCs services all parts 

of the country and U.S. territories through one 

national hotline number. Data collected from calls 

to PCs are uploaded into the National Poison Data 

System (NPDS). NPDS is a near-real time, national 

electronic data repository and web-based public 

health surveillance system. CDC uses NPDS data 

for surveillance of disaster-related exposures and 

associated illnesses (e.g., CO poisoning, foodborne 

outbreak). During a disaster, PCs can flag calls related 

12
to the event with a code based on a predetermined 

case definition or inclusion criteria. This allows for 

easy, systematic tracking of all event-related calls.43 

At the national or regional level, PC data can be used 

to indicate

•	 the extent of toxic exposures related to the disaster 

through call frequencies over time, 

•	 the basic demographic distribution of 

toxic exposures related to the disaster and 

potential vulnerable populations who may be 

disproportionately affected, 

•	 health communication messaging needs of the 

affected population, and 

•	 the severity of toxic exposures and illness related 

to the disaster through a medical outcome 

measure used by all PCs.47 

Local and state public health personnel can also 

leverage this data to supplement existing disaster 

surveillance systems (e.g., to track CO exposure 

during disasters). At the local level, public health 

agencies can use this information for event mapping 

down to the zip code level, or case-finding of high 

priority exposures related to the disaster. You should 

establish partnerships with PCs before a disaster to 

provide for effective surveillance at the local level. 

Such partnerships can help local and state public 

health collaborate with PCs to access and use their 

data and technology to conduct public health 

disaster surveillance activities.43 

Affected Workers

In addition to the general public, health care and 

response workers can be affected by injury or illness 

during disasters, especially emergency responders, 

who often have the highest exposures. CSTE and 

CDC’s National Institute for Occupational Safety and 

Health (NIOSH) have a number of resources available 

for assessing worker health effects and exposures. 

CSTE’s Occupational Health Subcommittee is a useful 

 13
resource (http://www.cste.org/members/group.

aspx?id=106606). Each state has an occupational 

safety and health contact (http://www.cdc.gov/

niosh/statosh.html). NIOSH also has occupational 

health surveillance resources (http://www.cdc.gov/

niosh/topics/surveillance/). 

For assessing emergency responders, The 

Emergency Responder Health Monitoring and 

Surveillance (ERHMS) system is a multi-agency 

health monitoring and surveillance framework that 

includes recommendations and tools for protecting 

emergency responders. This tool can help identify 

potential exposures and detect and address health 

issues relief and response workers that may arise 

from their work. 

More information about ERHMS is available at 

http://www.cdc.gov/niosh/topics/erhms/default.

html.

Unstructured Data

Nontraditional sources of surveillance information 

that can be useful include news and media outlets. 

Unstructured data from these sources include 

information that is not part of an organized 

database designed to be quantitatively analyzed.23

Access to data (e.g., media reports of disasterrelated mortality) on the Internet is widespread 

and can help with timely detection of health events 

and more complete situational awareness. During 

Hurricane Sandy, for example, CDC evaluated 

the usefulness and accuracy of online media 

reports for disaster-related mortality surveillance. 

Epidemiologists used key word searches to track 

media reports in the affected region for Sandyrelated deaths and to obtain demographics and 

circumstance of death. Data from the online media 

reports provided timely information on disasterrelated mortality and could serve as a supplemental 

source of data in disasters.48 Additionally, memorial 

websites posted after mass fatality events might list 

mortality data, and social media sites may identify 

morbidity trends or outbreaks.19-51 These types of 

data may have lower specificity and reliability, but 

they can be valuable in a disaster situation where 

timely information is key. They can provide valuable 

information to supplement data gathered through 

more traditional sources such as public health and 

health care providers.23

14
Analyzing Data Develop a Data Analysis Approach

After having gathered the surveillance data, you 

want to analyze it by person, place, and time.14

In disaster situations, you will want to conduct 

analysis and reporting frequently to quickly and 

effectively identify potential health issues and 

transmit that information to decision makers so 

they can implement timely interventions.19,52 During 

the response phase, daily analysis and reporting 

is encouraged.52 As the disaster progresses and 

surveillance needs shift or surveillance reverts 

back to more passive systems, you may consider 

transitioning to weekly or more infrequent 

analysis. In the preparedness phase, determine 

the appropriate analytic approach. Consider the 

technical capacity available for analysis, level of 

analysis complexity, and how frequently you will 

tabulate data.14,27 Data analysis is driven by your 

surveillance system’s purpose and design.53

Descriptive analyses are useful in disaster situations 

because they are often simple, quick to calculate, 

and provide information for concrete public health 

action in an understandable manner. This approach 

involves calculating rates and identifying high-risk 

population groups. It involves answering questions 

of person, place, and time, such as “How much injury 

is occurring in a population?” and “Is one part of the 

population more negatively affected by the disaster 

than another?”12,25,27 For unexpected results, you 

can conduct more in-depth analysis or research to 

identify factors contributing to those outcomes.53

For example, Alabama and Texas analyzed morbidity 

and mortality data focusing on carbon monoxide 

exposure following Hurricanes Katrina and Rita 

in 2005. After conducting general descriptive 

statistics, they conducted more in-depth data 

analysis on specific results, including determining 

correlation between generator placement and 

carboxyhemoglobin (COHb) levels found in 

patients.54 

 15
Additionally, the Sphere Project* recommends 

stratifying data based on sex, age, individual 

vulnerability, affected and host populations, 

and context (e.g., shelter and non-shelter) when 

possible.55 After the 2010 Haiti earthquake, 

epidemiologists stratified data from the sentinel 

surveillance system by location, identifying the 

regions which accounted for a majority of reported 

conditions, as well as by age, identifying the 

morbidity of those under 5 years of age.30 It might 

also help to disaggregate by community member 

and response or relief workers. Stratifying data in this 

manner can help to identify potentially vulnerable 

groups and those disproportionately affected by the 

disaster. It can also help identify the occurrence of 

morbidity and mortality during the disaster. Relief 

workers and community members may be affected 

by the same disaster differently because their roles 

and exposures may differ.56,57 However, detailed 

disaggregation may be difficult during the early 

stages of a disaster. 

Frequencies

Common and useful measures for analyzing injury or 

illness frequency include incidence and prevalence.53

Incidence measures the occurrence of new cases of 

death, disease, or injury in a population. Prevalence 

measures the existing cases of death, disease, or 

injury .19,53 When providing case counts, clearly 

define whether the counts are related to new 

(incident) cases or current (prevalent) cases in the 

period. 

Incident cases or prevalence counts are usually 

simple and easy to understand. They can be useful 

for identifying clusters of disease and for health 

planning. An example is identifying needs, such as 

the number of beds or doses of vaccine required in 

a shelter.25 However, counts alone may not provide 

all of the information needed nor allow you to 

compare events in population groups of differing 

sizes or in different locations.19 For example, you 

cannot compare the 10 cases of illness in one 

shelter to the 20 cases of illness in another shelter 

without knowing the population of each shelter. As 

a shelter’s population fluctuates widely, a system 

(e.g., “heads in beds”) can help keep track of the 

denominator as the response situation evolves. For 

surveillance data to be useful, case counts must 

be related to the population size.25 You can do this 

by calculating incidence, prevalence, and other 

morbidity and mortality rates.19,25

Rates are measures of risk that allow you to compare 

the frequency of morbidity and mortality in different 

places, times, or population groups.25 Usually, a 

calculation of the number of cases and rates includes 

a description of the population (person), location 

(place), and the period (time) for the condition.25

•	 You could analyze data by person to identify 

subgroups (e.g., age, sex) that may be at increased 

risk for negative health outcomes by comparing 

instances of morbidity and mortality in various 

groups (e.g., general population, women, children, 

disabled, elderly). 

•	 You could analyze data by place by adjusting for 

differences in the size of the population in the 

assigned geographic areas. For instance, you could 

compare rates of injury in the disaster affected 

population to the rates occurring in a non-disaster 

affected population in the same region. 

•	 You could analyze data by time to describe trends 

and detect changes in disease occurrence or 

frequency. This can help determine if you have 

an outbreak of diarrheal illness in a shelter or if 

death among children younger than 5 years have 

increased as a result of the disaster.25

* The Sphere Project is a multi-agency, nongovernmental organization 

initiative to improve humanitarian actions during disaster response. The 

Sphere Handbook presents a Humanitarian Charter and a set of minimum 

standards for humanitarian response to disasters. It provides concepts for 

planning, implementation, monitor, and evaluation in responses and supports 

disaster preparedness activities and contingency planning. More information is 

available at http://www.spherehandbook.org/.

16
For example, after Hurricane Opal, surveillance data 

for 20 conditions were analyzed by time, comparing 

the proportional morbidity rates of ED visits for 

these conditions for 6 days after the hurricane 

to the ED visits 6 days before the hurricane.58

Although calculating rates such as these can be 

beneficial, denominator or baseline data may not be 

available to make these calculations in the disaster 

setting. Analysis may then be limited to calculating 

incident cases or prevalence only. Basic analysis 

such as providing incidence or prevalence rates is 

commonly done in surveillance and provides a quick 

picture of what is going on in the field.59,60 

The analysis you conduct depends on the objectives 

of your surveillance and the design of your system, 

as well as the availability of resources. Table 1 

lists some common parameters for analyzing 

morbidity and mortality surveillance data in disaster 

situations.19,55

Before data analysis, consider the audience for 

your information and how you will present this 

information to them. By drafting your table shells 

early on, you will be prepared to insert your results 

into the shells for quick reporting turnaround. 

Monitoring Anomalies

When interpreting your surveillance data, first 

think of the limitations of your information and of 

the specific type of surveillance system and data 

collection methods used. Different systems have 

inherent strengths and weaknesses; be familiar with 

those before analyzing and interpreting your data.53

Doing so will help you determine whether any 

anomalies in data patterns are the result of bias (e.g., 

recall, sampling) or are important health events that 

need to be addressed. In addition, you want to keep 

in mind the objectives of your surveillance system 

and key questions you are trying to address. Other 

useful questions to consider when monitoring for 

anomalies include the following:

•	 What are potential areas where you expect an 

increase in frequency of reports? 

•	 What are the alert thresholds or signal detection 

levels for your surveillance system?

•	 Is there an increase in frequency of a reported 

health condition? If so, is it related to the disaster 

and does this increase signify a need for response?

•	 Are cases clustered by time or geographic 

location?

•	 Have there been any changes to surveillance 

system or data collection over time?53

Monitoring for anomalies in your surveillance data 

will help determine whether or not public health 

action is required. For example, a spike in the 

incidence and 30-day mortality from myocardial 

infarctions and stroke were found after Hurricane 

Sandy in New Jersey.61 To help interpret your 

surveillance data and make decisions, the Sphere 

Project recommends using supplementary data 

from other sources (e.g., surveys, baseline data, 

BRFSS, NHANES, health department surveys).55 If 

the expertise and resources are available, consider 

building algorithms into the surveillance system 

and analysis to identify statistical anomalies in the 

data. However, this may not be practical for disaster 

situations.62 To better detect anomalies, it may be 

helpful to analyze certain data more frequently in 

the initial phases of a disaster.53 This can provide a 

more immediate picture of the ongoing changes in 

morbidity and mortality in the affected population. 

It also might reveal biases in the data that need to 

be investigated.

 17
Table 1. Definitions and formulas for surveillance parameters. 

Measure of 

Frequency

Measure Definition

Counts Incident cases† The occurrence of new cases of death, disease, or injury in a 

population over a specified period

Prevalent cases† The existing cases of death, disease, or injury in a population 

over a specified period

Morbidity and 

mortality rates

Incidence rate (new 

cases)‡

The number of new cases of a disease or injury that occur 

during a specified period per unit of person-time at risk (can be 

stratified by age and sex)

Prevalence or 

prevalence rate (total 

existing cases)†

The proportion of people in a population who have a particular 

health condition at a specified point in time or over a specified 

period

Crude mortality rate 

(CMR)‡

The rate of death in the entire population (includes all people, 

regardless of sex or age)

Cause-specific 

mortality rate§

The mortality rate from a specified cause for a population in a 

specified period

Age-specific 

mortality/morbidity 

rate (<5 years, >5 

years)‡

A mortality/morbidity rate limited to a particular age group 

(e.g., under-5 mortality rate [U5MR] is the rate of death among 

children younger than 5 years in a population)

Incidence proportion 

(attack rate, generally 

used for infectious 

conditions)†

The proportion of an initially disease-free population that 

develops disease, becomes injured, or dies during a specified 

(usually limited) period

Proportional 

morbidity/mortality§

The proportion of all deaths/new or existing cases in a specified 

population over a period attributable to a specific cause

Case fatality rate 

(CFR)‡

The proportion of people with a health condition in a specified 

period who die from it

Program 

process rates

Health facility 

utilization rate‡

The number of outpatient visits per person per year (if it is 

possible, distinguish between new and old visits and use new 

visits to calculate the rate)

Number of 

consultations per 

clinician per day‡

The average number of total consultations (new and repeat 

cases) seen by each clinician per day

† CDC 2012c

‡ The Sphere Project 2011

§ Abdallah and Panjabi 2008

18
Plan for Report Generation and 

Results Dissemination

Information gathered from the surveillance system 

is most useful if quickly shared with stakeholders to 

use for public health action.7,12 You should identify 

stakeholders during the preparedness phase. They 

may include public health agencies, government 

officials, relief and response workers, the affected 

community, and the media. Establishing reporting 

and communication plans during the preparedness 

phase helps ensure this information is transmitted 

appropriately. The format in which results are 

presented will depend on your audience. In general, 

provide results in a clear and concise manner that 

can be understood by nontechnical audiences.12,19,35

When communicating or reporting data, include the 

following:

•	 Sources of data, including potential limitations

•	 Your findings

•	 The meaning or interpretation of the findings

•	 Actions to take63

Decision makers, stakeholders, and partners at all 

levels must understand the data results so they 

can readily act on the recommendations your data 

support. Evidence-based reports provide details to 

support those actions, but a summary statement 

can help provide focus. That statement, a single 

overriding communication objective (SOCO), 

provides actionable items based on the data.63 In 

short, make sure that you communicate a clear 

public health message rather than simply relaying 

data.14 The SOCO provides a response for the 

following questions: 

•	 What is new?

•	 Who is affected?

•	 What works best?63

Graphs, tables, and maps are useful tools that assist 

in rapid data review and comprehension.12,7,19 When 

creating visuals, ensure they are simple and clear so 

they are easier to understand. Epidemic (epi) curves 

can be created to give a visual display of the onset 

of health problems associated with the disaster. The 

epi curve displays the time trend or distribution 

over time, pattern of spread, outliers, scope, and 

magnitude of health problem.64

Finally, make sure that all stakeholders receive your 

surveillance summary reports. Before you implement 

a surveillance system, determine your reporting 

protocol. Decide who will receive information and 

how often you will report surveillance results to your 

stakeholders. Examples of mechanisms for sharing 

your information include 

•	 daily or weekly summary reports (e.g., emergency 

operation center situational reports) and

•	 in-depth briefing meetings. 

After the disaster has transitioned to the mitigation 

phase, publishing your surveillance results in journal 

articles or other documentation is important so 

others can benefit from the lessons you have learned 

from the disaster. 

 19
Challenges of Surveillance in Disasters

Disasters are often challenging situations, even 

when the response is well planned, understand 

the issues that complicate surveillance in disaster 

situations. Disaster surveillance challenges discussed 

in this section include timing constraints, competing 

priorities, missing baseline data, difficulty obtaining 

denominator data, lack of standardized data 

collection and reporting, lack of representative 

information and underreporting, resource 

considerations, and infrastructure damage.

Surveillance challenges in disaster situations 

include the following:

•	 Time constraints

•	 Competing priorities

•	 Missing baseline data

•	 Difficulty obtaining denominator data

•	 Lack of standardized data collection and 

reporting 

•	 Lack of representative information and 

underreporting

•	 Resource consideration

•	 Infrastructure damage

Time Constraints 

Timely information is a key component in 

responding effectively to disasters. Without 

timely data, it becomes more difficult to detect 

and address public health issues present during 

a disaster. Data must be collected and analyzed 

rapidly, under challenging conditions, with forces 

outside your control impeding efforts to perform 

disaster-related morbidity and mortality surveillance. 

Because disasters often have a sudden onset, 

quickly implementing a system is difficult, unless 

one is already in place.21 Timeliness differs in various 

stages of the disaster. In the response phase of a 

disaster, for example, time and resources for data 

collection, analysis, and reporting are often limited.19 

In contrast, more time may be available to conduct 

more comprehensive surveillance in the recovery 

phase.

Keep in mind that setting up flexible surveillance 

systems in advance or building surveillance systems 

into existing infrastructure using existing systems, 

partnerships, and resources allows you to implement 

disaster surveillance more swiftly during a disaster 

response.15 Surveillance activities that rely on 

existing systems function more smoothly because 

the capacity to collect and analyze data is already in 

practice. During the response phase of a disaster you 

may end up collecting and analyzing a wide range 

of unnecessary data. You can minimize wasted time 

and effort by prioritizing the indicators collected 

based on what is most essential and practical for 

use.19

Competing Priorities

During a disaster, the various stakeholders 

have differing and often competing priorities. 

Government agencies may focus on restoring 

infrastructure, whereas health agencies work to 

provide medical care. Differing priorities can affect 

resource availability for surveillance. Prioritizing data 

and information needs and tailoring indicators to 

the disaster phase, type of disaster, and potential 

impacts of the disaster will be important.5

Begin with clear surveillance objectives. This will 

also help you prioritize necessary information that 

will be collected by the surveillance system and 

facilitate decision making. Establishing cross-agency 

coordination (e.g., between disaster management 

officials and departments of health) will streamline 

disaster surveillance activities and increase 

efficiencies.5,65

20
Missing Baseline Data

You need baseline health information to determine 

if you have a true increase in a disease or worsening 

health status in the affected population and to 

assess population risk and vulnerability.5

 However, 

the needed data are often missing or non-existent. 

This can occur when large portions of the population 

are displaced, the health care infrastructure is 

severely damaged, or no previous surveillance 

system collected the information you need. 

Baseline health information is available from 

multiple sources. These include previously 

established surveillance systems, such as the 

Behavioral Risk Factor Surveillance System. 

Published data are also available from CDC WONDER, 

the Web-Based Injury Statistics Query and Reporting 

System (WISQARS), census records, and surveys.14,65

Difficulty Obtaining Denominator Data

Gathering denominator data to calculate rates 

of morbidity and mortality also may be difficult. 

The population under surveillance may change 

frequently and residents may have evacuated 

an area or been displaced. Traditional census or 

population data may not adequately reflect the 

current population in the affected area. As a result, 

the population denominator may not be accurate 

or stable.65 Alternative sources of denominator 

data include shelter population counts, hospital 

admissions, and special surveys or assessments 

during the disaster. 

Lack of Standardization in Data Collection and 

Reporting

The need to collect information across multiple 

sites is challenging, especially if data collection and 

reporting are not standardized. Aggregating data 

across jurisdictions is important to target disaster 

response and relief, implement interventions, and 

evaluate intervention effectiveness.3,5

Ideally, data collection and reporting will be 

standardized during the preparedness phase. The 

process should be simple, flexible, and acceptable 

to the multiple organizations operating the 

surveillance system and using the results.

Pre-existing standardized surveillance templates 

and case definitions are available for use (http://

emergency.cdc.gov/disasters/surveillance/).5

Lack of Representative Information and 

Underreporting

When underreporting occurs, the surveillance 

system may not be representative or may fail to 

identify significant health issues.27 During disasters, 

underreporting can be a significant hurdle. Even in 

non-disaster circumstances, you may see substantial 

underreporting of cases. This is especially true for 

illnesses that are difficult to diagnose and where 

case definitions are overly complex. Logistical 

challenges, misconceptions about the need for 

surveillance, and a lack of disaster surveillance 

specific training can also lead to underreporting. 

The timing, location, and methodology of your 

data collection might affect how representative the 

data are of the affected population. For instance, 

information gathered from surveillance in facilities 

such as shelters or emergency clinics may not be 

representative of the larger population. The data 

gathered will instead represent the populations 

present in those locations, but not the larger 

affected geographic area.5,65

Having health care workers familiar with disaster 

surveillance, and a simple and efficient surveillance 

system for data collection, can help address these 

issues. Remember that a lack of reporting does 

not mean the absence of morbidity and mortality. 

Similarly, do not assume an increase in reporting 

represents an actual increase in cases. When 

reporting data, remember to take into account these 

considerations and any potential biases in results.5,65 

 21
Resource Considerations

Some of the direct and indirect costs related to 

surveillance include 

•	 data collection, entry, management, and analysis; 

•	 information dissemination; 

•	 staff time, investment, and travel; and 

•	 collecting, testing, and, transporting specimens 

(e.g., environmental samples, laboratory case 

confirmations).20

Conducting surveillance may be considered too 

costly if it takes resources from other response 

and relief efforts.5

 Design surveillance systems to 

minimize their cost and burden, while still meeting 

identified information needs.27 This may involve 

determining trade-offs between the cost of data 

collection and the value of the information. Try 

to limit data collection to only the most essential 

information and use the least labor-intensive 

method possible that still maintains the needed 

quality, scope, and detail to meet your objectives.14 

Creating strong objectives, using an existing 

surveillance system, and educating stakeholders 

about the value of surveillance may also help 

to sway decision makers to conduct disaster 

surveillance.5

Infrastructure Damage

Disasters can severely damage or destroy local 

hospitals and health care systems. When that 

happens, health care services are interrupted or 

22
limited and established health care surveillance 

systems (e.g., hospital surveillance) may stop 

working. In such instances, outside relief and health 

organizations, such as the American Red Cross, 

provide temporary medical assistance and care, but 

they may not have the same surveillance capacity 

as hospitals. Additionally, the few operating medical 

care facilities are likely to be overwhelmed and 

unable to conduct surveillance. 

The disaster setting also presents logistical 

problems or obstacles to surveillance. For example, 

power and telephone outages may disrupt 

communication networks. Damaged or destroyed 

roads or transportation systems may slow or stop 

data collection. Such problems interrupt the usual 

reporting mechanisms, leading to an underreporting 

of health events. Infrastructure damage and illness 

and injury among health care workers may keep 

them from responding to a disaster and conducting 

surveillance. In these cases, alternative or outside 

volunteers with limited surveillance experience may 

be trained for the specific event and used. This could 

affect data collection quality.5

During times of damaged or destroyed 

infrastructure, working within your incident 

management system (IMS) is beneficial to aid with 

resources, logistics, and coordination. Flexibility 

is also important. You may need to use pencil 

and paper to collect data if electronic recording 

is unavailable. You also may need to conduct 

surveillance activities from a location other than 

your health department. Think about creative ways 

to gain information from resources not affected by 

the disaster. For example, satellite imagery, such 

as the overhead photos of the tsunami area in the 

Indian Ocean, can be used to identify the extent 

of a disaster. FEMA or the Army Corps of Engineers 

may also have estimates of damage. For damaged 

healthcare systems, working with temporary 

onsite healthcare providers (e.g., American Red 

Cross), outside workers trained in surveillance, and 

community leaders to collect data is a potential 

solution.5,65

Disaster surveillance has many uses, but data must 

be collected rapidly under less than ideal conditions. 

The data must be compiled quickly and in a logical 

format. Various forces outside of your control also 

might limit or prevent you from performing disasterrelated morbidity and mortality surveillance. A 

lesson learned from conducting public health 

surveillance of Hurricane Katrina evacuees was the 

need to establish surveillance systems and federal, 

state, and local partnerships before a disaster 

occurs.3

 23
Key Considerations in Conducting ey Considerations in Conducting 

Surveillance eillance

Disasters are unpredictable and do not uniformly 

affect all areas. Because public health action in 

disasters often occurs at the local level, surveillance 

systems need to be flexible and adaptable to the 

needs at hand. As you plan disaster surveillance 

activities, consider whether your existing or 

proposed system includes those characteristics. To 

prevent complicating the system and overtaxing 

scarce resources, consider limiting the number of 

conditions under surveillance to those most relevan

to your situation’s objectives.

Answering the following questions can help 

you anticipate and address some of the unique 

difficulties you may face as a result of the 

challenging circumstances surrounding surveillance

during disasters. 

t 

Are your existing systems flexible and can you 

adapt them?

Choosing an appropriate strategy for surveillance 

will depend on what systems and other health and 

data collection resources are already present in an 

area.20 Before setting up a new, ad hoc surveillance 

system, check whether any existing systems are 

available that will meet your information needs or 

that can be modified to address disaster information 

gaps. Typically, existing surveillance systems 

will need to be modified. More than half of the 

jurisdictions that reported conducting disaster 

surveillance activities in the past 10 years required 

modifications to meet disaster needs.9

 Surveillance 

systems also need to be flexible and easily 

adaptable.9

Working with existing surveillance resources has 

many benefits. By using or modifying an existing 

system, you eliminate the need to develop a 

surveillance system from scratch, saving time and 

resources that are often severely limited in disaster 

situations. In addition, health workers will not need 

to be retrained to use a new surveillance system. 

They will be familiar enough with the existing 

systems to easily adapt to small modifications in data 

24

reporting or collection methodology. Health care 

workers experienced in using the systems can aid 

and instruct field responders who are less familiar 

with the system. This helps ensure data collection 

and reporting quality. Finally, using existing 

surveillance systems allows for data that are more 

easily compared with those collected in non-disaster 

surveillance, providing a baseline for comparisons.

If using or modifying an existing system is not 

an option, consider creating one that has the 

flexibility and potential to continue to be useful 

beyond the disaster. Such a system can be used to 

both conduct disaster surveillance and help build 

surveillance capacity in an area that may have lacked 

it previously. Disaster surveillance forms can be 

created during the preparedness phase and then 

used or modified to meet the specific needs of your 

situation. As noted previously, CDC has developed 

standardized morbidity and mortality forms that can 

be modified to suit your needs.

You can access those forms at 

http://emergency.cdc.gov/disasters/surveillance/.

What are the start and stop triggers/thresholds?

When planning your disaster surveillance system, 

knowing when to start surveillance, what factors 

will trigger investigations, and when to stop 

disaster surveillance activities is useful. Knowing 

your thresholds will help systematically start and 

stop your investigation at the appropriate times. 

These thresholds will vary depending on a disaster’s 

severity and scope. Some triggers for starting 

disaster surveillance include the following: 

•	 Information needs (e.g., suspected outbreaks of 

infectious disease, reports of high rates of mental 

illness, controlling rumors)

•	 Impact on the population (e.g., whether or not 

people have been displaced or are in shelters)
•	 Resource availability (e.g., status of the public 

health and health care infrastructure, capacity to 

conduct surveillance)

•	 Opening of multiple or long-term evacuation 

shelters (e.g., whether or not people have been 

displaced or are in shelters, potential for spread of 

illness) 

Be flexible during a disaster and know when to 

prioritize your actions. For instance, if you are unable 

to conduct surveillance in every shelter opened 

during a hurricane response, you could potentially 

prioritize them by size, how long they will be open, 

or population movement into and out of the facility. 

Plan for stopping surveillance or transitioning back 

to more routine surveillance systems. Defining the 

span of time an initial surveillance system will cover 

is useful for determining when surveillance should 

stop. At the end of the predetermined time, the data 

gathered from a surveillance system can be assessed 

to determine whether surveillance activities need 

to be extended.25 Factors relating to the event itself 

or the affected populations could signal a good 

stopping or transitioning point. For instance, when 

people begin returning to their homes, shelter 

surveillance may no longer be necessary or relevant. 

However, in instances where the extent of the 

damage and level of displacement persist for an 

extended period, surveillance activities may need to 

be continued for a longer time span. For example, 

mortality rates remained elevated long after 

Hurricane Katrina passed, and high rates of chronic 

illness and morbidity continued for years after the 

storm.65-6 In most circumstances, after a situation 

has become more stable, routine surveillance is 

functional again, or information needs have shifted, 

you will work to transition out of surveillance entirely 

or back to a passive system.

Can existing surveillance forms capture disasterrelatedness?

Even when your jurisdiction is not directly affected 

by a disaster, large-scale events elsewhere can 

result in short- and long-term displacement of 

affected populations across the country. Having data 

collection instruments that can flag disaster-related 

health effects will be valuable for tracking victims 

no matter where they disperse. For instance, after 

Hurricane Katrina many evacuees were sheltered 

in Colorado where the state conducted health 

surveillance on evacuees, notifying emergency 

departments to identify and report evacuee visits 

through a Health Alert Network (HAN) message.67

Including a way to flag disaster-relatedness on 

forms such as death certificates can also help to 

address some of the challenges related to using 

EDRS as surveillance for disaster-related mortality.45

Medical examiners, coroners, physicians, and others 

participating in routine surveillance or working with 

surveillance forms and other certificates of morbidity 

and mortality should be given guidance and training 

on recording and certifying disaster-related deaths 

so that this process is done in a standardized 

manner. 

 25
Who are the relevant stakeholders?

As part of surveillance planning, you should identify 

the relevant stakeholders. This includes persons 

who requested the surveillance or information, field 

responders, emergency managers, officials across 

multiple disciplines and levels of government, 

non-governmental organizations, data providers, 

and those funding your surveillance activities. 

Partnerships and collaboration are key to a 

successful surveillance system; establish them before 

a disaster occurs.39 Stakeholders will also determine 

the information needs of a situation and access to 

available types of resources. Each health care setting 

may have a distinct data reporting style and various 

information needs.3

 

In working with government officials, health 

care organizations, relief agencies, and other 

stakeholders and partners, take into account the 

political, financial, and human resources needed 

to successfully implement a disaster surveillance 

system. Having the support of high ranking 

government officials is important to ensure political 

commitment and funding to mobilize resources.7

Similarly, federal, state, and local partnerships may 

help provide coordination capacity and financial and 

other resources. 

How is surveillance information going to be 

used?

Before conducting surveillance, you should know 

how the information you are collecting is going to 

be used. Are you characterizing disease or injury 

in the displaced population? Are you interested in 

looking at mental health issues? Are you monitoring 

for outbreaks of infectious disease in shelter 

populations or gastrointestinal illness in flooded 

areas? Knowing why you are collecting information 

will help to determine your surveillance strategy 

and will guide development of your objectives. If 

surveillance information will be used to monitor 

disaster-associated reproductive health impacts, for 

example, you will include these in your objectives 

and include questions or components in your 

26

reporting system for pregnancy and other related 

factors.

What information do you have about the affected 

population?

As part of the planning and preparation process, 

gather background data on the geographic areas 

that may be affected by a disaster, the major disease 

risks in those areas (e.g., vector-borne illness, high 

dependence on supplemental oxygen), and the atrisk and affected populations. 

To help identify at-risk groups in your population, 

you can use tools available online from CDC at 

http://www.cdc.gov/nceh/hsb/disaster/

atriskguidance.pdf, http://stacks.cdc.gov/view/

cdc/7552, and http://svi.cdc.gov/. 

The scope of a surveillance system, including the 

geographic area and population covered, can be 

narrowed using background information.25 For 

instance, looking at high risk areas for flooding or 

earthquakes helps you narrow the geographic area 

within which you conduct surveillance.21 Background 

information helps you determine the extent of your 

surveillance system. The information may indicate 

a need for universal coverage, where an entire 

population or representative sample is selected to 

conduct surveillance for the condition of interest 

(e.g., food poisoning, bioterrorism agents). Perhaps, 

instead, you could use a system in which sentinel 

sites (e.g., a few hospitals in an oil spill impact area), 

or health care providers are selected. In addition to 

information provided by the health system, relief 

workers, and local community groups, consider 

gathering information from unconventional sources 

such as newspapers, the Internet, or social media, 

which can provide important early warnings.68

Background information focuses your efforts. It helps 

you avoid gathering unnecessary data and wasting 

limited resources.
What issues of security and confidentiality need 

to be considered?

Ideally, potential security issues and confidentiality 

concerns are addressed in the planning phase. 

The ability to protect patient information will 

vary with the policies, regulations, and statutes in 

your jurisdiction. Consider issues resulting from 

having small numbers of cases that could result 

in patient identification, even if names, addresses, 

and other personal identification information are 

protected or not collected. Consider how you can 

maintain confidentiality for organizations and those 

reporting to the surveillance system. For example, 

the need to name particular locations should be 

balanced against the negative effects of naming 

those locations. Public health organizations should 

be familiar with their institutional review board 

policies to determine whether review and approval 

or exemption is required before developing the 

surveillance system.

What phase of the disaster is it?

Finally, knowing what phase of the disaster you need 

to or plan to implement surveillance in will affect 

the goals and objectives of your surveillance. In the 

response phase, for example,

•	 surveillance may be conducted for a shorter 

period; 

•	 data collection methods may be simpler, more 

observational, and involve active surveillance 

methodologies; 

•	 case definitions may be simpler, involve a few 

critical conditions, and may not require laboratory 

confirmation; and 

•	 information will be used for immediate action and 

mortality reduction. 

On the other hand, during the recovery or mitigation 

phase, 

•	 surveillance can be transitioned to a passive 

system; 

•	 data collection methods may be more complex 

and involve entire populations; 

•	 instead of sentinels, data collection may be 

incorporated into the established health care or 

health information infrastructures; 

•	 case definitions may be more complex, involving 

laboratory diagnosis and a larger number of 

conditions; and 

•	 information may be used for a wider range of longterm health and monitoring needs, addressing less 

urgent information needs, and assessing quality of 

care and intervention effectiveness.19

Additionally, deaths can be characterized according 

to whether they occur before, during, or after impact 

of a disaster to provide more detailed information on 

how to prevent injuries and death.6 

Figure 1. The Disaster Cycle (Source: FEMA)

 27
ConclusionConclusion

IMAGE

Conclusion

Whether you already have a system for conducting 

disaster surveillance or are just beginning, evaluating 

these systems regularly is important. Evaluation is 

the periodic assessment of a surveillance system 

for its quality, efficiency, and usefulness toward 

achieving the overall objectives of the system.12,69,70

This process ensures that the system is effectively 

monitoring disaster-related health events.69 To help 

in guiding such evaluations, CDC has published 

“Updated guidelines for evaluating public health 

surveillance systems” (http://www.cdc.gov/mmwr/

preview/mmwrhtml/rr5013a1.htm).69 The guidelines 

outline a systematic method for approaching 

surveillance system evaluations. It has been used 

to evaluate several disaster-related mortality 

surveillance systems including Hurricane Ike in 

2008.71,72

Conducting surveillance during disasters is a 

necessary but often complicated task. How you 

conduct disaster surveillance will be influenced by 

many factors and challenges. You can use the various 

existing tools and resources described in this primer 

to help address these challenges and effectively 

track disaster-related morbidity and mortality. 

The data you collect can provide decision makers 

with the information to make informed decisions. 

We hope the information presented here prompts 

public health departments to consider and begin 

conducting disaster surveillance and further enables 

such activities. 

28
Glossary

Active surveillance — A surveillance system in which public health staff members regularly contact health 

care providers, laboratories, hospitals, the public, and others to seek information about health conditions for 

a limited period, usually weeks or months.

Case definition — A set of standard criteria for classifying whether a person has a particular disease, 

syndrome, or other health condition. A case definition frequently includes criteria for person, place, and 

time.

Disaster — A serious disruption of the functioning of society, causing widespread human, material, or 

environmental loss that exceeds the local capacity to respond, requiring external assistance.

Disaster epidemiology — The use of epidemiology to measure the short- and long-term health effects of 

disasters and to predict the consequences of future disasters.

Disaster related health effects — Direct and indirect effects:

Direct – Health effects caused by the actual physical forces or essential elements of the disaster.

Indirect – Health effects caused secondarily by anticipation of the disaster or by unsafe or unhealthy 

conditions that develop in connection with the disaster.

Disaster surveillance — An epidemiologic tool that provides ongoing, systematic collection, analysis, and 

interpretation of data on injuries, illnesses, and deaths. The information is used in planning, implementation, 

and evaluation of public health response. It enables public health agencies to track and identify morbidity 

and mortality linked to an event and provides information for future disaster response.

Incidence — The occurrence of new cases of disease or injury in a population over a specified period (e.g., 

total number of head and neck injuries in one week). 

Morbidity — The state of being ill or diseased, or the incidence or prevalence of illness in a population.

Mortality — The incidence of death in a population relating to many different types of conditions.

Passive surveillance — Regular reporting of disease data by health institutions that see patients and are 

part of a reporting network. There is no active searching for cases. Cases are reported through passive 

notification by health care facilities or practitioners

Rates — Measures of risk that allow comparison of the frequency of morbidity and mortality in different 

geographic locations, times, or population groups.

Sentinel Surveillance — An active surveillance system that collects data from a limited number of recruited 

participants or providers to report on specific health events to estimate trends in the larger affected 

population.

Syndromic Surveillance — An active or passive surveillance system that uses signs and symptoms, primary 

complaints or presumptive diagnoses, or other characteristics of a disease to define cases, rather than using 

specific clinical or laboratory diagnostic criteria.

Glossary

 29
Acknowledgements

The following are links to tools mentioned in this primer.

BioSense Platform 

http://www.cdc.gov/nssp/biosense/index.html

ICD-10 

http://www.cms.gov/Medicare/Coding/icd10/

CDC Ready-to-Use Morbidity and Mortality Surveillance Form Templates 

http://emergency.cdc.gov/disasters/surveillance/

CDC “Updated Guidelines for Evaluating Public Health Surveillance Systems”

http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5013a1.htm

CSTE Occupational Health Subcommittee

http://www.cste.org/members/group.aspx?id=106606

CDC List of Occupational Safety and Health Contacts at State and Territorial Health Departments

http://www.cdc.gov/niosh/statosh.html

CDC Occupational Health Surveillance Resources

http://www.cdc.gov/niosh/topics/surveillance/

Emergency Responder Health Monitoring and Surveillance (ERHMS)

http://www.cdc.gov/niosh/topics/erhms/default.html

CDC “Planning for an Emergency: Strategies for Identifying and Engaging At-Risk Groups”

http://www.cdc.gov/nceh/hsb/disaster/atriskguidance.pdf

ATSDR “The Social Vulnerability Index (SVI)”

http://svi.cdc.gov/

CDC “Public Health Workbook to Define, Locate, and Reach Special, Vulnerable, and At-Risk 

Populations in an Emergency”

http://stacks.cdc.gov/view/cdc/7552

Links

30
References

1. United Nations International Strategy for Disaster Reduction. 2009 UNISDR Terminology on Disaster Risk Reduction. Geneva 

(Switzerland): United Nations; 2009. Available from: http://www.unisdr.org/files/7817_UNISDRTerminologyEnglish.pdf 

2. Centers for Disease Control and Prevention (CDC). Community Assessment for Public Health Emergency Response (CASPER) 

toolkit. 2nd ed. Atlanta (GA): CDC; 2012. Available from: http://emergency.cdc.gov/disasters/surveillance/pdf/CASPER_Toolkit_

Version_2_0_508_Compliant.pdf.

3. Wolkin AF, Noe RS. Disaster surveillance. Presentation from: Clinical Outreach and Communication Activity (COCA) conference 

call; 2007 October 26; Available from: https://web.archive.org/web/20091028001004/http://www.bt.cdc.gov/coca/summaries/

pdf/disastersurveillance_121807.pdf.

4. Malilay J. Tropical cyclone. In: Noji EK, editor. The public health consequences of disasters. New York (NY): Oxford University Press; 

1997.

5. Wetterhall SF, Noji EK. Surveillance and epidemiology. In Noji EK, editor. The public health consequences of disasters. New York 

(NY): Oxford University Press; 1997.

6. Ragan P, Schulte J, Nelson SJ, Jones KT. Mortality surveillance 2004 to 2005 Florida hurricane-related deaths. American J Forensic 

Med Pathology. 2008;29(2):148–53. 

7. Nsubuga P, White ME, Thacker SB, Anderson MA, Blount SB, Broome CV, et al. Public health surveillance: a tool for targeting 

and monitoring interventions. In: Jamison DT, Breman JG, Measham AR, et al., editors. Disease control priorities in developing 

countries. 2nd ed. Washington, DC: World Bank; 2006.

8. Buehler JW, Whitney EA, Smith D, Prietula MJ, Stanton SH, Isakov, AP. Situational uses of syndromic surveillance. Biosecur Bioterr 

2009;7(2):165–77. 

9. Simms E, Miller K, Stanbury M, Heumann M, Miller T. Disaster surveillance capacity in the United States: results from a 2012 CSTE 

assessment. Council of State and Territorial Epidemiologists (CSTE); 2013.

10. STIPDA: Injury Surveillance Workgroup 5. Consensus recommendations for injury surveillance in state health departments. 

Atlanta (GA): State and Territorial Injury Prevention Directors Association; 2007.

11. CDC. Disaster epidemiology. Preparedness and Response for Public Health Disasters [webpage]. Atlanta (GA): CDC; 2012b [cited 

2015 Feb 11]. Available from http://www.cdc.gov/nceh/hsb/disaster/epidemiology.htm 

12. Thacker SB, Berkelman RL. Public health surveillance in the United States. Epidemiol Rev 1988;10:164–90. 

13. Thacker SB, Stroup DF. Public health surveillance. In Brownson RC, Petitti DB, editors. Applied epidemiology: theory to practice. 

New York (NY): Oxford University Press; 1998.

14. Garcia-Abreu A, Halperin W, Danel I. Public health surveillance toolkit: a guide for busy task managers. Washington, DC: The World 

Bank; 2002.

15. Smith PF, Hadler JL, Stanbury M, Rolfs RT, Hopkins RS, CSTE Surveillance Strategy Group. “Blueprint version 2.0”: updating public 

health surveillance for the 21st century. J Public Health Manag Pract 2013;19(3):231–9. 

16. Thacker SB. Historical development. In: Lee LM, Teutsch SM, Thacker SB, St. Louis ME, editors. Principles and practice of public 

health surveillance. New York (NY): Oxford University Press; 2010. 

17. Schnall AH, Wolkin AF, Noe RS, Hausman LB, Wiersma P, Soetebier K, et al. Evaluation of a standardized morbidity surveillance 

form for use during disasters caused by natural hazards. Prehosp Disaster Med 2011;26(2):90–8. 

18. Agency for Toxic Substances and Disease Registry (ATSDR). Glossary of terms [webpage]. CDC; 2009 [cited 2015 Feb 11]. Available 

from: http://www.atsdr.cdc.gov/glossary.html.

19. Abdallah S, Panjabi R. Epidemiology and surveillance. In: Christensen Rand E, editor. The Johns Hopkins and Red Cross Red 

Crescent public health guide in emergencies. 2nd ed. Geneva: International Federation of Red Cross and Red Crescent Societies; 

2008. Available from: http://www.jhsph.edu/research/centers-and-institutes/center-for-refugee-and-disaster-response/

publications_tools/publications/_CRDR_ICRC_Public_Health_Guide_Book/Forward.pdf.

20. Duffell E, Toskin I. Guidelines for HIV surveillance among tuberculosis patients. 2nd ed. Geneva (Switzerland): World Health 

Organization; 2004.

21. Dominici F, Levy JI, Louis TA. Methodological challenges and contributions in disaster epidemiology. Epidemiol Rev 2005;27:9–12.

22. Last JM. A dictionary of epidemiology. 2nd ed. New York (NY): Oxford University Press; 1988.

23. Sosin DM, Hopkins RS. Public health surveillance for preparedness and emergency response: biosurveillance for human health. 

In: Lee LM, Teutsch SM, Thacker SB, St. Louis ME, editors. Principles and practice of public health surveillance. New York (NY): 

Oxford University Press; 2010. 

24. World Health Organization. National passive surveillance. Immunization, Vaccines, and Biologicals [webpage]. WHO; 2015 [cited 

2015 Feb 11]. Available from http://www.who.int/immunization/monitoring_surveillance/burden/vpd/surveillance_type/

 31
passive/en/.

25. CDC. Principles of epidemiology in public health practice: an introduction to applied epidemiology and biostatistics. 3rd ed. 

Atlanta (GA): CDC; 2012c. Available from: http://www.cdc.gov/ophss/csels/dsepd/SS1978/SS1978.pdf.

26. Roush SW. Surveillance indicators. In: Roush SW, McIntyre L, Baldy LM, editors. Manual for the surveillance of vaccine-preventable 

diseases. 5th ed. Atlanta (GA); 2011.

27. Teutsch SM. Considerations in planning a surveillance system. In: Lee LM, Teutsch SM, Thacker SB, St. Louis ME, editors. Principles 

and practice of public health surveillance. New York (NY): Oxford University Press; 2010. 

28. McNabb SJ, Kelso KY, Wilson SA, McFarland L, Farley TA. Hurricane Andrew-related injuries and illnesses, Louisiana, 1992. South 

Med J 1995;88(6):615–8. 

29. Glynn MK, Backer LC. Collecting public health surveillance data: creating a surveillance system. In: Lee LM, Teutsch SM, Thacker 

SB, St. Louis ME, editors. Principles and practice of public health surveillance. New York (NY): Oxford University Press; 2010. 

30. CDC. Launching a national surveillance system after an earthquake—Haiti, 2010. MMWR 2010;59(30):933–8. 

31. Uscher-Pines L, Farrell CL, Babin SM, Cattani J, Gaydos CA, Hsieh YH, et al. Framework for the development of response protocols 

for public health syndromic surveillance systems: case studies of 8 US states. Disaster Med Public Health Prep 2009;3(2 

Suppl):S29–36. 

32. CDC. BioSense [webpage]. Atlanta: CDC; 2015 [cited 2015 April 30]. Available from: http://www.cdc.gov/biosense/index.html

33. CDC. Monitoring health effects of wildfires using the BioSense system --- San Diego County, California, October 2007. MMWR. 

2008;57(27):741-7. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5727a2.htm.

34. CDC. Disaster Epidemiology: frequently asked questions. Preparedness and Response for Public Health Disasters [website]. 

Atlanta (GA): CDC; 2014 [cited 2015 Feb 11]. Available from: http://www.cdc.gov/nceh/hsb/disaster/faqs.htm.

35. Western K. Epidemiologic surveillance after natural disaster. Washington, DC: Pan American Health Organization; 1982.

36. University of North Carolina School of Medicine, North Carolina Public Health. North Carolina Disease Event Tracking and 

Epidemiologic Collection Tool [webpage]. UNC. 2015. Available from: http://www.ncdetect.org/.

37. Florida Department of Public Health. Surveillance Systems [webpage]. Florida Department of Health. Available from: http://

www.floridahealth.gov/diseases-and-conditions/disease-reporting-and-management/disease-reporting-and-surveillance/

surveillance-systems.html.

38. Heffeman R, Mostashari F, Das D, Besculides M, Rodriguez C, Greenko J, et al. System descriptions New York City syndromic 

surveillance systems. MMWR. 2004;53(Suppl):23-7. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/su5301a6.

htm.

39. Noji EK. The public health consequences of disasters. Noji EK, editor. New York (NY): Oxford University Press; 1997

40. University of Wisconsin-Extension, Disaster Management Center. Epidemiologic surveillance after natural disaster: a study 

guide and course text. University of Wisconsin-Extension; no date; Available from: http://epdfiles.engr.wisc.edu/dmcweb/

BC08EpidemiologicSurveillance.pdf.

41. Combs DL, Quenemoen LE, Parrish RG, Davis JH. Assessing disaster-attributed mortality: development and application of a 

definition and classification matrix. Int J Epidemiol 1999;28:1124--9

42. Bartolomeos K, Kipsaina C, Grills N, Ozanne-Smith J, Peden M. Fatal injury surveillance in mortuaries and hospitals: a manual for 

practitioners. Geneva (Switzerland): World Health Organization; 2012.

43. Wolkin A, Schnall A, Law R, Schier J. Using poison center data for postdisaster surveillance. Prehosp Disaster Med 2014;29(5):521–

4.

44. HealthIT.gov. Meaningful use case studies: Immunization registries bring tremendous value after natural disaster. HealthIT.gov 

[website]. 2013 [cited 2015 Feb 11]. Available from: http://www.healthit.gov/providers-professionals/louisiana-health-carequality-forum-case-study.

45. Noe RS. Electronic disaster mortality surveillance—is it possible? A conceptual framework. Atlanta (GA): Centers for Disease 

Control and Prevention; 2014. Available from: https://www.syndromic.org/storage/documents/Webinars/EDRS/All_EDRS_

Rebecca.pdf.

46. Howland RE, Madsen AM, Nicaj L, Noe RS, Casey-Lockyer M, Beiger E. Assessing electronic death registration and American Red 

Cross Systems for mortality surveillance during Hurricane Sandy, October 29–November 10, 2012, New York City. Disaster Med 

Public Health Prep 2014;8(6):489–91. 

47. Law RK, Schier JG, Martin CA, Olivares DE, Thomas RG, Bronstein AC, et al. National surveillance for radiological exposures and 

intentional potassium iodide and iodine product ingestions in the United States associated with the 2011 Japan radiological 

incident. Clin Toxicol 2013;51(1):41–6. 

32
48. Olayinka O, Bayleyegn T, Noe RS, Lewis LS, Arrisi V, Wolkin AF. Evaluation of real-time mortality surveillance based on media. 

Disaster Med Public Health Prep. In press. 

49. Legacy.com. Superstorm Sandy memorial site. Legacy.com [website]. 2015 [cited 2015 Feb 11]. Available from http://www.legacy.

com/memorial-sites/superstorm-sandy/.

50. NowTrending.HHS.gov [website]. Washington, DC: US Department of Health and Human Services; 2015. [cited 2015 July 22]. 

Available from https://nowtrending.hhs.gov/.

51. Odlum M, Sunmoo Y. What can we learn about the Ebola outbreak from tweets? Am J Infection Control 2015;43(6):563–71.

52. Berrios-Torres SI, Greenko JA, Phillips M, Miller JR, Treadwell T, Ikeda RM. World Trade Center rescue worker injury and illness 

surveillance, New York, 2001. Am J Prev Med 2003;25(2):79–87.

53. Sullivan PS, McKenna MT, Waller LA, Williamson GD, Lee LM. Analyzing and interpreting public health surveillance data. In: Lee 

LM, Teutsch SM, Thacker SB, St. Louis ME, editors. Principles and practice of public health surveillance. New York (NY): Oxford 

University Press; 2010. 

54. CDC. Carbon monoxide poisonings after two major hurricanes --- Alabama and Texas, August—October 2005. MMWR. 

2006;55(9):236-9. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5509a4.htm#tab2. 

55. The Sphere Project. Humanitarian charter and minimum standards in humanitarian response. Bourton on Dunsmore (UK): 

Practical Action Publishing; 2011.

56. Brinker K, Head CA, Johnson CY, Funk R. Injuries and illness among American Red Cross responders—United States, 2008–2012. 

Disaster Med Public Health Prep 2014;8(5):404–10. 

57. Rusiecki JA, Thomas DL, Chen L, Funk R, Jodi M, Dayton MR. Disaster-related exposures and health effects among US Coast Guard 

responders to Hurricane Katrina and Rita: a cross-sectional study. J Occup Environ Med 2014;56(8):820–33. 

58. CDC. Surveillance for injuries and illnesses and rapid health-needs assessment following Hurricanes Marilyn and Opal, 

September-October 1995. MMWR. 1996;45(4):81-5. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/00040093.

htm.

59. CDC. Early warning disease surveillance after a flood emergency – Pakistan, 2010. MMWR. 2012d;61(49):1002-7. Available from: 

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6149a2.htm.

60. CDC. Surveillance for illness and injury after Hurricane Katrina --- three counties, Mississippi, September 5—October 11, 2005. 

MMWR. 2006:55(9):231-4. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5509a2.htm.

61. Swerdel JN, Janevic TM, Cosgrove NM, Kostis JB. The effect of Hurricane Sandy on cardiovascular events in New Jersey. J Am Heart 

Assn. 2014;3:1-11. Available from: http://jaha.ahajournals.org/content/3/6/e001354.full.

62. Hauenstein L, Wojcik R, Loschen W, Ashar R, Sniegoski C, Tabernero N. Putting it together: the biosurveillance information system. 

In: Lombardo JS, Buckerridge DL, editors. Disease surveillance: a public health informatics approach. Hoboken (NJ): Wiley and 

Sons; 2007.

63. Remington PL, Nelson D. Communicating surveillance information for action. In: Lee LM, Teutsch SM, St Louis ME, Thacker SB, 

editors. The principles and practice of public health surveillance. 3rd ed. New York (NY): Oxford University Press; 2010.

64. Rosenberg PS. Epidemic curve Wiley StatsRef: statistics reference online. Chichester (UK): John Wiley and Sons; 2014.

65. World Health Organization. Analysing disrupted health sectors: a modular manual. Geneva (Switzerland): WHO; 2009.

66. Gautam S, Menachem J, Srivastav SK, Delafontaine P, Irimpen A Effect of Hurricane Katrina on the incidence of acute coronary 

syndrome at a primary angioplasty center in New Orleans. Disaster Med Public Health Prep 2009;3:144–150.

67. CDC. Illness surveillance and rapid needs assessment among Hurricane Katrina evacuees—Colorado, September 1–23, 2005. 

MMWR 2006b;55(9):244–7. 

68. Pan American Health Organization. Natural disasters: protecting the public’s health. Washington, DC: PAHO; 2000. 

69. CDC. Updated guidelines for evaluating public health surveillance systems. MMWR 2001;50(RR13):1–35. 

70. World Health Organization. Communicable disease surveillance and response systems: guide to monitoring and evaluating. 

Geneva (Switzerland): WHO; 2006.

71. Faraq NH, Rey A, Noe R, Bayleyegn T, Wood AD, Zane D. Evaluation of the American Red Cross disaster-related mortality 

surveillance system using Hurricane Ike data – Texas 2008. Disaster Med Public Health Prep. 2013;7(1):13-9. 

72. Choudhary E, Zane DF, Beasley C, Jones R, Rey A, Noe RS, et al. Evaluation of active mortality surveillance system data for 

monitoring hurricane-related deaths – Texas, 2008. Prehosp Disaster Med. 2012;27(4):392-7.

 33
Notes

34

Centers for Disease Control and Prevention

Division of Environmental Hazards and Health Effects

National Center for Environmental Health

Health Studies Branch

770-488-3410

www.cdc.gov/nceh/hsb