in

Acute Care

Facilities

influenzoutbrea

Detection & 
in

Acute Care

Facilities

influenza

outbreaks

Detection & Control of

Jointly developed by the

National Center for Infectious Diseases

and The National Immunization Program

Department of Health and Human Services

Centers for Disease Control and Prevention

Printed September 2001

1

What is

the

impact of

influenza

and 

who is

at risk?

Annual influenza epidemics cause infection in 10-20% of the

population and result in an average of >110,000 hospitalizations

and 20,000 deaths in the United States. Persons most

susceptible to complications or death from influenza are

 persons 65 years of age 

 children <2 years of age 

 persons of any age with certain medical conditions

 children receiving long-term aspirin therapy 

 women who are in their second or third trimester of

pregnancy during the influenza season (fall or winter)

Medical conditions include:

 heart or lung disease 

(e.g., asthma, chronic

obstructive pulmonary

disease, congestive heart

failure) 

 renal failure 

 diabetes 

 immune compromising illness 

(e.g., HIV/AIDS, immunosuppression from steroids or

other medications that may

compromise the immune

system) 

Source: MMWR 2001;50 (RR-4):1-46

BOX 1
2

What are the symptoms

of influenza?

Influenza is a respiratory illness characterized by the abrupt

onset of

 fever

 chills

 headache

 myalgia,

i.e., body aches

with accompanying

 fatigue

 cough

 sore throat

 nasal congestion

While the fever, body aches, and headache may typically last

for three to five days, the cough and fatigue may last for more

than two weeks. Some persons may not have typical influenza

symptoms, but may only exhibit exacerbation of chronic

medical conditions (Box 1). Some children primarily may

have fever, with nausea, vomiting or abdominal pain, and

infants may have symptoms similar to a severe systemic bacterial infection.

The most common complications are secondary bacterial

pneumonia and worsening of chronic medical conditions.

Influenza virus also can cause primary pneumonia, but this is

much less common. Rarely, children taking aspirin can

develop Reye’s Syndrome if they get sick with influenza.

What are the complications

from influenza?
3

Influenza is easily transmitted from person to person. The

virus is spread primarily by the coughing and sneezing of

infected persons or sometimes by direct contact, either with

infected persons or a contaminated surface. Once influenza is

introduced into a facility by infected healthcare personnel,

patients, or visitors, it can quickly spread

and cause illness in other hospitalized

patients and healthcare personnel,

especially among those who are unvaccinated. During an outbreak in a hospital

ward or nursing home, as many as 70% of

staff and patients may become infected.

How is influenza

transmitted?

What is the incubation period for influenza,

and how long is a person contagious?

Infected persons start to develop symptoms 1-4 days after they

are exposed. They may be able to spread influenza to other

people from the day before getting symptoms through 5-7 days

after symptoms start. Children may be contagious for 7 or

more days.
4

The most important means to prevent influenza from spreading

in an acute care facility is influenza vaccination of both

patients and healthcare personnel. The Advisory Committee

on Immunization Practices (Box 2) recommends annual

vaccination of all healthcare personnel against influenza.

When influenza is

introduced into an

acute care facility,

prompt recognition

of influenza

infection and

initiation of

infection control

measures can limit

the spread of

disease.

How can influenza outbreaks

in acute care facilities 

be prevented?

About ACIP

CDC’s Advisory Committee on

Immunization Practices (ACIP)

publishes recommendations and

updated information about the

control and prevention of

influenza each year, including the

use of influenza vaccine and

antiviral agents. Annual ACIP

recommendations and other

information on influenza, including

national influenza surveillance

updates, can be found at the

following CDC website:

http://www.cdc.gov/ncidod/

diseases/flu/fluvirus.htm.

BOX 2
5

Why should acute care facilities

conduct surveillance for influenza

and influenza-like illness?

An active surveillance program can help acute care facilities

identify outbreaks of influenza early and prevent influenza

from spreading to patients and healthcare personnel, thereby

decreasing influenza-related complications among patients and reducing work

absenteeism. When the onset of

influenza season in the community is

identified, facility leaders should initiate

measures to increase awareness and

intensify efforts to diagnose and prevent

influenza illness in both patients and

healthcare personnel (Boxes 3–5).

Surveillance can be conducted in a number of settings,

including:

1. Inpatient surveillance

 Document incidence of reported influenza and

influenza-like illness (Box 3)

 Develop case definitions for healthcare and

community-acquired influenza 

 Consider patients who develop influenza-like illness

72 hours after facility admission as potential cases of

healthcare-acquired influenza-like illness 

What is ILI?

Influenza-like

illness (ILI) is

defined as an

elevated

temperature

(e.g., 100° F

or 37.8° C)

plus upper

respiratory

symptoms

(e.g., cough or

sore throat).

BOX 3 How should surveillance

be conducted?
6

 Initiate influenza testing when healthcare-acquired

influenza is detected during surveillance, particularly

when 

▪ one or more patients are identified with healthcareacquired laboratory confirmed influenza 

▪ a cluster (e.g., 3) of patients with healthcareacquired influenza-like illness are identified on the

same floor or ward during a short (e.g., 48-72 hour)

period 

 Consider daily monitoring for influenza-like illness in

selected settings, especially on wards with particularly

vulnerable patients, such as intensive care units,

oncology units, and other “sentinel” floors 

 Evaluate whether infection control measures (e.g.,

droplet precautions) are properly instituted for

influenza-positive patients, and investigate whether

the infection was acquired in the community or while

hospitalized 

2. Emergency Department surveillance

 Consider influenza testing of patients being admitted

from the emergency department who have influenzalike illness with no other identified pathogen 

 Facilitate the timely initiation of droplet precautions

through early suspicion and diagnosis among patients

being admitted, to lessen the chance of influenza

spreading to personnel or other patients 

3. Employee surveillance

 Consider requiring that healthcare personnel with

influenza-like illness go to employee health services for

influenza testing 

 Consider excluding healthcare personnel who test

influenza-positive or have influenza-like illness from

care of patients at high risk for influenza complications 

4. Laboratory surveillance 

 Establish regular contact between infection control

and laboratory personnel regarding influenza-positive

specimens 

 Update clinical personnel regularly about the

availability and use of diagnostic tests 
7

Practical Suggestions for a

Successful Influenza Surveillance Program

The level of surveillance implemented might vary significantly

by hospital; facilities should tailor these suggestions as

appropriate to the level of infection control support and

capacity at their institution and to the vulnerability among the

patient population. Efforts should begin with passive

surveillance, and if confirmed cases of influenza are detected

through passive surveillance, more active surveillance should

be considered. 

PASSIVE SURVEILLANCE

 Review microbiology laboratory reports for positive

influenza cultures or rapid tests 

 Improve quality of passive surveillance by educating nursing

and medical staff in inpatient units, the emergency

department, and employee health regarding 

▪ influenza activity in the community

▪ availability and use of rapid influenza tests

▪ importance of testing patients and personnel with

influenza-like illness 

ACTIVE SURVEILLANCE

 Test patients admitted through the Emergency Department

with recent onset (e.g., 4 days) of influenza-like illness

 Conduct surveillance for influenza-like illness in patients and

personnel and keep an “influenza-like illness list” on patient

care units and in employee health 

▪ instruct nurses to identify patients with influenza-like

illness after every shift

▪ forward information to infection control or other nursing

personnel, and use it to target further testing and/or

infection control measures

▪ test patients and healthcare personnel with influenza-like

illness

BOX 4
8

Overview of

influenza

surveillance

CDC conducts surveillance

for influenza in the United

States each year from

October through mid-May.

Influenza surveillance on

the national level is

designed to

 Determine when

influenza viruses are

circulating, identify

circulating strains, and

detect changes in the

viruses

 Monitor influenzarelated illness

 Measure the impact of

influenza on deaths BOX 5

MONITORING COMMUNITY

INFLUENZA SURVEILLANCE

Information regarding influenza

surveillance is available through

CDC Voice Information System INFLUENZA UPDATE

(888) 232-3228

CDC Fax Information Service

(888) 232-3299

Website

http://www.cdc.gov/ncidod/

diseases/flu/weekly.htm

From October through May, the information is

updated at least every other week. In addition,

periodic updates about influenza are published

in CDC’s Morbidity and Mortality Weekly

Report. State and local health departments

should be consulted for information about

state or local influenza activity, and for

reporting influenza outbreaks and receiving

advice regarding outbreak control.
9

Each week, the vital statistics offices of 122 cities report the total number of death cerfor which either pneumonia or influenza are identified.

Source: CDC, Influenza Surveillance Reports

Pneumonia and Influenza Mortality for 122 U.S. Citi

January 1997 through August 2000

Weeks

% of All Deaths Due to P&I

FIGURE 1
10

FIGURE 3 Morbidity Reports from U.S. Sentinel Physicians

National Summary, 1999-2000

Approximately 550 physicians around the country report each week the total number of patients seen and the number of those patients with influenza-like illness (ILI)

by age group. Nationally, influenza morbidity as reported by U.S. sentinel physicians

peaks when the maximal percentage of total patient visits are due to ILI.

FIGURE 2 U.S. WHO and NREVSS

Collaborating Laboratory Reports, National Summary, 1999-2000

Approximately 75 World Health Organization collaborating virology laboratories

and approximately 50 laboratories from the National Respiratory and Enteric Virus

Surveillance System located throughout the United States report the total number

of respiratory specimens tested, and the number positive for influenza by type and

subtype, during the influenza season. These results help to determine the timing of

influenza activity nationally. 

Week

Week

Number of Isolates

Percent Positive

Source: CDC, Influenza Surveillance Reports,

(http://www.cdc.gov/ncidod/diseases/flu/fluvirus.htm)

Source: CDC, Influenza Surveillance Reports,

(http://www.cdc.gov/ncidod/diseases/flu/fluvirus.htm)
11

State health departments report the estimated level of influenza activity in their

state each week. When activity occurs, it is reported as sporadic, regional, or

widespread. These levels are defined as follows:

SPORADIC

Influenza cases, either laboratory-confirmed or influenza-like illness (ILI), are

reported, but reports of outbreaks in places such as schools, nursing homes,

and other institutional settings have not been received. 

REGIONAL

Outbreaks of either laboratory-confirmed influenza or ILI are occurring in

geographic areas containing less than 50% of the state’s population. A

geographic area could be a city, county, or district.

WIDESPREAD

Outbreaks of either laboratory-confirmed influenza or ILI are occurring in

geographic areas representing more than 50% of the state’s population. Peak

influenza activity occurs when the highest number of states report either

regional or widespread influenza activity.

FIGURE 4 Influenza Activity as Assessed

by State and Territorial Epidemiologists, 1999-2000

Source: CDC, Influenza Surveillance Reports,

(http://www.cdc.gov/ncidod/diseases/flu/fluvirus.htm)
12

The World Health Organization

(WHO) network of collaborating

centers for influenza is a surveillance system that has provided

important information on strains 

of influenza since its inception in

1947. This network helps to

monitor influenza activity in all

regions of the world. The network

now consists of 110 national

influenza centers in 83 countries,

and 4 WHO collaborating centers

in Atlanta, GA, USA; London, UK;

Tokyo, Japan; and Melbourne,

Australia. 

WHO has developed a web-based

database called FluNet on which

data from centers in the influenza

network are entered. The data

consists of weekly reports of

influenza activity in each location

and includes the numbers of

influenza-positive specimens

detected. There is a cumulative

seasonal summary included in the

database, providing a description

of recent and current influenza

activity around the world. The data

are geographically referenced at

the country level, and charts,

maps and tables are available for

view on the FluNet website. The

database dates from 1997, and it

includes data from countries on all

continents. 

Source: WHO FluNet, http://oms.b3e.jussieu.fr/flunet

Acute care facilities should conduct surveillance for acute

care facility-acquired influenza or influenza-like illness,

particularly during the influenza season (from October through

April in North America). However, sporadic cases of influenza

can occur at any time of the year (Figures 1–4).

When should surveillance

be conducted?

The WHO network of collaborating centers for influenza 

BOX 6 http://oms.b3e.jussieu.fr/flunet
13

Why is laboratory testing

for influenza important?

Influenza is very difficult to differentiate from other pathogens

on the basis of clinical symptoms alone. Other pathogens that

can cause similar symptoms include, but are not limited to,

Mycoplasma pneumoniae, adenovirus, respiratory syncytial

virus (RSV), rhinovirus, parainfluenza viruses, and Legionella

spp. Many pathogens, including influenza, RSV, and parainfluenza, cause outbreaks in a seasonal pattern (Figure 5). 

*Influenza data collected only from October–May each year through WHO Collaborating Laboratories Surveillance

System. RSV and parainfluenza data collected continuously through National Respiratory Enteric Viruses Surveillance

System. The relative contribution of influenza may not be to scale compared with other viruses included in the graph.

Source: CDC, unpublished data

FIGURE 5

Etiology of Influenza-like Illness (ILI) 

Seasonal occurrence of influenza, RSV, and parainfluenza types 1 and 3

United States, 1996-1999*
14

When should influenza

testing be done?

Based on facility surveillance, infection control personnel

should establish threshold levels (Box 7) of influenza or

influenza-like illness (Box 3) at which influenza testing and

outbreak control measures should be initiated. Physicians may

use a lower threshold for testing individuals at high risk for

influenza-related complications. Droplet precautions should be

initiated pending laboratory confirmation of influenza.

Threshold level for influenza

is reached when

 One or more patients are

identified with healthcareacquired laboratory confirmed

influenza or 

 A cluster (e.g., 3) of patients

with healthcare-acquired

clinically suspected (i.e.,

influenza-like illness) influenza

is identified on the same floor

or ward during a short (e.g.,

48-72 hour) period 

BOX 7
15

What

laboratory

tests can

be used 

to confirm

the

diagnosis

of

influenza?

Appropriate patient samples to collect for laboratory testing

can include a nasopharyngeal or throat swab, nasal wash, or

nasal aspirates, depending on which rapid test is used (Table

1). Samples should be collected within the first 4 days of

illness. Rapid influenza tests provide results within 24 hours;

viral culture provides results in 3-10 days. Most of the rapid

tests are >70% sensitive for detecting influenza and >90%

specific. Because as many as 30% of samples that would be

positive for influenza by viral culture may give a negative rapid

test result, negative rapid tests should be followed by viral

culture in a sub-sample of the swabs collected. Viral culture

can also identify other causes of influenza-like illness when

influenza is not the cause.

Serum samples can be tested for influenza antibody to

diagnose acute infections. Two samples should be collected per

person: one sample within the first week of illness and a

second sample 2-4 weeks later. If antibody levels increase from

the first to the second sample, influenza infection likely

occurred. Because of the length of time needed for a diagnosis

of influenza by serologic testing, other diagnostic testing

should be used for rapid detection of possible outbreaks.
16

Laboratory Diagnostic Procedures

for Influenza1

INFLUENZA TYPES ACCEPTABLE TIME FOR POINT-OF-CARE PROCEDURE DETECTED SPECIMENS RESULTS MARKET

Viral Culture A and B • NP Swab2 5-10 Days3 No

• Throat Swab

• Nasal Wash

• Bronchial Wash

• Nasal Aspirate

• Sputum

Immuno- A and B • NP Swab2 2-4 Hours No

fluorescence • Nasal Wash

• Bronchial Wash

• Nasal Aspirate

• Sputum

Influenza A A and B • NP Swab2 2 Hours No

Enzyme • Throat Swab

Immuno- • Nasal Wash

Assay (EIA) • Bronchial Wash

Directigen A A • NP Swab2 <30 Minutes Yes

(Becton- • Throat Swab

Dickinson) • Nasal Wash

• Nasal Aspirate

Directigen A and B • NP Swab2 <30 Minutes Yes

Flu A and B • Throat Swab

(Becton- • Nasal Wash

Dickinson) • Nasal Aspirate

• Bronchial Wash

FLU OIA A and B4 • NP Swab2 <30 Minutes Yes

(Biostar) • Throat Swab

• Nasal Aspirate

• Sputum

Quick Vue A and B4 • NP Swab2 <30 Minutes Yes

(Quidel) • Nasal Wash

• Nasal Aspirate

Zstat Flu A and B4 • Throat Swab <30 Minutes Yes

(ZymeTx)

RT-PCR A and B • NP Swab2 1-2 Days No

• Throat Swab

• Nasal Wash

• Bronchial Wash

• Nasal Aspirate

• Sputum

Serology A and B • Paired Acute and >2 Weeks No

• Convalescent

• Serum Samples5

1 List may not include all test kits approved by the U.S.

Food and Drug Administration as of September 1, 2001

2 NP = nasopharyngeal

3 Shell vial culture, if available, may reduce time for

results to 2 days

4 Does not distinguish between influenza A and B types

5 A fourfold or greater rise in antibody titer from the

acute- (collected within the 1st week of illness) to the

convalescent-phase (collected 2-4 weeks after the

acute sample) samples is indicative of recent infection. 

TABLE 1

See product package inserts for further information
17

 Cohort those with influenza or influenza-like illness

(Box 3) on a ward designated to accept patients with

suspected or confirmed influenza (Box 8)

 Initiate droplet precautions for persons with influenzalike illness or confirmed influenza infection, including

wearing masks when within 3 feet of the patient,

wearing gowns if clothing is likely to be soiled by body

fluids, and practicing hand hygiene before and after

patient contact

 Offer influenza vaccine to patients and healthcare

personnel who have not been vaccinated 

 Consider offering influenza antiviral medications

(Table 2) for treatment of ill patients and healthcare

personnel and for prophylaxis of exposed patients,

unvaccinated personnel, and those vaccinated 

<2 weeks before exposure

 Monitor personnel for influenza-like illness and

restrict ill personnel from patient care

 Restrict visitors with influenza-like illness

 Continue to monitor for healthcare-acquired influenza

and for patients being admitted to the facility who

have influenza infection

See Figure 6 and Box 9 for more information on control

measures for influenza outbreaks.

What control measures should be used

for influenza or influenza-like illness?
18

Summary Control Measures

to Consider for Influenza in

Acute Care Facilities

 Cohort patients with suspected

or laboratory-confirmed

influenza on a designated

ward and place on droplet

precautions

 Vaccinate unvaccinated staff

and patients

 Restrict movement of staff

between wards

 Limit visitors with respiratory

illness

 Limit new non-influenza-like

illness admissions to

designated cohort ward

 Restrict ill staff from patient

care

 Treat influenza cases with

antiviral medications

 Offer prophylaxis to exposed

non-ill patients and unvaccinated staff with antiviral

medications 

BOX 8
19

Flow Chart for Surveillance and Control

of Influenza in Acute Care Facilities

Monitor for Influenza

and Influenza-like

Illness (ILI)

(Box 3)

Influenza

or ILI Cluster

Identified

(Box 7)

Collect Swabs from

3 or More Patients

with ILI

All Tests Influenza

Negative; ILI

Cases Continue

Swab Again and

Investigate

Other Causes

All Tests

Influenza

Negative

Investigate Other

Causes; Continue

ILI Surveillance

All Tests Influenza

Negative; No

More ILI Cases

Continue

ILI Surveillance

(Box 4)

One or More

Specimens Positive

for Influenza*

(Table 1)

Consider 

Control Measures

(Box 8)

**Additional information regarding rapid diagnostic tests for detection

of influenza virus can be found in the following publication:

Anonymous. Rapid diagnostic tests for influenza. Med Lett Drugs

Ther 1999;41:121-2.

FIGURE 6
20

Practical Suggestions for

Cohorting Patients with Influenza

or Influenza-like Illness

During Influenza Outbreaks

Cohorting patients can be difficult to accomplish in many

hospitals, and institutions must individualize plans for

cohorting based on the availability of local resources

(personnel, facility design, etc.). The following is a suggested

hierarchical approach:

 When possible, place patients with documented or

suspected influenza in a private room

 When the number of patients with influenza exceeds the

available private rooms, try to place influenza cases

together in multi-bed rooms or wards

 When patients with and without influenza must be placed

in a room together, try to avoid including uninfected

patients most susceptible to influenza complications

(Box 1)* 

 When multiple influenza cases are admitted, minimize the

number of staff having contact with infected patients by

assigning all influenza patients to a single or small group

of healthcare personnel

 When numerous cases are identified, consider placing all

patients with documented or suspected influenza in one

designated unit or ward, i.e., an influenza cohort, and

assign vaccinated nursing personnel to work in the

designated influenza cohort unit

*Acute care facilities should use droplet precautions to reduce transmission of influenza in

patients sharing a room. Droplet precautions call for a distance of at least three feet between

patients, preferably separated by a physical barrier (e.g., curtain).

BOX 9
21

Comparison of Influenza Antiviral Drugs 

INFLUENZA PRIMARY AGENT VIRUS AFFECTED ADMINISTRATION SIDE EFFECTS 

Amantadine§ Influenza A Oral Central nervous system/ 

Gastrointestinal 

Central nervous system/ 

Rimantadine¶ Influenza A Oral Gastrointestinal 

Zanamivir Oral Respiratory 

Influenza A and B inhalation 

Oseltamivir Influenza A and B Oral Gastrointestinal 

* The indications/dosing and side effects listed were current as of August 2001. For more current

information, please consult the package inserts. For information on use and dosing in children, consultpackage inserts and ACIP recommendations.

§ Consult drug package insert for dosage recommendations for administering amantadine to persons with

creatinine clearance 50 ml/min.

† A reduction in dosage may be indicated for persons >65 years of age; consult drug package insert for

dosing recommendations in this age group.

¶ A reduction in dosage is recommende

drug package insert for further dosage 

‡ A reduction in dosage is recommende

package insert for further dosage reco

 Zanamavir is not currently approved fo

time of publication.
22

What can acute care facilities

do to prepare for possible

influenza outbreaks?

 Make sure that all healthcare personnel receive

influenza vaccination by

 Offer vaccine to unvaccinated patients before they are

discharged

 Have a written policy concerning influenza outbreak

management and ensure that key healthcare

personnel, especially nurses, are aware of it

 Disseminate information to physicians about influenza

testing and use of influenza antiviral medication

 Institute surveillance for influenza-like illness (Box 3)

among healthcare personnel and patients

IMPROVING ACCESS TO

VACCINE e.g., using a

mobile cart to vaccinate

healthcare personnel in

their work areas, at

conferences, in lunchrooms, or in other meeting

areas (Box 10).

ANNUALLY PROVIDING

REPORTS of vaccination

levels by employee unit.

Information should be

disseminated to personnel

and their supervisors and

may be used to foster a

spirit of competition. Set

target vaccination goals

and publicize running vaccination totals throughout

the facility during vaccination periods. Nominal

awards may be beneficial

in improving coverage and

should be considered. 

Recognition should be

given to employee units

with high coverage levels.

ADDRESSING

REMINDERS from the

employee health department to all healthcare

personnel and their supervisors. The reminders

should include a list of

places and times that

vaccination will be offered.

EDUCATING PERSONNEL

ANNUALLY about the risks

of influenza to their

patients, themselves, and

their families, and about

the benefits of vaccination.

Personnel should receive

data about the impact of

influenza, if known, in their

facility. Ideally, vaccination

should be offered at the end

of such education sessions.
23

Influenza 

vaccination 

percentage by occupation,

Facility A

 Physician/Physician

Assistant 39.7%

 Housekeeping 30.2%

 Phlebotomists 27.2%

 Nursing 26.3%

 Transport/Services 25.9%

 Technicians 23.1%

(respiratory, X-ray)

 Clerical 21.4%

BOX 10a Strategies used 

to successfully 

improve influenza 

vaccination, Facility A

 Intensive education

 Mobile vaccine carts in

work areas

 Employee reminders

 Local health department

campaign

 Targeted intervention

– specific occupations,

e.g., nursing

– personnel caring for

specific populations

BOX 10b

Strategies to improve

healthcare personnel vaccination rates

In 1996 and 1997, a survey conducted in hospitals

participating in the National Surveillance System for

Healthcare Personnel (NaSH) found that only 28% of

healthcare personnel were vaccinated against

influenza. Physicians were most likely to be

vaccinated; nurses were less likely to be vaccinated

than personnel in housekeeping or phlebotomists,

despite nurses’ frequent close contact with patients

at high risk for developing complications from

influenza. 

One NaSH facility, noting low nurse vaccination rates

[BOX 10a], developed a campaign targeted at nurses

[BOX 10b]. As a result, the influenza vaccination rate

in this facility increased dramatically, both overall

and especially among nurses [BOX 10c]. Nationally,

influenza vaccination in healthcare personnel is

alarmingly low compared with other groups for

whom vaccination is recommended, even in

personnel who are at high risk for developing

complications from influenza [BOX 10d]. A targeted

campaign with active intervention can be particularly

effective in increasing the percentage of healthcare

personnel who are vaccinated.

Source: CDC, unpublished data

BOX 10
24

Self-reported influenza vaccination of U.S. adults in 1996-97

Source: 1997 National Health Interview Survey

% Vaccinated

All adults 65 yrs. of age 63%

Healthcare personnel with high risk (aged 18-64 yrs.)* 38% 

All healthcare workers** 34%

**One or more high-risk medical conditions including diabetes, current cancer treatment, or chronic heart,

lung, or kidney disease.

**Healthcare workers included persons currently employed in healthcare occupations, regardless of setting,

and persons currently employed in healthcare settings without a healthcare occupation.

Walker FJ, Singleton JA, Lu PJ, Strikas RA. Influenza Vaccination of Healthcare Workers in the United

States, 1989-97 [Abstract]. Infection Control and Hospital Epidemiology 2000:21:113.

BOX 10d

Healthcare personnel influenza vaccination by year 

and occupation, Facility A vs other NaSH facilities

BOX 10, CONT.

0

10

20

30

40

50

60

70

80

1996 1997

Percentage Vaccinated

Facility A

Nurses, Facility A

Facilities 

excluding A

Year

BOX 10c
25
26
For additional copies of this booklet,

please call the Public Health Foundation

FREE 1-877-252-1200

For more information about influenza

or influenza vaccination, call FREE 1-800-232-2522

or see our website at

www.cdc.gov/ncidod/hip/infect/flu.htm

or

www.cdc.gov/ncidod/diseases/flu/fluvirus.htm

or

www.cdc.gov/nip/flu

TOLL

TOLL

Department of Health and Human Services

Centers for Disease Control and Prevention

Printed September 2001

Safer • Healthier • People