316704A April 29, 2020 8:30 AM

cdc.gov/coronavirus

This document highlights basic principles of contact 

tracing to stop COVID-19 transmission; detailed guidance for 

health departments and potential contact tracers is forthcoming.

Contact tracing, a core disease control measure employed by local 

and state health department personnel for decades, is a key strategy 

for preventing further spread of COVID-19. Immediate action is needed. 

Communities must scale up and train a large contact tracer workforce 

and work collaboratively across public and private agencies to stop the 

transmission of COVID-19.

Certain core principles of contact tracing must always be adhered to:

• Contact tracing is part of the process of supporting patients with suspected or 

 confirmed infection.

• In contact tracing, public health staff work with a patient to help them recall 

 everyone with whom they have had close contact during the timeframe while 

 they may have been infectious.

• Public health staff then warn these exposed individuals (contacts) of their 

 potential exposure as rapidly and sensitively as possible.

• To protect patient privacy, contacts are only informed that they may have been 

 exposed to a patient with the infection. They are not told the identity of the patient 

 who may have exposed them.

• Contacts are provided with education, information, and support to understand 

 their risk, what they should do to separate themselves from others who are not 

 exposed, monitor themselves for illness, and the possibility that they could spread 

 the infection to others even if they themselves do not feel ill.

• Contacts are encouraged to stay home and maintain social distance from others 

 (at least 6 feet) until 14 days after their last exposure, in case they also become ill. 

 They should monitor themselves by checking their temperature twice daily and 

 watching for cough or shortness of breath. To the extent possible, public health 

 staff should check in with contacts to make sure they are self-monitoring and 

 have not developed symptoms. Contacts who develop symptoms should promptly 

 isolate themselves and notify public health staff. They should be promptly 

 evaluated for infection and for the need for medical care.

Contact tracing is a specialized skill.

To be done effectively, it requires people with the training, supervision, and access to social 

and medical support for patients and contacts. Requisite knowledge and skills for contact 

tracers include, but are not limited to:

• An understanding of patient confidentiality, including the ability to conduct 

 interviews without violating confidentiality (e.g., to those who might overhear 

 their conversations)

• Understanding of the medical terms and principles of exposure, infection, 

 infectious period, potentially infectious interactions, symptoms of disease, 

 pre-symptomatic and asymptomatic infection

• Excellent and sensitive interpersonal, cultural sensitivity, and interviewing skills 

 such that they can build and maintain trust with patients and contacts

• Basic skills of crisis counseling, and the ability to confidently refer patients and 

 contacts for further care if needed

• Resourcefulness in locating patients and contacts who may be difficult to reach or 

 reluctant to engage in conversation

• Understanding of when to refer individuals or situations to medical, social, or 

 supervisory resources 

• Cultural competency appropriate to the local community

COVID-19

CONTACT TRACING

Part of a Multipronged Approach to Fight the COVID-19 Pandemic 

COVID-19 Contact Tracing for Health Departments
Contact tracing is part of the process of supporting patients and 

warning contacts of exposure in order to stop chains of transmission. 

Given the magnitude of COVID-19 cases and plans to eventually relax mitigation efforts 

such as stay at home orders and social distancing, communities need a large number 

of trained contact tracers. These contact tracers need to quickly locate and talk with the 

patients, assist in arranging for patients to isolate themselves, and work with patients to 

identify people with whom the patients have been in close contact so the contact tracer 

can locate them. The actual number of staff needed is large and varies depending on a 

number of factors including but not limited to:

• The daily number of cases

• The number of contacts identified

• How quickly patients are isolated, and contacts are notified and advised to stay 

 home, self-monitor, and maintain social distance from others 

The time to start 

 building the trained 

 workforce is now.

Time is of the essence.

Identifying contacts and ensuring they do not interact with others is critical to protect 

communities from further spread. If communities are unable to effectively isolate patients 

and ensure contacts can separate themselves from others, rapid community spread of 

COVID-19 is likely to increase to the point that strict mitigation strategies will again be 

needed to contain the virus. 

Contact tracers need to:

• Immediately identify and interview people with SARS CoV-2 infections and 

 COVID-19 (i.e., disease)

• Support isolation of those who are infected

• Warn contacts of their exposure, assess their symptoms and risk, and provide 

 instructions for next steps

• Link those with symptoms to testing and care 

Based on our current knowledge, a close contact is someone who was within 6 feet 

of an infected person for at least 15 minutes starting from 48 hours before illness 

onset until the time the patient is isolated. They should stay home, maintain social 

distancing, and self-monitor until 14 days from the last date of exposure. 

Contact investigation in care facilities, other congregate living 

settings and households with many people living in one house 

is a priority. 

Contact investigation of patients with COVID-19 potentially exposed at work and 

patients in health care facilities, congregate living settings or housing with many people 

is complex. Appropriate engagement with infection control and occupational health 

programs is recommended. Priority settings include: 

• Health care facilities including long-term care facilities

• Group home/board

• Homeless shelters

• Federal, state and local correctional facilities

• Crowded, multigenerational housing

In addition to health care workers, it is important to assess interactions between residents 

and all staff, including but not limited to activity coordinators, food service staff, and 

sanitation management. Transitional case management plans should be put in place for 

patients in isolation and contacts who are separated for monitoring. Management plans 

should also be created for transitioning from one setting to another, such as transitions 

from hospitals to acute or long-term care facilities or home isolation, or from prison and 

jail to parole and probation.

CONTACT TRACING Part of a Multipronged Approach to Fight the COVID-19 Pandemic 

COVID-19 Contact Tracing for Health Departments
Social services and housing will be needed for contacts unable to 

separate themselves from others in their current living situation. 

Separating contacts from people who are not exposed is critical to the success of any 

contact tracing effort and requires social supports for individual compliance and medical 

monitoring. First and foremost is the assessment of an individual’s ability to stay in home 

and maintain social distance from others, a safe environment that provides the necessary 

supports (private room and bathroom, adequate food and water, and access to medication) 

and the ability to practice adequate infection control. For a portion of the U.S. population 

this will be a challenge, particularly for some of the most vulnerable populations. 

Support services for consideration include but may not be limited to housing, food, 

medicine, and economic supports. For contacts without a primary care provider, linkage 

to clinical care may be needed. Support for medical monitoring includes patient care 

packages (e.g., thermometers, sanitizers, mask, gloves) and technological supports for 

medical monitoring (e.g., mobile phone apps). If possible, contacts should be asked to 

voluntarily stay home, monitor themselves, and maintain social distancing from others. 

However, health departments have the authority to issue legal orders of quarantine, should 

the situation warrant that measure.

Communication with the public is crucial. 

Engagement of the public with contact tracers must be 

widely accepted in order to protect friends, family, and 

community members from future potential infections. 

Key public officials and community leaders will need to be 

engaged and supportive of contact tracing efforts. Consider 

reaching out to community leaders as part of the neighborhood-level contact tracing 

team. To be successful, a community will need public awareness, and understanding and 

acceptance of contact tracing and the need for contacts to separate themselves from others 

who are not exposed. Community members need to take responsibility to follow the 

guidance from public health agencies.

Data management and technology will be needed. 

Case investigation, contact tracing, and contact follow-up and monitoring will need to be 

linked with timely testing, clinical services, and agile data management systems to facilitate 

real-time electronic transmission of laboratory and case data for public health action. 

Technology partners are key in the modification of existing systems and the development 

of new user-friendly data interfaces to manage multiple data streams with seamless 

interoperability. Case management tools can help automate key pieces of the contact 

tracing process, making the overall process more efficient. Ideally, data systems would also 

include automated reports to aid in monitoring progress and outcomes of contact tracing. 

Data sharing agreements between local, tribal and state, and federal jurisdictions need to 

be established or augmented to ensure timely and accurate data collection and sharing. 

The adoption of emerging technologies that can assist private and public health 

practitioners with client communication, medical monitoring, and strategies to amplify 

contact tracing may greatly help with scaling up contact tracing as needed. 

Ongoing monitoring and assessment of contact tracing efforts 

will be needed. 

Public health agencies and their partners will need to monitor some key components of 

their programs to improve performance as needed. Potential metrics routinely reviewed 

could include the following process and outcome measures: 

• Case interviewing: Time to interview from symptom onset and from diagnosis; 

 proportion interviewed; median number of contacts elicited; proportion with no 

 contacts elicited.

• Contact notification: Proportion of contacts notified; time from first potential 

 exposure to notification.

• Contact follow-up: Daily proportion of contacts whose status is evaluated; 

 proportion of contacts with symptoms evaluated within 24 hours of onset of 

 symptoms; proportion of contacts who complete their full self-monitoring period 

• Contact tracing efficacy: Percent of new COVID-19 cases arising among contacts 

 during self-monitoring period.

CONTACT TRACING Part of a Multipronged Approach to Fight the COVID-19 Pandemic 

COVID-19 Contact Tracing for Health Departments