Contact Tracing for COVID-19

The public health evaluation of close contacts to patients with laboratory-confirmed or probable COVID-19 may vary depending on the exposure setting. Contacts in special populations and/or congregate settings require additional considerations and may need handoff to a senior health department investigator or special team. Additional guidance on managing these contacts can be found in Outbreak Investigations.

Close contact evaluation and monitoring priorities

In jurisdictions with testing capacity, symptomatic and asymptomatic close contacts to patients with confirmed and probable COVID-19 should be evaluated and monitored. For areas with insufficient testing support and/or limited public health resources, the following evaluation and monitoring hierarchy (Box 4) and the case investigation and contact tracing prioritization recommendations can be used to help guide prioritization. The hierarchy is based on the assumption that if close contacts listed in Priority 1 become infected, they could potentially expose many people, those at higher risk for severe disease, or critical infrastructure workers. If close contacts in Priority 2 become infected, they may be at higher risk for severe disease, so prompt notification, monitoring, and linkage to needed medical and support services is important.

When prioritizing close contacts to evaluate and monitor, jurisdictions should be guided by the local characteristics of disease transmission, demographics, and public health and healthcare system capacity. Some states require mandatory testing for specific circumstances. Local decisions depend on local guidance and circumstances.

COVID-19 Contact Tracing Workflow

Step 1: Rapid notification of exposure

For contacts in your health department’s jurisdiction:

• A close contact to a patient with confirmed or probable COVID-19 should be notified of their exposure as soon as possible (within 24 hours of contact elicitation). The patient may elect to notify some or all of their close contacts before the contact tracer.
• The identity of the patient or other identifying information will not be revealed, alluded to, or confirmed by the contact tracer, even if explicitly asked by a contact.
• Contacts can be notified through different channels such as phone, text, email, or in-person (if appropriate) in the primary language of the individual. Special consideration should be given to ensure culturally and linguistically appropriate communications, if possible. The protocol should clearly outline the primary and secondary means of notifying a contact.
• Protocols should be in place to provide services to people who are deaf or who have hearing loss.
• Depending on the information elicited during the case investigation, locating information for the contact may be insufficient. Tips on additional resources that may be used to obtain missing locating information can be found in Appendix B. Every effort should be made to reach the contact remotely before attempting in-person communication.

Step 2: Contact interview

• Every effort should be made to interview the close contact by telephone, text, or video conference instead of in-person. The interview should be conducted in the individual’s primary language (through interpretation services, if necessary). For in-person interviews, guidance on recommended infection prevention and control practices at a home or non-home residential setting can be found on CDC’s Evaluating PUIs Residential page.
• Appendix C includes critical data elements that can be incorporated into a jurisdiction’s form used to interview contacts to assess symptoms, better characterize their underlying risk for infection, and assess home and social factors that could impact compliance with self-quarantine.
• Notification of Exposure – A Contact Tracer’s Guide for COVID-19 focuses on communication strategies for contact interviews and provides suggested language for each topic area covered in an interview.

Step 2a: Recommendations for close contacts

People who are identified as close contacts should follow CDC guidelines to protect themselves and others. Recommendations for close contacts to quarantine, get tested, and wear well-fitting masks after exposure to people diagnosed with COVID-19 will vary depending on their up to date vaccination status and history of prior COVID-19 diagnosis within the past 90 days. People who have come into close contact with persons diagnosed with COVID-19 should follow the recommendations outlined on the COVID-19 Quarantine and Isolation web page.

All close contacts should monitor for COVID-19 symptoms and promptly get tested and isolate away from others if they develop symptoms. People with symptoms of COVID-19 should seek emergency medical care immediately if they develop emergency warning signs.

Step 2b: Assessing quarantine support needs

Emphasis should be placed on helping close contacts identify any need for social support during quarantine.

Quarantine of close contacts exposed to COVID-19 prevents transmission to others and is critical to the success of case investigation and contact tracing efforts. For most, quarantine can take place at home. If possible, close contacts should be asked to voluntarily stay home, monitor themselves, and maintain social distance from others. Recommendations for close contacts vary based on their up to date vaccination status or history of prior infection in the past 90 days. Close contacts who are required to quarantine should follow the recommendations outlined on the COVID-19 Quarantine and Isolation webpage. Adherence to quarantine instructions may depend on the support provided to close contacts.

Quarantine requires that a close contact remain in a specific room separate from other non-exposed people and pets in the home, and ideally with access to a separate bathroom. The contact tracer should assess an individual’s ability to quarantine in a safe environment that provides access to a private room and bathroom, as well as access to adequate food and water among other considerations.

For a portion of the U.S. population, having a safe environment with a private room and bathroom, and adequate food and water will be a challenge. Considerations must also be made for close contacts who express fear of abuse or violence if they must quarantine at home. Additionally, some close contacts (e.g., single parents, nursing mothers, parents with children and toddlers, and other primary caregivers) may face other challenges, such as having to provide child care or dependent adult care, that may affect their ability to quarantine. Social services, housing, and other supportive services will be needed for those contacts who are unable to separate themselves from others in their current living situation. See Support Services for further considerations.

Close contacts will also need to be supported with health coaching to ensure that each day they monitor their temperature and the onset of any COVID-19 symptoms and have access to clinical services should symptoms appear. Coordination of access to telehealth services may be needed for contacts without virtual access to a primary care provider. If possible, close contacts in need of additional support should be provided a COVID-19 kit with the following resources during quarantine*:

• Washable cloth face covering
• Gloves
• Digital thermometer
• Alcohol-based hand sanitizer and soap
• COVID-19 health education materials (translated into the appropriate language)
• EPA-registered household disinfectantexternal icon and instructions for cleaning and disinfecting your home for those sharing space with others
• A hotline/warmline to address any support needs during the quarantine period, including medical support

*The composition of the COVID-19 kit will depend on the jurisdiction’s resources.

Step 3: Medical monitoring

• Contacts who agree to self-quarantine will ideally receive active daily monitoring through real-time communication methods (e.g., telephone calls, video conferencing) to check-in on their temperature and COVID-19 symptoms throughout the length of their self-quarantine.
• If a jurisdiction’s resources do not allow for active daily monitoring, contacts will be asked to self-monitor and communicate remotely (e.g., email, recorded video, telephone message, text, monitoring apps) to notify public health authorities of their health status and promptly communicate any new symptoms or symptoms of increasing severity. A daily temperature/symptom log pdf icon[215 KB, 2 Pages] can be provided to the contact electronically to aid in self-monitoring.
• For those individuals self-monitoring and sharing reports remotely, reports must be received by the agreed upon time each day, and protocol must address follow-up actions for contacts who do not report out.
• Contacts who develop and report symptoms should be linked to clinical care and testing. For contacts who report testing, follow up to confirm results.
  • If positive, the contact will be referred to a case investigator.
  • If negative, symptomatic contacts should continue to self-quarantine and follow all recommendations of public health authorities. A second test and additional medical consultation may be needed if symptoms do not improve.
  • If testing is not available, symptomatic close contacts should be advised to self-isolate and be managed as a probable case. Self-isolation is recommended for people with probable or confirmed COVID-19 who have mild illness and are able to recover at home.

Step 3a: Monitoring and isolation instructions

• Clients with probable or confirmed COVID-19 should be advised to self-isolate immediately, if they are not doing so already. Self-isolation is recommended for people with probable or confirmed COVID-19 who have mild illness and are able to recover at home.
• It should be made clear to the client whether the isolation instructions are voluntary or mandatory, as determined by state or local public health authorities.
• Advise clients to cancel or postpone plans that involve social gatherings, vacations or other planned travel until cleared for these activities by public health authorities (based on the guidance above).
  • Local and state health departments may request federal public health travel restrictions, which prevent listed travelers from boarding commercial airplanes and trigger public health notification if they enter the United States by land or sea, to support state- or local-mandated isolation for infected individuals.
  • ​Support with federal public health travel restrictions may be requested by public health partners by contacting the CDC quarantine station with jurisdiction for the area.
• If needed, jurisdictions should refer clients for social support services (for example, food, childcare, housing, and other services) to help encourage clients to stay at home and comply with isolation.
• If clients refuse to comply voluntarily with self-isolation instructions, jurisdictions should consider what options (e.g., legal order for isolation) are available to them under relevant state or local legal authority.
• The client should be informed of COVID-19 symptoms to monitor for and be instructed to get medical attention immediately if he/she experiences any emergency warning signs, such as trouble breathing. Clients with no primary healthcare provider will need linkage to telemedicine or phone consultation.
• The client should also be informed of ways to prevent infection among those living in their household.
• Additional isolation guidance should be reviewed with the client and instructional materials provided. Sample materials can be found on the CDC website:
  • 10 things you can do to manage your COVID-19 symptoms at home pdf icon[448 KB, 1 Page]
  • What to Do If You Are Sick
  • When You Can be Around Others After You Had or Likely Had COVID-19
• All instructions should be provided in a client’s primary language.

Step 4: Contact close out​

• The duration of quarantine will depend on whether the close contact develops symptoms. To determine the end of quarantine and the timing for contact close out refer to current CDC guidance for quarantine.
• Close contacts who are symptomatic or test positive should begin isolation.
• Close contacts should watch for symptoms and wear a well-fitting mask around other people for 10 days after their last close contact.