Contact Tracing
Case investigation and contract tracing are key measures used by public health professionals for decades to prevent the spread of infectious disease (Centers for Disease Control and Prevention [CDC], n.d.; CDC., 2020a). Contact tracing can be used for any communicable disease that can be passed from person-to-person.
After a person has been diagnosed with an infectious disease, public health professionals may conduct contact tracing to identify, monitor, and support contacts who have been exposed to, and possibly infected with the disease.
When close contacts are promptly identified, quarantined, and monitored for symptoms of the disease, the chain of disease transmission is broken and further spread of the infection is prevented. Contacts in healthcare facilities, long-term care facilities, group homes, shelters, correctional facilities, or crowded multigenerational housing should be prioritized (Centers for Disease Control and Prevention, 2020a).
The following steps outline a typical contact tracing workflow (Centers for Disease Control and Prevention, 2022a):
Step 1: Identify and Follow Up With Client
| Infectious diseases are triaged and assigned to a public health professional for follow up. | Client is interviewed with specific questions to ask. | Client isolated and referred to support services or a medical provider. | Sometimes the client is monitored for symptoms. |
Step 2: Identify Contacts
| Determine the infectious period and identify close contacts during that time. | Close contacts may include: Household members, intimate partners, coworkers, or other people | Gather the contacts’ full name, phone number or email, home address, exposure setting, & date of exposure. |
Step 3: Notify Contacts
| Contact the close contact to notify them of exposure. | Keep the original case’s information private and provide education about the disease. | Screen clients and identify their risk of transmission or complications. | Some living or work settings may have a higher risk.* |
| *congregate settings , multi-family/ generational households , factories, food processing facilities, homeless shelters , long term care facilities | |||
Step 4: Monitor Contacts
| Quarantined and monitor contacts. | Testing may be available for asymptomatic or symptomatic contacts. | Monitor for symptoms and refer for testing, to a medical provider, or other support services. |
During the contact tracing process, it may be necessary and helpful to provide or link a client with mental health crisis support. This may include but is not limited to trauma-informed outreach services, mental first aid, and suicide prevention resources (Public Health Institute, 2020).
Bookmark the following resources:
Project Firstline: Access infection control education and resources including videos and media graphics, interactive resources, print materials, and training toolkits (Centers for Disease Control and Prevention, 2024).
Trauma Informed Care: An overview and training about using trauma informed care approaches (Trauma-Informed Care Implementation Resource Center, 2025).
Data management and technology
Technology may be a key tool in contact tracing to identify, notify, and monitor contacts. Technology can also help keep data and contacts organized, in addition to making the overall process more efficient. Technology may also be used as a means to share data between jurisdictions or states when appropriate.
Bookmark Applications of Digital Tools for Precision Public Health in the COVID-19 Era: Where Are We?
This describes two systematic reviews of the use and limitations of digital tools in public health surveillance in the pandemic response (Center for Disease Control and Prevention, 2021).
Communication
When communicating with clients, it is important to establish client rapport, use effective dialog, and problem-solve with the client. During the conversation, work to:
- Establish trust
- Listen actively
- Use open-ended questions
- Be flexible in the interview process
- Collaborate with the patient to solve problems
- Establish open dialogue to facilitate future communication
If a client is required to isolate or quarantine, they may have barriers that need to be addressed by the investigator. Assess your client’s individual needs and help them problem solve. Support may be required for the following:
- Safe living environment
- Childcare, adult care, dependent individuals
- Access to food and essential items
- Access to medical care and medications
- Mental health considerations
Culturally and linguistically diverse populations
People of certain populations, including historically marginalized racial and ethnic groups, members of tribal nations, immigrants and refugees, may have unique health differences challenges due to disparities in economic and social conditions (Centers for Disease Control and Prevention, 2020b). Health departments should strive to employ a diverse workforce to effectively engage the community and while also collaborating with community serving organizations.
When conducting client interviews and contact tracing, it’s important to do the following (Centers for Disease Control and Prevention, 2020b):
- Conduct investigations in a culturally appropriate manner
- Deliver trauma-informed care and practice cultural humility (Celentano et al., 2021)
- Provide an interpreter for individuals who have limited English proficiency
- Ensure privacy and confidentiality of data collected and ensure the client is aware of these safeguards
Community engagement & partnership
Successful contact tracing is dependent upon the level of trust and participation within a community. Public health messaging must be clear, consistent, and positive to generate understanding and acceptance of the contact tracing process (COVID-19 Contact Tracing Playbook, 2021). Consider the following community engagement measures:
- Authentically partner with key public officials, informal community leaders and community organizations
- Identify key community leaders—formal and informal—to help community members be aware of and understand the case investigation and contact tracing process (Centers for Disease Control and Prevention, 2020a)
- Develop messages about WHY contact tracing is an important way to protect family, friends, and community members from contracting an infectious disease.
- Use message maps to help a share clear, reliable, understandable, and truthful information and share using a variety of platforms
- Develop messages that dispel misinformation and redirect individuals to reliable sources
- Develop messaging that targets a specific audience and use culturally sensitive materials in multiple languages. Ensure that messages reach their intended audience