Contact tracing
Contact tracing identifies people who may have been exposed to an infectious case and supports measures to reduce onward transmission.
Case investigation: A public-health inquiry that gathers information about an infected person’s illness, activities, and possible sources of infection. It establishes the infectious period, locations, and encounters needed to identify contacts.
Tuberculosis contact investigation: A public-health investigation that evaluates people exposed to a person with infectious tuberculosis. Long, close exposure and latent infection make household and other contact assessment central.
Infectious period: The interval during which an infected person can transmit a pathogen to others. This interval bounds which encounters are relevant to a case’s trace.
Syndromic surveillance: Monitoring health indicators, such as symptom patterns, to detect unusual disease activity before diagnoses are complete. Surveillance detects signals across populations; tracing follows up specific cases and their contacts.
Contact elicitation: The process of identifying people who may have encountered an infectious person during a relevant exposure period. Interviews and other records turn a case’s movements into a list of possible contacts.
HIV partner notification: A service that confidentially informs sexual or injecting partners of possible HIV exposure and offers testing. It applies tracing principles while prioritizing consent, confidentiality, and access to testing.
Incubation period: The time between infection and the onset of symptoms. It helps set the duration of monitoring or quarantine after exposure.
Isolation: Separation of people who are infected or suspected of being infected from others. Isolation manages cases, whereas quarantine and monitoring address exposed contacts.
Exposure assessment: An evaluation of whether an encounter created a meaningful possibility of pathogen transmission. It determines which reported encounters warrant follow-up.
COVID-19 contact tracing: Identification and follow-up of people exposed to SARS-CoV-2 during the COVID-19 pandemic. Large case numbers and presymptomatic spread tested tracing at population scale.