Contact tracing is the activity of identifying the relevant contacts of a person with an infectious disease (index patient) and ensuring that they are aware of their exposure and implement necessary measures. The term relevant reflects specificity of the actual disease in terms of person, place and time.
Contact – case definition
Contact tracing is defined as the identification and follow-up of persons who may have come into contact with an infected person. Contact tracing is an important part of epidemiologic investigation and active surveillance. (WHO)
Persons can be labelled as contacts if they comply with the definition of the contact; they spent sufficient time and in physical proximity with the index case that has stage of disease suitable for transmission.
Why to do contact tracing?
When the contact tracing is done?
In general contact tracing is carried out when the transmission route is a direct contact casual or sexual.
Principles of contact tracing
Principles of contact tracing are the same for all diseases but they differ in length of follow up and frequency of monitoring sessions.
Contact listing and follow up
All persons considered to have had exposure as by the definition of the contact and taking into consideration different risk categories should be listed as contacts, using predefined (standardised) contact listing form.
How far into case history should we investigate?
The periods for potential contact tracing differ among diseases and should be taken as a general guide only: