Question: I’ve been reading a lot about the need for contact tracers to begin reopening. Can you explain what exactly contact tracing is, how it works, and why it’s important?
Answer: Contact tracing is a key element of public health response to infectious disease. When we identify a new case (e.g. someone who is infected with a virus that can be spread person to person, here SARS-CoV-2) we want to next identify everyone who has been in contact with that infected person. We want to find these contacts in order to alert them of their possible risk, to help link them to care, and to help prevent them from spreading the virus to others. Generally, the three components of contact tracing are:
- Contact identification (ask the infected person to identify all the people they’ve interacted with during the period the may have been infectious);
- Contact listing (find and talk with the contacts as quickly as possible, inform them of their risks and educate them about the disease, and especially for those high risk contacts, request that they self-quarantine); and
- Contact follow-up (regular check-ins to monitor for symptoms and test for infection).
In the United States, our health departments are typically set up to do contact tracing related to sexually transmitted infections. When it comes to contact tracing for COVID-19, CDC has a number of resources and offers these principles to groups across the country who are gearing up to expand contact tracing.
The contact tracing component of the response is so important because once we stop using the blunt hammer of extreme social distancing, we need to have a more nimble and precise response that allows us to quickly identify all cases (widespread testing) and all potential cases (widespread contact tracing), and keeps these folks from engaging with the wider population (isolation) to thereby limit the spread of the virus. This will require a huge effort, including massive workforce expansion, as well as good will and trust of the people.