Effectiveness of Contact Tracing

Angie Szumlinski Studies

During 2020, mitigation of SARS-CoV-2 largely depended on non-pharmaceutical interventions such as physical distancing, hand hygiene, universal masking, isolation, and quarantine. Contact tracing and quarantine of exposed contacts are intended to limit the number of infected contacts and lessen the risk of transmission. Contact tracing is a resource-intensive, multi-step process with many potential steps at which persons with COVID-19 or their contacts might be missed or notified too late of their infection exposure.

These findings are relevant to decisions regarding the allocation of public health resources among the various prevention strategies and for the prioritization of case investigations and contact tracing efforts.

COVID-19 Case Investigation and Contact Tracing in the US, 2020” – R. Ryan Lash, PhD et al.

A recent study published in JAMA Network Open was conducted to determine the proportion of cases and their contacts reached by public health authorities, the amount of time needed to reach them and to compare the risk of a positive COVID-19 test result between contacts and the general public during 4-week assessment periods. We all know how labor intensive contact tracing is, how difficult it can be to obtain contact information from individuals who may be exposed, and more importantly, how many times people are contacted and fail to respond!

This study suggests that contact tracing had suboptimal impact on SARS-CoV-2 transmission, largely because 2 of 3 cases were either not reached for interview or named no contacts when interviewed.

Stay well, stay informed, and stay tuned!