Prompt investigation and contact tracing of Covid-19 cases are still one of the best tools to prevent further transmission and to track variants, according to the US Centers for Disease Control and Prevention.

“Source investigation is important to identify origins and transmissions of viral variants or variants of concern,” said Dr Melanie Taylor, a senior adviser for the contact tracing innovation section of CDC’s Covid-19 emergency response, during the CDC’s Weekly Partner Call.

Source investigation is a method that is used for communicable diseases that investigates the potential source of infection and identify people who may have been exposed or infected within the given pathogen. The CDC encourages that all positive Covid-19 cases are contact traced within a timely six-day window.

“We also know that as vaccine coverage increases source investigation, case investigation and contact tracing can identify remaining pockets of transmission,” Taylor said.

The CDC is encouraging employers and school administrators to collaborate with contact tracers for the most effective community public health strategy and contact tracing data.

The CDC’s traditional contact tracing efforts have focused on the prompt investigation of people diagnosed with Covid-19 and early identification, notification and quarantine of people who may have been recently exposed.

The CDC estimates there are approximately 60,000 contact tracers in the US, 29% speak a language other than English and 43% are under 30 years old.