The California Department of Public Health (CDPH) recently expanded the definition of “close contact” to better acknowledge that COVID-19 is an airborne disease, rather than one spread by respiratory droplets. 

For the purposes of the CDPH’s recommendations regarding isolation and quarantine periods for persons infected with or exposed to COVID-19, “close contact”  is now defined as someone sharing the “same indoor airspace” (e.g., home, clinic waiting room, airplane etc.) for a cumulative total of 15 minutes or more over a 24-hour period (for example, three individual 5-minute exposures for a total of 15 minutes) during an infected person's (laboratory-confirmed or a clinical diagnosis) infectious period.

Previously, “close contacts” meant “being within six feet of a COVID-19 case for a cumulative total of 15 minutes or greater in any 24-hour period within or overlapping with the infectious period.”

In addition, as the SARS-CoV-2 virus has recently evolved to have a shorter incubation period (on average 2-3 days), CDPH recommendations regarding relevant time periods for restricting movement by quarantine have been updated to acknowledge this shorter period.

The new guidance defines the “infectious period” as:

• For symptomatic persons: Two days before the infected person had any symptoms through day 10 after symptoms first appeared (or through days 5-10 if testing negative on day five or later), and 24 hours have passed with no fever, without the use of fever-reducing medications, and symptoms have improved.
• For asymptomatic persons: Two days before the positive specimen collection date through day 10 after positive specimen collection date (or through days 5-10 if testing negative on day 5 or later) after specimen collection date for their first positive COVID-19 test.

For the purposes of identifying close contacts and exposures, infected persons who test negative on or after day 5 and end isolation are no longer considered to be within their infectious period. Such persons should continue to follow CDPH isolation recommendations, including wearing a well-fitting face mask through day 10.

These new definitions will have a significant impact on employers’ obligations and workplace policies on exposure notifications, testing and face coverings as the number of individuals who will be considered to be in “close contact” with an infected individual will expand. Employers should review and update their current workplace safety policies and procedures to ensure compliance with the new guidance from CDPH.