On January 9, 2024, the California Department of Public Health (“CDPH”) issued an order modifying certain COVID-19 definitions. The revisions reflect the CDPH’s updated intervention priorities, which are “now focused on protecting those most at risk for serious illness, while reducing social disruption…”

The revised definition of “infectious period,” for purposes of isolation and exclusion of confirmed COVID-19 cases, is:

• For symptomatic confirmed cases, from the day of symptom onset until 24 hours have passed with no fever, without the use of fever-reducing medications, AND symptoms are mild and improving.
• For asymptomatic confirmed cases, there is no infectious period for the purpose of isolation or exclusion. If symptoms develop, the criteria above will apply.

These revisions are incorporated into Cal/OSHA’s COVID-19 Prevention Non-Emergency Regulations, and so impacts employer obligations, including those related to isolation and quarantine. Employers no longer need to exclude asymptomatic COVID-19 from work and symptomatic COVID-19 cases must be excluded from work for at least 24 hours.

The revision also impacts “close contacts,” which only occur during a COVID-19 case’s “infectious period.” Similarly, workers are part of an “exposed group” during an “outbreak” when an employee COVID-19 case was present during their “infectious period,” so the revised definitions will result in fewer “outbreaks.”

CDPH also introduces a new term, “potential infectious period,” which is, “2 days before symptoms began or the positive test date (if no symptoms) through 10 days after symptoms began or testing positive.” However, that term is not used in the Non-Emergency Standards and CDPH does not explain under what circumstances that definition will be relevant.

CDPH also directs people to follow the recommendations in its most recent masking guidance.

The order does not apply to healthcare settings. You can read the January 9, 2024, order here, and CDPH’s related “Questions & Answers” here.