By Brent I. ClarkBenjamin D. BriggsAdam R. Young, Patrick D. Joyce, and Craig B. Simonsen

Seyfarth Synopsis: The CDC continues to expand its guidance on the potential routes of COVID-19 transmission, changing its definition of “close contact” of 15 minutes or more within 6 feet, to now mean 15 minutes aggregated across an entire day, and not just a single continuous 15 minute period.

For the last several months, the CDC has advised that COVID-19 can be transmitted via multiple routes. Of those routes, household members, intimate partners, and “close contacts” are at highest risk of transmission. Formerly, the CDC defined “close contact” to be a contact within six feet, for 15 consecutive minutes or more. These 15 consecutive minutes were based on an understanding of sufficient viral load to transmit the disease. The former guidance was released before CDC’s mask guidance and made no mention of facemasks. As a result, employers and contact tracers could infer that “close contact” meant unmasked contact.

However, on October 21, 2020, the CDC updated its definition of “close contact” to mean “someone who was within 6 feet of an infected person for a cumulative total of 15 minutes or more over a 24-hour period* starting from 2 days before illness onset (or, for asymptomatic patients, 2 days prior to test specimen collection) until the time the patient is isolated.” Now, “cumulative minutes of exposure at a distance of 6 feet or less can be used as an operational definition for contact investigation.”

This is a large shift for employers and contact tracers, and will require increased resources to help identify contacts over 15 minutes cumulatively in a 24-hour period and will significantly reduce the workforce available to employers. For example, CDC’s new definition could mean that a person who had thirty separate 30-second interactions with a COVID-19 positive contact through a day would be considered a “close contact,” requiring them to quarantine.

The CDC has also removed the contacts’ use of facemasks as a consideration in the analysis, explaining that “because the general public has not received training on proper selection and use of respiratory PPE, such as an N95, the determination of close contact should generally be made irrespective of whether the contact was wearing respiratory PPE. At this time, differential determination of close contact for those using fabric face coverings is not recommended.” Accordingly, close contacts come from 15 or more cumulative minutes of exposure, regardless of facemask use.

To support this change in definition, the CDC provided evidence from an exposure in a correctional setting, indicating that an employee “had multiple brief encounters with six incarcerated or detained persons while their SARS-CoV-2 test results were pending.”  Subsequently, all six detained persons received positive COVID-19 test results. The employer then conducted a contact tracing investigation, using video surveillance footage to determine that the employee never spent 15 consecutive minutes within 6 feet of the detained persons. Subsequently, in the next few days, the employee became ill and also tested positive for COVID-19. During all interactions, the correctional officer wore a microfiber cloth mask, gown, and eye protection. In addition, the employee reported no other known close contact exposures to persons with COVID-19 outside work and no travel outside the state during the 14 days preceding the illness onset.

As recently blogged, the CDC has also expressed concerns about airborne transmission, where transmission can occur from virus particles suspended in the air.

Employers may need to revise their policies, procedures, and record-keeping analyses to be consistent with the CDC’s new guidelines. For more information on this or any related topic, please contact the authors, your Seyfarth attorney, or any member of the Workplace Safety and Health (OSHA/MSHA) Team.