The National Institutes of Health, headquartered in Bethesda, had 28 cases of coronavirus at the end of last week among its nearly 40,000 national staff members. The research institute has required most employees to telework since March 12.

The National Institutes of Health, based in Bethesda, Maryland, confirmed for WTOP on Monday that it has over two dozen staff members who have tested positive for COVID-19.

Reached via email, NIH said as of March 27, there were 28 staff members diagnosed with the novel coronavirus. The NIH cases are included in the Montgomery County and Maryland count.

Since March 12, staff members have been encouraged to work from home. Currently, that is allowed through May 1.

NIH explained in its message to WTOP that when a staff member tests positive for COVID-19, labs they worked in are fully disinfected. In addition, any contacts they may have had while on site are alerted to their potential exposure.

“Those individuals are asked to self-quarantine at home if their exposure constitutes a significant risk of infection,” the email to WTOP noted.

If workers are feeling healthy enough, they’re encouraged to then continue their work from home.

NIH has labs and staff in a number of states and oversees almost 40,000 staff members.

WTOP’s Megan Cloherty contributed to this report.