(CNN)Three universities in the Washington, DC, region -- American, Georgetown and Johns Hopkins -- have partially reinstated campus mask mandates following an uptick in Covid-19 cases in the area, according to statements from the institutions.
3 DC area universities partially reinstate mask mandates due to rise in Covid-19 cases
American University (AU) reinstated an indoor masking requirement effective Tuesday, where "masks will be required in all campus buildings except when individuals are alone in private offices, inside residence hall rooms with only roommates, or when actively eating or drinking," according to an email shared with the AU community.
AU will revisit the mandate on May 9, the email said.
On April 7, Georgetown University (GU) reinstated an indoor mask mandate for its medical center and main campuses only, where they've seen a significant increase in Covid-19 cases, primarily among undergraduate students, according to a statement.
The requirement is in place "until further notice," GU said.
Johns Hopkins University (JHU) reinstated their mask mandate on April 6 for all people "in common areas of residence halls or in university dining facilities, except when actively eating or drinking," according to an email to the university community last week.
JHU, located in Baltimore, around 40 miles north of DC, is monitoring conditions and consulting with health experts "in hopes of soon lifting the temporary precautions," spokeswoman Jill Rosen said.
JHU said its mandate follows travel-related Covid-19 cases reported since spring break. Both AU and GU noted the impact of the Omicron BA.2 subvariant in their masking rule announcements.
The highly contagious subvariant is the dominant coronavirus strain in the United States, causing more than half of all Covid-19 infections reported at the end of last month, according to the US Centers for Disease Control and Prevention.
Nationally, cases are trending upward in more than half of states, though case numbers are still relatively low. With an average of around 34,000 new cases per day, the daily case rate in the US remains one of the lowest since mid-July.
On Monday, Philadelphia became the first major US metropolitan area to announce the return of mask requirements, noting its case count was 50% higher than 10 days ago. The city will reinstate masking indoors starting April 18.
Since the start of the month, "nearly 100 undergraduate students" -- residential and non-residential -- at JHU have had a positive Covid-19 test, JHU's student health vice provost Kevin Shollenberger said in the email. The university is requiring Covid-19 testing twice a week for undergraduates until April 22.
GU is requiring all undergraduate students to take a PCR test on April 18, after returning from Easter break, unless they've tested positive in the last three months, according to the university's statement.