A high school in D.C. will be closed Monday after a staff member had contact with the District's second patient to test positive for the new coronavirus, according to the mayor's office.
A man in his 50s spent one night in D.C. after arriving from Nigeria and before testing positive for COVID-19. That man stayed at a residence with three other people who tested negative for the coronavirus, including a woman who works at School Without Walls High School.
Though she doesn't have symptoms, the school district hired a contractor to do a deep cleaning Sunday, according to D.C. Public Schools. The school will get a second cleaning Monday before students and staff are allowed to return.
"There is no immediate risk to students and staff," DCPS said in a letter to families. "However, out of the outmost of caution, we are closing the school for one day."
The employee is quarantined.
The man who traveled from Nigeria is getting treatment at a hospital in Maryland.
D.C's first coronavirus patient is a city resident and rector at Christ Church Georgetown, city and church officials said.
Mayor Muriel Bowser and public health officials have sought to reassure the public and said the District has adequate tests to evaluate patients. The mayor did not declare a state of emergency or cancel major events.
The city has the capacity to test dozens of cases every day at local labs, officials said last week.
Officials recommended standard hygiene practices such as washing your hands frequently and wiping frequently touched surfaces.
Three people in Maryland were diagnosed Thursday with the coronavirus. Those patients, a woman in her 50s and a married couple in their 70s, live in Montgomery County, just north of D.C., and fell ill after taking a cruise in Egypt.
Maryland Gov. Larry Hogan announced two more cases Sunday — a Harford County woman in her 80s who is hospitalized and a Montgomery County man in his 60s who was briefly hospitalized. Both caught the virus while overseas.
A U.S. Marine assigned to Fort Belvoir in Fairfax County, Virginia, tested positive with coronavirus on Saturday, the Pentagon said. The Marine "recently returned from overseas, where he was on official business," Pentagon chief spokesman Jonathan Rath Hoffman said on Twitter.
Virginia's second positive case is a man in his 80s who also took a Nile River cruise.
Additionally, organizers of the Conservative Political Action Conference (CPAC) said Saturday evening that someone who attended the conference last week in National Harbor, Maryland, was diagnosed with the coronavirus. Organizers said the person is being treated in New Jersey and did not come in contact with the president or vice president, who attended the event.
Stay with NBC Washington for more details on this developing story.