Prince George’s County Executive Angela Alsobrooks announced that three cases of the coronavirus have been confirmed in the county at a press conference Tuesday.

Alsobrooks said Prince George’s County officials were alerted to the first case at about 6 p.m. last night, and the second two cases about 10 minutes before the press conference began.

A county resident in her 50s contracted the virus on a trip to Boston from Feb. 25 to Feb. 27, and investigations are still underway to determine whether there was further exposure within the county, Alsobrooks said. A couple also tested positive after returning from an international cruise trip, she said.

The three individuals who tested positive are currently self-quarantined in their homes and are in “good condition,” said Alsobrooks. 

Last Thursday, Gov. Larry Hogan declared a state of emergency after three cases of the coronavirus — all in Montgomery County — were confirmed. Two more cases — one in Montgomery County and one in Harford County — were announced in a Sunday press release.

[Read more: UMD prepares for potential move online in light of Maryland coronavirus cases]

Washington, D.C., Mayor Muriel Bowser confirmed the district’s first “presumptive positive” case in a tweet Saturday. 

At the press conference, Prince George’s County Health Officer Ernest Carter emphasized that the outbreak is an “evolving situation,” as guidance from science and public health experts will continue to change. 

“Right now, we’re gathering information from the patients to help us determine the exposure risk,” he said. “Prince George’s County is prepared and ready to do everything we can to keep residents as healthy as possible.” 

County officials decided to activate the county’s emergency operation center at an “enhanced level” on March 4 —  before any cases were confirmed in Maryland — Alsobrooks said. This morning, these centers switched from an enhanced level to a “partial activation level” in an effort to release additional resources, she said. 

Ronnie Gill, director of emergency management in the county, said coordination between county agencies — such as the fire department, the department of social services and the office of communications — will increase in response to the outbreak.

Furthermore, county officials are concerned for senior residents and others who have chronic medical conditions, Alsobrooks said. Nursing homes across the county have implemented CDC guidelines to ensure that their senior citizens remain healthy, she added. 

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The county has also been handing out factsheets about the virus for seniors who don’t live in nursing homes, don’t have internet access or struggle with technology, said Alsobrooks. 

Frequently-used surfaces in county public schools are also being cleaned, and restrooms are being regularly restocked with soap and hand sanitizers, said Barry Stanton, chief operating officer for Prince George’s County Public Schools. 

Additionally, school-sponsored international travel in Prince George’s County has been canceled, and out-of-state travel is being monitored, Stanton said. 

Public transportation in the county will continue as usual, Alsobrooks said, as buses will be cleaned at a minimum of twice a day.

Carter said the virus primarily spreads through coughing and sneezing, and that it takes patients from two to 14 days to begin feeling symptoms — which include a fever, cough and difficulty breathing. 

Alsobrooks and Carter advised residents to wash their hands frequently — for at least 20 seconds, and with soap or hand sanitizer. 

“If you are sick, stay at home and don’t go out unless you have to go to the doctor,” Carter said. 

Residents can sign up to receive emergency notifications about COVID-19 at, said Gill. 

County officials urged residents to utilize 911 only for emergencies, and to dial 211 for more information about the coronavirus. Residents can also call a coronavirus hotline at 301-883-6627. 

“If you develop these symptoms and if you have concerns you have been in close contact with a person known to have COVID-19, seek medical care,” said Carter. “We can all do our part to contain the virus.”