With a hot meal in their stomachs, the men gathered for nightly chapel service, where the Rev. Ron Stanley told them about the homeless shelter rules — and the coronavirus.

Stanley, a leader in the men’s ministry at Central Union Mission in the District, began what will become regular health briefings with the men at the shelter early this week.

The Centers for Disease Control and Prevention was monitoring the spread of the virus, he said. He encouraged the men to wash their hands with soap and water for at least 20 seconds several times a day, and to use the hand sanitizer that was spread throughout the building in dispensers and small bottles.

“I’m certain that they’re aware of what’s going on with the coronavirus. It’s going to take a minute. Probably by Friday, it will be pretty well ingrained,” Stanley said Monday.

As the nation copes with the spread of the novel coronavirus, which has infected more than 800 people in the United States and more than 100,000 around the globe, advocates say the country’s homeless are an especially vulnerable population.

Homeless men and women are generally older, with chronic health issues and compromised immune systems, making them more susceptible to diseases of all sorts. Many don’t have access to restrooms or facilities to wash their hands on a regular basis, which is a key way to prevent the spread of the virus.

If they become infected, they don’t have a home in which to self-quarantine and could possibly infect others housed in homeless shelters, according to the Central Union Mission.

Shelter staff members have begun looking for symptoms of the virus, such as shortness of breath and fever, when the men check in, president and CEO Joseph Mettimano said.

“People who are chronically sick and have compromised immune systems, the regular flu every year can be deadly, so we’re watching for those symptoms anyway,” he said. “But there is an extra measure of vigilance when they’re checking in at the front desk. Because this one is so strong and problematic that we’re going to try to keep it outside the building.”

“Once it’s in the building,” he said, “it can spread very rapidly in a facility like this.”

The staff now wipes down doorknobs and other surfaces of the red-brick converted schoolhouse near Union Station every few hours. They’ve posted tips from D.C. health officials on how to prevent the spread of germs.

The District’s first confirmed infection was the rector of Christ Church Georgetown, the Rev. Timothy Cole, who became sick after returning from a Feb. 22 conference of Episcopal leaders in Louisville.

Cole has been quarantined at MedStar Georgetown University Hospital in stable condition, and two other people affiliated with the church have also been diagnosed.

D.C. Mayor Muriel E. Bowser (D) on Monday encouraged hundreds who attended the church on Feb. 24 or between Feb. 28 and March 3 to remain home until 14 days have passed since they were in the building.

Starting last Sunday, Christ Church was scheduled to host Georgetown Ministry Center’s rotating winter shelter for the homeless for three weeks, said Wanda Pierce, the ministry center’s interim executive director.

Pierce said the nonprofit learned from Christ Church on Saturday — the same day Cole was diagnosed — that the church couldn’t host the shelter, which rotates among 11 ministries.

Homeless men usually spend the night at the churches, where parishioners and volunteers prepare dinner, according to Pierce. Two other shelters will fill in for Christ Church, Pierce said.

The District has also reported three more cases: A man who was treated in Maryland but developed symptoms in the District after traveling there from Nigeria; a 77-year-old man who had attended the Biogen conference in Boston, which has been connected to other cases; and a 79-year-old man for whom no other details were released.

The city has increased sanitation and hygiene supplies at living and eating locations that serve the homeless in an attempt to stop the virus, said Laura Zeilinger, director of the Department of Human Services.

Outreach teams are giving out hand sanitizer to the homeless and encouraging them to visit the shower and restroom facilities at the District’s day center, if needed, according to Zeilinger.

So Others Might Eat, an interfaith community organization that provides meals for the homeless, has also given out hand wipes and provided sanitizing stations, said spokeswoman Kate Wiley. The organization has been deep-cleaning its dining room and clinics, she said.

At Central Union on Monday, a chaplain encouraged a man who coughed in his hands to cough into his elbow. Another employee gave the man a container filled with hand sanitizers.

After their dinner of barbecue chicken and candied yams, the men spending the night at the mission waited for chapel service. A White House briefing on the virus, led by Vice President Pence, played on the television screen above.

“All you can do is take precautions and hope you develop immunity,” said Michael Abrams, who said he is a Navy veteran. “This is the modern plague.”

Abrams said he was not worried about being infected with the virus.

Stanley, the pastor of Mount Olive Baptist Church in the District, asked the men if anyone had a prayer request. Some did.

One man wanted prayers for finding a room for rent. Another asked for strength to endure.

A third man asked Stanley to pray for those suffering from natural disasters, and those in China, the epicenter of the virus.