Update 1/22/2020: 

Water testing conducted by the city came back negative for legionella bacteria at the 801 East Men’s Shelter, per the Department of Health and Human Services. The resident who contracted Legionnaires’ disease appears to have contracted it elsewhere.

Original: 

A man who stayed at a D.C. homeless shelter has been diagnosed with Legionnaires’ disease, prompting the city to test the shelter’s water supply for potential contaminants that could have caused the illness.

Legionnaires’ disease is a potentially fatal bacterial infection that spreads through the vapor or mist of contaminated water, leading to a severe form of pneumonia. People with weakened immune systems are particularly vulnerable.

The city realized there was a potential problem last week after the D.C. Department of Health was notified that a patient at a local hospital was being treated for Legionnaires’. Upon investigation, officials learned that the man had been a resident at the Catholic Charities 801 East Men’s Shelter on the campus of the St. Elizabeths hospital in Ward 8, according to assistant city administrator Jay Melder. WJLA first reported the case.

The city shut off water use to the shelter for one night on January 2, Melder says. They installed filters on every water fixture in the facility, including all shower heads and drinking fountains, the next day, according to Melder. With the filters on, the shelter is safe to use and “there is no public health concern regarding legionella [bacteria] in the water,” he says.

The city has also sent a water sample to a lab for testing, which will take 10 to 15 days to return the results.

All of this is being done “out of an abundance of caution,” Melder says. “There isn’t any test that says there is contamination of any water at 801.”

The shelter did a similar test of the water after another case of Legionnaires’ was discovered last summer, and the test was negative for the offending bacteria, he says.

The 801 East Men’s Shelter is located on the campus of St. Elizabeths East Hospital, a psychiatric hospital whose water supply was contaminated with legionella bacteria  last year. The facility was without safe water for drinking or bathing for nearly a month, forcing staff and sick patients to rely on bottled water and outdoor showers.

Melder says that contamination is totally unrelated to the current situation. “There’s no linkage between the two. They’re different water systems actually, so there isn’t a way for them to be connected,” he says.

A spokesperson for Catholic Charities, which oversees social services at the shelter, says in a statement that “we’re working closely with the city to ensure that the residents are kept safe and following the direction and lead of the city. Catholic Charities is responsible for the social services being provided at these large low-barrier shelters, but the city manages the oversight, maintenance, and systems of these facilities. The staff at the shelter is keeping residents apprised of the situation as it unfolds.”

There have been no further reported cases of Legionnaires’, per Melder. The city handed out informational pamphlets to shelter residents, explaining why there were filters on the taps and the symptoms of Legionnaires’.

The shelter has a capacity of 380 beds, with 52 additional beds added in the colder part of the year. At Sunday’s highest count, there were 290 people in the shelter, Melder says.

The patient with Legionnaires’ was treated for the condition and is now out of the hospital, Melder says. “The patient is alive, they sought medical treatment and are back to their regular routine,” he says.

This story has been updated with comment from Catholic Charities and with the results of water testing.