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Students returning to in-person classes could face a health risk besides COVID-19 – Legionella bacteria in the water supply

Legionella bacteria could pose risk at schools
Legionella bacteria could be lurking in some schools' water supplies 06:09

Health officials are warning parents and students returning to in-person instruction that COVID-19 might not be the only health risk they should be concerned about. 

Traces of Legionella — the bacteria responsible for Legionnaires disease — have been found at multiple schools in Ohio and Pennsylvania after months of sitting empty during the pandemic-related lockdowns. 

"This is a really serious topic, and the detection of Legionella at eight schools in the last week alone, three more yesterday, is a serious discovery," Andrew Whelton, an associate professor of civil engineering and environmental and ecological engineering at Purdue University, told CBSN. "We haven't really done much testing in the United States. There are no regulations that require either testing or disclosure of test results."

According to the Centers for Disease Control and Prevention, Legionnaires disease is a serious and sometimes fatal type of pneumonia which can be caught by breathing in mist from water contaminated with the bacteria. 

"It causes a lung infection, if it's at high enough dose. And that lung infection can be fairly serious for people who have immunocompromised immune systems, or prior smokers that have… preexisting conditions," Whelton said. 

Legionella is "ubiquitous" in the environment, he explained, but being inside buildings' water systems is what allows it to "multiply.

Whelton outlined three conditions that could be behind the Legionella detected at these schools: stagnant or slowly-flowing water, warmer water temperatures and "little to no chemical disinfectant." Similar concerns have been raised about the potential buildup of bacteria in office buildings during lengthy shutdowns.

Moreover, schools that "flush out the water" have seen a resurgence in the bacteria, leading researchers to believe that consistent maintenance is needed to keep the threat down.

"There's a need to continually to maintain, bring in freshwater into the building that has chemicals that keeps that Legionella at bay. So It's really managing the risk," Whelton said. 

While having schools sit empty for months could have allowed the bacteria grow undisturbed, Whelton said there are no federal standards for testing for pathogens in schools' water. He credited the individual schools themselves for detecting it in their water supply.

"What you're seeing nowadays… is schools are taking initiative to do testing themselves because they want to take action to protect the faculty, staff and kids," he said. 

Legionnaire's disease is most harmful to those age 50 and older, people with a chronic lung disease or people with cancer or other health issues that weaken the immune system. The CDC says it kills about 1 in 10 patients.

However, Whelton warns of a potential for co-infections bringing a new threat, which has already been observed in China. 

"People who were susceptible to COVID also had Legionnaires disease infections, and so that's something we're looking for in the U.S.," he said. "In Illinois, one of the individuals indicated that they went to get treated for COVID, and after three days of a 104 temperature the doctor figured out that it was actually Legionnaires disease."

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