Legionella bacteria found in some Flint homes

Karen Bouffard
The Detroit News

Legionella bacteria has been found in some Flint homes by scientists attempting to identify the source of the city’s deadly Legionnaires’ disease outbreak in 2014-15.

A research team led by Wayne State University will now work to see if the new bacteria traces back to samples collected from people who were sickened during the epidemic.

Wayne State researchers said on Wednesday the bacteria was found in a “small number” of homes tested in September. They’ve tested about one-third of 284 homes they plan to investigate. They also discovered levels of bacteria-killing chlorine lower than recommended in about 20 percent of the homes tested.

Shawn McElmurry, the Wayne State University associate professor who’s leading the study, said he hopes to negotiate an agreement with the Michigan Department of Health and Human Services to compare his group’s samples with those collected from people who were sickened in the outbreak. He said he’s discussed the issue with state health officials and is “hopeful” researchers will be granted access to the isolates.

“I don’t see why they would not share that with us,” McElmurry said.

Asked if the state will allow the comparison, spokeswoman Jennifer Eisner said Wednesday only that the health department “has not received a study protocol from Wayne State University requesting those isolates.”

McElmurry, an associate professor of civil and environmental engineering, noted that Legionella is common in the environment as microorganisms can thrive during warmer months and not all strains cause Legionnaires’ disease.

There have been 14 Legionnaires’ cases in Genesee County so far this year, and McElmurry’s group has asked the Genesee County Health Department for access to the homes of those 14 residents.

“To be clear, these results are not necessarily outside what would be expected in other residential water systems, so this is not necessarily a surprising finding,” McElmurry said. “Nonetheless, we committed to sharing our findings with the public, and we feel that this is noteworthy.”

Genesee County’s outbreak started after Flint changed its water source from Detroit’s water system to the Flint River in April 2014. From June 2014 though October 2015, 91 people contracted the respiratory illness and 12 died. During that time, widespread lead poisoning and other health problems emerged after corrosion control chemicals weren’t applied to the river water.

According to McElmurry, damage to the Flint water system from the corrosive water had made it more difficult to maintain proper chlorination levels.

The city switched its water source last October back to the Great Lakes Water Authority.

But the outbreak of Legionnaires’ cases was kept secret until January, when Gov. Rick Snyder announced the spike in cases in Genesee County. Snyder and state health officials said it was unclear if it was tied to Flint’s river water.

Officials said it was impossible to identify the source of the outbreak because Legionella samples, called clinical isolates, were never collected from patients, and an exact DNA match of the strain was required.

A Detroit News investigation later found that the state laboratory produced 12 clinical isolates from Legionnaires’ patients in Flint, but the state had never compared them to Legionella collected from the city’s water supply.

The Detroit News reported in February that Flint’s water had never been tested for Legionella despite being identified in fall 2014 as a likely source of the disease outbreak. None of the five government agencies involved in Flint’s water crisis previously tested the city water system for the deadly bacteria.

The respiratory disease is caused by a bacteria in fresh water that leads to a severe form of pneumonia and can be found in large plumbing systems, hot tubs and air-conditioning units.

Wayne State University was awarded a $3.1 million grant in July for an independent 18-month study to find out if the outbreak of Legionnaires’ disease in Flint was linked to changes in the city’s water system.

Participants include scientists from Flint’s Kettering University, Michigan State University, the University of Michigan, the University of Colorado, Henry Ford Health System and others.