Research shows 80 percent of Legionnaires’ cases linked to water supply; state disagrees with study

Research shows 80 percent of Legionnaires’ cases linked to water supply; state disagrees with study

Research done by Wayne State University, the University of Michigan and Colorado State University shows that 80 percent of Legionnaires’ cases in Flint between 2014 and 2015 are linked to the city’s drinking water supply source transition to the Flint River.

The research also concluded that Flint residents consuming water supplied by the Flint River were seven times more likely to contract the potentially fatal, pneumonia-like disease.

The Michigan Department of Health and Human Services (MDHHS) calls the research flawed.

The findings were published in two highly regarded academic journals, the Proceedings of the National Academy of Science and mBio, published by the American Society for Microbiology.

The Flint River

The universities were part of the Flint Area Community Health and Environment Partnership (FACHEP), led by Wayne State researchers specializing in environmental engineering and public health. Their charge was to conduct an independent study to evaluate the possible association between changes in Flint’s water system and public health, specifically the recent Legionnaires’ disease outbreak.

“During the period when their water was supplied from the Flint River, Flint residents were seven times more likely to develop Legionnaires’ disease,” says lead author Sammy Zahran, professor of economics at Colorado State University. “After public announcements urging residents to boil their water, there was a lower risk of developing the disease, likely because people avoided using their water.”

The findings and their publication put the three universities at odds with MDHHS, which called the research “inaccurate” and “incomplete.”

“The relationship has been challenging,” said one person associated with the research program. “It was even more challenging as results came in.”

FACHEP provided MDHHS with a draft of the articles.

MDHHS reviewed the draft articles, as did an external, independent third party, KWR Watercycle Research Institute, based in the Netherlands. KWR was asked to review the FACHEP project on behalf of the Michigan Department of Management and Budget.

According to MDHHS, KWR and the department found numerous flaws in the articles, which were brought to FACHEP’s attention and “appear to remain unaddressed.”

“By publishing these inaccurate, incomplete studies at this point, FACHEP has done nothing to help the citizens of Flint and has only added to the public confusion on this issue,” MDHHS says.

FACHEP stands by its findings.

“Our study shows that during the water crisis, the risk of a Flint resident having Legionnaires’ disease increased as the amount of free chlorine in their water decreased,” says Shawn McElmurry, associate professor of civil and environmental engineering at Wayne State University and the FACHEP principal investigator. “Since municipalities typically evaluate the risk of waterborne illnesses by measuring free chlorine, a better understanding of how chlorine is deactivated can inform future water management policies and practices.”

Chlorine is a chemical that is routinely added to drinking water to kill microbes.

The analysis also suggested “chlorine residual levels recommended by regulatory agencies (0.2 or 0.5 parts per million) may not be sufficient to protect communities from Legionella pneumophila exposure when water quality conditions are such that they support strong Legionella pneumophila growth. These were the conditions in Flint during and immediately after the water change.

“After the city returned to the Lake Huron water source supplied by the Great Lakes Water Authority, the risk of a Flint neighborhood presenting with Legionnaires’ disease retreated to historically normal levels,” according to the study.

FACHEP says its researchers conducted an exhaustive analysis of data on Legionnaires’ cases in Genesee, Wayne and Oakland Counties from 2011 to 2016.

However, MDHHS maintains the researchers not only failed to accurately describe conversations with the department, but used variables in its data set that inaccurately reflect the timing associated with cases of Legionnaires in Flint.

“Researchers also overestimate the risk to public health by focusing on a strain of the bacteria, serogroup 6, that is not typically associated with Legionnaires’ disease,” MDHHS says.  It says not a single case of serogroup 6 Legionnaire’s disease was identified in Genesee County, despite widespread use of Legionella cultures.

Researchers say there is a pattern.

“In laboratory tests of disease risk, the serogroup 6 strain isolated from Flint and Detroit homes resembled the serogroup 1 bacteria obtained from Legionnaires’ disease patients in Southeast Michigan,” says Michele Swanson, professor of microbiology and immunology at the University of Michigan Medical School and senior author of the mBio article. “The strains obtained from Flint and Detroit residences are similar to bacteria isolated from Legionnaires’ disease patients in other countries, as judged by their genetic fingerprint.”

Both FACHEP and MSHHS agree more research is needed to evaluate the risk of this strain.

“Publishing this report now, however, implies that a public health risk exists when there may not be one,” MDHHS says.

Based upon concerns over FACHEP’s methodology, the State of Michigan informed the organization it was only willing to continue the partnership under the independent review and oversight of KWR.  FACHEP rejected the offer.

“We must be independent,” says one person associated with FACHEP. “We have concluded that we will look for funding elsewhere to continue our work.”

To read the article published in Proceedings of the National Academy of Science, please click here. To read the article in mBio, please click here. There is a cost involved.

For additional detail regarding the scientific concerns MDHHS has regarding these two journal articles you can read the following:




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