The 2014-2015 Legionnaire's outbreak that killed at least 12 people in Flint, Mich., was likely a result of the decision to change the community's water supply to the Flint River resulting in high levels of lead in the community's water, according to an unpublished study recently released to CNN.
The study was conducted by Marc Edwards, PhD, a professor in the department of civil engineering at Virginia Tech University in Blacksburg. Dr. Edwards detected lead in Flint's drinking water in 2015, which Michigan state officials denied.
Dr. Edwards recreated the Flint water crisis in a laboratory setting to determine whether or not it could have been the source of the Legionnaires' outbreak. His findings suggest the outbreak was a result of state officials switching the city's water supply to the Flint River and not properly treating the water with an anti-corrosive agent.
"What we discovered was that when the Flint River water went into the system it released a lot of iron and removed the disinfectant from the water," Dr. Edwards told CNN. "Those two factors, the iron as a nutrient and the disinfectant disappearing, allowed Legionella to thrive in buildings where it could not do so previously... The triggering event was very clearly the use of Flint River water without any corrosion control. Had the corrosion control been in the water, disinfectant would have been higher, iron would have been lower, probably the outbreak would not have occurred."
Sign up for our FREE E-Weekly for more coverage like this sent to your inbox!
The Michigan Department of Health and Human Services has contended McLaren Flint Hospital was responsible for the Legionnaires' outbreak, resulting in a public feud between the two entities as McLaren Flint has maintained the water supplied to the hospital was already contaminated. Dr. Edwards told CNN both parties were at fault as the hospital was still ultimately responsible for stopping the spread of disease within the facility.
"We have great respect for Dr. Edwards and his work. But we are not aware of water samples from the city of Flint['s] water system that genetically link to any cases, as would be necessary to make a causal determination," said the MDHHS in a statement to CNN.
McLaren Flint said it is receptive to Dr. Edward's research.
"We have not seen the same level of concern or scientific diligence from officials with the Michigan Department of Health and Human Services, so we welcome the researchers' ongoing efforts and hope they are able to increase the volume on this important discussion."
Legionnaires' disease is caused by Legionella bacteria. It is not spread via person-to-person contact or by drinking water, but can be contracted by inhaling mist from contaminated water sources, such as cooling misters and plumbing systems
Before the water crisis garnered national attention, 92 cases of Legionnaires' disease were confirmed in Genesee County, Mich., from 2014 to 2015. Twelve of those cases resulted in death. Recent research indicates the actual number of Legionnaires' cases related to the outbreak may have been higher than reported as cases of pneumonia in the county may have not been properly diagnosed as Legionnaires'.