Could Contaminated Water Have Caused Legionnaires Outbreaks in Flint, Michigan?

Could Contaminated Water Have Caused Legionnaires Outbreaks in Flint, Michigan?
Toxins and Chemicals

Two outbreaks of Legionnaires disease in and around Flint, Michigan, have health officials looking into whether they were caused or at least affected by the ongoing water-contamination problem going on in that city.

The Michigan Department of Health and Human Services is investigating the outbreaks, in 2014 and 2015, which sickened 87 people and killed 10 in Genesee County. The sick ranged in age from 26 to 94, and fell ill between either June 6, 2014, to March 9, 2015, or May 4, 2015, to Oct. 29, 2015, the agency said.

President Barack Obama declared a federal emergency in Flint on Jan. 16, freeing up $5 million in federal aid to immediately assist with the public health crisis, but stopped short of agreeing to Gov. Rick Snyder’s request for a disaster declaration, which would have provided even more federal funding. [1]

Flint’s drinking water became contaminated with lead after the city switched its water source in 2014 from Lake Huron to the more corrosive and polluted Flint River. The Lake Huron water came pretreated by the Detroit Water and Sewage Department. The temporary switch was intended to save the city money, while Flint was under the control of a state-appointed emergency manager.

The State Department of Environmental Quality has acknowledged it made a mistake in failing to require that corrosion-control chemicals be added to the Flint River water, but it took the government a year to admit there was a problem.

State officials largely ignored residents’ complaints about the odd taste, odor and color of their tap water. The state also dismissed reports of high lead levels in the blood of Flint children from pediatrician Dr. Mona Hanna-Attisha before for the first time publicly acknowledging a problem in October 2015. [2]


It is unclear whether the Legionnaires cases are related to the water crisis, but Michigan health officials believe it’s possible.

“While Legionellosis cases are not uncommon, we are concerned about the increase in cases seen in Genesee County,” Dr. Eden Wells, chief medical executive with the MDHHS, said in a statement today. “We are releasing this report and continuing surveillance and investigations to ensure that appropriate actions are being taken to protect the health of the residents of Flint.”

The dangerous bacterial disease is caused by naturally-occurring bacteria legionella. The bacteria are typically spread through water droplets, usually in the summer or early fall, and infect people who inhale the droplets. Legionnaires has been linked to air-cooling towers, swimming pools, hot tubs, and water misters used in grocery store produce departments.

There were 45 confirmed cases of Legionnaires disease in the first outbreak, and 47% of those sickened used water from Flint at their homes. More than half of those individuals had suspected health care-associated Legionnaires’ disease after they had “healthcare facility exposure in the two weeks prior to their illness onset,” officials said. Even so, officials couldn’t rule out the possibility that they contracted the disease elsewhere, since the bacteria are naturally occurring.

Just as the government failed to inform the public of the elevated lead levels in Flint city water, officials didn’t sound the alarm until last week, when Gov. Snyder held a news conference to announce that officials had seen a spike in the number of cases of a severe form of pneumonia caused by the legionella bacteria.

Geralyn Lasher, a spokeswoman for the Michigan Department of Health & Human Services, claims the potential link was kept under wraps because critical samples weren’t gathered from patients and it took 6-7 months for health officials to interview those affected.

“(Interviewers) were asking people to remember what they had done for the two weeks prior to being sick, but were asking months later,” Lasher said.

Emails show that representatives of the Genesee County Health Department and Flint’s water treatment plant met to discuss the first outbreak and whether the contaminated city water had anything to do with it on Oc. 17, 2014.

They discussed the county’s “concerns regarding the increase in Legionella cases and possible association with the municipal water system,” according to an e-mail obtained by MLive obtained through a Freedom of Information Act request.

The correspondence shows that county officials waited on the city for months to respond to requests about the water plant. The county was finally forced to file an FOIA request in order to gain information. [3]

One scientist says he’s not at all surprised about the outbreaks – in fact, he saw them coming.

“Research by Dr. Amy Prudent and myself and our team here at Virginia Tech published last year actually predicted that this sort of thing would happen,” said Marc Edwards, professor of Civil and Environmental Engineering at Virginia Tech. Edwards is a nationally renowned expert on water treatment and corrosion.

“Now, this is a new result, but the general idea is that the lack of corrosion control in the Flint system ate up the disinfectant, the chlorine that’s normally put in the water to kill these bacteria and it also caused the release of iron to the water. And so those two factors in our laboratory experiments dramatically increased the amount of Legionella that grew in water heaters and hot water systems,” he said.

Edwards stressed that “it’s not 100% sure” that the Legionnaires outbreak is linked to the water crisis, but the association “looks very strong.”


[1] Detroit Free Press

[2] ABC News

[3] Detroit Free Press

[4] Michigan Radio