Health Officials Investigate If Legionnaires Outbreak in Flint, Michigan, Linked to Water Crisis

— -- Health officials are investigating whether two Legionnaires' disease outbreaks in and around Flint, Michigan, were caused or impacted by the ongoing water-contamination crisis, authorities said today.

The Michigan Department of Health and Human Services has launched an investigation into two outbreaks of Legionnaires' disease, in 2014 and 2015, which sickened 87 -- killing 10 of them -- in Genesee County. Those sickened ranged in age from 26 to 94, and became sick between either June 6, 2014, to March 9, 2015, or May 4, 2015, to Oct. 29, 2015, the agency said.

Elevated lead levels have been found in Flint's water supply after the source was temporarily changed from Detroit's municipal supply to the Flint River. It is unclear if the Legionnaires' cases are linked to the water crisis but Michigan health officials said they were looking into the possibility.

"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 naturally occurring bacteria legionella can cause a dangerous bacterial disease if it is inhaled. The bacteria are generally spread through water droplets, usually in the summer or early fall, and have been linked to air-cooling towers, pools, hot tubs and even water misters at the grocery stores, since the light mist can be an ideal transport for the bacteria to enter the lungs.

Most people exposed will not get sick, but older people and those with compromised immune systems are at risk for developing a serious infection or pneumonia.

Of the 45 confirmed cases in the first outbreak, 47 percent used water from the City of Flint at their homes. In addition, more than half of those people had suspected health care-associated Legionnaires' disease after they had "healthcare facility exposure in the two weeks prior to their illness onset," officials said. However, officials could not rule out that they contracted the disease from a different environmental exposure, since the bacteria is naturally occurring.

It was after the second outbreak that health officials started looking into a possible link to the ongoing water crisis, according to Michigan Department of Health and Human Services spokeswoman Jennifer Eisner.

A full report about the second wave of legionella cases and where people contracted the disease has not been released by the health department, but officials said it remains unclear how patients contracted the illness in at least 10 cases. In those Legionnaires' cases, the patients had "no exposure to a Flint hospital in the two weeks prior to illness nor were their homes on the Flint water system," according to the health department. Officials are still investigating how or where those patients were exposed. Legionnaires' disease has an incubation period of two to 10 days.

The health department said it may be hard to connect the legionella cases to the Flint water crisis since there is a lack of bacterial specimens from these patients. If the same kind of bacteria found in the patients were also found in the water system or in other parts of the environment, the health department could determine a source of the outbreak.

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, told ABC News that the aging water infrastructure in Flint may have allowed legionella bacteria to "set up house."

In addition, estimating an accurate number of people who have been sickened by the disease can be difficult because not all doctors test for Legionnaires' disease unless they are told to look out for the infection or if their patient does not get better, said Schaffner, who is not involved with the investigation in Michigan.

The water crisis started when the city disconnected from Detroit's water supply and began drawing its water from the Flint River. It was intended as a stop-gap measure until the completion of a pipeline to Port Huron Lake as the source for Flint's water.

But it was later discovered that lead from the old pipes had begun to leach into the water due to improper treatment. And even though the supply was switched back to the Detroit water supply in October, the anti-corrosive chemicals that were used to prevent the leaching have not yet been able to stop lead from being present in the water, a state spokeswoman told ABC News last month.