LANSING, Mich. (WOOD) — The state health department says it can’t confirm if a spike in cases of Legionnaires’ disease in Genesee County was related to lead contamination in Flint water — but it can’t rule out the bad water as the cause, either.

In a report released Thursday, the Michigan Department of Health and Human Services said that between June 2014 and November 2015, there were 86 cases of Legionnaires’ and one case of the milder Pontiac fever in Genesee County. Among those 87 cases, there were nine deaths associated with the disease.

Genesee County normally sees eight to 10 cases of Legionnaires’ disease each year.

Thursday’s release says that 31 of the cases (35.6 percent) were in people who used Flint water in their homes. 26 cases (29.8 percent) were in people who had no known exposure to Flint water.

MDHHS says it looked at other possible exposures to the bacteria that causes Legionnaires’ and wasn’t able to identify a community exposure. It says it is still looking at the issue, and is working with the county health department, state Department of Environmental Quality, federal Centers for Disease Control, and Environmental Protection Agency.

Part of the difficulty in absolutely confirming the source of the illness, the MDHHS said, is that investigators didn’t have enough case specimens.

Earlier this month, the state said that the 45 cases between June 2014 and March 2015 caused seven deaths, but Thursday’s report revised that number to five. It also said the 42 cases between May and October 2015 caused four deaths rather than the previously stated three.

Those figures changed, the release said, because some of the deaths happened more than 30 days after the person was discharged from the hospital.

Legionnaires’, a respiratory illness that can lead to a serious form of pneumonia, and the less serious infection Pontiac fever are caused by the Legionella bacteria. That bacteria grows best in warm water, like hot tubs, cooling towers, hot water tanks, potable water systems and decorative fountains, according to MDHHS. The illnesses are not contagious between people.——Online:MDHHS report on Legionnaires in Genesee County from June 2014 to March 2015 (PDF)MDHHS report on Legionnaires in Genesee County from May 2015 to October 2015 (PDF)Centers for Disease Control on Legionnaires’ disease