LOCKPORT - The State Health Department said Friday it is investigating a cluster of eight cases of Legionnaires' disease around Eastern Niagara Hospital in Lockport.
The investigation, which also includes the Niagara County Health Department, began after the hospital, in a state-mandated test, discovered that a cooling tower on its building contained water that tested positive for greater-than-permitted levels of Legionella, the bacterium that causes the pneumonia-like disease.
"There are several other cooling towers and other potential sources in the area besides Eastern Niagara Hospital that are being tested. There is no evidence to date that establishes a link between Eastern Niagara Hospital and the cluster of cases in the community," the state Health Department said in an emailed statement.
Niagara County Public Health Director Daniel J. Stapleton said there are Legionella investigations going on in communities other than Lockport.
"We get these every year," Stapleton said. "It's not an uncommon thing."
As of Thursday, the State Health Department had logged 16 confirmed cases of Legionnaires' disease in Niagara County so far this year, including the eight in the Lockport cluster. There were 12 cases in 2014 and another 12 in 2015.
Erie County had 63 cases of Legionnaires' disease in both 2014 and 2015, and has had 42 so far this year.
"Most healthy individuals do not become infected with Legionella bacteria if they have been exposed," the State Health Department's statement said. "People at higher risk of getting sick are those 50 years of age or older, current or former smokers, those with a chronic lung disease or those with a weakened immune system."
Legionella occurs "in the natural environment," Stapleton said. "It likes warm, moist places."
Legionella is typically transmitted by breathing in "aerosolized water," or mist, "that is contaminated with the bacteria, not by drinking the water," the state's statement said. "Public water systems are not commonly found to be the source of Legionella outbreaks."
Stapleton said the state now requires monthly testing in any facility with large air handling units, which is how the high reading in the hospital cooling tower was discovered.
"The hospital has taken steps to disinfect the cooling tower. As required by new state regulations, the hospital will conduct additional testing to confirm the remediation was successful," the State Health Department statement said.
If the tests show more than 1,000 colony forming units of Legionella bacteria per milliliter of water, the facility is required to inform the state and county health departments.
A spokeswoman for the hospital could not be reached Friday.
The hospital chlorinated its drinking water supply for a few days in August 2014 after Legionella was found in the pipes.
The bacterium and the disease received their names after 221 members of the American Legion became ill at a convention in a Philadelphia hotel in 1976, and 34 died of the disease.