This 1978 electron microscope image made available by the Centers for Disease Control and Prevention shows Legionella pneumophila bacteria, which are responsible for causing the pneumonic disease Legionnaires' disease. Credit: Francis Chandler / CDC via AP

Four people are hospitalized after contracting Legionnaires’ disease in the Bangor area.

Legionnaires’ disease is a type of pneumonia that can result when people breathe in droplets of water contaminated with a type of bacteria that naturally occur in freshwater environments such as lakes and streams, but that can spread to infrastructure such as air conditioning and large plumbing systems, according to the Maine Center for Disease Control and Prevention.

The agency is investigating whether the cases are coincidental or if there is common exposure, according to spokesperson Robert Long.  

The Maine CDC didn’t specify where in the Bangor area the cases occurred, but are alerting health care providers so they can consider testing for the illness which may lead to the identification for additional cases.

About 9,000 cases were reported in the U.S in 2019 and Maine has averaged 21.4 cases since 2016, the agency said.

Those at increased risk of getting sick are people ages 50 and older; current or former smokers; people with chronic lung disease, weak immune systems or cancer; and those with underlying illnesses, according to the Maine CDC. Most people who get sick make a full recovery, however, 1 in 10 people who get Legionnaire’s will die.

To prevent the growth of Legionella bacteria, the Maine CDC urges Mainers to flush their water heaters every year, remove and clean shower heads, clean and disinfect humidifiers and regularly clean CPAP machines and nebulizers.