Five people have developed Legionnaires disease following possible exposure to contaminated water droplets from a cooling tower in downtown Lincoln, New Hampshire, state health officials say.
The five people developed the disease — a severe form of pneumonia caused by Legionella bacteria — in June and July, New Hampshire’s Department of Health and Human Services said in a news release Monday.
They “may have been exposed” at a cooling tower behind the RiverWalk Resort, a hotel in a bustling tourist area in downtown Lincoln, authorities said.
Testing by the DHHS and the state Department of Environmental Services confirmed the presence of Legionella bacteria contaminating the cooling tower.
The five people didn’t share specific locations of exposure, but they had reported visiting various areas of downtown Lincoln, the DHHS said.
Four of the five were initially hospitalized and later discharged. All five have recovered from their illnesses, state health officials told NBC News on Tuesday.
“RiverWalk is partnering with DHHS to address the contamination, with additional test results for the cooling tower expected next week,” the release said.
As the cooling tower is still operating amid remediation, “there may continue to be some risk of exposure to the public, especially for people within a half-mile of the cooling tower’s location,” officials warned, sharing a photo of the radius of potential Legionella exposure. The remediation work includes mechanical cleaning and disinfection of the entire cooling system, as well as long-term cleaning and water management plans.
RiverWalk Resort told NBC Boston on Monday that remediation work at the cooling tower, including a complete sanitation process, was completed after it started Friday morning.
“We have been and will continue to partner with DHHS and DES to ensure the safety and protection of our guests and community,” Vice President Renee Blood said in a statement.
Legionella bacteria exist naturally in bodies of fresh water, but they can be a threat to people when they spread in building water systems like cooling towers or water tanks, according to the Centers for Disease Control and Prevention.
Most people catch Legionnaires disease by inhaling the bacteria from water in the form of small water droplets or mist, the CDC said. Infections generally don’t spread from person to person.
While most healthy people exposed to Legionella don’t get sick, people who are older, current or former smokers and people with weakened immune systems or certain medical conditions, including chronic lung disease and diabetes, are at higher risk for developing the disease, state health officials said.
Many exposed to the bacteria develop mild symptoms or none at all. However, they can cause a more serious pneumonia called Legionnaires disease, “which can be fatal if left untreated,” the release said. Symptoms, such as fever, cough and shortness of breath, usually appear two to 14 days after exposure.
Dr. Benjamin Chan, New Hampshires state epidemiologist, warned in the news release: “Anybody who has visited the area near the contaminated cooling tower should monitor themselves for symptoms.”
“People who develop fever or other symptoms of pneumonia within 14 days after spending time in this area should talk to their healthcare provider about testing for Legionella infection,” he said.