Aoutbreak in California’s wine country has caused one death and nearly a dozen hospitalizations since mid-July, and public health officials have found one possible source of the bacteria that causes the illness, authorities said Wednesday.
High levels of Legionella bacteria were found in a water sample taken from a cooling tower at Embassy Suites Napa Valley, although none of those who were sickened had visited or stayed at the hotel, according to a Napa County statement.
“The cooling tower has since been taken offline, which mitigates any ongoing risk to public health,” the statement said.
County and state public health investigators have been working with hotel staff to “remediate the source of exposure” but “we must continue to investigate other cooling towers and water sources in the outbreak area, as it is common to find more than one source,” Dr. Karen Relucio, the county’s health officer, said in the statement.
Legionnaires’ disease is a type of pneumonia caused by a bacteria that grows in warm water. It was named for the outbreak where it was first identified, at a 1976 American Legion convention in Philadelphia.
People can get Legionnaires’ disease when they breathe in water vapor containing the bacteria.
“Outbreaks are commonly associated with buildings or structures that have complex water systems, like hotels and resorts, long-term care facilities, hospitals, and cruise ships,” according to the US Centers for Disease Control and Prevention. “The most likely sources of infection include water used for showering, hot tubs, decorative fountains, and cooling towers.”
The disease isn’t contagious, and can be treated with antibiotics, but can be dangerous for some people, such as those with pre-existing conditions. Symptoms include muscle aches, fever and chills.
A dozen Napa County residents have been hospitalized with the disease since July 11. Three remain hospitalized and one person died, the county said.
That person was over the age of 50 and had “risk factors for severe disease,” the county said.
There were about 10,000 reported cases of Legionnaires’ disease in the United States each year, but the disease is probably underdiagnosed and the real annual figure may be much higher, according to the CDC.
The disease usually lasts between two to five days and can range from a mild cough to a “rapidly fatal” case of pneumonia, according to the World Health Organization. Complications from the disease can include respiratory failure, shock and acute kidney failure.
“Although Legionnaires’ disease is a rare infection, this is a reminder that the bacteria that cause it are common in nature and can be found in man-made water systems,” Relucio said. “This means it’s very important for owners and managers of water systems that can create aerosols to take steps to prevent Legionella from growing and spreading in water systems.”