Updated at 4:31 p.m. Wednesday — Napa County public health authorities have reported finding bacteria that cause Legionnaires’ disease on the property of a Napa city hotel, one day after the announcement of a local death from the disease.
Preliminary testing of human-made water sources detected high levels of the Legionella bacterium in a sample taken from a cooling tower at the Embassy Suites by Hilton Napa Valley at 1075 California Blvd., the county announced in a news release Wednesday afternoon. However, none of the 12 people in Napa County to have fallen ill from the disease since July – one of whom has died – are known to have stayed at or visited the hotel, according to the statement.
The county added it is continuing its investigation into any other potential sources of unsafe levels of the bacteria.
“Our joint investigation team continues to work with Embassy Suites staff to remediate the source of exposure,” Dr. Karen Relucio, Napa County’s public health officer, said in the statement. “Finding Legionella in one water sample is an important piece of the puzzle, 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.”
Becky Craig, Napa County’s interim executive officer, announced a news conference on the discovery and the Legionnaires’ outbreak for 5:30 p.m. Wednesday. Updates from the conference were not available before the Napa Valley Register went to press.
Health officials in Napa County nine confirmed cases of Legionnaires' disease in Napa and Calistoga, county officials announced Friday.
Tuesday evening, Napa County said the outbreak of Legionnaires’ disease it had first announced Friday has caused one death and several hospitalizations. The ailment has sickened 12 people overall since July 11.
One or two cases in Napa County per year are typical, although the risk to residents and visitors remains low despite the recent outbreak, county officials said last week.
Legionella, the bacterium that causes the disease, grows in warm water. Most cases can be traced to contamination of artificial water systems such as cooling towers for air conditioning in buildings or decorative fountains.
Napa County Public Health is working closely with a joint investigation team from the California Department of Public Health, U.S. Centers for Disease Control and Prevention, and the Napa County Environmental Health Branch of the Planning Building and Environmental Department, the county said. Authorities are sampling water for Legionella and recommending remediation strategies where appropriate to prevent further transmission.
The reported fatality was the first one identified in the county "for several years," the county said.
"We are deeply saddened by the death of this individual," Relucio said Tuesday. "Our thoughts and condolences go out to the family. We share concern for all impacted by this outbreak."
Symptoms of Legionnaires' disease include fever, chills, muscle aches and cough. It is not transmitted person-to-person, only from breathing in water vapor containing the bacteria. There is no danger from most home air conditioning units, which do not use water vapor for cooling.
People at a higher risk for serious illness include those over 50, cigarette smokers, and people with chronic lung disease or compromised immune systems. Legionnaires' disease is treatable with antibiotics.
While Legionnaires’ cases are rare, the Napa outbreak is a reminder that the bacteria causing the disease are common in nature and can be found in man-made water systems, Relucio said in the county’s announcement Wednesday.
"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,” she said.
Strategies to prevent the growth of Legionella bacteria in the home include flushing faucets and shower heads that have not been recently used, as well as cleaning, disinfecting and maintain all devices that use water, such as humidifiers, respiratory therapy devices, shower head and faucet aerators, water heaters, and hot tubs.
With reports from Register reporter Howard Yune and Bay City News Service.