Legionnaires’ disease outbreak leads to one death, 11 hospitalizations in Northern California

An outbreak of Legionnaires’ disease in Napa County, Calif., over the past month resulted in the death of one person and the hospitalization of 11 others, health officials said.

Napa County Public Health said officials identified high levels of Legionella bacteria, which causes the disease, in a cooling tower at Embassy Suites by Hilton Napa Valley, but officials did not identify any of the patients as having stayed at or visited the hotel. All of the known patients are county residents.

“Our joint investigation team continues to work with Embassy Suites staff to remediate the source of exposure,” Napa County Health Officer Karen Relucio said in a 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,” she said.

Legionnaires’ disease is a serious type of pneumonia with symptoms including fever, cough and headaches, according to the Centers for Disease Control and Prevention (CDC). 

Legionella bacteria are found naturally in freshwater and can grow in a building water system and spread in droplets small enough for people to breathe in.

Infected people do not generally spread the disease to other people, but the CDC says it is possible in rare circumstances.

The CDC and the county health department say those most at risk include current or former smokers, people over the age of 50, those with chronic lung disease and people with compromised immune systems. 

Health officials said the patient who died was over the age of 50 and had risk factors for severe disease. Three of the other 11 patients remain hospitalized.

“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,” said Relucio. “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.”

An Embassy Suites by Hilton Napa Valley spokesperson said the hotel is cooperating fully with health officials in their investigation of the outbreak, and the hotel has begun remediation after contacting its water treatment provider.

“The safety and well-being of our guests and team members are of paramount importance, and Embassy Suites by Hilton Napa Valley continues to make every effort to ensure all practices and standards are in line with strict safety and security regulations,” the spokesperson said.

“We are aware of public reports by Napa County Public Health of a Legionnaires’ outbreak in the area and preliminary findings in our cooling tower,” they continued. “We are waiting for a full report with test results from the health department, however, remain diligent in our commitment to providing a safe, hospitable environment for all.”