Case of Legionnaires’ Disease Confirmed on O‘ahu

Legionella fibroblast. PC: State of Hawaiʻi, Department of Health, Disease Outbreak Control Division

The Hawai‘i Department of Health is currently investigating a confirmed case of legionellosis, commonly known as Legionnaires’ disease, in an adult resident of Honolulu.

The individual is hospitalized and receiving treatment. The source of the infection has not been determined.

Department officials say there have been six cases of individuals confirmed to have Legionnaires’ in Hawai‘i so far this year–including four residents and two visitors.  All the cases this year have been unrelated and isolated incidents.

Legionellosis is caused by the bacterium, Legionella. People typically get sick 2-10 days after they breathe in tiny droplets of water in the air containing the bacteria. The bacteria can be found in many places in the environment, such as plumbing systems and hot water tanks, air-conditioning cooling towers, fountains, and whirlpool spas.

“Our investigators are working diligently to determine how the individual got infected and what measures can be taken to prevent any future infections from occurring,” said Danette Wong Tomiyasu, deputy director of health resources administration. “As always, we appreciate our ongoing collaboration with healthcare providers to better understand and prevent infectious diseases in Hawai‘i.”

People at increased risk for legionellosis infection include people ages 50 years or older, current or former smokers, and people with weakened immune systems or chronic medical conditions, such as emphysema, chronic obstructive pulmonary disease, diabetes, or kidney or liver failure. People should to speak with their healthcare provider if they have specific concerns about their risk.

The most common symptoms of legionellosis are fever, cough, shortness of breath, body aches, and headaches. People should see a doctor right away if they develop pneumonia. Legionnaires’ disease is treatable with standard antibiotics used to treat pneumonia.

Legionellosis is a reportable disease in Hawai‘i and nationally, each case is investigated by DOH. In Hawai‘i, cases are often individual, sporadic instances related to recreational, travel-related, and hotel lodging activities. For the past five years, Hawai‘i has had an average of 10 reported cases of individuals per year with no deaths reported. In 2017, 43% of the cases were in non-residents with infections associated with travel-related activities.

For more information about legionellosis, visit: CDC website; DOH website: and the DOH factsheet.