Late last week, officials with University of Washington Medical Center (UWMC) reported to county health officials two patients being treated in their cardiac care unit diagnosed with the serious type of bacterial pneumonia–Legionnaires’ disease.


On Friday, Public Health – Seattle & King County received notification from UWMC that one of the patients had passed away. Legionella, the etiology of Legionnaires’ disease, is believed to be a contributing factor in the death.

Public Health says the investigation is ongoing and in the early phase. They are working closely with UWMC to determine if other patients may have been infected, to identify a potential source of the infections, and to address any ongoing risk.

UWMC is cooperating fully with this investigation and is taking appropriate steps to protect patient and staff safety, and to assure that patients with pneumonia get appropriate laboratory testing.

Legionellosis is a bacterial disease of the lungs caused by Legionella pneumophila. The disease can range from a mild respiratory illness to severe pneumonia and death. The most common form of legionellosis is known as “Legionnaires’ disease,” named after an outbreak in 1976 when many people who attended an American Legion conference in Philadelphia became ill.

Most people contract the disease by inhaling mist or vapor from a water source contaminated with the bacteria.   The disease is not contracted by drinking contaminated water, and person-to-person spread of legionellosis does not occur.

People of any age may get Legionnaires’ disease, but the disease most often affects persons older than 50.  The disease is rare in people younger than 20 years of age.  People at high-risk of acquiring the disease include current and former smokers, persons with chronic lung disease like emphysema or COPD, or those with compromised immunity (like patients who receive corticosteroids or have had an organ transplant).  People with underlying illnesses, such as cancer, kidney disease, diabetes, or AIDS are also at higher risk.

According to the Centers for Disease Control and Prevention (CDC), it is estimated that between 8,000 and 18,000 people are hospitalized with legionellosis in the United States each year.