While the Legionnaires’ disease outbreak at Disneyland has dominated the news cycle, other Legionnaires’ disease cases have popped up across the country:

  • In northern California: A Sonoma County woman died recently from Legionnaires’ disease, the Sonoma County Public Health department announced Nov. 27. The case – the fourth in the county this year – is the first reported death due to Legionnaires’ disease in 2017. None of this year’s four cases involved a common source. The county usually documents fewer than 10 cases a year; in 2016, eight cases were reported.
  • In the Midwest: A case of Legionnaires’ disease was confirmed in the Kansas City metro area, according to KCTV5. A woman sickened with Legionnaires’ disease has been in a medically induced coma for two weeks. She underwent surgery today at Liberty (MO) Hospital, according to family members. Those family members said she may have contracted the disease while working at the Ford Plant in Claycomo, but no confirmed source has been identified by local health officials.
  • In the East: A resident of Beechtree Commons, a senior housing community in Penn Hills, PA, was confirmed with Legionnaires’ disease on Nov. 2, according to the Allegheny County Health Department. Tests conducted on the water system were negative for Legionella at the two-building complex, which houses about 100. It is unknown where the resident became infected.

Case count increases across U.S.

Legionnaires’ disease is a severe type of pneumonia or lung infection. It is “an emerging disease in the sense that the number of recorded cases of Legionnaires’ in the United States continues to increase,” said Laura Cooley, MD, MPH from the Respiratory Diseases Branch of the Centers for Disease Control and Prevention (CDC).

Cooley said she believes the increase is due to a rise in the susceptibility of the population, with more and more people on immunosuppressive medications. In addition, there could be more Legionella in the environment, with warmer temperatures creating the right conditions for bacterial growth.

About 25,000 cases annually

The CDC estimates that 25,000 cases of Legionnaires’ disease occur in the U.S. yearly. Only 5,000 cases are reported, however, because of the disease’s non-specific signs and symptoms.

Legionella bacteria are contracted by inhaling microscopic water droplets in the form of mist or vapor. The bacteria, which thrive in warm water, are found primarily in human-made environments, such as cooling towers and air-conditioning systems, to name just a couple.

Cases are more commonly reported during the summer and early fall but can happen any time of the year, as illustrated by these recent reports.