Legionnaires Disease Marches Through Peak Season, Cases Mount Annually
The number of legionellosis cases reported in the U.S. has increased 217 percent over the last decade, according to a recent study by the Centers for Disease Control and Prevention (CDC). Legionnaires disease, a serious, sometimes lethal pneumonia, and Pontiac fever, an illness similar to influenza are the two most common forms of legionellosis, which is caused by Legionella bacteria.
June through October is the peak season for legionellosis, which is transmitted when microscopic water droplets containing legionella bacteria are inhaled. Most often, water sources in commercial settings are involved including the spray from showers, faucets, fountains and whirlpools, or water dispersed through a ventilation or cooling systems.
Between 2000 and 2009, 22,418 cases of legionellosis were reported, with the number of cases reported annually rising from 1,110 in 2000 to 3,522 in 2009. Almost a quarter of the reported cases were travel-related, most of which involved only domestic travel. About 5 percent of cases involved travel on a cruise ship.
