As the United States marks its 250th anniversary, it also reflects on a darker milestone: the 50th anniversary of the discovery of Legionnaires’ disease. This disease first came to public attention during the country’s bicentennial celebrations in 1976, une année already troubled by outbreaks of swine flu in Texas and bubonic plague in California.
In July of that year, a mysterious respiratory illness struck dozens of attendees at the Bellevue-Stratford Hotel in Philadelphia, leaving many severely ill and causing 34 fatalities. The cause of this outbreak puzzled scientists for months until Joseph McDade, a microbiologist at the Centers for Disease Control and Prevention (CDC), identified a new bacterium responsible for the disease. He named it Legionella in tribute to the primarily World War II veterans who were infected while attending an American Legion convention at the hotel. The hotel’s cooling tower was ultimately pinpointed as the source of the bacterium.
Although today Legionnaires’ disease rarely garners widespread attention, at the time it was labeled the “epidemic of the century.” Alarmingly, cases caused by this bacterium have been increasing globally in recent years. Experts attribute this rise to factors such as higher global temperatures, insufficient monitoring and prevention measures, and the bacterium’s remarkable ability to evade detection by residing within amoebae until conditions favor infection.
Uncommon Reservoirs of Legionella
The Legionella bacterium does not spread from person to person but instead proliferates through contaminated water sources. Remarkably, investigations have revealed its presence in a variety of unexpected environments, ranging from ice rink Zambonis to hotel cooling systems. These findings underscore the challenges in controlling the spread of the pathogen, which thrives in man-made water systems where it can multiply unnoticed.