Abelardo Aguilar (1917–1993)
In July 1976, some 4,000 World War II veterans who were members of the American Legion assembled in Philadelphia to participate in the bicentennial celebration of the signing of the Declaration of Independence. Some 600 of these veterans were staying at the landmark Bellevue-Stratford Hotel, the convention headquarters. Within days, 221 conventioneers experienced fever, cough, and breathing difficulties, with 34 subsequently dying. From an influenza epidemic seen six months earlier to conspiracy theories involving Communists trying to kill American veterans, there was no shortage of speculation regarding the cause of the mysterious disease.
In December 1976, Joseph McDade, a Centers for Disease Control scientist, determined the cause of Legionnaires’ disease: Legionella bacteria, previously identified in 1947 but only associated with animal illnesses. The microbe resided in the water of cooling towers of the hotel’s central air conditioning system and was spread as an aerosol on the unsuspecting conventioneers. Subsequent outbreaks of Legionnaires’ disease have occurred in the United Kingdom (1985), the Netherlands (1999), Australia (2000), and most extensively in Spain (2001), affecting some 650 individuals. Legionnaires’ disease is still with us: There are 10,000–50,000 cases each year in the United States, and the fatality rate ranges from 5 to 30 percent.
Among the earliest and still most effective treatments for Legionnaires’ disease is erythromycin. In 1949, Abelardo Aguilar, a Filipino scientist, sent soil samples to his employer Eli Lilly for testing. From one sample, erythromycin was isolated from the Streptomyces mold by a research team lead by J.M. McGuire and marketed as Ilosone in 1952. Although erythromycin does not resemble penicillin in its chemistry or mechanism of action, it is useful in combating similar microbes. Erythromycin is considered one of the safest antibiotics and is a common alternative for individuals who are allergic to penicillin.
The first member of the macrolide class of antibiotics—so-called because of their large, bulky chemical structure—erythromycin is preferred for the treatment of such conditions as diphtheria, pneumonia, and whooping cough.
SEE ALSO Penicillin (1928), Tetracyclines (1948), Ampicillin (1961).
The cause of Legionnaires’ disease was found to be Legionella bacteria, spread as an aerosol via a hotel’s air-conditioning system. Erythromycin is its most effective treatment.