“I Am the Baby Killer!” House Flies and the Spread of Polio

Abstract

Prior to the Spanish-American War (1898), the nonbiting common house fly, Musca domestica L. (Diptera: Muscidae), was thought to be an annoying but harmless fact of life. Not only was the house fly believed to “lend life and beauty to the landscape,” but it was also considered as a helpful scavenger “wisely provided by nature” (Rogers 1989). An epidemiological investigation of the typhoid fever epidemic in the national assembly camps during the Spanish-American War changed that perception forever. The U.S. Army's Typhoid Board, headed by Maj. Walter Reed, established that the house fly was a mechanical vector for the typhoid bacillus, Salmonella typhi (Cirillo 2006). The board's evidence was so impressive that Leland O. Howard, chief of the U.S. Department of Agriculture's Bureau of Entomology, proposed renaming the house fly the “typhoid fly” to focus attention on its importance as a public health menace (Howard 1911). The newly acquired understanding of the link between house flies and disease was to have significant cultural, economic, and scientific repercussions in 1916, during the nation's most devastating polio epidemic. Polio has afflicted humankind since antiquity. An Egyptian funeral stele dating from the Eighteenth Dynasty (1580-1350 BCE) depicts a priest from Ruma with a withered and shortened leg and his foot in the equinus position typical of the flaccid paralysis of polio (McHenry 1969). Polio (previously termed infantile paralysis and poliomyelitis) is a viral infection spread from person to person by contact with feces-contaminated hands, food, water, or inanimate objects. Poliovirus enters the body via the mouth, travels through the digestive …