Who discovered the bacterial cause of typhoid fever?

Karl Joseph Eberth discovered the bacterial cause of typhoid fever. In 1880, the German pathologist described a bacillus in the organs of patients who had died from typhoid and proposed that it caused the disease.

Eberth’s observation was an important step in connecting a specific microorganism with a specific illness, but the discovery was not immediately complete. In 1884, Georg Gaffky confirmed Eberth’s findings and successfully grew the organism in culture. The bacterium consequently became known for years as Eberth’s bacillus or the Gaffky–Eberth bacillus.

The organism is now called Salmonella enterica serovar Typhi, commonly shortened to Salmonella Typhi. It spreads mainly through food or water contaminated with human feces. William Budd had earlier provided influential evidence that typhoid could spread through contaminated water, but he did not discover the bacterium itself. Robert Koch later helped verify Eberth’s work rather than receiving primary credit for the discovery.