What disease is caused by the bacterium Salmonella typhi?

The bacterium Salmonella typhi causes typhoid fever. The modern formal name is Salmonella enterica serovar Typhi, but “Salmonella typhi” remains a widely recognized name for the same human-adapted pathogen.

Typhoid fever spreads when people ingest food or water contaminated with feces from an infected person or carrier. After passing through the digestive system, the bacteria can multiply in intestinal lymphoid tissue and spread through the bloodstream. Typical illness includes a gradually rising fever, headache, weakness, abdominal discomfort, and sometimes constipation, diarrhea, or rose-colored spots.

Typhoid is different from the more common salmonellosis associated with many other Salmonella strains and food poisoning. Humans are the only known reservoir for S. Typhi. Antibiotics can treat the infection, while vaccination, safe water, sanitation, and careful food handling help prevent transmission. Paratyphoid fever is a related but distinct disease caused by Salmonella Paratyphi.