Salmonella is a bacterium that causes one of the most common enteric (intestinal) infections in the United States – salmonellosis. In any case, today the number of known strains of the bacteria totals over two thousand.
The term Salmonella refers to a group or family of bacteria that variously cause illness in humans. Salmonellaserotype typhimurium and Salmonella serotype enteritidis are the most common in the United States. Salmonella Javiana is the fifth most common serotype in the United States and accounted for 3.4% of Salmonella isolates reported to the CDC during 2002.
Most Salmonella infections are caused by eating contaminated food, especially food from animal origins. One study found that 87% of all confirmed cases of Salmonella were foodborne, with 10 percent from person-to-person infection and 3% caused by pets.
Salmonella infections can have a broad range of illness, from no symptoms to severe illness. The most common clinical presentation is acute gastroenteritis. Symptoms include diarrhea, and abdominal cramps, often accompanied by fever of 100°F to 102°F (38°C to 39°C). Other symptoms may include bloody diarrhea, vomiting, headache and body aches. The incubation period, or the time from ingestion of the bacteria until the symptoms start, is generally 6 to 72 hours; however, there is evidence that in some situations the incubation can be longer than 10 days. People with salmonellosis usually recover without treatment within 3 to 7 days. Nonetheless, the bacteria will continue to be present in the intestinal tract and stool for weeks after recovery of symptoms—on average, 1 month in adults and longer in children.
Salmonella infections usually resolve in 3 to 7 days, and many times require no treatment. Persons with severe diarrhea may require rehydration, often with intravenous fluids. Antimicrobial therapy (or treatment with antibiotics) is not recommended for uncomplicated gastroenteritis. In contrast, antibiotics are recommended for persons at increased risk of invasive disease, including infants younger than 3 months of age.