Salmonella spp. is present in all countries (Wilson 1991). The centralized production and wide distribution of manufactured foods in developed nations periodically facilitates large outbreaks of salmonellosis (Pegues et al. 2005).
Gastroenteritis is the most common syndrome of infection with nontyphoidal Salmonella. Some 60-80% of cases occur sporadically. After an incubation period of 6-72 hours, patients experience sudden onset of diarrhea, nausea, and sometimes vomiting. Those symptoms are frequently accompanied by fever, headache, abdominal pain, and chills. Myalgia is sometimes reported. Rarely, patients manifest pseudoappendicitis or mimicry of the intestinal changes of inflammatory bowel disease (Heymann 2004; Pegues et al. 2005).
Microscopic examination of stool specimens during the acute phase reveals neutrophils and sometimes red blood cells.
Salmonella gastroenteritis is usually self-limited. Fever commonly resolves within 48-72 hours after onset. Diarrhea usually resolves within 3-7 days, after 10 days at most; however, patients continue to shed the agent in stool for 4-5 weeks, depending on the serotype of Salmonella. Patients who receive antimicrobial therapy may shed for longer periods (Pegues et al. 2005).
Severe Salmonella gastroenteritis leads to dehydration and hospitalization in 2.2 cases per million in the US population. The disease causes about 580 deaths per year in the United States, primarily in elderly or immunocompromised people (Pegues et al. 2005).
Bacteremia occurs in 1-4% of immunocompetent patients who have Salmonella gastroenteritis. Any serotype of the agent may be responsible. Among adults, the risk of bacteremia is greater for Salmonella-infected people who are immunocompromised (Pegues et al. 2005).
Salmonella infection may be microbiologically confirmed by plating freshly passed stool samples onto a primary culture medium. Selenate-based enrichment broths can facilitate the recovery of low numbers of organisms. Rapid immunoglobulin M (IgM) antibody-based serologic tests may supplement stool culture (Pegues et al. 2005).
Uncomplicated gastroenteritis may be treated simply with ingestion of oral rehydration solution to replace water and electrolytes. Antibiotics are indicated in adults who are debilitated; who have HIV infection, continued fever, or high fever; or who manifest extraintestinal infection. Ciprofloxacin, ampicillin, or amoxicillin may be administered to adults. Trimethoprim-sulfamethoxazole and chloramphenicol may be effective for treating people who have microbial-resistant strains (Heymann 2004).
Salmonellosis is sometimes the first manifestation of HIV infection. People with HIV are at much higher risk than the general population for salmonellosis, and the risk of Salmonella