Salmonella Infections

Salmonella, part of the Enterobacteriaceae family, are gram-negative, nonencapsulated, flagellated, facultative anaerobic, nonlactose fermenting bacilli that infect small intestinal epithelial cells. Pediatricians need to be familiar with the clinical features, epidemiology, diagnosis, management, and prevention of 3 distinct salmonellosis syndromes: nontyphoidal Salmonella (NTS) gastroenteritis, NTS extraintestinal disease, and typhoidal Salmonella (TS) enteric fever.

NTS infections are a worldwide common cause of gastrointestinal disease in immunocompetent individuals, whereas extraintestinal disease from NTS occurs predominantly in infants and other high-risk populations. TS are the cause of enteric (typhoid and paratyphoid) fever, a systemic disease with significant mortality and morbidity in developing countries.

NTS are a common cause of bacterial gastroenteritis worldwide, with 153 million cases leading to 57,000 deaths reported annually. In the United States, NTS cause 1.2 million illnesses and 450 deaths annually, with the highest incidence in children younger than 5 years. Most human NTS infections come from 2 serotypes of Salmonella enterica: Enteritidis and Typhimurium. NTS have a wide range of reservoirs and hosts, including humans, poultry, reptiles (turtles, lizards, snakes, iguanas), and amphibians (frogs, salamanders, newts). The major mode of transmission is by ingestion of contaminated animal food products. Other modes of transmission are contact with colonized animals, consumption of contaminated water and nonanimal food products, and fecal-oral spread. The most common sources of infection in the United States are chickens and eggs. Incubation is typically 6 to 12 hours (range, 6–72 hours). Immunocompetent individuals typically experience self-limited acute gastroenteritis with nausea, emesis, abdominal pain, fever, and watery, nonbloody diarrhea lasting less than 10 days. Some infected individuals can experience bloody diarrhea, whereas some may be asymptomatic. …