Technical Information
Technical information is taken directly from the December 2001 CDC Division of Bacterial and Mycotic Diseases: Salmonellosis

Salmonella bacteria in tetrathionate enrichment broth stained using direct FA staining technique (1969)

Clinical Features
Fever, abdominal cramps, and diarrhea (sometimes bloody). Occasionally can establish localized infection (e.g., septic arthritis) or progress to infection throughout the body

Etiologic Agent
Enterobacteriaceae of the genus Salmonella, a gram-negative rod-shaped bacilli. Approximately 2000 serotypes cause human disease.

Incidence
Fever, abdominal cramps, and diarrhea (sometimes bloody). Occasionally can establish localized infection (e.g., septic arthritis) or progress to infection throughout the body

Sequelae
Estimated >500 fatal cases each year; 2% of cases are complicated by chronic arthritis.

Transmission
Contaminated food, water, or contact with infected animals.

Risk Groups
Affects all age groups. Groups at greatest risk for severe or complicated disease include infants, the elderly, and persons with compromised immune systems

Surveillance
National surveillance is conducted through the Public Health Laboratory Information System (PHLIS) for culture-confirmed cases and through the National Electronic Telecommunications System for Surveillance (NETSS). Active laboratory- and population-based surveillance is conducted in FoodNet sites

Trends
Half of salmonellosis cases are caused by 2 serotypes: S. Enteritidis (SE) and S. Typhimurium (ST). The proportion of salmonellosis caused by SE has increased markedly during the last two decades; SE is now the second most common cause of salmonellosis after ST. The incidence of ST has remained stable, but an increasing proportion of isolates show resistance to multiple antimicrobial agents. An increasing problem of reptile-associated salmonellosis is caused by the growing popularity of pet iguanas.

Challenges
Identifying unrecognized major sources of Salmonella infections. Assuring adequate supply of serotyping reagents; controlling SE infections through changes in the egg industry and education of food service workers and consumers; and developing effective education methods and materials to prevent reptile-associated salmonellosis.

Opportunities
Improving detection of dispersed outbreaks through use of statistical outbreak detection algorithms and providing this capability to state health departments; training state health department personnel in Salmonella serotyping; and encouraging use of antimicrobial agents in veterinary medicine

Additional Resources

Frequently Asked Questions about Salmonellosis

Center for Disease Control and Prevention Salmonellosis Information

NOTE: All images taken from the CDC Public Health Image Library website.