Reptile-Associated Salmonellosis in Children

Abstract & Commentary

Synopsis: A retrospective review of 1387 cases of salmonellosis revealed that almost half of cases in children younger than 5 years of age were associated with contact with a reptile.

Source: Wells EV, et al. Reptile-Associated Salmonellosis in Preschool-Aged Children in Michigan, January 2001-June 2003. Clin Infect Dis. 2004;39:687-691.

A retrospective study of 1387 cases of salmonellosis, representing about 88% of all cases reported through a comprehensive system to the Michigan Department of Community Health from January 2001 through June 2003, found that 106 cases reported exposure to a reptile. Analysis of the age distribution revealed that 50 of these cases occurred in children younger than 5 years of age, representing 13.9% of the 360 cases among children in this age group. Of these 50 cases, 35 (70%) occurred in infants, and 14 (28%) occurred in infants younger than 2 months of age. In contrast, the remaining 56 cases represented only 5.5% of cases that occurred in patients > 5 years of age.

The most common serotypes were Salmonella Typhimurium (7 cases; 14%), Salmonella Poona (6 cases; 12%), Salmonella Enteritidis (5 cases; 10%), and Salmonella Typhimurium (var 5-) (3 cases; 6%).

Comment by Hal B. Jenson, MD, FAAP

The major source of salmonellosis is contaminated food, but reptile-associated Salmonella infection is a re-emerging disease that now accounts for about 6% of the estimated 1.2 million sporadic Salmonella infections that occur in the United States each year. Turtles were a major source of reptile-associate salmonellosis until FDA legislation in 1975 banned the commercial distribution of small (< 4 inches long) turtles. Most states subsequently prohibited the sale of small turtles. However, exotic reptile pets such as iguanas, lizards, and snakes (including boas) have become very popular, with a parallel increase in the incidence of reptile-related Salmonella serotypes isolated from humans. It is estimated that more than 1 million farm-bred baby iguanas have been imported into the United States from Central and South America, becoming the most popular reptile pet. The American Veterinary Medical Association estimates that there are now as many as 2.8 million pet reptiles in 1.5-2.5 million households in the United States. Approximately 90% of all reptiles carry, and intermittently shed, Salmonella in their feces, which survives for prolonged periods on environmental surfaces. Salmonellosis has also been associated with African pygmy hedgehogs, which are mammals.

The increased risk of salmonellosis among children is important not only as a cause gastrointestinal illness, but especially for the greater risk in this age group of progression to septicemia, meningitis, and death. The risk is highest among infants, especially those younger than 3 months of age, which is the basis for the recommendation for treatment of all gastrointestinal Salmonella infections in infants younger than 3 months of age.

The results of this study indicate that despite awareness of the confirmed association and the heightened risk to young children, many reptile owners remain unaware of the risk for salmonellosis from reptile contact. The CDC has published recommendations to prevent transmission of Salmonella from reptiles and amphibians to humans,1 but only a few states require point-of-sale information to persons purchasing a pet reptile. The CDC recommendations include:

  • Pet store owners, healthcare providers, and vet erinarians should inform reptile and amphibian pet owners of the risk of salmonellosis.
  • Children younger than 5 years of age and immunocompromised persons should avoid contact with reptiles and amphibians and any items that have been in contact with reptiles and amphibians.
  • Reptiles and amphibians should not be kept in households with children younger than 5 years of age. Expectant parents should be instructed to remove these pets before the child’s birth.
  • Reptiles and amphibians should not be allowed in daycare centers.
  • Persons should always wash their hands thoroughly after handling reptiles and amphibians.
  • Reptiles and amphibians should not be allowed to roam through living areas, or to enter kitchens or food-preparation areas.
  • Reptiles and amphibians in zoos and exhibits should not have direct or indirect contact with patrons, except in designated areas with ade quate handwashing and exclusion of food items.

Reference

1. Centers for Disease Control and Prevention: Reptile-Associate Salmonellosis-Selected States, 1998-2002. MMWR. 2003;52:1206-1209.

Hal B. Jenson, MD, FAAP, Chair, Department of Pediatrics, Director, Center for Pediatric Research, Eastern Virginia Medical School and Children’s Hospital of the King’s Daughters, Norfolk, VA, is Associate Editor for Infectious Disease Alert.