AN OUTBREAK OF SALMONELLOSIS AMONG CHILDREN ATTENDING A REPTILE EXHIBIT AT A ZOO

Objective: In January 1996, an outbreak of diarrhea caused by Salmonel la Enteritidis occurred in children attending a Komodo dragon exhibit at a metropolitan zoo. We sought to determine the extent of the outbre ak and mode of transmission. Study design: A case-control study was co nducted. Controls were randomly selected from zoo membership lists and matched to patients by age group and date of exhibit visit. Results: Of 65 patients identified, 39 had confirmed and 26 had suspected cases . The median age was 7 years (range, 3 months to 48 years) 55% were ma le, and 56% had bloody diarrhea. Twenty-six patients and 49 controls w ere enrolled in the case-control study. No patients and two (4%) contr ols reported touching a dragon; however, 83% of patients but only 52% of controls touched the wooden barrier that surrounded the dragon pen (odds ratio = 4.0, 95% CI 1.2 to 13.9). Washing hands at the zoo after visiting the dragons was highly protective (OR = 0.14, 95% CI 0.03 to 0.7). Cultures from the patients, one dragon, and the exhibit barrier s yielded Salmonella Enteritidis, phage type 8. On the basis of an att ack rate of 4.3% among exhibit attendees under 13 years old on whom da ta were collected, we estimate that 315 additional cases of salmonello sis occurred among visitors in this age group. Conclusion: This large outbreak demonstrates the importance of environmental contamination in the transmission of Salmonella from reptiles, and the protective valu e of hand washing. Recommendations regarding reptile exhibits and rept ilian pets should emphasize this indirect route.