Introduction

CDC collaborated with public health, veterinary, and agriculture officials in many states and the U.S. Department of Agriculture National Veterinary Services LaboratoriesExternal (NVSL) to investigate an outbreak of human Salmonella Muenchen infections linked to contact with pet crested geckos purchased from multiple stores in different states. Crested geckos are popular pet lizards that come in a variety of colors.

Public health investigators used the PulseNet system to identify illnesses that were part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA “fingerprinting” is performed on Salmonella bacteria isolated from ill people by using a technique called pulsed-field gel electrophoresis, or PFGE. PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks.

A total of 22 people infected with the outbreak strain of Salmonella Muenchen were reported from 17 states between January 1, 2014 and June 16, 2015. The number of ill people identified in each state was as follows: Florida (1), Iowa (1), Illinois (1), Indiana (1), Kansas (1), Maryland (1), Massachusetts (1), Minnesota (1), Montana (1), New Hampshire (1), New York (1), Ohio (2), Pennsylvania (2), Tennessee (1), Virginia (1), Washington (2), and Wisconsin (3).

Dates that illnesses began ranged from January 1, 2014 to May 9, 2015. Ill people ranged in age from younger than 1 year to 57 years, with a median age of 14. Fifty-five percent of ill people were female. Three (14%) people were hospitalized. No deaths were reported.

Investigation of the Outbreak

Epidemiologic, laboratory, and traceback investigations conducted by officials in local, state, and federal public health agencies indicated that contact with pet geckos was the likely source of this outbreak.

In interviews, ill people answered questions about contact with animals and foods consumed during the week before becoming ill. Eleven (85%) of 13 people interviewed reported contact with reptiles or their environments before becoming ill. The percentage of ill people in this outbreak reporting contact with a reptile is substantially higher than the percentage of U.S. households that reported owning a pet reptile in a 2013-2014 survey conducted by the American Pet Products Association (4.6%). When asked about the type of reptile, all 11 people reported contact with crested geckos.

The Minnesota Public Health Laboratory isolated the outbreak strain of Salmonella Muenchen from a sample collected from an ill person’s pet crested gecko.

CDC’s NARMS laboratory conducted antibiotic resistance testing on Salmonella Muenchen isolates from three ill people infected with the outbreak strain; all three isolates were susceptible to all antibiotics tested on the NARMS panel.

This investigation is over; however, illnesses linked to contact with pet crested geckos could continue to be reported at a low level because pet crested gecko owners might be unaware of the risk of Salmonella infection. This outbreak was a reminder on the need for people to follow simple steps to enjoy their pet and keep family members healthy. CDC does not recommend that pet owners get rid of their geckos. However, if pet owners decide to do so, they should contact a local reputable pet store or reptile rescue for a safe way to relinquish their pet. Do not let a pet gecko loose into the environment.