Outbreak Investigation Updates by Date
Published on March 13, 2020 at 3:00 PM ET
This outbreak investigation is over. Always wash your hands after touching pet turtles or their environments. Don’t buy turtles with shell lengths less than 4 inches. Read more about how to stay healthy around turtles.
January 24, 2020
CDC and public health officials in several states are investigating a multistate outbreak of human Salmonella Typhimurium infections linked to contact with small pet turtles.
Public health investigators are using the PulseNet system to identify illnesses that may be 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 standardized laboratory and data analysis method called whole genome sequencing (WGS). CDC PulseNet manages a national database of these sequences that are used to identify possible outbreaks. WGS gives investigators detailed information about the bacteria causing illness. In this investigation, WGS showed that bacteria isolated from ill people were closely related genetically. This means that people in this outbreak are more likely to share a common source of infection.
As of January 22, 2020, a total of 34 people infected with the outbreak strain of Salmonella Typhimurium have been reported from nine states. A list of the states and the number of cases in each can be found on the Map of Reported Cases page.
Illnesses started on dates ranging from July 29, 2019, to December 3, 2019. Ill people range in age from 1 to 71 years, with a median age of 7. Children younger than 12 account for 65% (22 of 34) of ill people. Sixty-five percent of ill people are female. Eleven hospitalizations have been reported among the 29 ill people with information available. No deaths have been reported. Of 28 ill people with ethnicity information available, 17 (61%) are Hispanic.
Illnesses might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks. Please see the Timeline for Reporting Cases of Salmonella Infection for more details.
WGS analysis did not identify antibiotic resistance in 33 bacterial isolates (32 isolates from ill people and one turtle isolate). One additional clinical isolate contained a resistance gene for ampicillin. This resistance likely will not affect the choice of antibiotic used to treat most people. Testing of three clinical isolates using standard antibiotic susceptibility testing methods by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory found no resistance.
Investigation of the Outbreak
Epidemiologic and laboratory evidence indicate that contact with small pet turtles is the likely source of this outbreak.
In interviews, ill people answered questions about animal contact in the week before they became ill. Of 22 people interviewed, 18 (82%) reported contact with a pet turtle. Eleven people remembered the size of their turtle, and all of them reported contact with turtles whose shells were less than 4 inches long. Ill people reported buying small pet turtles from flea markets, swap meets, or receiving turtles as a gift. Testing of a turtle and its environment at one ill person’s home yielded the outbreak strain.
Previous Salmonella outbreaks have been linked to pet turtles with a shell length less than 4 inches. In 1975, the U.S. Food and Drug Administration bannedexternal icon the sale and distribution of turtles with shells less than 4 inches long due to their link to Salmonella illnesses in people.
Turtles can carry Salmonella germs that can make people sick, regardless of their size or where they were purchased. Pet owners should always follow steps to stay healthy around their pet.
This investigation is ongoing, and CDC will provide updates when more information becomes available.