Snapping turtles, including the Common Snapping Turtle (Chelydra serpentina) and the Alligator Snapping Turtle (Macrochelys temminckii), are native reptiles. Like all reptiles, these turtles naturally carry microorganisms that can cause illness in humans, a phenomenon known as zoonotic disease. Because they live in aquatic environments rich in bacteria, snapping turtles harbor pathogens on their shells, skin, and in their digestive tracts. Understanding this potential for disease transmission is necessary to prevent the transfer of these microorganisms to humans through handling or environmental contamination.
The Primary Bacterial Threat: Salmonella
The most widely documented and significant public health threat associated with snapping turtles is the presence of Salmonella bacteria. These bacteria are naturally found in the intestinal tracts of many reptiles, including turtles, which serve as asymptomatic reservoirs for the organism.
The bacteria are shed intermittently through the turtle’s feces, contaminating its outer shell, skin, and habitat surfaces. Humans become infected by accidentally ingesting the bacteria, often through hand-to-mouth contact after touching a contaminated surface or the turtle itself. This infection in humans is known as Salmonellosis, which is a form of gastroenteritis.
Symptoms in people typically begin between six hours and six days after infection and include diarrhea, abdominal cramps, fever, and sometimes vomiting. For most healthy adults, the illness is self-limiting and resolves within a week. However, the infection can be far more serious for certain vulnerable populations.
Infants, children younger than five years old, adults over 65, and those with compromised immune systems are at a much higher risk. In these individuals, the Salmonella infection can become invasive, spreading from the intestines to the bloodstream and other body sites, potentially leading to life-threatening complications like septicemia. Because of this high-risk profile for young children, the sale of small turtles with shells less than four inches long has been banned in the United States since 1975.
Other Potential Pathogens and Parasites
While Salmonella receives the most attention, snapping turtles carry a spectrum of other potential pathogens from their aquatic environments. Bacteria commonly found in freshwater habitats, such as Aeromonas and E. coli, may also be present on the turtle’s body and in its water. These organisms can pose a risk, particularly if they enter a break in the skin, such as a scratch or a bite wound.
The Alligator Snapping Turtle has been noted to carry Citrobacter freundii, another bacterium that can cause infection in humans. Exposure to water contaminated by turtle waste may also introduce bacteria like Leptospira or Mycobacterium species, which pose a greater risk to individuals with weakened immunity.
Turtles can also host various internal and external parasites. Internal parasites, including protozoa and helminths like roundworms, can be shed in the turtle’s feces. External parasites, such as leeches or ticks, may attach to the turtle’s skin or shell, and these arthropods can be vectors for other diseases.
Reducing Risk Through Safe Handling and Hygiene
Mitigating the risk of disease transmission from snapping turtles relies on consistent and thorough hygiene practices. The single most effective action is mandatory handwashing immediately after any contact with the turtle, its habitat, or its water. Hands should be washed with soap and warm water for at least 20 seconds, and alcohol-based sanitizer should be used if soap is unavailable.
It is also important to maintain a strict separation between the turtle’s environment and human food areas. Snapping turtles and their enclosures, including water bowls or tanks, should never be allowed in kitchens or near surfaces used for food preparation or eating. Additionally, cleaning of tanks or enclosures should ideally be done outside of the home, using a dedicated space that is not also used for human bathing or dishwashing.
Handling a wild snapping turtle carries a high risk of injury due to its aggressive nature and powerful jaws. A bite from a snapping turtle can cause severe tissue damage and introduces a high concentration of environmental and internal bacteria directly into the wound, requiring immediate medical attention. When handling is unavoidable, such as moving a turtle crossing a road, one must approach cautiously from the rear and avoid grabbing the animal by the tail, which can cause spinal injury to the turtle.
Due to the significant zoonotic risks, particularly to children, and the specialized care requirements, keeping snapping turtles as pets is discouraged. Households with young children, pregnant individuals, or people with weakened immune systems should avoid having any reptile, including snapping turtles, as a household animal. Adhering to these safety protocols minimizes the chance of contracting a reptile-associated illness.