Lizards, whether pets or wild, can carry pathogens that pose health risks to humans. While these reptiles often appear healthy, they can harbor bacteria, parasites, and even viruses. Understanding these potential risks and implementing appropriate precautions can help manage concerns associated with interacting with lizards and their environments. The presence of these microorganisms does not necessarily indicate illness in the lizard, but it highlights the importance of safe handling practices.
Salmonella and Lizards
Salmonella is the most recognized bacterial risk associated with lizards and other reptiles. Most lizards naturally carry Salmonella without showing illness. This asymptomatic carriage means a healthy-looking lizard can continuously shed bacteria in its droppings, contaminating its body, enclosure, and any surfaces it touches.
Humans contract salmonellosis when they accidentally ingest these bacteria. Symptoms include diarrhea, fever, and stomach pain, appearing one to three days after exposure and lasting four to seven days. While most people recover without medical treatment, the infection can become more severe, spreading to other organs or the bloodstream, which may require hospitalization. Thousands of people in the United States contract salmonellosis from contact with reptiles annually.
Beyond Salmonella: Other Risks
Beyond Salmonella, lizards can carry other microorganisms affecting human health. Bacteria such as Campylobacter and Escherichia coli (E. coli) have been identified in lizards. Campylobacter can lead to gastrointestinal symptoms like diarrhea, abdominal pain, and fever in humans. Certain E. coli strains can cause persistent or severe diarrhea, stomach cramps, and vomiting.
Lizards may also host parasites transmissible to humans. Cryptosporidium is a protozoan parasite causing cryptosporidiosis. While many reptilian parasites are species-specific, some, like protozoa or mites, could transfer. However, bacterial pathogens remain the primary concern due to their common presence and ease of transmission from seemingly healthy reptiles.
How Diseases Spread and How to Prevent Them
Diseases from lizards spread through the fecal-oral route, meaning bacteria from their droppings are transferred to a person’s mouth. This often occurs indirectly through contact with contaminated surfaces or objects within the lizard’s environment. Touching the lizard, its enclosure, food and water dishes, or habitat water can transfer germs. If hands are not washed thoroughly afterward, these bacteria can then be ingested, especially when eating or touching one’s face.
Effective prevention centers on strict hygiene and proper management of the lizard’s environment. Handwashing is a primary preventive measure; hands should be washed with soap and water for at least 20 seconds immediately after touching reptiles or their living area. If soap and water are unavailable, hand sanitizer can be used as a temporary measure until thorough washing is possible.
Additionally, reptile enclosures and their contents should be cleaned outside the home, ideally not in kitchen sinks or bathtubs. Any surfaces that have come into contact with the lizard or its waste should be disinfected with bleach. Lizards should not be allowed to roam freely in areas where food is prepared, stored, or consumed.
Who is Most at Risk
Certain groups face a higher risk of developing severe illness from diseases carried by lizards. These individuals have immune systems less capable of fighting infections, making them more vulnerable to serious complications. Infants and young children, especially those under five years old, are particularly susceptible. They are more prone to hand-to-mouth contact and less likely to wash their hands, increasing their exposure risk.
Elderly individuals are also at increased risk due to weakened immune responses. Pregnant individuals represent another vulnerable group, as certain infections can pose risks to both the mother and the fetus. People with compromised immune systems, whether due to medical conditions like cancer or HIV, organ transplants, or medications such as chemotherapy, face a significantly elevated risk of severe or life-threatening infections. For these groups, direct contact with reptiles or their environment is not recommended.