For nearly six decades reptiles have been known to harbor pathogenic disease organisms that pose a potential threat to human health. Recognition that pet reptiles are a major source of human infection resulted in a 1975 ban on the sale of pet turtles with a shell length less than 10.2 cm (4 inches) in both the United States and Canada. The ban has, for the most part, remained in effect to this day.
Over the years, as other kinds of reptiles have become popular, the incidence of human disease has again increased significantly. For example, the growing popularity of green iguanas during the 1990s was accompanied by an increase in cases of reptile associated salmonellosis.
Diseases that can be transmitted between reptiles and humans are known as zoonotic diseases. In addition to Salmonella, they include Campylobacter, E. coli, Mycobacterium, Streptococcus and dozens of others.
It is clear that most, if not all, reptiles are persistent carriers of salmonella and other potentially pathogenic microorganisms as a normal part of their internal flora and fauna, and also as an incidental coating generally dispersed about their bodies.
For this reason, many public health agencies have issued advisories to pet stores and the public warning of the potential health hazards of handling reptiles or infected reptile-related accessories. For example, the US-based Centres for Disease Control (CDC) advise that the following categories of people avoid all direct or indirect contact with reptiles:
- Infants and children up to 5 years of age.
- Anyone with HIV/AIDS or other immunodeficiency disorders.
- Anyone who has had transplant surgery who is receiving anti-rejection therapy.
- Anyone who is on any drug that suppresses or alters immune function, including steroids, cancer chemotherapy, biological response modifiers and others.
- Anyone receiving radiation treatment.
- Pregnant women.
- Elderly, frail or people with poor nutritional status.
- Anyone subject to chronic infections.
- Anyone currently receiving or who has recently been receiving antibiotic treatment.
What is Salmonella?
Salmonella, the best known reptile-associated disease, is the genus name for a group of bacterial species that typically cause diarrheal illness, with sometimes lethal consequences, in humans. They occur naturally in almost all reptiles and are shed in reptile feces. Reptiles cannot be made salmonella-free.
Many salmonella species are extremely hardy and are able to survive both inside and outside of their hosts. For example, pathogenic salmonella in food are able to survive travel through the gastric acid of the stomach on their way to the intestines. Others have survived 89 days in tap water and 30 months in dried reptile stool.
Even the less invasive strains of salmonella can be lethal to someone with a compromised or immature immune system. The majority of reptile associated salmonellosis cases involve infants and small children.
Prevention
The only reliable way of substantially reducing and largely eliminating the problem of reptile-associated disease in humans is to end the keeping of reptiles as pets.
In the meantime, childcare centers, schools and children’s camps should not keep reptiles, and should not host reptile displays or shows, especially where contact with reptiles is allowed.
Reptiles should be kept out of households where children younger than one year and immunocompromised persons live. Anyone who may be at increased risk for infection or serious complications from salmonellosis should avoid all contact with reptiles.
If reptiles are already kept as pets, they should not be allowed to roam freely throughout homes or living areas, and should be kept out of kitchens and other food-preparation areas to prevent contamination.
In their natural state, reptiles and the microorganisms they carry pose almost no threat to humans. The artificial conditions of captivity however, often negatively impact and disrupt the natural reptile host/ microorganism relationship, resulting in a greater likelihood of opportunistic disease and the release of virulent disease organisms into the reptile’s environment.
Since many reptile keepers, a good portion of them children, are unaware of, misunderstand, downplay or ignore the threat of reptilian-associated disease, they do not adhere to strict sanitary practices when dealing with their animals. Attempts to educate pet stores and reptile keepers about disease risks and ways to minimize them have been largely unsuccessful. So reptile pet keeping provides a diversity of opportunities for reptilian-linked disease to threaten human health.
The pet industry often tries to portray the health risks posed by reptiles as comparable to the risks posed by domesticated companion animals, such as dogs and cats. In actual fact, reptile pets pose a significantly greater disease risk than domesticated animals do.
The only totally reliable way of resolving the problem of reptile-associated disease is to end the keeping of reptiles as pets. For this reason, Zoocheck encourages members of the public to refrain from purchasing reptiles as pets and for daycare centers, schools and children’s camps to disallow reptile displays and shows on their premises.