Severe acute respiratory syndrome (SARS), monkeypox, and a host of diseases can find their way into people from animals. Truth is, almost any critter can infect us.
So the huge growth in the popularity of exotic pets—snakes, lizards, monkeys, birds—is cause for concern.
According to the American Pet Products Association 2011/2012 National Pet Owners Survey, about 4.6 percent of U.S. homes house a reptile. You may like turtles, snakes, and lizards, but you should handle them with care. The CDC says reptiles infect about 70,000 people a year with the bacteria salmonella. In humans, salmonella can cause severe gastroenteritis and sepsis. Reptiles also can carry Edwardsiella tarda and Plesiomonas shigelloides, both of which also cause gastroenteritis in humans. Snakes can be carriers of Aeromonas shigelloides, a wormlike parasite, and Armillifer, a wormlike arthropod parasite, both of which can become parasites of humans.
Monkeys should not be kept as pets. In fact, many states in the U.S. ban private ownership of monkeys and other primates. Monkeys can carry and transmit diseases to humans, especially the herpes B virus, which can potentially be fatal to a person who is bitten, scratched, or spit on by a monkey. Also, as they age, their behavior can become unpredictable and sometimes violent, depending on the circumstances in which they're kept.
Some birds carry serious infections, too, including Chlamydophila psittaci, which causes severe pneumonia; avian influenza; aspergillosis, a lung and sinus infection; Cryptococcus neoformans, which can cause meningitis; histoplasmosis, a lung infection; and blastomycosis, a lung infection.
Here are other animals and some of the diseases that they may pass on to humans:
Cats. Cats can pass on toxoplasmosis, a parasitic infection that damages the developing fetus if a pregnant woman contracts it; sporotrichosis, a fungal disease of the skin and lymph nodes; rabies; cat-scratch disease; feline foamy retroviruses; Microsporum canis, which causes ringworm; Pasteurella multocida, which can cause a severe skin infection; Toxocara cati, a parasite that can cause loss of vision; and Campylobacter jejuni, which causes severe gastroenteritis.
Rodents. Rodents can infect humans with lymphocytic choriomeningitis, a type of meningitis or encephalitis that can cause birth defects if a pregnant woman contracts it; hantavirus, which cause a fatal respiratory disease; salmonella; Trichophyton mentagrophytes, which cause ringworm and other skin infections; Pasteurella multocida, which can cause a severe skin infection; Streptobacillus moniliformis or Spirillum minus, which causes rat-bite fever; Leptospira interrogans, which causes flu-like symptoms; Hymenolepis nana, a dwarf tapeworm, Hymenolepis diminuta, a rat tapeworm and salmonella.
Aquarium fish. Salt water and some freshwater fish tanks can contain Mycobacterium marinum, which can cause a skin infection. Exotic freshwater fish can carry Pseudomonas pseudomallei, which causes a lung infection, and salmonella.
Prairie dogs. These animals can infect humans with monkeypox, a relative of smallpox. In 2003, the CDC and the FDA issued a ban on the import of all African rodents, including African prairie dogs, due to the spread of monkeypox from these animals. The FDA lifted its portion of the ban in 2008, but the CDC ban remains in effect in order to prevent the reintroduction of monkeypox in the U.S. The imported prairie dogs were mingled with domestic prairie dogs available for sale, transmitting the monkeypox virus to them and on to humans.
Guinea pigs and hamsters. These pets can carry salmonella; lymphocytic choriomeningitis; Yersinia pseudotuberculosis, which causes an infection that mimics appendicitis; Campylobacter; Trichophyton mentagrophytes; Hymenolepis nana; and Trixacarus caviae, a parasitic skin infection found particularly in guinea pigs.
Civets. Civets born abroad can carry the virus that causes severe acute respiratory syndrome (SARS). In 2003, the CDC banned the importation of all civets.
Still, your odds of infection from an exotic pet are low, more so if you take care. Animals bred in the U.S. are less likely to carry diseases that can affect humans. However, you should always be careful when around exotic pets and other animals. You shouldn't handle animals such as reptiles, rodents, and small mammals that can pass on diseases, especially if your immune status is compromised.
The CDC suggests you keep reptiles out of areas where you prepare or eat food. Make sinks and bathtubs used by people a reptile-free zone, too. After handling or being near reptiles and other animals, you can head off a lot of infections if you wash your hands thoroughly with warm water and soap.
You should always educate yourself before buying or adopting a pet of any type. There are many resources for most types of pets that can be found online. Breed- and species-specific rescue groups exist in most states and in many cities and metropolitan areas. These groups can provide information about the particular type of pet you're interested in.