How do pet reptiles spread diseases and How are infections prevented?

Some people never learn. In October 1996, a three-week-old boy was brought into a hospital emergency room in Arizona suffering from a fever of 103.6, plus vomiting and bloody diarrhea that had been going on for more than two weeks.

Why it took two weeks for the parents to bring him in is almost certainly another story. When the staff took stool and blood cultures to try to figure out what was going on they found salmonella, serotype IV 44:z4,z23-, an extremely rare type of the bacterium.

In trying to figure out where this odd serotype came from, they examined a sample of stool from the family’s pet iguana and found exactly the same rare serotype. There was no question that the infant had been infected by the iguana. His family, prudently, gave the iguana to a relative. Then a month later, imprudently, they let the infant spend two days with that same relative. Forty-eight hours later, the kid was treated again at the emergency room for fever and diarrhea, and the same unusual serotype of salmonella was found in his stool.

In April 1997 in Kansas, a six-year-old came down with bloody diarrhea, abdominal cramps, vomiting, and a fever of 104.9. Salmonella was the cause again, serotype tymphimurium was found in his stool. They gave him antibiotics, ceftriaxone and amoxicillin/clavulanate. He got better.

Nine days later, his little brother came down with the same symptoms, and salmonella was found in his stool. No one else in the family was ill. The boys had a corn snake that they kept in their bedroom and handled regularly, and, you guessed it, the snake had salmonella tymphomurium in its stool as well. The parents had no idea that you could get sick from a snake.

The next month, in Massachusetts, another boy, this one an eight-year-old with a congenital immune deficiency, got severe vomiting, abdominal cramps, bloody diarrhea, and headaches. His stool had salmonella serotype St. Paul in it. Three days before the boy got sick, his parents had bought two iguanas from a pet store. They didn’t know that iguanas could carry salmonella, and when they returned the animals to the pet store, they learned that the pet store owner didn’t know this either. The iguanas were never tested, but it’s easy to guess what they would have found if they’d examined their stool.

In December 1998 a previously healthy five-month-old suddenly died at home in Wisconsin. They did an autopsy but were unable to find any obvious reason why the child had died. But when they did a culture of a heart blood sample, they found salmonella serotype Marina and concluded that the cause of death was septicemia caused by this organism. They found the exact same serotype in the stool of the family’s pet iguana. The infant had never even come in direct contact with the animal.

That consumers and pet store owners generally don’t know about the dangers of getting salmonella from reptiles has prompted the Centers for Disease Control (CDC) to encourage states to establish educational programs, including legally required point-of-sale information to anyone purchasing reptiles as pets. Iguanas, snakes, turtles, all popular pets. But you might want to rethink the idea of getting one (or reconsider your relationship with the one you already have) when you read stories like these and hear what the CDC recommends about pet reptiles:

• People should always wash their hands thoroughly with soap and water after handling reptiles or reptile cages.
• Children under five and people with weak immune systems should avoid contact with reptiles.
• Reptiles should be kept out of the house if there are children under one year old. If you’re having a baby, you should remove any reptiles from the house before the baby arrives.
• Reptiles should not be kept in child care centers.
• Reptiles should not be allowed out of their cages in a home.
• Reptiles should be kept out of kitchens or food preparation areas. Kitchen sinks should not be used to bathe them or to wash their cages, dishes, or aquariums. If bathtubs are used for this purpose, they should be cleaned thoroughly and then disinfected with bleach.

Many reptiles are permanently colonized with salmonella species and intermittently shed them in their stool. Over the past 20 years there has been a steady upward trend in the number of reptile-associated salmonella serotypes isolated from human blood and stool samples. And this has happened despite a 1975 ban on the commercial distribution of pet turtles less than four inches long, a ban that led to a 77 percent decrease in turtle-associated salmonella serotypes isolated from humans.

The popularity of snakes and iguanas as pets has apparently more than made up the difference. There are an estimated 7.3 million reptiles owned by about 3 percent of households, and since most reptiles won’t breed in captivity, the majority of pets are captured in the wild.

Iguanas in particular have become extremely popular, almost a million of them are imported into the United States every year. The CDC believes that if educational programs are ineffective, then the sale of other reptiles should be restricted as they are for turtles. There are roughly 93,000 cases of salmonella poisoning a year that are attributable to contact with pet reptiles or amphibians. Most of these cases are infants, young children, and immunocompromised people, and in these high-risk populations the infections can lead to serious complications such as septicemia and meningitis.

Reptiles are not the only problem. In April 1999 the Missouri Department of Health found a cluster of people, 40 of them, who had come down with salmonella infections, all of them serotype tymphimurium. Ninety-seven percent of them, they discovered, were exposed to chicks, ducklings, or young turkeys. The ones who washed their hands after handling the young birds got sick less than those who didn’t.

The next month, 21 people in Michigan also came down with salmonellosis, they were of various ages and both sexes, and the serotype in all of them was the same: infantis. In addition to their symptoms of diarrhea, fever, and vomiting, they also had in common the fact that they had handled chicks, ducklings, or other fowl just before falling ill.

By September, the CDC had determined that all of the infected fowl had come from one hatchery that was shipping 100,000 birds a week, mostly for raising in backyards for egg and meat production. Sometimes, especially during the Easter season, people get ducklings or chicks as pets, these animals probably don’t make great pets in any case, and keeping them in the house is especially ill-advised if there is a child under five or an immunocompromised person living there.

You’re going to read about some pretty nasty things you can catch from the pets you love, so we should say before going any further that we like animals. We have pets, and we’ve had many different ones over the years. And although research in the matter is still in its infancy, there are some studies that suggest that having pets can reduce stress and actually enhance health. But it is our unpleasant duty to inform you that not all of them are as sanitary as we might like them to be.

It doesn’t end with reptiles and chicks, either. Parrots and parakeets, cats and dogs, ferrets, wild animals in petting zoos, they all can carry diseases and transmit them to humans. But don’t give up your pets yet.