"Attack of the Tiny Animals" isn't a movie and hasn't hit Hollywood yet, but that fictional horror could be reality at a cute and fuzzy pet store near you.
Pet rodents could be an underrecognized source of the 1.4 million salmonella bacteria infections and 415 related deaths that occur annually in the United States, according to a new government report.
The report is published in today's New England Journal of Medicine. It details the first documented salmonella outbreak associated with pet rodents.
The report refers only to rodents, but experts say the danger doesn't stop at the hamster cages. "Pocket pets" are also a possible problem.
The term "pocket pet" describes any of a number of small mammals kept as pets -- rodents, ferrets, chinchillas or rabbits, for example -- that are by no means intended to live in your pocket but are little enough to fit.
"There have been documented cases of salmonella infections from pet chickens, turtles and reptiles including snakes. In the last couple of years, there has been a lot of news about salmonella in pet turtles," said Lawrence McGill, a diplomat to the American College of Veterinary Pathologists and veterinary pathologist in Salt Lake City.
Most cases of salmonella poisoning from pets go undetected because people don't realize what made them sick, so the danger could be greater than experts realize. To keep perspective, though, "let's keep things simple and straight," said veterinarian Marty Becker, co-author with Gina Spadafori of The New York Times bestseller "Why Do Dogs Drink Out of the Toilet?"
"One out of two children will be bitten by a dog by the age of 12, whereas a very few will contract salmonella," he said.
Pet Stores an Uncommon Source of Infection
In the last couple of weeks, there has been a lot of news about E. coli and salmonella contamination in produce, not in pets.
Most people get salmonella from eating tainted food, but this week government researchers warn that household pets can carry a dangerous and drug-resistant strain of the bacteria.
"We know that many animals can transmit diseases to humans and often think about severe diseases such as rabies or plague," said Gary Thompson, at veterinarian at the West Suburban Animal Clinic in Sylvania, Ohio.
Salmonella is another pet infection we need to be aware of, Thompson said.
Animals have salmonella in their intestinal tracts, and it's found in their droppings. If traces of the bacteria get on the animals' fur or bedding, people can become sick from touching it.
According to the report, cuddly pet store creatures are by no means guaranteed safe, but the dangers are avoidable and, frankly, uncommon.
"You'd probably be more likely to get salmonella from a ham sandwich than a hamster," said Nick Dodman, a professor at the Tufts Cummings School of Veterinary Medicine in North Grafton, Mass.
Unlikely as it is, the risk is real. Infections are sometimes spread from animals to man, like experts fear the H5N1 avian flu virus could someday be. Infections that are transmissible from animal to man are called zoonoses.
Salmonella Outbreak Strikes Rodents, Young Owners
During a multistate salmonella outbreak between December 2003 and September 2004, 28 patients from 19 different states suffered infection from the same strain of salmonella bacteria -- S.Typhimuriam.
A 4-year-old boy was hospitalized for five days in June 2004 with a dangerously high fever of 105 degrees Fahrenheit, diarrhea, and stomach cramps. He tested positive for the suspect strain.
Nine days before the boy fell ill, his family had bought a hamster from a retail pet store. The hamster was found dead two days after purchase.
Another boy age 5 had suffered diarrhea for two straight weeks in August 2004, with stomach cramps and high fever. He also tested positive for S..
The boy's family had bought a mouse from a retail pet store just days before the boy got sick. The mouse got sick soon after arriving at the family home.
Even though the mouse was ill, the boy often played with and kissed the mouse, according to the government report. One week after leaving the pet store, the mouse died.
After autopsy, cultures of the mouse's internal organs tested positive for the same bacterial strain that had infected his young owner and the boy before him -- S..
Researchers Trace Outbreak to Pet Distributors
After interviewing 22 of the infected patients -- or their parents -- researchers from the U.S. Centers for Disease Control and Prevention discovered that 13 of those patients had been directly exposed to rodents purchased from retail pet stores.
Those interviews were only part of a serious investigation.
CDC officials, state and local health departments, and the U.S. Department of Agriculture Animal Care conducted trace-back investigations in an attempt to link the infected patients to infected rodents, retail pet stores, rodent distributors, and breeders.
The rodents purchased at retail pet stores came most often from a pet distributor in Georgia or Arkansas, investigators found.
Rodent Strain Multidrug Resistant, Report Says
One chilling point from the government report was that the salmonella strain that had infected the rodents and their owners was drug resistant -- meaning that the powerful arsenal of the often-used antibiotics ampicillin, chloramphenicol, streptomycin, sulfisoxazole and tetracyclineantibiotics was useless against the bacteria.
Recent news reports have highlighted the dangers of another drug-resistant bacteria -- Methicillin Resistant Staphylococcus Aureus or MRSA -- which is sometimes fatal. None of the case reports mentioned in the new government report ended with human death.
"What is of concern here is that we are dealing with a multidrug-resistant strain," Thompson said.
The report speculates that the animals themselves became infected with the salmonella bacteria through crowded cages, dirty living conditions, and too much uncomfortable travel time.
Because pet stores frequently give antibiotics to their pocket pets and other animals -- just as some industry farmers give antibiotics to their livestock -- the salmonella bacteria actually build a sort of immunity against the antibiotics so the drugs become ineffective.
The report highlights the dangers of antibiotic overuse.
"Some distributors and producers use antibiotics haphazardly. This can be a problem," McGill said.
Pet Owners Can Prevent Infection
But the government findings can't stop future outbreaks. Consumers should be aware that animals can carry harmful bacteria and that children are especially vulnerable.
"[Veterinary] medicine needs to keep an eye on this problem," McGill said. "But our human counterparts must realize that [they share the responsibility]."
Years ago, McGill had a kitten with a salmonella infection that even his veterinary expertise could not cure. To save his wife and children from infection, the kitten was destroyed and euthanized.
"It was not an enjoyable experience," he said. His experience can be avoided.
Be aware that your pet could be infected with a harmful disease, and that even the cleanest-looking pet store can harbor some nasty diseases. Consumers and animal workers should be aware that rodents, like reptiles, can shed salmonella, which means that rodent feces are also potentially infectious. So watch out. Wash your hands.
But there's no need to part with your furry friends.
"I always encourage people to get rid of the risk but keep the pet," Becker said.
To prevent problems with pet infections, "remember what your grandma told you," Becker said.
Keep pets out of food preparation areas, and wash hands after holding, handling or cleaning up after pets.
Children in particular, need to wash their hands with soap and water every time they touch an animal and also after cleaning cages.
One other important factor in preventing salmonella is to work with your veterinarian to keep your animals in optimal health.
"Sometimes the carriers of salmonella show no obvious symptoms and it takes the trained, experienced eye of your vet -- along with some basic lab tests -- to look past obvious problems to potential problems," Becker said.
Keep a careful eye on kids and their pets, not matter how small. But don't throw the hamster out with the bedding, so to speak.
"All pets have the possibility of passing on this disease," Becker said. "So do other people, though."
For more information on healthy pets, check out: http://www.cdc.gov/healthypets/