A virus similar to smallpox apparently jumped from an imported African rat to pet prairie dogs, infecting at least four people — possibly dozens — in the disease's first appearance in the Western Hemisphere.
Fourteen people in Wisconsin are suspected of suffering from the monkeypox virus and four are confirmed, said City of Milwaukee health commissioner Dr. Seth Foldy. At least 10 more cases in Indiana and three in Illinois are suspected.
The Centers for Disease Control and Prevention said Saturday the prairie dogs likely were infected with the virus by a giant Gambian rat, which is indigenous to African countries, at a suburban Chicago pet distributor.
Thirteen of the people suspected of having the virus in Wisconsin were around prairie dogs, while the other apparently contracted it after handling a sick rabbit that had been around a prairie dog. Foldy said it doesn't appear anyone contracted the virus from another person.
Monkeypox in humans is not usually fatal, but causes rashes, fevers and chills. Doctors initially feared they might be facing smallpox, which causes similar symptoms, but scientists quickly eliminated that possibility after discovering the link between people and prairie dogs. Monkeypox's incubation period is about 12 days.
Two patients at Froedtert Memorial Lutheran Hospital in Milwaukee were in satisfactory condition Sunday, hospital spokesman Mark McLaughlin said. The two were isolated and doctors wore caps, gowns and masks whenever they interacted with them. Other suspected victims were treated and released.
The CDC said a preliminary investigation showed the virus was transmitted to humans as a result of close contact with the infected prairie dogs, although scientists were unable to exclude the possibility of human-to-human transmission.
Health officials are trying to contain the virus' spread by preventing more animals from becoming infected. Prairie dogs, usually found in southwestern and western states, aren't indigenous to Wisconsin.
Wisconsin's Department of Agriculture, Trade and Consumer Protection issued a warning telling people not to dump prairie dogs into the wild, agency spokeswoman Donna Gilson said. The agency also told state humane societies to isolate any prairie dogs people bring in.
Monkeypox has been found mostly in west African nations, Foldy said. The human mortality rate in Africa has ranged from one to 10 percent, but Foldy said the virus may be less lethal in the United States because people are typically better nourished and medical technology is far more advanced.
"We have isolation, soap, running water, sterile dressing materials, we have washing machines," Foldy said. "These are all things that have reduced the prevalence of germs that are spreadable by person-to-person contact."
The prairie dogs were sold by a Milwaukee animal distributor in May to two pet shops in the Milwaukee area and during a pet "swap meet" in northern Wisconsin, the CDC said.
The Wisconsin Department of Health and Family Services issued an emergency order Friday banning the sale, importation and display of prairie dogs. State agriculture officials plan to publish an emergency rule this week, Gilson said.
The Illinois Department of Agriculture has prohibited Phil's Pocket Pets, a pet distributor in Villa Park, Ill., where the prairie dogs may have been infected, from selling animals until the health of its animals is verified.
The owner of Phil's has given Illinois officials a list of all who bought prairie dogs, Gambian rats or other exotic animals since April 15, the Illinois Department of Public Health said. No telephone listing could be found for the store Sunday.
Eileen Whitmarsh's pet store was quarantined after she found lesions under her arms and on her scalp after handling one of the infected prairie dogs.
"I'm fine, it's a lot better than it was for those two, two and a half weeks," she told CBS News.
Illinois Gov. Rod Blagojevich on Saturday signed an executive order banning the sale, importation or display of prairie dogs or Gambian rats. Veterinarians were urged to report suspected cases of the disease.
Prairie dogs are burrowing herbivores that are commonly found in western rangeland, but their popularity as pets has grown in recent years. Last year 10,000 prairie dogs were shipped out of Texas to become pets, said David Crawford, executive director of the Rocky Mountain Animal Defense, a nonprofit organization that advocates for animal freedom.
Tammy Kautzer's Dorchester farm in central Wisconsin has been quarantined because she purchased two prairie dogs for pets during the Wausau swap meet. Less than two weeks after the purchase, her 3-year-old daughter, Schyan, was bitten by one of the animals and spent seven days in the hospital with a 103-degree F (40-degree C) fever, swollen eyes and red bumps on her skin.
"It was getting a little scary. She wasn't doing well," Kautzer said. "Three days straight (in the hospital), she just slept and cried. She'd tell me how scared she was."
Kautzer and her husband, Steve, also started to develop similar red bumps, but the family is now recovering. The prairie dog that bit the young girl has died. The other animal also became ill but is recovering.