MADISON, Wis. — Tests have confirmed that four people in Wisconsin contracted the monkeypox virus after coming into close contact with pet prairie dogs, marking the first time the disease has been discovered in the Western Hemisphere, health officials said Sunday.
The findings at least partially confirm that monkeypox has caused an outbreak of rashes, fevers and chills in people across the upper Midwest since early May.
Fourteen more people in Wisconsin are suspected of suffering from the virus, said Milwaukee Health Commissioner Dr. Seth Foldy. At least three more cases are suspected in Illinois and Indiana.
The outbreak stems from a batch of prairie dogs that came from a pet distributor in suburban Chicago. It was there that the prairie dogs may have been infected with monkeypox by a Gambian rat — a creature that is indigenous to African countries.
The detection of monkeypox in the United States represents a highly unusual discovery. The virus has been found mostly in west African nations — and had never before been seen in the Western Hemisphere.
The human death rate in Africa has ranged from 1 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.”
Still, the disease could be almost impossible to control ,and more people could become infected if it passes into other indigenous North American animals, Foldy said.
Thirteen of the infected people were near prairie dogs; the other apparently contracted it after handling a sick rabbit that had been near a prairie dog.
Foldy said it doesn’t appear anyone contracted the virus from another person.
Doctors initially feared they might be facing smallpox, which causes similar symptoms, Foldy said.
But doctors and scientists quickly eliminated that possibility after discovering the people-prairie dog link.
Smallpox is found only in humans and cannot be transmitted from animals to people, Foldy said.
“We asked the question but discounted it very early,” Foldy said.
Four people, including one as an outpatient, have been treated at Froedtert Memorial Lutheran Hospital in Milwaukee.
One has been released and the remaining two were in satisfactory condition Sunday, hospital spokesman Mark McLaughlin said.
“It eventually will clear up as you treat the symptoms,” McLaughlin said. “We don’t need people to go off the deep end.”
Wisconsin agriculture officials took steps Sunday to prevent the possible spread of monkeypox from prairie dogs to other animals.
The State Department of Agriculture, Trade and Consumer Protection issued a warning telling people not to dump prairie dogs into the wild, said Donna Gilson, the agency’s spokeswoman.
The agency also told state humane societies to isolate any prairie dogs people bring in.
The Wisconsin Department of Health and Family Services issued an emergency order Friday banning the sale, importation and display of prairie dogs.
The Illinois Department of Agriculture has prohibited Phil’s Pocket Pets, the suburban Chicago pet distributor, from selling animals until the health of its animals is verified.