MADISON, Wis. — Wisconsin officials said Friday it is unlikely that two health-care workers who fell ill after treating patients with the monkeypox virus were infected with the disease.
The cases would have been the first known U.S. human-to-human transmissions of the virus. Monkeypox, a disease related to smallpox but less lethal, appeared in the country for the first time when at least a dozen people had contact with infected pet prairie dogs.
A nurse in Milwaukee and a medical assistant in Marshfield showed symptoms similar to those of monkeypox after treating patients with the disease. The boyfriend of the medical assistant also showed symptoms.
Jeff Davis, Wisconsin's chief epidemiologist, said further examinations suggest the three do not have the disease, but the state was awaiting test results from the federal Centers for Disease Control and Prevention in Atlanta to rule it out.
"We're not saying anything final until we get those test results," Davis said.
By Friday afternoon, state health officials around the country had confirmed 12 human cases of monkeypox: four each in Wisconsin, Indiana and Illinois. Also, 71 possible cases had been reported.
Another possible case, involving an 11-year-old New Jersey boy, also had been reported, but the CDC told state officials Friday that he had the common childhood ailment chickenpox.
No one has died of monkeypox in the U.S., but at least 14 patients with symptoms have been hospitalized, including a child in Indiana with a confirmed case who also has encephalitis, or brain inflammation. Indiana Department of Health spokesman Matthew McCardle said Friday the girl was recovering.
Federal health officials have traced the outbreak to prairie dogs distributed by Phil's Pocket Pets of Villa Park, Ill.
The prairie dogs, which may have been sold to buyers in 15 states, were apparently infected at the business by a Gambian giant rat, a native of Africa, officials said.
Monkeypox causes pus-filled blisters, rashes, chills and fever.