MADISON, Wis. - Doctors initially feared a smallpox outbreak when they began seeing cases of a mysterious disease that has spread to at least 19 people who came into contact with pet prairie dogs in the Midwest.
The symptoms were alarmingly similar - fever, chills, rashes and swollen lymph nodes, said Milwaukee's health commissioner, Dr. Seth Foldy. It was when the prairie dog connection surfaced that they knew it must be something else.
"We asked the question but discounted it very early," Foldy said Sunday. "Smallpox has never been known to affect another species."
The Centers for Disease Control and Prevention said Saturday pet prairie dogs from a suburban Chicago pet distributor likely are infected with monkeypox, a member of the same viral family as smallpox. The pet rodents may have gotten the disease from another animal at the distributor.
The virus can pass animal-to-animal and animal-to-human, and scientists believe it can pass human-to-human, as well, but it had never been documented in North America, Foldy said.
So far, at least 17 people in Wisconsin and one each in Illinois and Indiana have become sick since early May with symptoms consistent with monkeypox after coming in contact with prairie dogs.
Illinois health officials were investigating three more potential cases in the metropolitan Chicago area, said Jena Welliever, spokeswoman for the state Department of Public Health. The three had contact with a prairie dog and had developed a rash, she said Sunday.
"It eventually will clear up as you treat the symptoms," said Mark McLaughlin, a spokesman for Froedtert Memorial Lutheran Hospital in Milwaukee, which has treated several patients with the symptoms.
"We don't need people to go off the deep end. This is not an epidemic in the public's common perception of that," he said.
Of the people infected, two remained isolated at the hospital in satisfactory condition Sunday, McLaughlin said. He said doctors treating them are wearing masks as a precaution.