Rare monkeypox virus spread by pet rodents reported in three American states

Health officials in the United States disclosed yesterday that up to 19 people in three Midwestern states may be suffering from monkeypox virus, an illness closely related to smallpox.

The disease, which is not usually fatal in humans, has never been detected in the Western Hemisphere before. There was concern that the sufferers, mostly in Wisconsin, may have caught the rare virus after contact with sick Gambian rats and prairie dogs, the ground-dwelling rodents common in the western US that are sometimes sold as pets.

"Public health officials ... have reported the first outbreak of human infections with a monkeypox-like virus to be documented in the Western Hemisphere," the Atlanta-based Centres for Disease Control (CDC) said yesterday. The disease is most commonly found in the rainforests of western and central Africa.

A pet distributor in Chicago, Illinois, has been quarantined. One of those infected reported having recent contact with exotic animals there. "Preliminary information suggests that animals from this distributor may have been sold in several other states," the CDC said.

A single case has also been reported in northern Indiana.

Symptoms in humans include a high temperature, rashes and swollen lymph nodes. Only four of those suspected to have contracted the virus were in hospital yesterday. There was a warning to Americans who own rodents as pets to report any signs of illness to the CDC. Wisconsin has meanwhile responded by imposing a ban on the sale or display of prairie dogs as pets.

The outbreak, if confirmed, is likely to fuel fears in America over exotic diseases invading its shores. Toronto has been struck by an outbreak of Sars, the respiratory disease that originated in China. And around the US, health agencies are gearing up to combat mosquitoes able to spread the West Nile virus, which has infected cities including New York in recent summers.