ROME (AP) _ Doctors have issued a nationwide warning about a prostitute who allegedly had unprotected sex with thousands of people, while knowing she had the virus that causes AIDS.

Italian media ran a photo of the woman Sunday, and physicians called for her clients to be tested for HIV.

More than 1,000 calls from around the country swamped two hotlines set up Saturday by police her hometown of Ravenna, 215 miles northeast of Rome, the Italian news agency ANSA reported.

Most of the callers were men but some were women who said they had had group sex involving the prostitute.

Ravenna police chief Filippo Ciccimarra estimated that thousands of people could have had unprotected sex with the woman. Italian news reports, without citing sources, put the estimate at 5,000.

The woman, who is in a Ravenna hospital for treatment for the virus, is being investigated on charges that she knew she had tested positive for HIV for two years without telling clients, Italian media reported.

They said police recently raided her apartment and found an address book of her alleged customers and medicine used to fight the virus.

The Rome daily La Repubblica reported that the woman was heavily in demand by men across Italy because she was willing to have sex with customers without using a condom.

Italy's leading AIDS researcher, Fernando Aiuti, said the reaction was ``way out of proportion ... as if you were dealing with a professional serial killer.''

Public health officials in St. Louis said last week that an HIV-positive man infected 18 women and girls in Missouri with the virus in the worst documented U.S. case of multiple infection.