Vietnam has recorded six more bird flu victims, taking the number of infections in the country to 61 since December, 18 of whom have died, state media reported on Wednesday.

The six were being treated in a Hanoi hospital, the Tuoi Tre newspaper quoted the National Institute for Clinical Research of Tropical Medicine as saying.

It said one hospital doctor who had been taking samples from carriers of the H5N1 virus had now developed a fever himself and was suspected of being infected.

The hospital was also treating two women found last month to have been infected with H5N1, the newspaper said.

The H5N1 virus has killed 18 Vietnamese since Dec. 16, 2004, when the disease resurfaced, taking the country’s toll to 38 since it appeared in late 2003. Twelve Thais and four Cambodians have also died.

Bird flu first emerged in the Mekong Delta in southern Vietnam in late 2003, then spread to the northern region where the virus appears to develop rapidly during the winter.

Scientists fear the avian flu, which is infectious in birds but does not spread easily among humans, could mutate into a form capable of generating a pandemic in which millions of people without immunity could die.