Vietnam's central Quang Tri provincehas been hit by bird flu, raising the total confirmed number of affected localities to 15 since early October.

Samples from over 500 ducks in Gio Linh district, which died late last month, were tested positive to bird flu virus strain H5,the Department of Animal Health under the country's Ministry of Agriculture and Rural Development announced Friday.

The dead ducks were part of a flock of some 5,000 raised by a local household. The provincial Veterinary Bureau has culled the entire flock, the department said.

A total of 24 localities nationwide have detected poultry deaths since Oct. 1. Tests showed that poultry were not infected with bird flu viruses in the two central provinces of Quang Nam and Quang Ngai and the southern province of Dong Thap.

The capital of Hanoi, the three northern provinces of Thai Binh,Hoa Binh and Hung Yen, and the two southern provinces of Bac Lieu and Long An have met criteria for announcing an end to bird flu outbreaks (detecting no new affected spots for at least three weeks). Therefore, the current number of bird flu-hit localities is reduced to 15, said the department.

The country's Health Ministry on Thursday confirmed 66 human cases of H5N1 infections, including 22 fatalities, in 25 cities and provinces since December 2004, bringing the total respective numbers since December 2003 to 93 and 42.

According to local newspaper Youth on Friday, among the infection cases, some people are infected with the bird flu virus strain H5N1, but they do not exhibit symptoms clearly. Two women from the southern region were confirmed to contract the virus two months after they had been discharged from hospital, the newspaper said.