The patient, whose age and sex were not given, died nearly a week ago in Ha Tay province bordering the capital Hanoi, the television report said, citing a report by the Vietnamese health ministry.

The latest death brings to 43 the number of people who have died of the human form of bird flu in Vietnam since the virus reappeared in Southeast Asia in late 2003.

Four other people have been reported infected with the H5N1 strain of the virus in Vietnam, the report said. Two have recovered and two are undergoing treatment, state media has reported.

Communist Vietnam, once the country worst hit by the disease, has won praise for containing earlier bird flu outbreaks through mass vaccination campaigns, culls of millions of poultry and public education campaigns.

But the virus has come back strongly this year, hitting scores of poultry farms especially in the densely populated northern Red River delta region in recent weeks.

Avian influenza outbreaks have been reported since May across 18 of Vietnam’s 64 provinces and municipalities, mostly among unvaccinated ducks and other waterfowl.

Neighboring China has stepped up anti-bird flu measures in its southern Guangxi region, which shares a 600-kilometer (400-mile) border with Vietnam, vaccinating birds, closing markets and banning cross-border poultry trade.

None of Vietnam’s five reported human infections, including the fatality,has yet been officially confirmed by the World Health Organization (WHO).

Worldwide, the virus has killed 191 people out of 313 infected patients, according to the WHO. Experts fear the death toll would rise sharply if the virus were to mutate and become easily transmitted between humans.