Officials in Bangladesh, Pakistan, and Vietnam have reported new outbreaks of H5N1 avian influenza in poultry this week.

In Bangladesh, an official from the government's livestock department said the H5N1 virus was detected at three farms in the northern part of the country, Reuters reported today. Workers culled about 6,000 chickens, which were buried over the last 2 days, the report said.

The country's last reported H5N1 outbreak occurred in May, according to a World Organization for Animal Health (OIE) report.

Meanwhile, a livestock official in Pakistan said yesterday that 45,000 chicks at a breeding operation in the Northwest Frontier province were destroyed and buried after a laboratory in Islamabad identified the H5N1 virus in samples from the flock, The Post, a Pakistani newspaper, reported today.

According to OIE reports, Pakistan's last poultry outbreak occurred in July.

Elsewhere, veterinary officials in Vietnam reported two more H5N1 outbreaks in ducks, according to a report from Xinhua, China's state news agency. An outbreak that began on Oct 29 in southern Vietnam's Tra Vinh province struck a flock of 2-month-old ducks, killing 400 and sickening 500, the report said.

On Oct 28 an H5N1 outbreak killed 210 of 400 ducks at a household in northern Vietnam's Nam Dinh province, the Xinhua report said.

According to OIE reports, Vietnam had six H5N1 outbreaks in October, all involving unvaccinated ducks. Besides Tra Vinh and Nam Dinh, affected provinces included Cao Bang in the north and Quang Tri in central Vietnam. Before October, Vietnam's last reported outbreaks occurred in August.

In other avian flu developments, authorities in Canada have lifted remaining restrictions on the movement of birds and bird products in Saskatchewan, according to an Oct 31 press release from the Canadian Food Inspection Agency (CFIA). The restrictions were imposed in late September when a highly pathogenic H7N3 strain of avian flu was detected in chickens at a commercial poultry operation in the province.

No other cases of avian influenza were found after the initial outbreak, the CFIA said. Import restrictions imposed by some countries after the outbreak will be addressed on a case-by-case basis, the CFIA said.