A new bird flu strain is developing unexpectedly in Vietnam and causing great concern to the government and public.

According to the National Animal Health Diagnosis Center, the new strain of bird flu virus, which is suspected to have higher risk of causing human death than previously known ones, appeared in July and widely spread in August in Vietnam's seven central and northern provinces.

Hoang Van Nam, head of Ministry of Agriculture and Rural Development (MARD)'s Animal Health Department, said that this virus, thought to belong to H5N1 - Clade 2.3.2.1, is different from the two strains of A and B that appeared in Vietnam in 2011, due to its higher pathogenic risk.

According to the department, as of Sept.6, the new virus strain has attacked seven central and northern cities and provinces, including Hai Phong, Thanh Hoa, Ha Tinh, Ninh Binh, Nam Dinh, Bac Can and Quang Ngai, and over 180,000 infected poultry have been culled so far this year.

Apart from the newly-found strain of the virus, the bird flu has developed unexpectedly in the country so far this year. Normally, avian influenza appears shortly before or after the traditional lunar Tet holidays (which often falls in late January and early February). However, it has appeared since July this year and fast spread without warning. In the Central Highlands Dak Lak province, about 30 influenza epidemic spots were found in only one day.

According to local experts, the epidemic would become more complicated once it reaches its peak in the coming months.

MARD has instructed the department to strictly supervise the import of poultry, especially breeding chicks, which are believed to make the suspected new strain virus to spread faster.

MARD also ordered the veterinary sector to soon report the preventive possibility of the currently-used vaccine against the new strain virus, as well as encouraged relevant agencies to use domestically-produced vaccine so as to take the initiative in preventing the epidemic.

Meanwhile, according to the Central Epidemic Prevention Institute, since August last year the UN Food and Agriculture Organization (FAO) has warned the change of the virus A/H5N1

Clade 2.3.2 in many Asian countries, including Vietnam, and that change is usual during the natural evolution of the virus.

This is a small change of the virus that creates a new strain, not yet a new virus. However, close supervision of the virus which is spreading among poultry should be taken so as to discover its change and set forth an appropriate strategy to fight the epidemic and protect human health, the Institute Director Nguyen Tran Hien told local media late last week.

Through strict supervision on human flu infected cases, we found nothing unusual. The most concern is that the virus A/H5N1 is spreading among poultry, and it can continue to have small changes, re-arrange the gene, and reunite with virus circulated among animals and human beings to become a new highly-toxic strain and transmittable to human beings, Hien said.

He also suggested the veterinary sector closely cooperate with the health service to enhance supervision on the avian flu among poultry and human beings as well as apply preventive measures so as to prevent the spreading of the disease among poultry and from poultry to human beings.

As of Sept.6, four cases of A/H5N1 infection had been recorded with two deaths in Vietnam, but the new strain of bird flu virus has not yet been found in humans, reported MARD.