WATT AgNet: Changes in avian flu virus in China causes concern

Within Asia, new outbreaks have been reported in poultry in Malaysia, Taiwan and Vietnam, as well as in Nigeria and Egypt.

Evolving avian flu virus in China

Cases of the avian influenza A virus of the H7N9 family in people were first detected in China four years ago, but a recent spike in cases has prompted global health agencies to sound an international alert for rapid detection and effective response systems.

In a joint announcement, the World Organisation for Animal Health (OIE) and the United Nations’ Food and Agriculture Organization (FAO) say that these two measures would reduce the risk associated with virus spread and the potentially deadly impacts on public health. Since December, the H7N9 virus has caused more cases of human flu globally than all other viruses combined.

Most human cases have been linked to contact with sick poultry or visits to live bird markets, where the birds showed little or no signs of infection. However, recent evidence from China’s Guangdong province indicates that H7N9 has become more pathogenic to poultry. High mortality has been seen in the birds within 48 hours of infection, while the virus still makes people very ill.

This genetic change could help control by making it easier to see when chickens are infected and introduce control measures. On the other hand, it also increases the likelihood of severe animal and economic losses in the poultry sector.

China’s agriculture ministry has raised a number of restrictions on poultry sales but with no end to new cases in sight, the OIE and FAO are calling on Asian countries to be on alert from signs of the virus - in its low or highly pathogenic form – and are calling for more investment in surveillance and virus detection to safeguard both public health and poultry trade.

In a first report for two months, China has recently informed the OIE about a new HPAI outbreak in a backyard duck flock in Hubei province, in which the H5N6 virus was detected.

Taiwan: More than 100 HPAI outbreaks so far this year

The total number of outbreaks of HPAI in Taiwan this year stands at 103, according to information from the Council of Agriculture reported by Focus Taiwan recently. That is an increase of 15 from last week. Almost 935,000 poultry have been destroyed.

The agriculture ministry in Taipei has reported 30 new HPAI outbreaks in poultry to the OIE over the last week. These included 22 locations where the H5N2 virus was detected, seven were positive for the H5N8 virus, and the more serious H5N6 variant was found at a duck farm in Hualien county. Although more rarely detected, the Taiwanese authorities are concerned about the H5N6 variant because it is more virulent and can be transmitted from the birds to people more easily.

More HPAI in Malaysia

Having confirmed the return of highly pathogenic avian influenza (HPAI) recently after an absence of 10 years, Malaysian veterinary authorities are battling to contain the spread of the disease in Kelantan.

Monitoring by the region’s veterinary service has revealed 28 poultry flocks positive for the H5N1 virus, The Malay Mail reported. Half of these were in the district of Kota Bharu. So far, the department has destroyed more than 33,000 poultry and 13,000 eggs to control the spread of the disease.

Vietnam: two new outbreaks

Based on recent reports from the animal health agency in Vietnam to the OIE, there have been two new outbreaks of HPAI in the country, both in backyard flocks. In the Can Tho province in the south, the H5N1 virus was detected, while the H5N6 variant was found in the flock in Quang Tri in central Vietnam. Almost 1,000 birds were lost to the disease in these two outbreaks.

Africa: Avian flu in Nigeria, Egypt, South Africa

Battling HPAI for more than two years already, the animal health agency in Nigeria has reported to the OIE a further three new outbreaks caused by the H5N1 virus variant. Just over 18,500 laying hens died or were destroyed as a result of the infection in the states of Plateau, Katsina and Bauchi.

OIE has also received a report from the veterinary authority in Egypt about three new outbreaks in small backyard poultry flocks during February. The cases – 75 in total - were in As Suways, Dumyat and Al Minya.

Low-pathogenic avian influenza linked to an H5N2 virus continues to be reported periodically to the OIE by South Africa’s agriculture department. Between mid-January and mid-February, 79 ostriches in two commercial flocks in Western Cape province tested positive for the virus.