2018 avian influenza cases drop by nearly 50%, strengthen prevention efforts

Now we have once again entered the peak period for avian influenza, so we need to strengthen our defenses in this regard. What exactly should be done? Let's take a look together.

Ducks must be screened before slaughter, and prevention efforts are working

To contain the spread of avian influenza, the Council of Agriculture has since last year mandated that all ducks across Taiwan be comprehensively screened for the virus before being brought to market. Council of Agriculture Deputy Minister Huang Chin-cheng said this method has worked. Since March 7, 2017, when poultry farms were once again confirmed to be infected with H5N6, no poultry farm has seen the same outbreak again for more than a year, confirming that H5N6 no longer exists in Taiwan's environment. It was later also confirmed that no poultry farm has seen further outbreaks of H5N3 or H5N8.

Council of Agriculture Deputy Minister Huang Chin-cheng admitted frankly that the remaining H5N2 is the hardest of all avian influenza viruses to eliminate. (Photo / Kuo Hsiu-chen)

Big data monitoring combined with prevention measures

In addition, in November last year the Council of Agriculture established the "Avian Influenza Prevention and Control Research Center," which for the first time used data such as poultry farm stocking density and waterfowl stocking density to analyze high-risk areas for avian influenza outbreaks across Taiwan, finding they are concentrated in Yunlin and Pingtung. Among them, Yunlin's Dongshi Township, Sihu Township, Mailiao Township, Taixi Township and Baozhong Township were the peaks. Huang Chin-cheng said these predictions were later confirmed to match exactly the locations where outbreaks occurred, and the results are highly valuable for reference.

The Council of Agriculture has also strengthened prevention efforts based on these high-risk areas. In addition to mandatory virus testing for ducks before slaughter, it tests 60 free-range chicken farms in high-risk areas every month. At the same time, referring to the research center's analysis, it has included all poultry farms within a 5 km radius of high-risk migratory bird habitat wetlands where avian influenza viruses have been detected in recent years, including Yilan's Shichao Wetland, Chiayi's Aogu Wetland, Kaohsiung's Qieding Wetland, Tainan's Yantian and Sicao Wetlands, for strengthened monitoring.

H5N2 is hard to eliminate; hopes of starting with egg-type breeding chicken farms

Huang Chin-cheng admitted frankly that the remaining H5N2 is the hardest of all avian influenza viruses to eliminate. This virus has long existed in duck farms, layer farms and egg-type breeding chicken farms, and across Taiwan layer farms show an average antibody positivity rate of about 50% to 60%. This shows that half of Taiwan's laying hens have been infected with H5N2.

Huang Chin-cheng said that most layer farms in Taiwan raise old, middle-aged and young generations together, and the H5N2 virus circulates in these environments, making it very difficult to require every farm to conduct virus screening and cull once the virus is detected. So this area is very hard to handle. At present, egg-type breeding chicken farms are more likely to be tackled first. Although they also raise three generations together, their antibody positivity rate is only 20% to 30%. In the future, the Council of Agriculture is considering starting with egg-type breeding chickens, requiring virus screening at every farm to gradually clear the virus completely.