The worst bird flu in Taiwan’s history, the culprit is being hunted down

Text by Zhu Shujuan

An outbreak of H5N2 subtype highly pathogenic avian influenza occurred in a laying hen farm in Dawushan, Pingtung County on January 9. Subsequently, outbreaks of H5N2 subtype highly pathogenic avian influenza occurred in Pingtung, Kaohsiung, and Avian influenza viruses have broken out in more than 200 chicken, duck, and goose farms in Tainan, Chiayi, Yunlin, Changhua, Taoyuan and other counties and cities. It is estimated that more than 1 million chickens will be culled, setting a record for the highest number of culls in Taiwan's history.

What’s more complicated is that so far this wave of avian influenza viruses has detected 4 highly pathogenic prototype viruses, including the old H5N2 avian influenza virus that originally existed in Taiwan. The Dawushan Laying Hen Farm in Pingtung County , a broiler farm in Tainan all belong to this type; the other three highly pathogenic types were discovered for the first time in Taiwan, including the new H5N2 subtype virus, H5N8 subtype virus, and H5N3 subtype virus.

Where did this wave of bird flu come from? The official tone is that it is brought by migratory birds, but there are doubts among the public.

This is the peak period for Taiwan's migratory birds to cross the border. Cai Xiangrong believes that this wave of epidemics is most likely to come from migratory birds. The evidence he presented is that the H5N8 virus itself was isolated from migratory birds. This virus has been isolated from three migratory birds in South Korea, Canada, the United States, and Japan. In addition, comparisons of H5N2 and H5N3 viruses almost all come from migratory birds.

Xie Kaikai, honorary professor of the Department of Veterinary Medicine at National Chung Hsing University, supported Cai Xiangrong’s statement. He said that the waterfowl farms where the outbreak occurred are all located in coastal areas. In November 2014, South Korea also just An outbreak of bird flu has occurred in waterfowl in Taiwan since December. Waterfowl on the west coast are raised in the open air. There may be a certain group of migratory birds passing through Taiwan. If they see water and feed at the waterfowl farm, they will pass by. He speculated that the amount of virus in the feces of these migratory birds was so large that bird flu broke out in waterfowl farms in so many counties and cities at the same time.

Jin Chuanchun, a professor at the Institute of Epidemiology and Preventive Medicine, School of Public Health, National Taiwan University, released a research report with Hong Kong professors from 2012 to 2013. The report pointed out that when chicken and duck feces, blood and serum were collected from a slaughterhouse in northern Taiwan to monitor viruses and serum, 80% of more than 800 chicken blood samples tested positive for H9N2 antibodies. However, Taiwanese officials have never announced that the H9N2 virus exists in Taiwan. Taiwanese chickens may have avian influenza vaccine. She requested that the Council of Agriculture should publish the eight-segment gene of the avian influenza virus and serum monitoring data as soon as possible for international scholars to review.

Chen Baoji said frankly that when the H5N2 low-pathogenic avian influenza virus broke out in Taiwan in 2003, due to insufficient culling efforts, the virus was not completely eliminated, causing the H5N2 virus to localize and mutate into a highly pathogenic prototype.

This proves that part of this epidemic may be caused by local virus mutation rather than simply caused by migratory birds? At present, the official statement and popular inference are inconsistent.

How much impact does the outbreak of bird flu have on people’s food safety? Chen Baoji said that in order to avoid mobile infections, the Council of Agriculture banned the slaughter of waterfowl for two days. It was also decided on January 13 that, in order to improve the processing time, poultry farms will be culled as long as the mortality rate reaches more than 20% and the specimens sent are confirmed to be infected with the H5 subtype virus.

Lu Taiying, director of the Environmental Protection Bureau of Pingtung County, said that the first discovered laying hen farm in Dawushan, Pingtung County, had as many as 120,000 laying hens to be culled, and its handling was a big challenge. Fortunately, after mobilizing manpower support, it was successfully completed, and for safety reasons, the poultry farms that were not infected with the virus were also disinfected. He mentioned that farmers have suffered heavy losses this time and the Committee of Agriculture should pay attention to the losses of farmers.

The repeated occurrence of avian influenza viruses in Taiwan has become a major public health issue. Guo Huaren, a professor at the Department of Agronomy at National Taiwan University, believes that livestock breeding in Taiwan has become large-scale, and high-density confinement has made animals physically and mentally unhealthy. As a result, drugs are frequently administered, and consumers eat sick animals that contain large amounts of antibiotics.

Zhu Zenghong reminded that animal husbandry policy should not only look at the economic aspect, but also consider food safety and epidemic prevention costs. He suggested that the Committee of Agriculture should establish a total concept and encourage businesses to raise less food and the public to eat less, which would be healthier. And this is the best way to prevent the epidemic.

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