Hundreds of thousands of birds are being culled in Europe and Eastern Asia as both regions grapple with a growing outbreak of highly pathogenic avian influenza (HPAI), one that—for now—affects only birds.
This particular strain of Avian Flu, A(H5N8), was identified in wild birds in Asia in 2010 and has since spread across the world. A renewed outbreak in 2020 sparked fears, taking place as it did as the world continues to grapple with the COVID-19 pandemic. In Japan, this has been the worst bird flu outbreak on record, having reached over 20 per cent of its 47 prefectures. In response, authorities ordered a record number of birds culled, with 3 million having already been killed.
Around 11,000 birds will be slaughtered and buried after the avian influenza was discovered at an egg farm in Higashiomi city in Shiga prefecture, the agriculture ministry said. Poultry imports have also been suspended from seven countries including Germany.
Earlier, some 19,000 ducks were reported killed by the virus in South Korea’s southwestern region, with 392,000 chicks and ducks in six farms culled as a preventative measure. China too has reported the presence of the disease among Swans in the Shanxi province.
“The virus found in Japan is genetically very close to the recent Korean viruses and thus related to viruses in Europe from early 2020, not those currently circulating in Europe,” Madhur Dhingra, a senior animal health officer at the Food and Agriculture Organisation, told Reuters. “This means that we currently have two distinct H5N8 HPAI epidemics in eastern Asia and Europe,” she said.
In Europe, France last week confirmed its first outbreak this year of the H5N8 strain in a duck farm in the Landes region. All the infected ducks there have been culled. Poland had planned to cull over 900,000 hens in a farm in its western region, while Denmark was to cull over 25,000 chickens.
According to the European Centre for Disease Prevention and Control (ECDC), multiple European countries including Belgium, Denmark, France, Germany, Ireland, the Netherlands, Sweden, and the United Kingdom have reported outbreaks of the HPAI viruses. The UK, notably, has been faced with disturbing scenes of swans spinning in circles and bleeding from their nostrils, a phenomena being investigated for its possible link to the bird flu.
To deal with the outbreak, all captive birds in Britain will have to be kept indoors from December 14, the government has said.
“Between 15 August and 7 December 2020, 561 highly pathogenic avian influenza (HPAI) virus detections were reported in 15 EU/EEA countries and UK in wild birds, poultry and captive birds, with Germany (n=370), Denmark (n=65), the Netherlands (n=57) being the most affected countries,” the ECDC said in its December 11 report.
Urging caution and high standards of surveillance, it nevertheless said the risk for the general population appeared low. “Maintaining high and sustainable surveillance and biosecurity particularly in high-risk areas is of utmost importance. Two human cases due to zoonotic A(H5N1) and A(H9N2) avian influenza virus infection were reported during the reporting period. The risk for the general population as well as travel-related imported human cases are assessed as very low.”
"An increasing number of outbreaks of HPAI A(H5N1), HPAI A(H5N5), HPAI A(H5N6) and particular HPAI A(H5N8) in poultry and wild birds were notified from a variety of Asian countries (China, Iran, Israel, Japan, Kazakhstan, Laos, Republic of Korea, Taiwan, Vietnam) and Russia. In contrast to the previous reporting period, no HPAI cases were reported from the African continent," the ECDC said.
It added that genetic analysis of the H5N8 strain identified between October and November in South Kroea showed that it belonged to a cluster detected in Europe in the first half of 2020, suggesting a persistent circulation of this virus strain, likely in wild birds in Asia.
Diagnostic group Novacyt has already devised a test for the virus.
“Novacyt has also taken the strategic decision to develop two new RUO PCR tests for avian influenza amid recent outbreaks. The European Centre for Disease Prevention and Control has announced that since October 2020, multiple European countries, including the UK and France, have reported outbreaks for highly pathogenic avian influenza (HPAI) viruses. Three different subtypes of HPAI viruses have been identified in wild birds and poultry, including A(H5N8), A(H5N5) and A(H5N1), with A(H5N8) being the most common,” the company said in a release.
“While no human infection due to these viruses has so far been detected and the threat to the general population is currently low, continued surveillance of avian influenza viruses in Europe is important to monitor virus evolution and emergences. As a result, Novacyt has developed two RUO PCR tests to assist in the current outbreaks,” it said.
Novocyt has also developed a test for the new strain of coronavirus found to have spread among humans from mink.
“Further to the announcement on 16 November 2020, Novacyt has launched the first RUO PCR test for a specific new mutation of the SARS-CoV-2 virus, known as Y453F. Originally found in mink in Denmark and The Netherlands, the Y453F mutation quickly spread to humans and has also been detected outside of Europe,” the company said.
What has worried scientists about the new strain is that the mutation “causes an amino acid change which affects antibody binding.”
“The Company believes this could have implications for vaccine strategies, which are predicated on stimulating a defined antibody response to the virus. While it is unknown what, if any, impact the amino acid modification will have on vaccines, Novacyt believes a RUO test could help scientists and clinicians to identify patients that carry the virus with the Y453F mutation,” it said.
