#15,659
While our attentions the past few days have been understandably focused on the spread of the UK and South African COVID variants, and what that might mean going forward, the concurrent avian flu epizootics in East Asia and in Europe have continued to expand since our last update.
Over the past week Japan has added a 12th (Tokushima) and 13th (Saitama) Prefecture to the list reporting outbreaks in poultry, raising their total to 33 farm outbreaks. South Korea, meanwhile, has seen more than a doubling in poultry farm outbreaks in the past two weeks (13 to 29).
Both nations are being affected by HPAI H5N8, carried in this fall by migratory birds, which likely picked up the virus from other birds in Siberia. Europe is reporting a similar pattern this fall as well (see ECDC: Avian Influenza Overview - Aug-Dec, 2020).
While HPAI H5N8 is not considered a zoonotic threat, it can be devastating to both wild birds and poultry. Both countries have lost millions of birds due to the virus, or to culling, since the beginning of November.
While this isn't the worst outbreak to hit South Korea, it has been record breaking in Japan.
Japan's latest outbreaks in poultry farms and detections in wild birds and/or the environment are detailed at Japan's Ministry of Environment Avian Influenza webpage. South Korea's Ministry of Agriculture (MAFRA) posts their daily updates here.
Meanwhile, the situation in Europe continues to worsen, with the UK's DEFRA's last full update issued on Dec 21st (see below), citing 14 HPAI outbreaks in poultry and/or captive birds in the United Kingdom up to December 20th.
Literally hundreds of outbreaks in wild birds and domesticated poultry have been reported across Europe since October in the worst outbreak seen there since their historic avian influenza epizootic of 2016-17.
Some excerpts from the latest DEFRA report, including a comparison of the opening 79 days of this year's outbreak compared to 2016's.
Updated Outbreak Assessment #10 Highly pathogenic avian influenza (HPAI) in the UK, and Europe
21 December 2020 Ref: VITT/1200 HPAI in the UK and Europe Disease Report
Since our last report (15 December) in the United Kingdom; there have been three further outbreaks of highly pathogenic avian influenza (HPAI) H5N8 in poultry, including the first in Scotland, and an outbreak of HPAI H5N1 in poultry. There have also been many cases of HPAI H5N8 in wild birds; and smaller numbers of cases of HPAI H5N1 (2 reports) and HPAI H5N5 (6 reports) also in wild birds.
Elsewhere in Europe, HPAI H5N8 has been reported in poultry in France and Poland. HPAI H5N8 in wild birds has been reported in Denmark, Germany, Italy, Norway, Poland and Slovenia with HPAI H5N1 also in wild birds in Italy. HPAI H5Nx (N untyped) has been reported in poultry in the Netherlands, and in wild birds in the Netherlands and in France.
(SNIP)
Comparison of 2020 figures with the 2016/17 HPAI H5N8 outbreak in EuropeThe number of cases in wild birds and outbreaks in poultry and captive birds are compared for this year with the 2016/17 HPAI H5N8 outbreak in Figure 1.The first case in wild birds this year was detected on 20 October 2020. In the 2016/17 outbreak of HPAI H5N8, the first case in wild birds was detected on 26 October 2016. When comparing this 2020 European outbreak to date; with the 2016/17 H5N8 outbreak, there are some interesting early differences and trends.
- The trend of captive bird outbreaks against time is similar, except that the number of outbreaks by Day 79 (at 14), is almost double that seen in 2016.- While poultry outbreaks increased approximately linearly with time in both years, the initial rate in 2016 was much higher than in 2020. Thus, at Day 79, there have been 67 outbreaks in poultry in 2020; whereas there were 281 in 2016.- The numbers of wild birds are much higher in 2020; with 700 at Day 79 this year, compared to 332 in 2016. For both years, the case rate in wild birds increased rapidly in November, falling slightly in December. However, numbers in the 2016/17 outbreak then increased greatly in late January/early February 2017, with a second wave of cases reflecting spill over to indigenous species.
(SNIP)
Conclusion
As a consequence of the HPAI H5N8 (predominantly) outbreaks in poultry and captive birds in the UK, also in Croatia, Denmark, France, Germany, Ireland, Netherlands, Poland and Sweden; as well as the increasing HPAI H5N8 cases in wild birds in the UK, Belgium, Denmark, France, Germany, Ireland, Italy, Netherlands, Norway, Poland, Slovenia, Spain and Sweden, and the known migration routes to the UK from these countries: the risk of HPAI incursion in wild birds in GB remains VERY HIGH. The overall risk of exposure of poultry in GB remains MEDIUM (with stringent biosecurity) TO HIGH (where there are biosecurity is not adequate.
After three years of relative quiescence, HPAI H5 has returned with a vengeance, and while the HPAI H5N8 strain (and its derivatives) are not considered to be significant threats to human health, we've also seen a noticeable uptick in H5N6 and H5N1 reports, including three human infections this fall - the first in over a year.
China: Xinhua News Reports H5N6 Human Infection In Hunan Province
China: Jiangsu Province Reports Fatal Human H5N6 Infection
Laos: First Reported H5N1 Human Infection In 18 Months
While none of this rises to the avian flu threat we were seeing before 2017 - with both avian H5N1 and H7N9 sparking significant localized human infections - it is a reminder that that novel flu viruses don't stop spreading and evolving just because are focused on the coronavirus pandemic.
