Yesterday’s surprise announcement (see Germany Reports H5N8 Outbreak in Turkeys) that an only recently emerged subtype of avian flu has somehow turned up in Northern Germany has agricultural agencies scrambling to try to determine how it arrived in Europe, and just how much of a risk it poses to other poultry operations in the region.
Last spring we watched this new H5N8 virus emerge in South Korea, and spread to dozens of poultry farms, resulting in the destruction of more than 13 million birds.
While no human infections were reported, this virus is a cousin of the H5N1 virus which fas a long history of occasionally infecting humans, often with tragic results. South Korea did report detecting Dogs With H5N8 Antibodies.
Today Defra (the UK’s Department for Environment, Food and Rural Affairs) has issued a preliminary outbreak assessment, that while short on answers, reminds poultry producers of the importance of surveillance and biosecurity measures.
The chaos, confusion, and economic losses sustained when the H5N1 virus arrived in Europe and the UK in 2006-07 are well remembered, and so no one is taking this new arrival lightly.
Department for Environment, Food and Rural Affairs Animal Health & Veterinary Laboratories Agency Veterinary & Science Policy Advice Team - International Disease Monitoring
Preliminary Outbreak Assessment
06 November 2014 Ref: VITT/1200 H5N8 HPAI in Germany
Disease Report Germany has reported an outbreak of highly pathogenic avian influenza, H5N8 in fattening turkeys in North East Germany (Mecklenburg Western Pomerania) (see map; OIE, 2014). Increased mortality was observed in one of the six sheds of 15 week old birds for fattening (total number of turkeys on the premises ~ 31,000 of which each shed contained 5,000). Disease control measures have been implemented including 3km and 10km protection and surveillance zones in line with Directive 2005/94/EC and the birds in the affected shed as well as all other poultry in the protection zone have been destroyed. There have been no recent traded consignments from the affected areas to the UK or other Member States.
Situation Assessment During the past year, HPAI H5N8 has been reported from several countries in the Far East, in Japan, the Republic of Korea (ROK) and China (near the border with the Democratic Republic of Korea). In ROK, in excess of thirty five outbreaks have been reported since early 2014 from commercial poultry (principally breeding ducks but also chickens) and additional detections in wild waterfowl, resulting in the destruction of over 12 million poultry. In China, positive samples were found at a market during routine surveillance under the national plan. Japan reported just a single outbreak.
Genetic characterisation of the viruses from both poultry and wild birds in ROK and China revealed there was very high sequence similarity with the haemagglutinin (HA) gene of H5N1 HPAI viruses isolated in China in 2011 and clustered within clade 22.214.171.124 indicating this newly emerged virus has derived following reassortment of H5N1 HPAI with other influenza viruses co-circulating in avian populations (Ku et al 2014; Lee et al 2014; Wu et al 2014). The predicted putative binding to host cell receptors is similar to H5N1 HPAI, preferentially binding the ‘avian’ receptor. However although no human infections with this virus have been reported to date, the potential risk to public health cannot be ignored. Wild Waterfowl and commercial ducks have been found to harbour the virus in ROK (Lee et al, 2014), where the infection caused depression, egg drop, some neurological signs and a slight increase in mortality. There is currently no evidence for the virus being present in wild waterfowl in Europe, although this possibility cannot be ruled out. In the absence of any other epidemiological explanation, virus introduction into Germany via wild birds appears highly plausible.
Conclusion This is the season for increased wild bird migration especially waterfowl as well as seasonal poultry production and therefore there is an increased risk of incursion of any notifiable avian disease into the poultry sector through direct and indirect contact with wild birds and / or poor biosecurity. The report in North East Germany at this time of year therefore does increase the level of risk of incursion to the UK, although it is difficult to predict quantitatively with any precise confidence without data on any potential reservoir species and current wild bird demographics. However current UK wild bird surveillance targeting higher risk species for H5N1 HPAI infection is aligned with current knowledge from the Far East on carrier populations for H5N8. We will continue to report on the situation. We would like to remind all poultry keepers to maintain high standards of biosecurity, remain vigilant and report any suspect clinical signs promptly.