On December 20, 2014, dr. G. Koch, leading virologist at Central Veterinary Institute (part of Wageningen UR) in Holland commented on LinkedIn where he explained the connections between the current outbreaks of Avian Influenza. He referred to publications on the website of Reconbinomics.
Dr. Koch commented: “Remarkably the HPAI H5N2 causing the outbreaks in Brittish Columbia Canada is a reassortant virus existing of 5 genes of the HPAI H5N8 that is detected in Republic of Korea in the from the beginning of 2014 onward and Pb1, NP and NA form LPAI viruses present in wild birds in North America. The H5 gene relates to clade 22.214.171.124. viruses detected in Asia This suggests a role for wild birds in the spread of this H5 virus”.
In a recent report, the Friedrich-Loeffler Institute(FLI) have signaled the spread and acceleration of H5N8 confirmed cases in Germany. The institute released sequences, A/turkey/Germany-NI/R3372/2014, from a turkey from Cloppenburg in Lower Saxony (see map) at GISAID from a December 15 collection. A partial (742 BP) H5 sequence was released, which was followed by a full N8 sequences, which was followed by a much larger H5 sequence (1342 BP). FLI is to be commended for the rapid release of these sequences.
The H5 was most closely related (1338/1342 matches) to A/duck/England/36254/14 and A/Chicken/Netherlands/14015526/2014, while the N8 was most closely related (1373/1377) to A/eurasian wigeon/Netherlands/emc-1/2014, A/eurasian wigeon/Netherlands/emc-2/2014, A/Chicken/Netherlands/14015526/2014, and A/turkey/Germany-MV/R2472/2014. The closest relationships were with isolates from The Netherlands which was expected because of the geographic proximity.
According to FLI H5N8 confirmed ducks in Emsland, which is even closer to The Netherlands, as well as a dead mallard in Aken which is in Anhalt-Bitterfeld and 200 miles southwest of Emsland, signaling an increase in geographic spread and an acceleration of detection rates.
Germany had reported the first case of H5N8 in Europe, on November 4 in Heinrichswalde in northeast Germany which was followed by confirmation of H5N8 in a wild teal. The three recent confirmations identify continuing spread through wild birds as well as poultry infections in spite of enhanced biosecurity.
Similarly, H5N8 was confirmed on multiple farms and wild birds in the Netherlands and sequences have also been deposited at GISAID. More recently, H5N8 was confirmed in Italy and sequences were released, A/turkey/Italy/14VIR7898-10/2014.
All sequences are closely related to each other and November sequences from Japan (A/duck/Chiba/26-372-48/2014 and A/duck/Chiba/26-372-61/2014), signaling a dramatic geographic expansion.
The expansion increased with reports of H5N8 in four dead pet falcons in Lynden, Washington, who had eaten a widgeon caught near Wiser Lake, as well as a backyard holding in Winston, Oregon where there were 100 chickens and guinea fowl. Although sequences have not been released for the US infections, the H5 and N8 were closely related to Genbank sequences from South Korea, confirming the close relationship to the above sequences.
In addition to H5N8, the US and Canada have reported H5N2. The first US sequence was from a northern pintail, which was part of a massive die-off at Wiser Lake. H5N2 and aspergilliosis were identified in dead ducks (about 600), but additional confirmations of H5N2 are expected. These sequences will likely be closely related to sequences in British Columbia, where H5N2 has been confirmed in 11 farms, including a cluster located 7 miles north of Wiser Lake.
H5N8 has 3 gene segments from Fujian clade 2.3.4 H5 (H5, PA, MP) and the H5N2 has 5 gene segments from H5N8, including Fujian H5 as well as 3 wild bird North American segments, including N2. More H5N2 and H5N8 infections in Canada and the US are expected in the near term.