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New H5 Outbreaks in Turkey Raise Surveillance Concerns
Recombinomics Commentary
December 28, 2005
Avian influenza due to virus subtype H5 was reported in four backyard flocks in the village of Köprüler, Aralik, Igdir province. The outbreak is located 7 km far from Armenia, 15 km from Iran, and 40 km from the Nakhichevan Autonomous Republic, Azerbaijan.
The above comments from the OIE Emergency Report from Turkey signal a new outbreak just north of the Middle East and raise additional concerns about surveillance and reporting by countries in the area.
Approximately 1200 out of 1559 poultry (chickens, geese, turkeys, and ducks) in the area have died, strongly indicating that the H5 detected was H5N1. Media reports have suggested that wild bird migrating south from the Caucasas have touched off the outbreak, which began on December 15.
There has been recent H5N1 activity reported in swans in the Volga Delta area (Astrakhan and Kalmykia) this month and wild birds from that area would be migrating south across the Middle East. However, the H5N1 isolated from the Volga Delta may be somewhat different than the H5N1 wildly detected in Siberia and Europe. Some reports indicate the recent Volga Delta isolates are more closely related to 2002-2003 H5N1 isolates from Vietnam which had a slightly different HA cleavage site (REIRRKKR) than the other wild bird linked isolates (GERRRKKR). I recent OIE summary from Russia indicated that all H5N1 from domestic poultry in Russia had the GERRRKKR cleavage site and were genetically similar to the Qinghai Lake isolates, which also had the HA cleavage site sequence, GERRRKKR.
However, the Ukraine and Romania have also cited new H5N1 outbreaks this month. The reported outbreaks in the Ukraine have been throughout the Crimea peninsula. Sequencing done in Russia identified a RERRRKKR cleavage site on a genetic background similar to the Qinghai Lake isolates. These data indicate some of the isolates in the Ukraine are unique and are recombinants. The RERRRKKR cleavage site is the most widely reported sequence in Asia, but has not previously been reported outside of Asia. Moreover, the isolates on the Crimea peninsula cause death in poultry 2-8 hours after symptoms and blindness has been reported in ducks ands geese.
As noted above, the latest report from Turkey is for an outbreak in a border region close to Armenia, Iran, and Azerbaijan. None of these countries has previously reported H5N1 outbreaks. The lack of reports for countries close to the additional outbreaks is also noteworthy. H5N1 has been detected in at least one swan in Romania that was banded in Hungary, but Hungary has never reported H5N1 outbreaks. Similarly, most of the Romanian outbreaks have been in or near the Danube Delta, half of which belongs to the Ukraine, yet all of the H5N1 Ukraine reports have been for outbreaks on the Crimea peninsula. Romania has also warned Bulgaria that H5N1 positive wild birds are migrating south from Romania to Bulgaria, but Bulgaria has never reported H5N1.
Many of the birds in the regions surrounding the Black and Caspian Seas migrate through the Middle East to Africa for the winter. However, none of the countries in the Middle East or Africa have filed OIE reports for H5N1, which is a reportable disease in animals.
Thus, the reports of H5N1 outbreaks this month in Romania, Ukraine, Volga Delta, and Turkey signal additional movement of H5N1 in Europe and raise serious questions about the surveillance and reporting methods of nearby countries in Europe, the Middle East, and Africa,
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