06.08.2014

Emerg Infect Dis vol. 20 (9) - September 2014

To date, 18 hemagglutinin (HA) subtypes and 11 neuraminidase (NA) subtypes have been identified in influenza A viruses. Influenza A viruses containing HA subtypes 1–16 circulate in aquatic birds, whereas those harboring HA subtypes 17 and 18 are found in bats.
On January 18, 2014, the government of South Korea reported an outbreak of highly pathogenic avian influenza A(H5N8) virus in breeding ducks in the southern part of Jeollabuk-Do Province. More than 12 million poultry have since been culled, but the spread of the virus continues in duck and chicken farms. South Korean researchers conducted a BLAST (Basic Local Alignment Search Tool) search to identify the closest gene sequences of H5N8 isolates collected from waterfowl droppings in the area where the outbreak began. They compared viruses from wild birds with those from affected poultry.
The scientists surmise that, because all eight genes of the waterfowl are closely related to an isolate from a duck farm, the recent H5N8 avian influenza outbreaks in South Korea were likely the result of introduction of the virus from wild birds to farm poultry.