She said the work "duck" probably originates from the Anglo-Saxon term ducas, used to show someone respect.
An initial investigation suggested that the duck corpses had originated from upstream and were not dumped by local Pengshan farmers, he said.
Its source has not yet been identified, but a study published in The Lancet suggested H7N9 was a mix of at least four viruses that originated in ducks and chicken.
Instead, infected duck meat, possibly originating from the German duck-fattening farms affected by the outbreaks in August 2007, might have caused these cases.
Common ducks are believed to have originated from the Mallard (Anas platyrhynchos).
Finally, 5 low-pathogenicity AIV were isolated: 3 distinct isolates that originated from garganey ducks sampled in the Inner Niger Delta in Mali (H5N3, H11N9, H12N5) and 2 isolates that originated from white-faced whistling ducks sampled in Ethiopia (H8N4) and Senegal (H1N1).
The HA gene might have originated from avian influenza viruses of duck origin, and the NA gene might have transferred from migratory birds infected with avian influenza viruses along the east Asian flyway.
No influenza virus (H5N1) was detected by RT-PCR from the raw duck blood and chicken hearts saved in the patient's home refrigerator or at the poultry seller where the duck blood and chicken hearts originated.
Considering the growing number of ND cases in ducks in recent years, some of the naturally occurring NDV virulent strains already have certain capability to produce disease in ducks, and, no matter where the viruses originated or how they mutated, the prevention of their spread in ducks should receive more attention and research in terms of preventing the occurrence and prevalence of ND.
Sequence data indicated that the hemagglutinin gene of this novel subtype H7N9 virus might originate from a subtype H7N3 virus in ducks and that the neuraminidase gene probably originated from a subtype H7N9 virus in wild birds (5 ) or ducks or chickens (6, 7 ).
