[My backlog. April 2006]
But there are dozens of strains of bird flu in circulation in the wild, Kida told delegates at the meeting, organised by The Lancet. In a four year study, which is still ongoing, he and colleagues isolated bird flu subtypes from over 10,000 samples of faecal matter from wild ducks in Alaska, Siberia, Mongolia, China and Japan. The frozen samples were collected from lakes during the winter. The researchers found 49 different bird flu strains.
And when they experimentally infected pigs with these bird flu strains, many of them underwent genetic reassortment. Pigs are thought to act as a “mixing vessel” for flu and other diseases, where new combinations of genes from different strains can come together. The team has also created 76 other flu subtypes in the lab by genetic reassortment.
They have 123 combinations of H and N subtypes stocked as potential vaccine strain candidates. Kida believes these may be “invaluable” as potential vaccine strains and also for diagnostics. “Any subtype could get into humans,” he says.
Overall, scientists have isolated every bird flu subtype – H1 to H15 and N1 to N9 –from ducks which remain symptom-free, says Kida.”
- http://www.newscientist.com/channel/health/ bird-flu/dn9101-theres-more-than-one-bird-flu-experts-warn.html