Via CIDRAP, Lisa Schnirring summarizes an eventful day: China reports 4 more H7N9 infections. Excerpt:
Les Sims, BVSc, an Australia-based animal health consultant with extensive experience with avian flu in Asia, told CIDRAP News that it's still too early to draw firm conclusions about the virus, but the history of avian flu viruses in the region and the apparent pattern of the human cases suggest that some or even most of the cases are likely the result of virus transmission from animals to humans.
Sims said his early review of genetic evidence in the public domain strongly suggests that the virus originally came from poultry. "In my view, it is only a matter of time before infected poultry will be detected," he said.
Avian infections with low-pathogenicity H7 viruses with a different neuraminidase (N) subtype have been reported in China and the broader region in the recent past, but genetic information suggests that the H7N9 virus marks the first detection of an H7 virus with internal genes from H9N2 viruses.
"The evidence I have seen suggests the virus is probably a low pathogenicity strain for poultry and if circulating in poultry would not necessarily be causing severe disease, which has implications for surveillance programs," Sims said. In contrast, mass poultry deaths in H5N1 are events that signal an imminent threat to humans.
Sims said he's not aware of any poultry vaccination programs for H7 viruses in Asia, except for Pakistan, where vaccines were used to battle a highly pathogenic H7 virus.
