Re: H5N1 in India
The report is that samples from three poultry workers from 2002 are
"positive" for H5N1, apparently confirmed by the CDC. I'd hold off
judgement just yet as we have yet to see any confirmation from the
CDC. I'm surprised the ProMED moderators took it so seriously at this
stage. Furthermore, no birds are reported to have gotten sick, and
nor have the three poultry workers, so even if it was H5N1, it clearly
wasn't a highly pathogenic form of the virus. This is yet to become a
real story (not to say it won't though).
Damien
posted by Damien @ 8:36 PM
1 comments
1 Comments:
I'm not surprised. H5N1 isn't highly pathogenic for all birds (ducks, geese, for example) but it is for others (chickens, turkeys). The key to HPAI is presence of polybasic amino acids at the cleavage site of HA0. That site is normally fairly narrow but in HPAI H5N1 the presence of "extra" aminoacids widens it out so that more proteases can cleave it into HA1 and HA2, a necessary event for infection.
Pathogenicity is not a feature of the organism, however, but of the agent and the host combined. Given the virulence of poultry H5N1 in humans, I am not at all surprised ProMed took it seriously.
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