A few points about the H5N1 outbreak that I'd like to share.
1. If we had a pan-influenza wastewater screen in place nationally that differentiates the influenza sources by sequencing (which isn't that hard to do), we probably would have detected this outbreak months ago.
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BTW, we submitted a CDC proposal earlier this year to do exactly this, but the topic was pulled from the BAA so the proposal wasn't even reviewed.
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2. We should not panic about the current outbreak in cattle. You aren't going to get influenza from pasteurized milk, and this virus isn't ready for human-to-human spread (yet).
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3. What we should be concerned about is that fact that the viruses is getting way too many chances. It keeps expanding its tropism. The more animals it replicates in, the more chances it gets to sample new configurations.
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4. When the virus makes it way it to pigs, that is when we need to start getting really nervous. Pigs are a mixing vessel where flu is more likely to adapt to respiratory spread in humans.
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5. In my opinion we should be focusing our attention on wastewater testing downstream of meat processing plants (for all types of animals). It wouldn't matter what tissue the virus is in, it would end up in the water and give us an early warning.
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We've detected and sequenced pig influenza from such sewersheds before (not H5N1), so I know it can work.
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6. Most important, we shouldn't shy away from surveillance because we want to avoid a panic. There is still time to stay ahead of this, but if we aren't careful I think it's just a matter of time before H5N1 makes it to humans.
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First, I think I was wrong about the lineage being JN.1 derived. I thought it was JN.1 because it had 22926C (455S), but it looks like it only acquired that recently.
In samples as recent as December the lineage lacked 455S and 456L. 2/
That would mean the lineage is BA.2.86-derived, which suggests it was acquired probably early 2024.
Caveat, as @LongDesertTrain points out, persist infections hate 455S. It’s possible that the lineage was JN.1, but reverted at 455, but then gained 2 nt creating 455A. 3/
Wastewater variant update. This is the composite data from over 1,000 US samples collected over the last 6 weeks. 1/
You have to extrapolate a little bit because several changes are shared by multiple lineages.
It appears that the new lineage I mentioned last week (MC.10.1 + 445P) is around 4% and is the fastest growing of the lot. It now has a PANGO designation - PA.1
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LP.8 is still expanding is is probably about 12% now. Since it is a KP.3.1.1 derivative, KP.3.1.1* might become dominant again.