Humans unlikely to infect poultry with H7N9? Data please!

The United Nations Food and Agriculture Organization (FAO) has said that poultry is not at risk of being infected by humans carrying H7N9 virus.

In fact, we have no evidence that affected people could transmit the virus to other species, including birds. The highest risk of virus introduction is uncontrolled live poultry trade between affected and unaffected areas.

But absence of evidence is not evidence of absence.

We have seen studies, like this one, that use a human H7N9 virus and use it to successfully infect chickens. So the virus is capable of replicating even if it is inefficient at spreading to other chickens or even ferrets ( a human surrogate of influenza infection). But then we do know that humans get infected from exposure to something in poultry markets.

I agree (for what that's worth), that the risk of spreading virus is more in the area of moving infected birds around, as well as their own migration movements. But I think it is too early be early to issue strong denials that humans may infect poultry until we find some data to support them.

Sources...

• CIDRAP article.
  http://www.cidrap.umn.edu/news-perspective/2014/02/china-reports-one-h7n9-case-fao-says-human-illnesses-arent-threat-poultry
• H7N9 transmissibility article
  http://www.sciencedirect.com/science/article/pii/S0042682213006855
• FAO statement
  http://www.fao.org/news/story/en/item/214244/icode/

Sunny summer or birds on the wing?

I'm no ornithologist. Week 7 had much to say about the approaching summer scaring away the H7N9 virus and the closure of live bird markets having stunted or stopped entirely the outbreak. 

I'm still not convinced - as I said yesterday. 

A continuation of that line of thinking, posed as question for today then; could the spread of H7N9 have peaked and fallen in relation to the travels of wild birds, not poultry? The paltry number of positive poultry cases could have acquired their virus from wild birds also. 

Also, how many of the males infected with H7N9 kept small birds as pets? Did any of them get those birds recently? Passerine birds, like the brambling, cover some distances when migrating with the seasons. The brambling also turned up amongst as co-contributor (of an H9N2) to H7N9's genetic makeup.

Birds are a rare duck with H7N9 infection...

Very few bird samples have tested positive for H7N9 (20 of 738 samples from Shanghai market birds).

Time to look beyond poultry?

H7N9 and a range of birds...

Influenza A H7N9 now found in pigeons, quail (at live poultry market in Huangzhou [NOT - see update. Ed. 16.04.13]) and chickens (subclinical disease).