Virology: Transmissibility of novel H7N9 and H9N2 avian influenza viruses between chickens and ferrets

[JJackson]

Re: Virology: Transmissibility of novel H7N9 and H9N2 avian influenza viruses between chickens and ferrets

Thanks. I looked at the links but I don't think the primary host is in the duck, poultry or wader groups but in something like the Bramling or some other bird group outside the classical water-fowl hosts. These are the ones I am not seeing in the sequence database - at least not in China post March 2013. All there is a few pigeons all sampled in the first few weeks of last seasons outbreak.

 

[Shannon Bennett]

Re: Virology: Transmissibility of novel H7N9 and H9N2 avian influenza viruses between chickens and ferrets

Not coming from infected chickens. Somehow that did not come as a big surprise to me. Can't find it in wild avian hosts....again not a big surprise. Not in ducks either. So where is it coming from? What do all of these people come into intimate contact with. Remember you have to have a high viral lode to become infected. Unless bramlings are ubiquitous visitors to cities in China, it would have to be something like sparrows, pigeons or dare I say it, mammals. Even sparrows are suspect as most people do not come into close enough contact to infect themselves. Nothing else makes sense.

 

[JJackson]

Re: Virology: Transmissibility of novel H7N9 and H9N2 avian influenza viruses between chickens and ferrets

Not coming from infected chickens. Somehow that did not come as a big surprise to me. Can't find it in wild avian hosts....again not a big surprise. Not in ducks either. So where is it coming from? What do all of these people come into intimate contact with. Remember you have to have a high viral lode to become infected. Unless bramlings are ubiquitous visitors to cities in China, it would have to be something like sparrows, pigeons or dare I say it, mammals. Even sparrows are suspect as most people do not come into close enough contact to infect themselves. Nothing else makes sense.

Shannon I think we are mainly getting it from chickens, I just do not think they are the primary host just unwilling intermediaries. I would like to see testing of any small birds (and mammals, rodents, cats etc.) that are present in and around poultry. Has anyone seen a pigeon transmission study?

 

[gsgs]

Re: Virology: Transmissibility of novel H7N9 and H9N2 avian influenza viruses between chickens and ferrets

I vaguely remember from spring 2013 that it was inefficient in pigeons
and we wondered why they were infected

------------------edit------------------------
Pathogenesis and transmission novel influenza A (H7N9) virus in poultry
M Pantin-Jackwood1*, P Miller1, E Spackman1, D Swayne1, M Torchetti2, L Susta1, D Suarez1
Results: ... Inoculation of the avian species examined with the
H7N9 virus resulted in infection of all species but no clinical signs. Virus shedding in quail,
chickens, turkeys, and Muscovy ducks was much higher and prolonged (≥ 10 dpi) than in
the rest of the species (≤ 6 dpi).
Quail effectively transmitted the virus to direct contacts but pigeons and Pekin ducks did not.
In all species, virus was detected at much higher levels from OP swabs compared with C swabs.
The HA gene and part of the PB2 gene from selected virus-positive OP swabs collected from chickens
and quail were sequenced to examine for changes in the virus after passage in these species.
All 8 samples examined had lysine at position 627 of the PB2 gene, similar to the parent human isolate.
However, 3 amino acid differences were observed in the HA compared with A/Anhui/1/2013: N123D,
N149D, and L217Q. The inoculum used in these experiments already contained D at position 123
and 149, but maintained the L at position 217. Four different combinations were observed in the
infected birds, indicating that most likely the inoculum had virus subpopulations that were
selected after passage in birds.

here is the pdf from a meeting in Capetown,Sep.2013, 59MB (takes some minutes to open),lots of articles
http://optionsviii.controlinfluenza.com/optionsviii/assets/File/Options_VIII_Abstracts_2013.pdf

Held every 3 years, Options for the Control of Influenza is the largest international scientific
conference exclusively devoted to influenza

 

[JJackson]

Re: Virology: Transmissibility of novel H7N9 and H9N2 avian influenza viruses between chickens and ferrets

Not pigeons then. Thanks