Thanks for the post.
Rather odd paper, to me.
– take a virus (the h5n1 variant, or part of the current family of variants) that’s known to kill a range of species, from flamingoes through ducks and geese and crows, to tigers, cats and humans, iinfect some captive songbirds with it, and discover that Hey, they (mostly) die.
Yes, I believe you’re broadly right about the route to humans. (Various literature indicates this.)
Seems what you need for flu that can threatens human is:
1. Take Highly Pathogenic Avian Influenza (or even mildly pathogenic) from wild birds – where it causes few or no apparent problems; and cannot infect humans.
2. Introduce to farming, maybe from ducks taken captive, maybe from wild ducks that mix with captive.
3. Allow it to evolve; perhaps in poultry (for reasons in above post, wild junglefowl maybe had little flu, so a species barrier).
Maybe some more evolution in pigs – till recently, I believe this had been thought crucial to get a flu that could infect humans.
4. If conditions right, Presto! – you get a virus strain/variant that can cause problems in humans too. (From what I recall of stuff I’ve read, maybe this has led to waves of flu outbreaks/pandemics, which could be dangerous as a new virus for us to deal with.)
Extra step 5, for h5n1: vaccinate poultry. If New Scientist right, this allows the new n nasty virus – “superflu” New Sci dubbed h5n1 variant – to smoulder in poultry, bit like a peaf fire it appears.
This way, you have a new virus at the end of all steps – something that was never present in wild birds.
So, I’d suggest that saying “wild waterfowl are regarded as the primordial reservoir hosts of these viruses..”
is somewhat akin to saying “rocks are regarded as the primordial source of nuclear weapons”
Question, though, is whether once introduced from poutry to wild birds, the new superflu can be transmitted by them.
Evidence so far: no. It can kill them, for sure. Maybe they can transmit locally, but this hasn’t been proven.
But so far, wild birds haven’t been efficient vectors of h5n1 variant, while poultry industry has spread it around much of Asia just fine.
(Russia situation unclear; but more info needed. Should, however, wonder why Russian outbreaks not reported till July – by which time, migratory birds should be ready to fly south [not birds hopping north from Qinghai]).
Remember, too, wild birds don’t vote, have little economic importance, v little strategic importance.
All factors v different to poultry industry.
So, wild birds make easy scapegoats. Readily blamed by arm-waving. (Yet I watch, too, for reports as Qinghai birds move south. My guess: h5n1 will have burned out amongst them by then. But, a guess.)