Where was we? Oh yeah.
The 3 elements of influenza evolution.
The mixing bowl and intercontinental transport: the wild mallard and a few other species of intercontinental travel. (Have to not have any immune reaction to influenza, other wise dead birds don't fly very far. Exception, H5 is so pathogenic that even the transport birds seldom complete their migration before mounting some sort of reaction. Remember, with influenza it is not the VIRUS that kills, it is the body's immune reaction that kills the patient.)
The ultimate recipient of interest to us, meaning, us, humans.
The middle man species- swine, domesticated ducks, turkeys, ferrets, chickens, crows, grouse, some pigeons. They have to have both upper respiratory receptors for human and the migrating, mixing bowl species. If not they, the virus selected can not be guaranteed to infect humans. THIS is why we have not had a bird flu, H5, pandemic yet.
Over 460 persons have been infected with H5 thus far but this is due to the heavy innoculum received from long time proximity to the infected domesticated birds & ducks. So heavy is the infection that it has to reach the lower respiratory receptors in sufficient quantity to cause infection.
The same probably occured with some of the H1N1 with the slaughter houses in Mexico and in Canda on the swine farms.
Remember, contagious goes both ways, swine/bird to human and human to swine/bird. BIG danger on swine farms for true reassortment in pigs naive to this novel H1N1, or in visiting wild ducks among the herds. It has been clearly documented to occur humans to chickens.
Now, that is an awful lot. Get me back on track. Does any of this apply to your topics? If not, please excuse my ramblings.
