Your comments about reassortment are accurate, as far as they go.
Two influenza A viruses can easily co-infect the same host. Since they each have 8 gene cassettes on separate pieces of RNA, those pieces of RNA tend to get mixed up, or reassort. As long as the new virus has one of each gene cassette, it is potentially infective.
Not every reassorted virus is equally pathogenic or infective; some of them are duds. But others can be more deadly than either parent.
Influenza virus RNA also mutates, which can cause an avian influenza virus to slightly change from preferring to attach to bird cells to preferring to attach to human cells. The controversial “gain of function” experiments (Kawaoka and Fouchier) were looking at exactly which mutations cause that shift.
Many emerging influenza viruses are a result of both processes, reassortment and mutation. Swine are an ideal host for influenza, because bird and mammal adapted viruses can both attach within the pig upper respiratory tract, where they can reassort and mutate to become more infective to humans.
Influenza is a particularly nasty virus. Even a mild flu can kill. I just read about a healthy teenage girl who died in days from influenza. She had not been vaccinated.
Oh, and there is a completely new influenza in livestock, influenza D. So far, it has only infected pigs and cattle.
Quarantine Zones for Avian Flu in Benton & Franklin Counties
OLYMPIA, WA - The Washington State Department of Agriculture (WSDA) Wednesday adopted an emergency rule to establish a quarantine zone for avian influenza that includes parts of Benton and Franklin counties.
The area covers about 20 miles around two locations where avian influenza has been identified in flocks of mixed poultry and other birds.
The quarantine area will be in force for at least 240 days and restricts the movement of eggs, poultry or poultry products out of the identified zone.
Exemptions will be made for operations that obtain special permits and meet specific criteria.
On Jan. 2, WSDA activated a multi-agency response plan following the confirmation of highly pathogenic H5N2 avian influenza in domestic birds in a Benton County flock.
Later, a second infected flock was identified in the area.
Work was completed Jan. 6 at both locations to control the spread of the virus.
The joint team of WSDA and U.S. Department of Agriculture officials will now work to clean and disinfect the two sites.
USDA plans to increase the amount of testing of poultry and other domestic birds within an area identified as 10 kilometers around the two flocks.
WSDA has not identified any new cases of avian influenza.
The virus has not been found in commercial poultry anywhere in Washington or the United States.
WSDA is encouraging bird owners to protect their domestic birds from contact with wild waterfowl and remain vigilant in their biosecurity measures.
There is no immediate public health concern due to the avian influenza virus detected.
Avian influenza does not affect poultry meat or egg products, which remain safe to eat. As always, both wild and domestic poultry should be properly cooked.