If the chicks hatch and have AI, then they wouldnt survive long. They could pass it to other birds in the flock though which is why there is a 30 day quarantine procedure where they should be placed by themselves for 30 days to see if they have any signs of sickness. If they do.... Well... They have to be incinerated. Even with all these import resrtictions, we still manage to have outbreaks in the US without a clear sign as to how they got it. USDA just cut off all poultry trades from every other country that has had a breakout within so long just as a precaution rather than 'because' they were the issue.
I don't think thats always the case, there are many different subtypes of avian flu. There was a recent outbreak of a H7N9 variety of avian flu on the borders of Vietnam and southern China. The main problem with that type is that it only mildly affected poultry and showed up when people started dying from being infected from their poultry. Thankfully doesn't look like this variety could transmit human to human as yet
http://www.nature.com/news/vietnam-on-high-alert-over-flu-risk-1.14764
Mixing strains and the genetic recombination of variants that could result could at some point bring a pretty disastrous event as i'm sure you're aware. We're coming up to the 100 yr anniversary of the spanish flu that killed between 50-100 million and we're probably due for another event in the not too distant future. That was an avian virus that mixed in swine and picked up some nice variants that allowed it to do direct human to human transfer.
Theres a big problem especially in southern california with it being an entry point of disease from foreign lands as its such a large transit point and people from all over the world. There was a recent case not in poultry but affecting the citrus industry where someone decided that it would be cool to bring in a variety of pommelo which is a variety of citrus thats preferred in the asian community from China. This small piece of twig that they then grafted onto a rootstock to create a larger tree brought in citrus greening disease and has resulted in a quarantine area in the san Gabriel valley. It has the potential to devastate the states citrus industry just as its done in Florida with billions lost. No known cure as yet.
http://www.latimes.com/business/la-fi-citrus-greening-quarantine-20150722-story.html
beyond avian flu theres probably a few other diseases that could be imported through un regulated egg imports. I can think of egg drop syndrome but I'm sure there are others.
http://www.poultryhub.org/health/disease/types-of-disease/egg-drop-syndrome-or-eds/
Thats why the USDA has a permit system and I hope that if this person wants to import this variety that they do it legally that way once the ban on Vietnam imports has been lifted.
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