we know it gets in the sewage, and we know there's fish swimming nearby. therefore....
with chickens (who should really be called chickii in context), it seems easy enough that they'd get it from feed, or maybe somebody handling them. that's not a difficult thought; that's obvious, and you have the burden of proof to demonstrate why it can't happen, if you're convinced.
further, if the thing gets frozen quickly, it could
it's another thing to think you can catch the virus by eating infected but cooked flesh, which is probably wrong.
you should be wearing gloves and taking proper precautions with uncooked chicken, regardless.
but, is it possible? i'd say it's highly likely, at this stage.