Unless you want to stop all international travel, blaming the spread of what doesn't appear to be a contagious disease on illegal aliens is absurd.
If and when bird flu becomes contagious among humans, this forum will blame it on illegal aliens. No doubt about it.
And in your ideal world there are no controls to isolate any sneezing, snot dripping, open sore oozing pus bags from working in food prep?
Drug-resistant TB worries officials [Mexico, S. Texas]
An illegal alien has a brush with death--and gets up to work again A social worker tracked down the friends and relatives who came to the U.S. with him.