Eugene, thanks for raising this questions. It has been proven that seagulls carry drug resistant E.Coli according to this article:
Times-Tribune, Scranton, PA
Letter to the Editor
Bird flu concern
Editor: The Wall Street Journal reported that highly contagious bird flu has infected turkey farms in Arkansas and Missouri.
Given that garbage landfills attract tens of thousands of seagulls, what assurance do we have that these birds are not introducing a risk of avian flu to Northeast Pennsylvania?