I appreciate the humor but I think your initial comparison is pretty bad.
Wild pigs don’t depend on waste from humans. They’re invasive to the Americas, sure, but there is a huge difference between hunting an invasive species that is wreaking havoc in the ecosystem (and possibly going through your “waste”) versus raising domesticated pigs in abysmal conditions — and all other associated negative consequences — for a market with inflated demand.
Also, the issue with H1N1 is, again, mostly due to farming.
So, no, pigs inherently aren’t “almost parasites” and although they can get diseases, like all animals, the threat of transmitting those diseases to humans come from farming practices.
Mosquitoes are consequential and our relationship with pigs is largely voluntary. The difference is enormous.