Housefly

Flies are a transmission vector for over 100 pathogens.

An excerpt from the article 22 facts about Housefly
Because they can travel up to several miles from their breeding sites, they spread various diseases and parasites found on fly body hairs, mouthparts, vomit, and feces. The pathogens spread by flies cause typhoid fever, cholera, salmonellosis, dysentery, tuberculosis, anthrax, and ocular inflammation.