Zoonosis

Any infectious or parasitic disease of animals that can be transmitted to humans. Unlike many disease organisms, zoonotic organisms are flexible and can adapt themselves to many different species. Zoonoses are usually caught from animals closely associated with humans, either as pets, food sources, or scavenging parasites, such as rats. Examples include toxocariasis, cat-scratch fever, some fungal infections, psittacosis, brucellosis, trichinosis, and leptospirosis. Rabies can infect virtually any mammal, but dog bites are a common cause of human infection worldwide. Other zoonoses are transmitted from animals less obviously associated with humans, usually by insect vectors. For example, yellow fever is transmitted by mosquito bites. (See also dogs, diseases from; cats, diseases from; rats, diseases from; insects and disease.)