A zoonosis is an infectious disease that can be transmitted from animals to humans and vice versa.
The majority of all pathogens that can cause disease in humans are transmitted from animals to humans. Causative agents can be viruses, bacteria, parasites
, worms or prions. Infection is via direct contact with animals, contaminated food or via vectors such as ticks and mosquitoes. Examples of zoonoses are BSE, the plague, malaria