Many zoonotic diseases, particularly those which then are passed from human to human, have originated in wild animals. A few are still acquired directly from the animals. HIV and SARS-CoV-2 are two examples of viruses that originated in wild animals but now are epidemic among humans. Table 3 provides examples of those that can still be acquired directly from the animal host.
Table 3. Zoonotic Diseases from Mammals.| Disease | Description | Animal Sources |
| Plague | Cases of plague caused by Yersinia pestis still exist in the western US. This disease causes severe flu-like symptoms, diarrhea, bleeding, vomiting, along with other symptoms. It can also be transmitted to pets. The diagram below shows plague ecology in the US. | Rodents and their fleas; also rock squirrels, prairie dogs, and others |
| Rabies | Lyssavirus sp. is transmitted via direct contact with an infected animal's saliva or with contact with animal brain/nervous system tissue. It has a complex life cycle causing flu-like symptoms but then cerebral dysfunction. Almost all cases are fatal without early treatment. | All mammals, especially bats, raccoons, skunks, and foxes in the US |
| Hanta Virus | People can be infected after contact with animals or their droppings. It can cause a severe respiratory disease called Hantavirus Pulmonary Syndrome, or hemorrhagic fever. Not usually found in the US. | Cotton rat, deer mouse, rice rat, and white-footed mouse |
| Giardiasis "Beaver Fever" | Giardia sp. is a protozoan parasite that can be carried by many animals and transmitted by the fecal-oral route. It causes diarrhea, cramps, and fever, but some people have no symptoms. | Beavers, coyotes, rodents, pets, and people |
