All warm-blooded species, including humans, may become infected with the<unk>  virus and develop symptoms. Birds were first artificially infected with<unk>  in 1884; however, infected birds are largely, if not wholly, asymptomatic, and recover. Other bird species have been known to develop<unk>  antibodies, a sign of infection, after feeding on<unk> -infected mammals. The virus has also adapted to grow in cells of cold-blooded vertebrates. Most animals can be infected by the virus and can transmit the disease to humans. Worldwide, about 99% of human<unk>  cases come from domestic dogs. Other sources of<unk>  in humans include bats, monkeys, raccoons, foxes, skunks, cattle, wolves, coyotes, cats, and mongooses (normally either the small Asian mongoose or the yellow mongoose).<unk>  may also spread through exposure to infected bears, domestic farm animals, groundhogs, weasels, and other wild carnivorans. However, lagomorphs, such as hares and rabbits, and small rodents, such as chipmunks, gerbils, guinea pigs, hamsters, mice, rats, and squirrels, are almost never found to be infected with<unk>  and are not known to transmit<unk>  to humans. Bites from mice, rats, or squirrels rarely require<unk>  prevention because these rodents are typically killed by any encounter with a larger, rabid animal, and would, therefore, not be carriers. The Virginia opossum has a lower internal body temperature than the<unk>  virus prefers and therefore is resistant but not immune to<unk> . The virus is usually present in the nerves and saliva of a symptomatic rabid animal. The route of infection is usually, but not always, by a bite. In many cases, the infected animal is exceptionally aggressive, may attack without provocation, and exhibits otherwise uncharacteristic behavior. This is an example of a viral pathogen modifying the behavior of its host to facilitate its transmission to other hosts. After a typical human infection by bite, the virus enters the peripheral nervous system. It then travels retrograde along the efferent nerves toward the central nervous system. During this phase, the virus cannot be easily detected within the host, and vaccination may still confer cell-mediated immunity to prevent symptomatic<unk> . When the virus reaches the brain, it rapidly causes encephalitis, the prodromal phase, which is the beginning of the symptoms. Once the patient becomes symptomatic, treatment is almost never effective and mortality is over 99%.<unk>  may also inflame the spinal cord, producing transverse myelitis. Although it is theoretically possible for<unk> -infected humans to transmit it to others by biting or otherwise, no such cases have ever been documented, because infected humans are usually hospitalized and necessary precautions taken. Casual contact, such as touching a person with<unk>  or contact with non-infectious fluid or tissue (urine, blood, feces), does not constitute an exposure and does not require post-exposure prophylaxis. But as the virus is present in sperm and vaginal secretions, it might be possible for<unk>  to spread through sex. There are only a handful of recorded cases of human-to-human transmission of<unk> , and all occurred through organ transplants from infected donors.
Rabies
Tomato fever
Scabies
Mumps
Barcoo fever
Polymeal
Spanish flu
Tongue disease