Rabies is a viral infection that is transmitted through the saliva or, rarely, by way of dried and aerosolized fecal matter of infected mammals. Normally, humans contract rabies by being bitten by an infected animal. It’s also possible, however, for infection to pass through mucous membranes, such as the eyes or lining of the mouth, if contact is made with infected saliva. Rabies infections typically incubate for up to three months, during which time there are no symptoms and treatment with rabies vaccination is highly effective. Once symptoms develop, however, treatment is no longer an option.
Discomfort
The first clinical symptoms of rabies are flu-like, according to the U.S. Centers for Disease Control and Prevention, or CDC. These include fever, fatigue, generalized aches and pains, and possibly an itchy or uncomfortable sensation at the site of the bite. Rabies travels through the nervous system from the site of infection toward the salivary glands and from there, infects the brain. As such, symptoms often develop in a similar order. Flu-like symptoms generally persist for several days and then may begin to resolve only to be replaced by other symptoms as the disease progresses.
Hydrophobia
One classic symptom of rabies, hydrophobia, is so associated with the disease that it has become a synonym for the illness. While rabies doesn’t truly cause fear of water, it causes intense salivation, coupled with spasming of the muscles of the throat. This makes swallowing both difficult and uncomfortable, notes MayoClinic.com. Humans and mammals respond rapidly to conditioning, and if a behavior or object is repeatedly associated with pain or discomfort, they learn to avoid and even fear it. As the act of drinking becomes increasingly painful, humans infected with rabies begin to fear water on a deep, instinctive level. This symptom eventually progresses to the point that even bathing or showering can bring on throat spasms and feelings of fear.
Cognitive Changes
In the last throes of rabies, humans experience intense hallucinations, significant changes in affect and personality, and agitation. The CDC notes that cognitive changes are among the last symptoms of rabies to appear and signal that death is rapidly approaching. Unfortunately, treatment of rabies symptoms is purely supportive—according to the CDC, there are fewer than 10 documented cases of human survival once symptoms of rabies appear. Drugs and medical intervention, however, can make death from rabies more comfortable and less frightening for an infected individual.
