Rabies is a viral disease that causes acute inflammation of the brain in humans and other warm-blooded animals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear it nearly always results in death. The time period between contracting the disease and the start of symptoms is usually one to three months; however, this time period can vary from less than one week to more than one year. The time is dependent on the distance the virus must travel to reach the central nervous system.
Rabies is caused by lyssaviruses including: rabies virus and Australian bat lyssavirus. Rabies is spread when an infected animal scratches or bites another animal or human. Saliva from an infected animal can also transmit rabies if the saliva comes into contact with the mouth, nose, or eyes. Overall dogs are the most common animal involved. More than 99% of rabies cases in countries where dogs commonly have the disease are caused by dog bites. In the Americas, bat bites are the most common source of rabies infections in humans, and less than 5% of cases are from dogs. Rodents are very rarely infected with rabies. The rabies virus travels to the brain by following the peripheral nerves. The disease can only be diagnosed after the start of symptoms.
Animal control and vaccination programs have decreased the risk of rabies from dogs in a number of regions of the world.Immunizing people before they are exposed is recommended for those who are at high risk. The high-risk group includes people who work with bats or who spend prolonged periods in areas of the world where rabies is common. In people who have been exposed to rabies, the rabies vaccine and sometimes rabies immunoglobulin are effective in preventing the disease if the person receives the treatment before the start of rabies symptoms. Washing bites and scratches for 15 minutes with soap and water,povidone iodine, or detergent may reduce the number of viral particles and may be somewhat effective at preventing transmission. Only a few people have survived a rabies infection after showing symptoms and this was with extensive treatment known as the Milwaukee protocol.
Rabies causes about 26,000 to 55,000 deaths worldwide per year. More than 95% of these deaths occur in Asia and Africa.Rabies is present in more than 150 countries and on all continents but Antarctica. More than 3 billion people live in regions of the world where rabies occurs. A number of countries including Australia, Canada, Japan, Malaysia, the United States, and Western Europe do not have rabies among dogs. Many small island nations do not have rabies at all.