Rabies

Rabies is a viral disease that causes inflammation of the brain in humans and other mammals. Early symptoms can include fever and abnormal sensations at the site of exposure, which are followed by nausea, vomiting, violent movements, uncontrolled excitement, fear of water, inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear, the result is virtually always death. The time period between contracting the infection and the start of symptoms is usually one to three months but can vary from less than one week to more than one year. The time depends on the distance the virus must travel along peripheral nerves to reach the central nervous system.

Rabies is caused by lyssaviruses, including the rabies virus and Australian bat lyssavirus. It is spread when an infected animal bites or scratches a human or other animals. Even in the absence of a bite or a scratch, saliva from an infected animal coming into contact with the eyes, mouth, or nose can transmit rabies. Rabies can also be transmitted through tears and nervous tissues. Globally, dogs are the most common animal involved. In countries where dogs commonly have the disease, more than 99% of rabies cases in humans are the direct result of dog bites. In the Americas, bat bites are the most common source in humans, and less than 5% of cases are from dogs. Rodents are very rarely infected with rabies. The disease can be diagnosed only after the start of symptoms, but prompt preventative treatment is recommended for anyone who has had contact with a rabid animal.

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 at high risk, including those 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. As of 2016, only fourteen people were documented to have survived a rabies infection after showing symptoms.

Rabies causes about 59,000 human deaths worldwide per year, about 40% of which are in children under the age of 15. More than 95% of human deaths from rabies occur in Africa and Asia. 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 and Japan, as well as much of Western Europe, do not have rabies among dogs. Many Pacific islands do not have rabies at all. It is classified as a neglected tropical disease. The global cost is estimated at US$8.6 billion per year in lost lives, medical care, and associated costs, besides the psychological trauma.