What is rabies?
Rabies is a serious virus, transmitted through the bite of a rabid animal. In humans, the virus affects mainly the brain and the nervous system, almost always resulting in death once symptoms develop. Rabies is found in many countries worldwide, though rates tend to be highest in developing countries in Asia and Africa. Globally, around 60000 people die from rabies every year and half of these are children. Children are at highest risk of infection as their developmental level and height leave them more vulnerable to bites. Other at risk groups include hikers in endemic countries, vets, military and wildlife personnel.
How can I get it?
Though all mammals are vulnerable to rabies infection, the most common source, particularly in developing countries is the dog. In the United States, dogs are not commonly associated with rabies, instead bats, foxes and raccoons carry the disease. The rabies virus is usually passed to humans through the bite of an infected animal, though more rarely, infection can occur as a result of a scratch, lick over an open wound or the mouth or eyes. In extremely rare cases, transplanted organs may carry the virus, passing this on to the recipient.
What are the effects?
The virus enters the nervous system where it replicates and damages the nerves and brain tissue. Here it may also hide from the body’s immune cells so that they cannot eliminate the virus. This may occur any time from 5 days – 7 years after being exposed to the virus. Once the virus has replicated, it may damage the spinal cord and enter the salivary glands so that it may be transmitted to the next host.
Symptoms of rabies are severe and include hydrophobia (attempting to drink or being presented with liquid causes spasm of the throat muscles), limb numbness, pain or tingling, itching, fever, pain on swallowing, change in behaviour, agitation, confusion, hallucination, paralysis, seizure and coma. Many symptoms represent the affect the virus has on the nerves and the brain. Patients presenting with symptoms most commonly do not survive longer than 18 days from the onset of symptoms. Those that have survived (less than 10 reported cases), have required critical care and have been left with severe disabilities.
How is it treated?
Rabies is treated with a dose of specific rabies antibodies, known as rabies immunoglobulin which helps the immune system neutralise the virus and stop it replicating. Additionally, a rabies vaccine is given, which helps the immune system eliminate the virus. Even though the disease is severe and highly fatal, human rabies is 100% preventable through efficient access to healthcare. Additionally a pre-exposure vaccination exists, Rabipur, which reduces the number of rabies vaccine doses needed after exposure from 5 to 2. Rabies immunoglobulin is also not needed when the individual has already had a pre-exposure vaccination. Though the vaccination does not eliminate the need for treatment after exposure to the rabies virus, it is particularly useful and important in those people who are at high risk of exposure (e.g vets, hikers, travellers in endemic regions) and who may not have prompt access to healthcare services. In many developing countries and in particularly remote areas, it may be very difficult to get hold of rabies immunoglobulin quickly.
You can also prevent rabies infection by avoiding wild animals. If you are bitten, you should promptly clean the wound by washing it under a cold tap, use alcohol or antiseptic if available and travel immediately to the nearest hospital or medical centre and explain that you may have been exposed.