September 28 has been World Rabies Day. It has been recognised as such by the United Nations and marked every year since 2007. The campaign is coordinated by the Global Alliance for Rabies Control. The day has been chosen as the World Rabies Day because it is the death anniversary of Louis Pasteur, who developed the first rabies vaccine.
Rabies is an incurable disease that causes inflammation of the brain and eventual death. There is no way to stop or retard the progression of the disease once it has begun, and death almost always results within two weeks. The disease causes up to 55,000 deaths annually. Therefore, effective vaccination is necessary to counter the threat of contracting rabies.
Rabies is caused by the bite of an infected animal, such as a dog or a bat. In India, rabies is caused mainly by non-vaccinated stray dogs, while in advanced countries, bats cause rabies far more often. However, the incidence of rabies in India and the rest of the subcontinent is far higher. This is due to ignorance about the disease, which means people often do not take prompt treatment after a dog bite. Also, there is an large population of stray dogs in most parts of India which exacerbates the problem. Vaccination at private clinics is expensive, but in public hospitals it is usually free of charge.
The problem with rabies is that symptoms do not usually occur immediately, but vaccinations must be taken within 48 hours (and an absolute maximum of a week) to prevent rabies from occurring after a dog bite. The symptoms (if post-exposure treatment is not taken promptly and correctly) usually manifest within one to three months, though there have been cases of symptoms occurring within a week, and after six years. The time lag between the bite and symptoms happens because the rabies virus must reach the central nervous system before the occurrence of symptoms. Additionally, it is thought that the distance of the place of bite from the brain and spinal cord also determines the period of onset of symptoms.
According to WebMD, rabies symptoms initially feel like influenza. They include fever and tingling at the site of exposure (the bite). After a few days, the person may develop violent movements, fear of water (hydrophobia), paralysis of the body, inability to consume food, confusion, loss of consciousness and an urge to bite others. Paranoia, anxiety, double vision and hallucinations also may occur. The end result is almost always death.
Rabies is present in the nerves and saliva of an infected animal. While human beings usually cannot fight a potential rabies infection without medication, some bird species have been known to develop antibodies and recover from the disease.
In humans, rabies transmission occurs mostly through dog or bat bites. Other animals like monkeys, raccoons, foxes, skunks, cattle, wolves, coyotes, dogs, mongooses and cats can also cause rabies. There have also been incidences of organ transplant from an infected donor causing rabies to the receiver, but this is extremely rare. A bite of an infected human being can however pass rabies to the receiver.
It is necessary to vaccinate domesticated animals, especially dogs, to prevent rabies in them. However, there are some telling signs of a dog infected with rabies. According to WebMD, the dog may show signs of restlessness and aggression, and try to bite at things or people. Alternatively, the dog may become extremely passive and less responsive than usual. They may also develop fever.
With the progression of the disease, the dog may become very sensitive to light, sound and touch. It may hide in dark places and develop paralysis of the throat muscles, which could result in foaming at the mouth. Paralysis of hind legs is also possible. Loss of appetite, weakness and seizures may also occur. Eventually, the dog dies.
A stray dog which seems more aggressive or more passive than normal, which is salivating or foaming at the mouth or eating unusual things is thus a suspect candidate for rabies. People need to watch out for such dogs. In India, several municipal corporations take up the task of vaccinating strays, yet a number of unvaccinated dogs roam the streets, posing great danger to people.
So what can be done to prevent rabies if you have been bitten by a stray dog?
According to the National Guidelines on Rabies Prophylaxis (of the Government of India), firstly, it is essential to immediately wash the wound thoroughly with soap and water. This is known to reduce the threat of infection.
Next, it is necessary to visit a clinic which provides anti-rabies vaccination as soon as possible. The doctor usually checks the area of the bite and decides treatment based on it known as Post-Exposure Prophylaxis (PEP).
The treatment usually involves administration of anti-rabies vaccine on days 0, 3, 7, 14 and 28. Rabies Immunoglobulin (RIG) is also administered. The treatment is given both intra-dermal and intra-muscular. A tetanus shot and a course of antibiotics may also be recommended.
There are two types of Rabies Immunoglobulin (RIG), which is essential to prevent rabies (vaccination alone is not enough after being bitten). Either can be provided to the bitten person:
- Equine Rabies Immunoglobulin (ERIG): ERIG is produced from hyper-immunisation of equine animals. It is cheap and readily available in India. The dose of ERIG is 40 IU per kg body weight of patient.
- Human Rabies Immunoglobulin (HRIG): HRIG is expensive but free from any side effects. The dose of the HRIG is 20 IU per kg body weight.
Purified chick embryo vaccine or purified duck embryo vaccine would be provided in addition to ERIG/HRIG.
There may be certain side effects of ERIG administration. According to MDTravelHealth.com, the most frequent reaction is pain, swelling, redness, or itching at the injection site. Other side-effects may include headache, nausea, abdominal pain, muscle aches, or dizziness. Allergic reactions are occasionally reported. But none of these side effects are anything to worry about.
It is important not to miss out on any anti-rabies doses. If a dose is missed on any day, it is necessary to take it as soon as possible. Abandonement of subsequent doses after the first medication on Day 0 can result in eventual development of rabies.
Cure for Rabies: The Milwaukee protocol
There is hope for a cure for rabies. In 2004, American teenager Jeanna Giese became the first known person to have survived an infection of rabies without being vaccinated. She was bitten by a bat on her way back from school, and received no further treatment after the bite wound was treated with hydrogen peroxide. She developed neurological symptoms after 37 days and was eventually diagnosed with rabies.
The doctors put Giese into an induced coma to temporarily halt brain function, which they thought would halt the progression of the disease. Giese was given a mixture of ketamine and midazolam to suppress brain activity, and the antiviral drugs ribavirin and amantadine, while waiting for her immune system to produce antibodies to attack the virus. The treatment succeeded and came to be known as the Milwaukee protocol. Though Giese had difficulty with walking and balance for several years hence, she became the first person to be cured of rabies.
Similar treatment has proved successful in 2 of another 20 patients so far. Overall, the treatment seems to have a success rate of less than 10%. However, it provides hope for an eventual cure for rabies. Until then, it is best to take precautions to avoid animal bites, and seek immediate and appropriate treatment if bites occur.