If you were to take a loved one to a doctor after they were to be bitten by a dog, you pretty much know the drill. A tetanus shot and multiple injections for protection against rabies. The reason, for so many injections, is because should a person develop rabies, there is no cure for it. For now, science can only prevent it from occurring by means of vaccinations. Dr Oliver D’Souza explores.
Rabies has always struck fear and panic in people. Once the symptoms set in, there is no turning back. Death is certain. In India itself, in spite of a vaccine against rabies, an estimated 20,000 people succumb to the disease. For diseases which can be easily prevented this is an unacceptable number. For this reason, world rabies day is celebrated on September 28, to create awareness regarding the disease and to help decrease the number of deaths. We have the largest number of rabies cases in the world. Almost 40% of the people bitten are boys less than 14 years of age. Numbers, however, are unable to convey the tragic stories that accompany these deaths.
Swetha had lost her husband several years ago. Her son was the only reason to continue living. One evening, he came home early after playing the whole day with his friends in the neighbourhood. He complained of fever and severe body pain. Sensing that something was serious, she rushed him to a hospital. His condition deteriorated every passing hour and he died the next day. A young life had been snuffed out. The death sent shock and disbelief among the neighbours.
Here was a boy, hale and hearty, had played with their children the whole day. They shared the same tumbler while drinking water, the same plate while eating snacks. Now he was dead. All his friends were thoroughly checked for every scratch and wound on their bodies. Parents skipped work as they kept vigil over their children. The slightest cough and sneeze sent them into a panic. Everyone was worried if it would be their child next. They were confused as there was no rabid animal in the area. The mob took over and slaughtered every stray animal in the vicinity. Yet not a single rabid animal was to be found. To this day, no one has been able to figure out how the child got rabies.
This panic isn’t new. The sight of rabid animals and the call to kill all stray dogs is as ancient as history itself. The word rabies comes from the Latin word “to rage” and has been correctly described as “the incurable wound”. It was known that being bitten by wild animals and domesticated dogs which were more aggressive than usual, having foaming of the mouth, would result in the disease. The most prominent example is in Britain, this lead to drastic measures of catching dogs without a leash and culling them. There were huge protests by animal rights activists but in the end the country was able to eliminate rabies. One of the reasons this worked is because of the fact that the U.K. is an island nation. India shares its border with other countries and hence such methods are unlikely to be effective.
The French biologist, Louis Pasteur has been credited with the discovery of the first vaccine for rabies. He invented it by creating a mild version of the rabies virus in 1885. Not long after he had made his vaccine, a young boy was bitten by a rabid dog. The distraught parents begged Pasteur for help. He had his doubts if it would work but went ahead and injected the boy. To everyone’s relief, the vaccine worked and thus began the race to find a more effective and safer version of the vaccine.
With the march of science, we were able to identify the organism which caused the disease and how it acted. Humans get the disease when an infected mammal bites, licks the face (Via the eyes) or broken skin. Most commonly it is a dog that has been attacked by foxes or other wild animals. Bats can also transmit the disease, but this is seen only in the American continent. Very few cases of bates transmitting the disease have been reported in India.
The saliva of an affected animal contains the RNA based rabies virus. Once the virus enters the human body via the wound, it multiplies in the muscle. Depending on the site it can take a few hours or weeks. It then heads to the nearest nerves. Here it continues to multiply or it may travel upwards until it reaches the brain. In the brain, it multiplies rapidly and causes inflammation of the brain. It then travels down towards the rest of the body and affects the nerves in the body. At this point, the virus can be seen in the saliva, tears, heart, hair roots and kidneys. The normal functioning of the nerves of the body is hijacked by the virus. This causes the symptoms one typically associates with rabies like being scared of water, light, sound and even a mild breeze.
The time it takes for the virus to cause disease can be as short as 5 days or as long as 2 years. This large variation in the time it takes for the disease to present itself is one of the reasons why sometimes it is difficult to identify when the person came in contact with the infected animal. During this initial period, there will be vague symptoms like mild fever or an upset stomach. In the next stage, they can be two ways that the disease presents itself. One is the stereotypical “Furious” form, with foaming at the mouth, hyper-aggressive behaviour. Or one sees the “paralytic” form where the person is weak, lethargic and unable to swallow. After this the muscles of the lung get affected, resulting in difficulty in breathing. This is then followed by the “coma” stage and after 5 – 7 days the person dies. Life can be prolonged for a short while but death is certain.
Ages ago, rabies vaccination meant almost 26 injections on the abdomen. This was a good way of frightening children not to pet stray animals. Now vaccination means just 5 injections. One as soon as possible (Day 0), repeated on day 3, 7, 14 and 28. It is injected into the muscles of the arms. Depending on the type of vaccine being used this can vary. Sometimes if the wound is severe, on the face or in small children; an immunoglobulin is given along with the first vaccine, usually at the site of the wound.
Till date, only one person on record has successfully been treated and cured of rabies. In 2004, a 15-year-old girl named Jeanna was bitten by a bat in Wisconson, USA. By the time her doctors had made their diagnosis, it was too late. To save her life, she was placed under a medically induced coma and her body was given time to fight off the infection. She survived the ordeal and now leads a healthy life.
If you are wondering how to prevent the spread of rabies, here are some suggestions:
1. Avoid petting unfamiliar or stay animals.
2. Vaccinate your pets.
3. If your pet has suddenly changed its behaviour – suddenly it is aggressive or stops eating and sleeps in a corner and prefers to be left alone; get your pet examined by a veterinarian.
4 Proper disposal of waste. We have door to door waste collection. Stop throwing food on the street. If there is a food source available, animals will come.
5. Report stray and sick animals to the authorities.
6. If you do get bitten, wash with soap and running water and get medical help. Do not try to trap the animal that bit you.
7. Remember, an animal may be infected long before it begins to signs of having rabies.
Parks Text Book Of Preventive & Social Medicine, 24th Edition