THIRUVANANTHAPURAM: More than 55,000 people die of rabies every year. Of this almost 95% deaths occur in Asia and Africa. Around 45% of all Rabies related deaths in the world occur in India and 40% of people who are bitten by suspected rabid animals are children under 15 years of age. Wound cleansing and immunization within a few hours after contact with a suspected rabid animal can prevent the onset of rabies and death.
Rabies is a zoonotic disease (a disease that is transmitted to humans from animals) that is caused by a virus. The disease affects domestic and wild animals and is spread to people through close contact with infectious material, usually saliva, via bites or scratches. The number of human deaths due to Rabies in India is 20,000 every year of the total of 55,000 global deaths. Estimated number of animal bites in India: 17.5 million per year. According to one study, only 70% of the people in India have ever heard of rabies, only 30% know to wash the wounds after animal bites and, of those who get bitten, only 60% receive a modern cell-culture-derived vaccine. (Source - Bulletin of the World Health Organization
Symptoms
The initial symptoms of rabies are fever and often pain or an unusual or unexplained tingling, pricking or burning sensation at the wound site. As the virus spreads through the central nervous system, progressive, fatal inflammation of the brain and spinal cord develops. Two forms of the disease can follow. People with furious rabies exhibit signs of hyperactivity, excited behavior, hydrophobia and sometimes aerophobia . Prolonged symptoms can lead to death by cardio-respiratory arrest. Paralytic rabies accounts for about 30% of the total number of human cases. In this form of rabies the muscles gradually become paralyzed, starting at the site of the bite or scratch. A coma slowly develops, and eventually can lead to death. The paralytic form of rabies is often misdiagnosed, contributing to the under-reporting of the disease.
Diagnosis
No tests are available to diagnose rabies infection in humans before the onset of clinical disease and unless the rabies-specific signs of hydrophobia or aerophobia are present, the clinical diagnosis may be difficult. Human rabies can be confirmed by diagnostic techniques that are aimed to detect the whole virus, viral antigens, viral-specific antibodies in the cerebrospinal fluid, or nucleic acids in infected tissues.
Transmission
Dogs are the main host and transmitter of rabies. Bat rabies has also recently emerged as a public health threat in Australia, America and Western Europe.
Transmission can also occur when infectious material , usually saliva, comes into direct contact with human mucosa or fresh skin wounds. Sometimes, rabies may be contracted by inhalation of virus-containing aerosol or via transplantation of an infected organ. There have been instances of unpasteurized milk from rabies infected cows however they are not proved yet. But consumption of meat or milk from a rabies infected animal is not recommended.
Preventive Measures after an animal bite
Post-exposure prophylaxis (PEP) or preventive actions after incurring an animal bite consists of local treatment of the wound, a course of potent and effective rabies vaccine that meets WHO recommendations; and
The administration of rabies immunoglobulin, if indicated. Removing the rabies virus at the site of the infection by chemical or physical means is an effective means of protection. Effective and quick treatment to the wound can prevent the onset of symptoms and death. Recommended first-aid procedures include immediate and thorough flushing and washing of the wound for a minimum of 15 minutes with soap and water, Povidone iodine or other substances that kill the rabies virus.
PEP depends on the type of contact with the suspected rabid animal (see table). The vaccination status of the suspected animal alone should not be considered when deciding whether to initiate prophylaxis or not.
Concentrated, purified cell culture and embryonated egg-based rabies vaccines have proved to be safe and effective in preventing rabies and are intended for both pre- and post-exposure prophylaxis. Intradermal administration of these vaccines is as safe and immunogenic as compared to intramuscular administration, and the costs are 60-80% lower. Kerala has IDRV centers attached to many Medical Colleges where the intra-dermal doses of Rabies Vaccines are administered.
Eliminating rabies in dogs
The most cost-effective strategy for preventing rabies in people is by eliminating rabies in dogs through vaccination. Vaccinating at least 70% of dogs breaks the cycle of transmission in dogs and in turn to humans. Preventing human rabies through control of domestic dog rabies is a realistic goal for large parts of Africa and Asia. Safe, efficacious and affordable dog rabies vaccines are available, and countries embarking on rabies elimination need easy access to quality assured dog vaccines for outbreak management. Community participation, education and public awareness are important elements of successful rabies control programs. People need to take responsibility for their dogs, prevent dog bites and know what to do when bitten.
Preventive immunisation in people
Pre-exposure immunization is also recommended for people in certain high-risk occupations such as laboratory workers dealing with live rabies virus and people involved in any activities that might bring them professionally or otherwise into direct contact with bats, carnivores, and other mammals in rabies-affected areas. World Rabies Day
On 28th September every year, the world unites in the fight against rabies. World Rabies Day is a day of activism and awareness. Often the fear of rabies pitches people against dogs. But when dogs are vaccinated it stops the disease at its source and prevents human deaths .In celebration of the interdependence of human and animal health, this year’s theme is ‘Together against Rabies’. The aim is to spread the word that rabies is a preventable diesease.
Dr Anup R Warrier, Consultant Infectious Diseases, Aster Medcity