Rabies Public Awareness and Control Strategies

Rabies Public Awareness and Control Strategies

      Rabies has been known since around 2000 BC. The first written record of rabies dictates that the owner of a dog showing symptoms of rabies should take preventive measure against bites. If another person were bitten by a rabid dog and later died, the owner was heavily fined. Rabies was considered a scourge for its prevalence in the 19th century. By an application of magical thinking, dogs were branded with the key in hopes of protecting them from rabies. The fear of rabies was almost irrational, due to the number of vectors (mostly rabid dogs) and the absence of any efficacious treatment. It was not uncommon for a person bitten by a dog merely suspected of being rabid to commit suicide or to be killed by others.

           In ancient times, the attachment of the tongue was cut and removed as this was where rabies was thought to originate. This practice ceased with the discovery of the actual cause of rabies. Louis Pasteur's 1885 nerve tissue vaccine was successful, and was progressively improved to reduce often severe side-effects.

           In 2010, an estimated 26,000 people died from rabies, down from 54,000 in 1990. The majority of the deaths occurred in Africa and Asia including Pakistan. India and Pakistan have the highest rate of human rabies in the world, primarily because of stray dogs, whose number has greatly increased. An estimated 20,000 people die every year from rabies in India, more than a third of the global total.

Transmission

       People are usually infected following a deep bite or scratch from an animal with rabies, and transmission to humans by rabid dog accounts for 99% of cases. Africa and Asia have the highest rabies burden in humans and account for 95% of rabies deaths, worldwide.

      In the Americas, bats are now the major source of human rabies deaths as dog-mediated transmission has mostly been broken in this region. Bat rabies is also an emerging public health threat in Australia and Western Europe. Human deaths following exposure to foxes, raccoons, skunks, jackals, mongooses and other wild carnivore host species are very rare, and bites from rodents are not known to transmit rabies.

         Transmission can also occur when infectious material, usually saliva, comes into direct contact with human mucosa or fresh skin wounds. Human-to-human transmission through bites is theoretically possible but has never been confirmed.

          Contraction of rabies through inhalation of virus-containing aerosols or through transplantation of infected organs is rare. Contracting rabies through consumption of raw meat or animal-derived tissue has never been confirmed in humans.

Signs and Symptoms

      The incubation period for rabies is typically 2–3 months but may vary from 1 week to 1 year, dependent upon factors such as the location of virus entry and viral load. Initial symptoms of rabies include a fever with pain and unusual or unexplained tingling, pricking, or burning sensation (paraesthesia) at the wound site. As the virus spreads to the central nervous system, progressive and fatal inflammation of the brain and spinal cord develops.

There are two forms of the disease:

• People with furious rabies exhibit signs of hyperactivity, excitable behaviour, hydrophobia (fear of water) and sometimes aerophobia (fear of drafts or of fresh air). Death occurs after a few days due to cardio-respiratory arrest.

• Paralytic rabies accounts for about 20% of the total number of human cases. This form of rabies runs a less dramatic and usually longer course than the furious form. Muscles gradually become paralyzed, starting at the site of the bite or scratch. A coma slowly develops, and eventually death occurs. The paralytic form of rabies is often misdiagnosed, contributing to the under-reporting of the disease.

Fear of Water

       Hydrophobia (fear of water) is the historic name for rabies. It refers to a set of symptoms in the later stages of an infection in which the person has difficulty swallowing, shows panic when presented with liquids to drink, and cannot quench their thirst. Any mammal infected with the virus may demonstrate hydrophobic.

       Saliva production is greatly increased, and attempts to drink, or even the intention or suggestion of drinking, may cause excruciatingly painful spasms of the muscles in the throat and larynx. This can be attributed to the fact that the virus multiplies and assimilates in the salivary glands of the infected animal with the effect of further transmission through biting. The ability to transmit the virus would decrease significantly if the infected individual could swallow saliva and water.

     Hydrophobia is commonly associated with furious rabies, which affects 80% of rabies-infected people. The remaining 20% may experience a paralytic form of rabies that is marked by muscle weakness, loss of sensation, and paralysis; this form of rabies does not usually cause fear of water.

Prevention and Control

       Rabies is a serious disease, but individuals and governments can and do take action to control and prevent, and, in some cases, wipe it out completely      

       Strategies include:

• Regular anti-rabies vaccinations for all pets and domestic animals
• Bans or restrictions on the import of animals from some countries
• Widespread vaccinations of humans in some areas
• Educational information and awareness

Individual precautions

• Protect small pets: Some pets cannot be vaccinated, so they should be kept in a cage or inside the house to prevent contact with wild predators.
• Keep pets confined: Pets should be safely confined when at home, and supervised when outside.
• Report strays to the local authorities: Contact local animal control officials or police departments if you see animals roaming
• Do not approach wild animals: Animals with rabies are likely to be less cautious than usual, and they may be more likely to approach people.
• Keep bats out of the home: Seal your home to prevent bats from nesting. Call an expert to remove any bats that are already present.
• Individuals should follow some safety rules to reduce the chance of contracting rabies. Vaccinate pets: Find out how often you need to vaccinate your cat, dog, ferret, and other domestic or farm animals, and keep up the vaccinations.

      People are encouraged to seek medical help after an encounter with a wild animal, even if they do not have bite marks or other outward signs of injury.

Post-exposure prophylaxis (PEP)

         Post-exposure prophylaxis (PEP) is the immediate treatment of a bite victim after rabies exposure. This prevents virus entry into the central nervous system, which results in imminent death. PEP consists of:

• Extensive washing and local treatment of the wound as soon as possible after exposure.
• A course of potent and effective rabies vaccine.
• The administration of rabies immunoglobulin (RIG), if indicated.

Effective treatment soon after exposure to rabies can prevent the onset of symptoms and death.

Written By :

                                                                 Muhammad Bakhsh

mbakhsh90@gmail.com

College of Veterinary and Animal Sciences, Jhang, Pakistan