What is Rabies

Although many of us are fond of animals, travel and adventures, there are always chances of falling sick or falling victim to a deadly disease. Many people love having pets like dogs, cats, rabbits etc. but fail to assess the health risks and take the right care. Animals, like humans, are susceptible to several diseases and health risks. This is particularly risky when we humans cohabit with animals in our homes, neighbourhoods and surroundings. Rabies is a highly dangerous and sometimes fatal disease that affects animals and humans.

A Brief History of Rabies

The book “Rabies” (2007) talks about a brief history of rabies and its understanding in the past. Rabies has been around for centuries. The fear of being bitten by a rabid wild dog or wolf was widespread. However, rabies still didn’t have a name, or a diagnosis, or a cure. At the time, no one made a connection between a dog bite and rabies. In the 19th century, it was Celsus who acknowledged that rabies was being caused by wild animals. There are historical records of violent onset of disease in wild animals especially wolves. When these attacked humans, humans contracted the same symptoms that often resulted in death.

Centuries later, rabies has been effectively and widely controlled due to large scale vaccination programs. In western and developed countries, such as Canada, canine rabies is almost eliminated but, rabies contracted from wild animals is on the rise. This is because vaccinating such an enormous number of wild animals is impossible. Therefore, The picture in the developing world is still grim with rabies outbreaks occurring from time to time. The most recent one was in Malaysia. Most rabies cases are a result of dog bites in developing countries.

What is Rabies?

According to the WHO, rabies is termed as a zoonotic disease. This implies that rabies is a disease transmitted from animals to humans. Rabies is caused by the virus of Lyssavirus genus of the Rhabdoviridae family. Dogs are the largest carrier of this disease with more than 99% being rabies caused due to a dog bite. However, there are other animals, mammals only, such as bats, raccoons, rabbits etc. that also contract the disease and transmit it.

How Does the Transmission of the Rabies Virus Occur?

The rabies virus is carried in the saliva of animals affected with rabies. Thus when a rabid animal bites another human or animal that has a wound from cuts, scratches or bites, the saliva enters the bloodstream easily. It is important to note that the rabies virus is ineffective on the skin that is intact. According to the WHO, the rabies virus is a deadly virus that infects the central nervous system of mammals. Thus when it reaches the brain of a mammal, it is already progressed to an advanced stage that results in brain disease and ultimately death. According to Healthline.com both wild and domestic animals can contract and transmit the disease. These are dogs, bats, ferrets, cats, rabbits, horses, woodchucks, crows, coyotes, goats, beavers, dogs, skunks, monkeys, raccoons and foxes. Thus persons and families working closely with livestock, living or travelling to a region where bats are common are more prone to getting rabies. Let us explore more.

Symptoms of Furious Rabies and Paralytic Rabies

The incubation period of the rabies virus which is generally the duration between the bite and the appearance of symptoms varies from four weeks to twelve weeks. However, incubation periods can last much longer right from a few days to six years.

According to Healthline.com, the initial onset of rabies is characterized by the victim having flu-like symptoms such as a fever, muscle weakness and tingling. Victims may also feel a burning sensation at the place of the bite. Since the rabies virus affects the central nervous system there are two types of complications resulting from rabies.

Rabies has two clinical manifestations —

  • Furious Rabies: This form of rabies is also known as classical or encephalitic rabies is the most common form of human rabies, accounting for approximately 80% of cases. Its symptoms include strange and erratic behaviour as rabies is a disease which affects the brain as mentioned before. Therefore symptoms in a person affected with furious rabies include hallucinations, anxiety, insomnia, agitation, excess salivation
  • Paralytic Rabies: The WHO reports that 30% of rabies cases result in paralysis. Its symptoms include the same symptoms as furious rabies. However, the only difference is that this form of rabies takes longer to affect the victim. Victims of paralytic rabies gradually become paralyzed, slip into a coma and eventually die. This form of rabies takes longer to set in, but the effects are just as severe.

Epidemiological Risks of Rabies

The following are situational circumstances that can make people more susceptible to this deadly disease:

  • Travelling to countries where rabies outbreaks are common
  • Exposure to areas infested with bats
  • Residing in rural areas or areas near forests where the presence of wild animals is very high. In addition, access to vaccines and healthcare in such areas is difficult and may worsen the victim’s situation if help is delayed.
  • Persons aged 15 years or less run a higher risk of being infected.
  • In developing and developed countries, people who like to go camping, trekking, and explore the outdoors are also at a high risk of getting rabies.

Suggestions for Rabies Control

Rabies is certified as a 100% vaccine-preventable disease by the World Health Organization. Systematic vaccination plans have controlled the disease significantly. However, rabies still remains a challenge in the developed and the developing world. In the case of the developing world, rabies control is a result of poor policy execution and public health control. Poverty is also an epidemiological factor which is responsible for the failure of rabies control in developing countries. People living in slums, homeless people or people living on the streets are extremely vulnerable to the disease. These areas are populated by stray dogs that are not spayed in time. Thus they reproduce and add to the stray animal population which increases the risk of contracting the disease in both animals and humans.

Therefore, it is very important to plan animal neutering programs and vaccination programs in such a way that they must coincide. This is important for rabies control to succeed because on one hand the animal population is controlled thereby reducing the burden of the disease. This implies a controlled animal (especially the stray dog) population within reasonable limits. A smaller animal population makes it easier for public health authorities to execute vaccination programs and ensure their success.

In the developed world, since rabies spreads in rural and forest areas, it is important for people to take precaution while travelling in the wild, for families to foolproof their homes and public health services to cooperate for more effective animal population control.

Thirdly, any wounds, cuts, scratches must be disinfected and treated. It is risky to ignore them especially when you are at risk of getting rabies. Very few people have known to survive rabies. However, this may not be the case with everyone. Therefore, preventive care is strongly advised for rabies control.

Author: Dr Harsh Desai, MD
Dr Harsh Desai is a Hospital Board Executive and General Practitioner (GP) with a special interest in Urology at Regency Medical Centre, Dar-Es-Salaam, Tanzania. He also has past experience in Pharmaceutical Industry within Regional Medical Affairs. He has a passion for introducing working models of primary and secondary healthcare delivery in the UK, into the African healthcare space.  https://www.regencymedicalcentre.com/

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