Disease Review: Rabies

A lot of people around the world are experiencing burnout. Burnout is a state of exhaustion caused by prolonged and excessive stress. There are a lot of ways to help alleviate this. To deal with burnout, you can turn to other people or pets such as dogs. But we should be wary of dogs we pet. There are certain diseases that people get from pets such as dogs. Dogs are the main source of human rabies deaths, contributing up to 99% of all rabies transmission to humans. 

Rabies is a deadly but preventable viral disease that plagued the human population for thousands of years. Even in ancient times, people understood that rabies could be passed on from animal bites. 

Rabies in History

Based on the characteristics of the disease, rabies is thought to have existed thousands of years ago. The first written record of rabies was in the Mosaic Esmuna Code of Babylon in 2300 B.C. It showed rabies causing death to humans and dogs. Babylonians had to pay a fine if their dog transmitted rabies to another person. It was also mentioned in the works of Aristotle in 300 B.C. noting that rabies is a disease that affects dogs and any other animal that the dog bites. 

In the first century A.D., the Roman scholar Celsus suggested that rabies are transmitted through the saliva of the rabid animal. He incorrectly suggested that holding people underwater will cure rabies. 

In the mid-eighteenth century, Britain’s rabies situation was so bad that there is a big reward in killing stray dogs. 

In the nineteenth century, rabies was widespread across Europe. In an outbreak in France in 1803, many people, dogs, and pigs were bitten by rabid foxes. The foothills of the Jura Alps were littered with dead bodies of infected rabid animals. By the middle of the nineteenth century, 60% of the dogs taken to the hospital were infected. 

The Discovery of Its Treatment

The first treatment for rabies was introduced by a French Chemistry Scientist Louis Pasteur in the 1880s. Pasteur was convinced that rabies did not occur spontaneously in rabid animals, but that each case derived from another. He thought that the obvious source was the saliva and he attempted to infect rabbits by inoculation of saliva from patients dying of rabies. The infected rabbits died. He continued his research using the spinal cord of the infected rabbits and was able to develop a vaccine. 

On July 6, 1885, a boy named Joseph Meister was mauled by a rabid dog. The local doctor told the family that the only person capable of saving the boy is Louis Pasteur. After much pleading from the family, he agreed. Joseph was inoculated by Pasteur 13 times in 10 days and made a complete recovery. Three months later a second patient was successfully treated and the news of the recoveries spread across. 

In 1921, an intense vaccination program started in Japan. The vaccine prepared by Ferni was used. The annual number in Japan of rabies cases in dogs dropped from 1,041 in 1918 to 60 in 1930. 

The Cause and Its Transmission

Rabies is caused by the rabies virus of the genus Lyssavirus which includes at least five other rabies-like viruses. Rabies virus is a rod or bullet-shaped, single-stranded, enveloped RNA virus. 

Rabies is a zoonotic disease which means the infectious agent, in this case, the rabies virus, is from animals and then transmitted to a human. 

The virus is primarily transmitted to humans through a deep bite or scratch from an animal with rabies. The virus-laden saliva will then enter into the wounds.

Transmission to humans by rabid dogs accounts for 99% of cases. But in America, bats are now the major source of human rabies deaths. Dog-mediated transmission is being prevented because of vaccination on dogs. Bat rabies is also an emerging public health threat in Europe and Australia. 

Rabies transmission through corneal or solid organ transplants has been recorded. Theoretically, human-to-human transmission through bites or saliva is possible but has never been confirmed. 

Rabies Symptoms

After the initial infection of rabies, the virus has to travel to the brains before it can cause clinical manifestation. The incubation period may vary from 1 week to 1 year but is typically 2-3 months, depending on the location of the entry and viral load. 

The first symptoms of rabies are similar to flu including fever, headache, nausea, vomiting, and anxiety. As the disease progresses, the virus spreads to the central nervous system. Once it reaches the brain, the virus further replicates, resulting in two clinical manifestations. 

The two manifestations are furious and paralytic rabies. Furious rabies results in hyperactivity, hydrophobia, or fear of water, excitable behavior. Death occurs after a few days due to cardio-respiratory arrest. Furious rabies is the most common form of human rabies. 

In paralytic rabies, muscles gradually become paralyzed starting at the site of the bite or scratch. A coma slowly develops, heart or lung failure, and then death. It takes a longer course than furious rabies.

Treatment and Prevention

Rabies is a very fatal disease. If you’ve been bitten by an animal, determine if the animal is healthy or not. If you are unsure, it is better to assume that the animal has rabies. 

Post-exposure prophylaxis (PEP) is the immediate treatment after rabies exposure. These prevent viruses from entering the central nervous system. PEP consists of extensive washing of the wound. Then a dose of human rabies immune globulin (HRIG) and rabies vaccine that meets WHO standards will be given. 

Rabies is a vaccine-preventable disease. The most cost-effective way of preventing rabies in people is the vaccination of dogs and other pets. Education on dog behavior and bite prevention is an essential supplement in the vaccine program.

The infection causes an estimated 50,000 deaths every year in over 150 countries, mainly in Asia and Africa. Around 40% of people bitten by rabid animals are children under 15 years of age. 

We can prevent the spread of rabies if we keep our dogs vaccinated. It is our duty to our dogs and the community.