In May 2024, a tragic incident in Alappuzha, Kerala, highlighted the ongoing threat of rabies in the 21st century. A nine-year-old boy died from rabies after being bitten by a stray dog. He was not vaccinated after the attack owing to the absence of major wounds. This preventable death prompted school assemblies that turned into science classes. A message was delivered to over 159,000 students across 740 schools, underscoring the critical need for immediate medical attention and vaccination after any animal bite to prevent rabies.
This incident serves as a stark reminder that, despite advancements in medical science and the availability of effective rabies vaccines, the disease remains a significant public health challenge. With a nearly 100% fatality rate once symptoms develop, rabies continues to be a formidable threat. World Rabies Day, observed on September 28 to commemorate the death of Louis Pasteur, encourages reflection on both the historical misconceptions that once shaped the approach to this deadly disease and the ongoing efforts to develop vaccines and modern strategies for rabies control. By connecting the past and present, we are reminded of the continuous need for awareness, education, and vaccination to eradicate rabies.
Weird theories
Historically, rabies has been surrounded by superstitions and misguided theories. One ancient remedy was consuming dog hair to cure rabies. Another 19th-century idea from Italian Monsignor Storti was to set up brothels for dogs—to counteract what he believed was canine sexual frustration. Such theories did nothing to stop the disease’s spread. Rabies, known for over 4,000 years, was first noted in ancient Mesopotamia and India, where early texts like the Susruta Samhita described its symptoms. However, understanding and treatment remained limited for centuries, with many misconceptions persisting. Despite this ancient awareness, progress in understanding and treating rabies stagnated for centuries.
Advent of vaccination
The 19th century marked a turning point in the battle against rabies with the advent of germ theory, which fundamentally shifted medical science’s approach to infectious diseases. Louis Pasteur turned his attention to rabies in the 1880s. At the time, the understanding of immunology was rudimentary, and the concept of viruses as distinct infectious agents was non-existent. Pasteur himself referred to the rabies pathogen as a “virus,” but this term merely signified an unknown infectious agent smaller than bacteria. Despite the lack of a clear understanding, Pasteur hypothesised that a weakened, or “attenuated,” version of the rabies virus could stimulate the immune system to fight off a real infection.
After years of painstaking work, which included drying infected rabbit spinal cords to weaken the virus, Pasteur developed a vaccine that could be administered after exposure but before the onset of symptoms, providing a critical window to save lives. This work was groundbreaking, especially considering that the immune system’s workings were poorly understood, and Pasteur’s methods were developed largely through trial and error.
Pasteur’s first major success came in 1885 when he treated a nine-year-old boy Joseph Meister, who had been severely bitten by a rabid dog. Given the high mortality rate associated with rabies, Meister’s survival following Pasteur’s vaccination regimen was hailed as a scientific triumph. However, it is important to note that modern ethical standards for clinical trials were not in place at the time. Pasteur’s decision to test the vaccine on human subjects, including Meister and other rabies victims, was driven by desperation and the absence of alternatives, rather than a fully informed understanding of the risks involved. After the smallpox vaccine was developed, there was an 89-year gap before Louis Pasteur created the rabies vaccine, the second vaccine ever developed.
The success of the rabies vaccine had far-reaching consequences. Just months after Meister’s treatment, four boys from Newark, New Jersey, who had been bitten by a rabid dog, were sent to Paris to receive the vaccine. Their successful recovery brought international attention to Pasteur’s work and solidified his reputation as a pioneer of modern medicine. The publicity surrounding these cases spurred the global demand for the rabies vaccine and led to the establishment of the Pasteur Institute in 1888, a research facility that would become a cornerstone in the development of many future vaccines.
Epidemiology in India
Rabies in India, as of 2021, caused 59,000 deaths, representing 33% of the global total. Notably, 96% of these fatalities resulted from dog bites, highlighting the urgent need for improved rabies control and dog vaccination programs to prevent this preventable disease. The overall economic cost of dog-mediated Rabies was estimated to be $8.6 billion.
Newer rabies immunoglobulin (Rabies Ig) and the rabies vaccine are essential for post-exposure prophylaxis (PEP) against rabies. Rabies Ig is specifically used for category 3 bites, which involve severe exposure such as transdermal bites or scratches, and provides immediate protection by supplying ready-made antibodies. It is administered once, ideally infiltrated around the wound, on day 0 with the first vaccine dose. The newer rabies vaccine is used for both category 2 and 3 bites; category 2 involves minor bites or scratches without bleeding. The vaccine stimulates the immune system to produce long-term antibodies and is given in a series of four intra-dermal doses on days 0, 3, 7, and 28 (Modified Thairegimen) or 0,3,7,14 and 28 intramuscular doses (Essen regimen) for unvaccinated individuals. Previously vaccinated individuals receive two doses on days 0 and 3 without Rabies Ig.
One Health Approach
The “One Health” approach, recognises the interconnection between people, animals, plants, and their shared environment. This strategy emphasises collaboration among veterinary, medical, and environmental sectors to effectively manage rabies at the human-animal-environment interface. Local bodies play a vital role in animal control efforts, such as stray dog population management, vaccination drives, and public education campaigns, which are critical to preventing rabies outbreaks.
To achieve the dream of zero rabies deaths by 2030, India needs to establish a robust surveillance mechanism, including GIS-enabled tracking, and ensure successful coordination among key sectors such as wildlife, urban and rural ministries, animal husbandry, the Ministry of Environment and Forests, the Ministry of Panchayat Raj, and the Health Ministry. Effective collaboration among these stakeholders is crucial, as operating in isolation will lead to little to no success in eradicating this preventable disease.
Published - September 27, 2024 06:00 am IST
