Rabies: all for one- one health for all

Rabies: all for one- one health for all

Dr. Maheshwarappa. Y. P.

M.V.Sc. in Veterinary Medicine, IVRI, Izatnagar, Bareilly (UP)

Designation: Assistant Manager, DKMUL, Karnataka – 575005

Email: rammahiraj@gmail.com

Introduction

History
            For millennia, societies have been haunted by the menace of rabies, dating back to the realization that a bite from a rabid animal led to a grim and inevitable demise. The term “rabies” finds its roots in either the Sanskrit word “rabhas” meaning “to do violence” or the Latin term “rabere” denoting “to rage.” In antiquity, the Greeks referred to rabies as “lyssa,” a term signifying violence. In modern times, the virus responsible for rabies is categorized within the genus “Lyssa Virus.”

In ancient India, around 3000 B.C., the deity of death was accompanied by a dog, which served as a messenger of demise. The earliest documented instance of rabies resulting in fatalities among both dogs and humans can be traced back to the Mosaic Esmuna Code of Babylon, dated to 2300 B.C., where Babylonians were required to pay a penalty if their dog transmitted rabies to another person. Even in contemporary India, rabid dogs continue to be responsible for the deaths of approximately 20,000 individuals annually.

In the first century A.D., the Roman scholar Celsus made an accurate observation by suggesting that rabies spread through the saliva of the biting animal. However, he proposed an ineffective remedy for rabies by submerging the afflicted individual in water. Tragically, those who did not drown ultimately succumbed to rabies. There were also other cruel and ineffective treatments for rabies during this time, such as cauterizing the wounds with a heated poker and the “hair-of-the-dog” approach. Homoeopathic medicine, which relies on the principle of “similars” or like-cures-like, involves placing hairs from a rabid dog on the wound or having the patient ingest them. It’s worth noting that while a “hair-of-the-dog” remedy might alleviate a hangover, it had no curative effect on rabies.

The first significant breakthrough in rabies treatment emerged during the 1880s when a French chemistry instructor by the name of Louis Pasteur was experimenting with chicken cholera. While conducting his research, he made an intriguing observation: virulent cultures, when exposed to environmental conditions, lost their disease-causing properties.

Additionally, he noticed that chickens inoculated with this weakened or “attenuated strain” became immune to subsequent inoculations with fresh, virulent cultures.

Encouraged by his success, Pasteur went on to develop an attenuated vaccine for anthrax in cattle, which proved to be effective. Following this achievement, he turned his attention to rabies, a global menace. His initial experiments with animals yielded promising results, but Pasteur recognized the need for further refinement of his attenuated vaccine before considering human trials.

On July 6, 1885, a 9-year-old boy named Joseph Meister suffered a severe attack from a rabid dog. Local medical care was administered to treat his wounds, and the family was informed that the only person who could potentially save Joseph was Louis Pasteur. After numerous pleas, Pasteur reluctantly agreed, but not before consulting with several reputable physicians who had grimly assessed Joseph’s condition as that of a “dead boy walking”. Joseph underwent a series of 13 inoculations within 11 days and remarkably made a full recovery. Word quickly spread, and patients from all around the world began seeking Pasteur’s help. By the time of Pasteur’s passing nine years later, more than 20,000 individuals had received his post-exposure prophylactic vaccine.

Definition

Rabies is a viral disease that affects the central nervous system and can be prevented through vaccination. It is a zoonotic disease, once clinical symptoms manifest in an individual, rabies becomes almost 100 per cent fatal. In as many as 99 per cent of cases, domestic dogs are the primary source of rabies virus transmission to humans. However, rabies can also affect both domestic and wild animals. Transmission to people and animals occurs through saliva, typically via bites, scratches, or direct contact with mucous membranes such as the eyes, mouth, or open wounds. Children aged 5 to 14 years are particularly vulnerable to rabies infection.

Rabies is found on every continent except Antarctica, with Asia and Africa accounting for over 95 per cent of human fatalities associated with the disease. Nevertheless, reported rabies cases are infrequent, and the official numbers often significantly deviate from the estimated scale of the problem. Each year, over 29 million individuals worldwide receive post-exposure prophylaxis (PEP), a measure estimated to avert hundreds of thousands of rabies-related deaths annually. The global economic cost of dog-mediated rabies is projected to be around US$ 8.6 billion annually, not accounting for the unquantified psychological distress experienced by affected individuals and communities.

Symptoms
            The incubation period for rabies generally spans 2 to 3 months, although it can range from as short as 1 week to as long as 1 year. This variation depends on factors such as the location where the virus enters the body and the viral load introduced. Initial symptoms of rabies encompass general indications such as fever, pain, and unusual or unexplained sensations like tingling, pricking, or burning at the site of the wound. As the virus progresses into the central nervous system, it leads to a progressive and ultimately fatal inflammation of the brain and spinal cord. While clinical rabies in humans can be managed to some extent, it is exceedingly rare to achieve a cure, and even when managed, it often results in severe neurological deficits.

There are two forms of rabies

• Furious rabies manifests as heightened activity, agitated conduct, hallucinations, impaired coordination, hydrophobia (an aversion to water), and aerophobia (a fear of drafts or fresh air). Unfortunately, death ensues within a few days due to cardio-respiratory arrest.
• Paralytic rabies contributes to 20 per cent of the total number of human cases. This variant of rabies typically follows a less dramatic and often lengthier progression compared to the furious form. It involves a gradual paralysis of muscles that begins at the site of the wound. Over time, a coma slowly sets in, ultimately leading to death. Paralytic rabies is frequently misdiagnosed, which contributes to the underreporting of this disease.

Diagnosis
                    Current diagnostic tools are not suitable for detecting rabies infection before the onset of clinical disease. Unless the rabies-specific signs of hydrophobia or aerophobia are present, or a reliable history of contact with a suspected or confirmed rabid animal is available, clinical diagnosis is difficult. Human rabies can be confirmed intra-vitam and post-mortem by various diagnostic techniques that detect whole viruses, viral antigens, or nucleic acids in infected tissues (brain, skin or saliva).

Present diagnostic methods are inadequate for identifying a rabies infection prior to the manifestation of clinical symptoms. Unless distinct signs of rabies-like hydrophobia or aerophobia are evident, or there is a reliable history of contact with an animal confirmed or suspected of carrying rabies, making a clinical diagnosis becomes challenging. Human rabies can be confirmed both during a person’s life (intra-vitam) and after death (post-mortem) through a range of diagnostic techniques that detect complete viruses, viral antigens, or nucleic acids in infected tissues like the brain, skin, or saliva.

Transmission

Rabies is typically contracted by individuals through a deep bite or scratch from an animal infected with the virus, with dogs accounting for approximately 99 per cent of such cases. Transmission can also occur if the saliva of infected animals directly contacts mucous membranes (such as the eyes or mouth) or open skin wounds.

In the Americas, hematophagous bats have now become the primary source of human rabies fatalities, as the transmission of rabies by dogs has largely been brought under control in this region. Additionally, bat-mediated rabies is emerging as a growing public health concern in Australia and Western Europe.

Human deaths resulting from exposure to foxes, raccoons, skunks, jackals, mongooses, and other wild carnivore host species are exceedingly rare, and it is not known for bites from rodents to transmit rabies.

While there have been reported cases of rabies contraction through the inhalation of aerosols containing the virus or via the transplantation of infected organs, these occurrences are exceptionally rare. Theoretically, human-to-human transmission through bites or saliva is possible, but no confirmed cases have been documented. The same holds true for the transmission of rabies to humans through the consumption of raw meat or milk from infected animals.

WHO response

                    Rabies has been incorporated into the World Health Organization’s (WHO) 2021–2030 Roadmap for addressing neglected tropical diseases on a global scale. This roadmap outlines regional and step-by-step objectives for the eradication of specific diseases, with rabies being one of the targeted diseases. Given its zoonotic nature, effectively tackling rabies necessitates thorough cross-sectoral collaboration at the national, regional, and worldwide levels.

• The United Against Rabies Forum (UAR), established by the World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the World Organisation for Animal Health (OIE, formerly known as OIE), serves as a collaborative platform involving multiple stakeholders. Its mission is to advocate for action and increased investment in rabies control efforts.
• Rabies plays a significant role in enhancing the capabilities of the One Health workforce.
• WHO collaborates with its partners to provide guidance and assistance to countries as they formulate and implement their national plans for eliminating rabies. However, there is a pressing need to improve disease surveillance, data reporting, and the monitoring of rabies programs, which remains a top priority.
• WHO develops technical guidelines pertaining to rabies and offers support for capacity development in various countries.
• In 2019, Gavi, the Vaccine Alliance, incorporated human rabies vaccines into its Vaccine Investment Strategy for 2021–2025. This decision aimed to facilitate the expansion of rabies post-exposure prophylaxis (PEP) in countries eligible for Gavi support. Unfortunately, the pandemic led to the temporary suspension of several new Gavi vaccine programs, including rabies. However, in June 2023, the Gavi Board decided to resume these programs. The planning for the rollout of human rabies vaccines has now commenced.

The path to successful rabies elimination programs hinges on several crucial factors, including community involvement, beginning with modest initiatives, spurring long-term investment through economic stimulus packages, securing government commitment, showcasing both effectiveness and cost-efficiency and rapidly expanding efforts. By prioritizing and providing ample financial and political support, the goal of rabies elimination is not only attainable but also realistic.

Prevention and Control

Rabies prevention and management can be effectively addressed through a “One Health Approach,” which entails collaborative efforts across the animal, human, and environmental health sectors. In the context of India’s specific national and geopolitical circumstances, the following measures can significantly contribute to the success of rabies control programs

1. Systematic Data Collection and Compilation

A fundamental aspect of the One Health approach is the establishment of a systematic data collection and compilation system. This allows for the ongoing assessment of progress, the identification of endemic and sporadic disease patterns, and an understanding of their socioeconomic impact. Such data are invaluable in crafting national-level strategies and control programs.

2. Coordination and Data Sharing

Effective coordination and data sharing among the animal, human, and environmental health sectors are essential for a unified response to rabies.

3. Efficient Surveillance

Implementing efficient and effective surveillance mechanisms to track the spread of rabies is critical for early intervention and control.

4. Availability of Post-Exposure Prophylaxis (PEP)

Ensuring the sufficiency and accessibility of PEP is crucial, as it is the primary means of preventing rabies in humans following a suspected rabid animal bite. Urban areas should prioritize both pre-exposure prophylaxis (PrEP) and PEP availability in government and non-government hospitals.

5. Increased Vaccine Coverage

Mass vaccination of dogs is a cost-effective strategy for rabies control.

6. Public Awareness

Launching public awareness programs, particularly targeting vulnerable communities, is key in combatting any disease epidemic, including rabies.

7. Strengthening Laboratory Capacity

Investing in and enhancing laboratory capabilities are essential for timely and accurate diagnosis.

8. Research Activities

Conducting epidemiological field research on rabies can provide valuable insights into associated risk factors, dominant modes of transmission, socioeconomic implications, and local disease dynamics. This research serves as a strong foundation for the development of integrated, multi-sectoral strategies for rabies management.

ALL FOR ONE- ONE HEALTH FOR ALL: RABIES CONTROL IN INDIA AND WORLD

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