Countdown to World Rabies Day (2)

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By Dr Ibikunle Faramade

… Continued

 

Inflammation of the Brain Illustrated

Rabies Synopsis

• Rabies is a serious public health problem in over 150 countries and territories, mainly in Asia and Africa. It is a viral, zoonotic, neglected tropical disease that causes tens of thousands of deaths annually, with 40% being children under 15.
• Dog bites and scratches cause 99% of the human rabies cases, and can be prevented through dog vaccination and bite prevention.
• Once the virus infects the central nervous system and clinical symptoms appear, rabies is fatal in 100% of cases.
• However, rabies deaths are preventable with prompt post exposure prophylaxis (PEP) by stopping the virus from reaching the central nervous system. PEP consists of thorough wound washing, administration of a course of human rabies vaccine and, when indicated, rabies immunoglobulins (RIG).
• If a person is bitten or scratched by a potentially rabid animal, they should immediately and always seek PEP care.
• WHO and its global partners aim to end human deaths from dog-mediated rabies through a comprehensive One Health approach promoting mass dog vaccination, ensuring access to PEP, health worker training, improved surveillance, and bite prevention through community awareness.

Clinical Signs of Rabies in Dogs 

Rabies signs in animals are similar, with a change in behavior (either an aggressive or wild animal becoming tame and calm, or a calm animal becoming aggressive), paralysis or partial paralysis in many cases, abnormal vocalization (dogs barking strangely), animals attacking inanimate objects (like biting rocks or trees), hydrophobia and drooling of saliva and foaming at the mouth. There is also uncoordinated movement and loss of gait (ataxia), accounting for the description of the disease in the Yoruba language as DIGBOLUGI (literally translated as collision with trees), among others.

Symptoms of Rabies in Humans 

The incubation period for rabies is typically 2–3 months but may vary from one week to one year, depending on factors such as the location of virus entry and the viral load. Initial symptoms of rabies include generic signs like fever, pain and unusual or unexplained tingling, pricking, or burning sensations at the wound site. As the virus moves to the central nervous system, progressive and fatal inflammation of the brain and spinal cord develops. Clinical rabies in people can be managed but very rarely cured, and not without severe neurological deficits.

Manifestations of Rabies in Humans:

• Furious Rabies results in hyperactivity, excitable behaviour, hallucinations, lack of coordination, hydrophobia (fear of water) and 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 paralysed, starting from the wound site. A coma slowly develops and eventually death occurs. The paralytic form of rabies is often misdiagnosed, contributing to the under-reporting of the disease.

Rabies from Sources Other Than Dogs

• In the Americas, where dog-mediated rabies is mostly controlled, hematophagous (blood-feeding) bats are now the primary source of human rabies. Bat-mediated rabies is also an emerging public health threat in Australia and parts of Western Europe.
• Human deaths following exposure to foxes, raccoons, skunks, and other wild mammals are very rare, and bites from rodents are not known to transmit rabies.
• Contraction of rabies through inhalation of virus-containing aerosols, consumption of raw meat or milk of infected animals, or through organ transplantation is extremely rare.
• Human-to-human transmission through bites or saliva is theoretically possible but has never been confirmed.

Diagnosis

• Currently there are no WHO-approved diagnostic tools for detecting rabies infection before the onset of clinical disease.
• Clinical diagnosis of rabies is difficult without a reliable history of contact with a rabid animal or specific symptoms of hydrophobia or aerophobia.
• Accurate risk assessment is crucial for deciding on Post Exposure Prophylaxis administration.
• Once symptoms emerge, and death is inevitable, offering comprehensive and compassionate palliative care is recommended.
• Postmortem confirmation of rabies infection is done by various diagnostic techniques that detect whole viruses, viral antigens, or nucleic acids in infected tissues (brain, skin or saliva)

Rabies Prevention

Vaccinating dogs, including puppies, through mass dog vaccination programs is the most cost-effective strategy for preventing rabies in people because it stops the transmission at its source. Public education for both children and adults on dog behaviour and bite prevention, what to do if bitten or scratched by a potentially rabid animal, and responsible pet ownership are essential extensions of rabies vaccination programmes

Human Vaccination 

Effective vaccines are available to immunize people both before and after potential exposures. Pre-exposure prophylaxis (PrEP) is recommended for people in high-risk occupations (laboratory workers handling live rabies and related viruses) and people whose professional or personal activities might lead to direct contact with infected animals (animal disease control staff and wildlife rangers).  Post-exposure prophylaxis (PEP) is the emergency response to a rabies exposure. This prevents the virus from entering the central nervous system.

Exposure Risk and Indications for Post Exposure Prophylaxis (PEP)

Depending on the severity of exposure, administration of a full PEP course is recommended as follows:

Categories of contact with suspect rabid animal	Post-exposure prophylaxis measures
Category I – touching or feeding animals, animal licks on intact skin (no exposure)	Washing of exposed skin surfaces, no PEP
Category II – nibbling of uncovered skin, minor scratches or abrasions without bleeding (exposure)	Wound washing and immediate vaccination
Category III – single or multiple transdermal bites or scratches, contamination of mucous membrane or broken skin with saliva from animal licks, exposures due to direct contact with bats (severe exposure)	Wound washing, immediate vaccination and administration of rabies immunoglobulin/monoclonal antibodies

NB: Category II and III exposures require human rabies vaccination.

In conclusion, effective prevention of rabies and the achievement of zero case of rabies by 2030 as part of the Sustainable Development Goals of the United Nations is only achievable if the vaccination coverage of dogs is improved upon in every area, including hard to reach terrains in peri – urban and rural areas. To win the battle against rabies therefore requires collaborative efforts of all and sundry. Bottom up approach with emphasis on citizens’ active participation is however crucial to make rabies a disease of the past.

It is feasible!

It is possible!!

Dr. Ibikunle Faramade is a veterinary pathologist, sustainable development practitioner, animal welfare advocate and a lecturer at the Federal College of Animal Health & Production Technology, Apata. Ibadan. He’s the C.E.O of the Society for Animal Rights Protection, a non-profit and a non-governmental organization dedicated to the promotion of animal welfare, animal rights and prevention of cruelty tos animals. animalrightsprotection2020@gmail.com , +2348028305284