Key Notes on Global Rabies Control Programs

Key Notes on Global Rabies Control Programs

World Rabies Day is observed annually on September 28 to raise awareness about rabies prevention and control efforts globally. It commemorates the anniversary of the death of Louis Pasteur, who developed the first rabies vaccine. Organized by the Global Alliance for Rabies Control (GARC) and supported by the World Health Organization (WHO), the day aims to highlight the importance of rabies vaccination in animals and public education on rabies prevention.

Rabies is a preventable viral disease transmitted through the bites of infected animals, primarily dogs. Left untreated, it is almost always fatal once symptoms appear, making awareness and early vaccination critical. The theme of World Rabies Day often changes each year, focusing on different aspects of prevention, treatment, or awareness.

The goal is to eliminate rabies by increasing vaccinations in animals, particularly dogs, and promoting public knowledge about post-exposure treatments in humans. Rabies can be found in a wide range of animals, but the probability of rabies infection is higher in mammals, particularly those that are capable of transmitting the virus to humans. Some of the animals most commonly associated with rabies include:

1. Dogs:

Dogs are the leading cause of rabies transmission to humans worldwide, especially in developing countries. Dog bites are responsible for the vast majority (up to 99%) of human rabies cases.

2. Bats:

In regions where dog rabies has been largely controlled (such as North America), bats are the primary source of rabies infections in humans. Bats can carry and transmit rabies even without biting.

3. Foxes:

Foxes are common carriers of rabies, particularly in Europe and parts of North America. Rabies outbreaks among fox populations are often closely monitored by wildlife health authorities.

4. Raccoons:

In North America, raccoons are another significant wildlife carrier of rabies. They can transmit the virus to humans and pets through bites or scratches.

5. Skunks:

Skunks are also known carriers, particularly in North America. They have a relatively high likelihood of contracting and spreading rabies.

6. Monkeys:

In some areas, such as parts of Asia and Africa, monkeys can be carriers of rabies, especially in regions with large populations of stray or wild monkeys.

7. Other Mammals:

Other mammals like coyotes, wolves, mongoose, ferrets, and cats can also contract and spread rabies. However, the risk varies depending on the region and the local control of rabies in domestic and wild animal populations.

Non-mammals (like birds, reptiles, amphibians, and fish) do not carry or transmit rabies.

The probability of rabies being found in a specific animal depends on regional control efforts, such as vaccination programs and the prevalence of the virus in wildlife populations.

Rabies symptoms in animals can vary depending on the species and the progression of the disease, but they generally follow a similar pattern as the virus affects the nervous system. There are two main forms of rabies: “furious rabies” and “paralytic (dumb) rabies.” Below are common symptoms in various animals:

1. Dogs:

Furious rabies:

Extreme aggression, restlessness, and irritability

Biting or snapping at objects, animals, or humans, sometimes inanimate objects

Hypersensitivity to light, sound, or touch

Foaming at the mouth due to difficulty swallowing

Paralytic rabies:

Weakness or paralysis, especially in the hind limbs

Drooping of the jaw due to paralysis of facial muscles

Loss of coordination, staggering

Quietness, with less aggression than in furious rabies

Death usually occurs within a few days after symptoms appear.

2. Cats:

Furious rabies:

Sudden unprovoked aggression, attacking other animals or humans

Excessive vocalization (howling, growling)

Foaming at the mouth, difficulty swallowing

Irritability and restlessness

Paralytic rabies:

Gradual paralysis, beginning with difficulty in walking

Drooping jaw, difficulty eating and drinking

Coma and eventual death

3. Bats:

Furious rabies:

Unusual daytime activity (as bats are nocturnal), flying erratically

Increased aggression and biting behavior

Paralytic rabies:

Weakness, inability to fly

Paralysis of the wings or legs

Death usually within a few days of symptom onset

4. Foxes, Raccoons, and Skunks:

Furious rabies:

Uncharacteristic boldness, approaching humans or animals without fear

Aggressive biting or attacking behavior

Excessive drooling and foaming at the mouth

Paralytic rabies:

Staggering, loss of coordination

Paralysis of limbs and facial muscles

Sudden death within days after the onset of symptoms

5. Cattle and Livestock:

Furious rabies:

Sudden aggression, attacking other animals or humans

Excessive vocalization (mooing or bellowing)

Excessive drooling and difficulty swallowing

Sudden restlessness or nervous behavior

Paralytic rabies:

Drooping head and jaw, inability to chew or swallow

Gradual paralysis of limbs and death

6. Monkeys:

Furious rabies:

Aggression, biting other monkeys or humans

Irritability, agitation, and restlessness

Frothing at the mouth

Paralytic rabies:

Lethargy and weakness

Paralysis starting in the limbs

Gradual loss of consciousness, leading to death

7. Horses:

Furious rabies:

Extreme agitation, biting or striking at other animals or people

Excessive salivation

Anxiety and restlessness

Paralytic rabies:

Progressive paralysis, usually starting in the hind limbs

Incoordination, stumbling

Difficulty swallowing, leading to eventual death

General Signs Across Species:

Change in behavior: Friendly animals may become aggressive, and shy animals may become bold.

Hypersensitivity: Animals may become sensitive to touch, light, or sound.

Foaming at the mouth: Difficulty swallowing causes excessive drooling and foaming.

Paralysis: As the disease progresses, the animal may experience partial or full paralysis.

Death: Death typically occurs within days of the onset of symptoms, particularly in the paralytic form.

Since rabies is almost always fatal after symptoms appear, it’s crucial to prevent rabies through vaccination and avoid contact with wild animals that behave unusually.

Rabies symptoms in humans typically appear in stages, beginning with general symptoms and progressing to severe neurological issues. Once symptoms develop, rabies is almost always fatal, making immediate treatment after exposure (post-exposure prophylaxis) crucial. The symptoms can be broken down into three phases: prodromal phase, acute neurological phase, and coma.

1. Prodromal Phase (Lasts 2–10 days):

This phase occurs after the incubation period (which can range from weeks to months after the bite or exposure).

Flu-like symptoms:

Fever

Fatigue or general weakness

Headache

Nausea and vomiting

Pain or itching at the bite site (even if the wound appears healed)

Anxiety, agitation, or irritability

Loss of appetite

Discomfort or a feeling of unease (malaise)

2. Acute Neurological Phase (Lasts 2–7 days):

This phase includes more severe and specific symptoms as the virus attacks the central nervous system.

Hydrophobia (fear of water):

One of the hallmark signs of rabies, where the person experiences intense spasms of the throat muscles when trying to drink, causing a fear of water.

Aerophobia (fear of air):

A fear or sensitivity to moving air, which can cause muscle spasms and pain.

Hyperactivity and agitation:

The person may become extremely restless and confused, with periods of agitation and aggressive behavior.

Hallucinations and delirium:

The person may experience vivid hallucinations, delusions, or altered mental states.

Excessive salivation and difficulty swallowing:

The virus can cause difficulty in swallowing, leading to excessive drooling or foaming at the mouth.

Seizures:

Uncontrolled body movements and convulsions.

Fever and increased heart rate

There are two primary forms of rabies in humans:

Furious rabies: This form is characterized by extreme agitation, hydrophobia, and aggressive behavior.

Paralytic rabies (dumb rabies): This form involves less aggression and more gradual muscle weakness, paralysis, and coma.

3. Coma and Death:

Paralysis: Gradual paralysis often starts in the extremities and progresses to the respiratory muscles, leading to difficulty breathing.

Coma: After the neurological symptoms progress, the person may fall into a coma.

Death: Death typically results from respiratory failure or cardiac arrest, often within days after the onset of severe symptoms if untreated.

Note:

Rabies is almost always fatal once symptoms appear. However, post-exposure prophylaxis (PEP)—a series of rabies vaccinations given shortly after exposure—can prevent the onset of symptoms and save lives.

If anyone is bitten or scratched by an animal suspected of having rabies, immediate medical attention is necessary. Washing the wound thoroughly and starting PEP as soon as possible is critical for preventing the disease from progressing.

 Prevention, Control, and Treatment of Rabies

1. Prevention

The best way to combat rabies is through prevention, which includes both vaccination and avoiding exposure.

Vaccination of Animals:

Dogs and Cats: Regular rabies vaccinations for pets are the most effective way to prevent the spread of rabies to humans. Pet owners should follow the recommended vaccination schedules.

Wildlife Vaccination: In some areas, wildlife (such as raccoons, foxes, and bats) are vaccinated using oral rabies vaccines distributed in baits to reduce the risk of transmission to humans and domestic animals.

Livestock Vaccination: In regions where rabies is prevalent, vaccinating livestock can help prevent the spread of rabies through farm animals.

Human Vaccination:

Pre-exposure Prophylaxis (PEP): People at high risk of rabies exposure (veterinarians, animal handlers, laboratory workers, travelers to areas where rabies is common, etc.) can receive rabies vaccinations before potential exposure to the virus. This involves a series of vaccines over a few weeks.

Avoiding Animal Bites:

Stay away from stray or wild animals, especially in regions where rabies is common.

Teach children to avoid contact with unfamiliar animals.

Do not approach or handle wild animals, especially if they are behaving strangely (e.g., being overly aggressive or unusually friendly).

Managing Pets:

Keep pets indoors or supervise them outdoors.

Avoid contact between pets and wild animals.

Public Health Awareness:

Community awareness programs can help educate people on the dangers of rabies, proper wound care, and the importance of vaccination.

2. Control

Rabies control is a multi-faceted approach involving animal management, public health efforts, and surveillance.

Stray Animal Control:

Managing and reducing the number of stray dogs and cats through sterilization and vaccination programs is key to reducing rabies transmission.

Trap-neuter-return (TNR) programs can help control feral cat populations, reducing the risk of rabies spread.

Rabies Surveillance:

Monitoring animal populations for signs of rabies and testing animals that display unusual behavior is important for tracking and controlling outbreaks.

Prompt reporting of animal bites or unusual wildlife behavior to local health authorities helps contain potential rabies risks.

Vaccination Campaigns:

Mass vaccination campaigns targeting domestic dogs and cats can drastically reduce the prevalence of rabies, especially in developing regions where the virus is endemic.

Wildlife Management:

In regions where rabies is common in wildlife, baiting programs using oral rabies vaccines can help reduce the virus among wild animal populations.

3. Treatment

Once symptoms of rabies appear, the disease is almost always fatal, but immediate action after exposure can prevent the onset of symptoms.

Post-Exposure Prophylaxis (PEP):

PEP is the most effective treatment after potential exposure to rabies. It involves a series of rabies vaccinations administered immediately after a person is bitten, scratched, or exposed to saliva from an infected animal.

Immediate Wound Care: Thoroughly wash the wound with soap and water for at least 15 minutes to remove as much virus as possible. Applying antiseptics like iodine or alcohol can also help reduce viral load.

Rabies Immunoglobulin (RIG): For people who have not been previously vaccinated, RIG may be given along with the first dose of the rabies vaccine. It provides immediate passive immunity by neutralizing the virus near the exposure site.

Vaccine Schedule: The PEP rabies vaccine is typically administered in a series of four to five doses over several weeks, depending on the individual’s vaccination history.

Milwaukee Protocol:

This experimental treatment has been used in a few rare cases where symptoms had already appeared, involving placing the patient in a medically induced coma to allow the immune system to fight the virus. However, the success rate is extremely low, and this treatment remains experimental.

Prof Sunit Kumar Mukhopadhayay

ECM APCRI (Association of Prevention & Control of Rabies in India) Asstt Editor IPHA Journal.