Definition

Rabies is an infection of the central nervous system caused by the rabies virus. This disease is also commonly referred to as hydrophobia. The rabies virus is extremely deadly, causing 55,000 deaths annually. Rabies can be transmitted from animals to humans through exposure to animal saliva, such as licking wounds, licking mucous membranes (mouth, nose, eyes, genitals), and scratches. Animals that can transmit rabies include dogs, monkeys, ferrets, cats, and bats.

More than 15 million people are exposed to the rabies virus, with 40% of them being children under the age of 15. In Indonesia, data shows that only nine provinces are rabies-free: Bangka Belitung, Riau, DKI Jakarta, Central Java, Yogyakarta, East Java, West Kalimantan, West Papua, and Papua. In Indonesia, there are at least 168 new cases per year, with 98% of them transmitted from dog bites.

Due to its deadly nature, rabies vaccination is necessary, especially for people with high exposure risks.

Causes

The rabies virus belongs to the Rhabdoviridae family and is found in animals. After a bite or lick occurs, rabies will enter an incubation phase lasting 3 to 8 weeks, during which the virus will replicate in the nerves. The virus then travels through the nerves to the central nervous system, namely the brain and spinal cord. At this stage, the bite wound has usually healed. Once it reaches the brain, the virus spreads rapidly to the brainstem, nerves, and saliva for further transmission.

Animals that can transmit rabies include:

• Livestock and pets, such as cats, cows, dogs, goats, and horses.
• Wild animals, such as bats, wolves, raccoons, monkeys, beavers, and skunks.

Risk factor

Factors that can increase the risk of contracting rabies include:

• Travelling to or living in rabies-endemic areas.
• Engaging in activities with animals, such as bat hunting or camping in the wild.
• Working in the veterinary field.
• Working in a laboratory researching rabies.
• Animal bites in areas closer to the brain, such as the face or neck, can cause the rabies virus to reach the brain more quickly, leading to earlier symptom onset.
• Having weakened immune conditions, such as HIV/AIDS, diabetes, or taking immunosuppressive drugs.
• Bat bites and scratches.

Symptoms

The initial symptoms of rabies can resemble the flu and last for several days. Advanced symptoms of rabies include:

• Fever.
• Headache.
• Nausea and vomiting.
• Restlessness or agitation.
• Confusion and anxiety.
• Hyperactivity.
• Difficulty swallowing.
• Excessive salivation.
• Fear of drinking water due to inability to swallow water.
• Fear of air blowing on the face.
• Hallucinations.
• Inability to sleep.
• Weakness in some parts of the body in a small percentage of patients.

Diagnosis

Doctors diagnose rabies based on symptom data and a history of animal bites or contact with wild animals, physical examinations, and supporting tests. After a wild animal bite, you cannot predict whether the animal had rabies or whether you were exposed to rabies. Therefore, supportive tests are important to confirm rabies. Doctors will conduct laboratory tests, such as PCR from saliva, cerebrospinal fluid (CSF) analysis, and antibody tests done two weeks after the bite.

Doctors will also categorize cases based on World Health Organization (WHO) criteria:

• Category I: Touching or feeding wild animals, or licking intact skin.
• Category II: Bites on the skin and/or non-bleeding scratches.
• Category III: Bites or scratches causing skin breakage or wounds.

Management

To date, there is no effective treatment for rabies. Although a small number of people survive rabies infection, most cases result in death. Early treatment and rapid administration of rabies vaccine or serum can help prevent rabies.

If you are bitten by a wild animal with rabies, you will receive several injections to prevent rabies from further infecting you. If the biting animal cannot be found and tested, it is safer to assume the animal has rabies. There are two types of rabies medications:

• Rabies vaccine (VAR): Intended for Category II and III. The rabies vaccine is given as an injection in the arm. If you have never received a rabies vaccine before, you will receive four doses over the next 14 days. If you have been vaccinated before, you will receive two injections within three days.
• Rabies serum (SAR): Intended to prevent rabies from infecting you. This serum consists of immunoglobulin (antibodies). SAR is not given if you have already been vaccinated against rabies. This medication is injected into the area suspected of rabies exposure or a non-bleeding bite.

VAR and SAR are safe for pregnant women and children. In cases of active rabies infection with the above symptoms, VAR and SAR are not beneficial.

In some cases, it is important to determine whether the animal you contacted has rabies risk. This procedure helps determine whether you need VAR/SAR.

• Pets and livestock: These animals will be observed for 10 days to check for rabies signs and symptoms. If none are present, you do not need SAR or VAR. Consult your doctor.
• Wild animals caught: These can be tested to determine rabies status, usually by examining the brain. If no infection is found, you do not need SAR or VAR.
• Uncaptured animals: If the animal cannot be captured, consult your doctor on the next steps.

Complications

Rabies can cause complications such as respiratory failure, acid-base balance changes in the body and brain fluids, brain swelling, and coma. In some cases, rabies can lead to death. Rapid treatment can help prevent more severe complications.

Prevention

Steps to prevent rabies transmission include:

• Vaccinate your pets: Cats and dogs can receive rabies vaccinations. Consult your veterinarian.
• Supervise your pets: Especially when they are outdoors to prevent contact with wild animals.
• Protect small pets from predators: Rabbits and other small pets like hamsters should be kept in cages to avoid wild animal bites. These small animals cannot be vaccinated against rabies.
• Avoid wild animals: Wild animals with rabies usually are not afraid of humans. Wild animals are generally not friendly and do not approach humans, so be cautious of wild animals that come close or seem unafraid.
• Consider rabies vaccination: If you travel or frequently are around animals that may have rabies.

When to see a doctor?

Seek immediate help at a nearby healthcare facility if you are bitten by an animal or exposed to an animal suspected of having rabies. The doctor will consider further treatment based on the type of wound you have.

Even if you are unsure of a bite or contact with a wild animal, see a doctor immediately. This can happen if a bat enters your home while you sleep, as bats can bite without waking you. If you find a child or disabled person in contact with a bat, take them to the nearest healthcare facility immediately.

Looking for more information about other diseases? Click here!