What is Rabies Disease?

Rabies is a viral disease that primarily affects the central nervous system (CNS) of mammals, including humans. This ancient disease, which has been recorded for millennia, is nearly always fatal once clinical symptoms appear. However, rabies is also preventable through vaccination, making it a focal point of public health efforts worldwide. 

Tabular Data:

Best Scrubs Collection

Rabies Virus

Rabies is caused by the rabies virus, a member of the Lyssavirus genus within the family Rhabdoviridae. It is a single-stranded RNA virus, which means it mutates easily, and is neurotropic, meaning it primarily affects nervous tissue. The virus typically enters the body through the bite of an infected animal, but it can also be transmitted through scratches or exposure to saliva in open wounds or mucous membranes like the eyes or mouth.

Transmission

Rabies is most commonly transmitted through the bite of a rabid animal. In many parts of the world, especially in Asia and Africa, domestic dogs are the primary source of human rabies infections. However, in regions like North America and Europe, where dog vaccination programs have been more successful, wild animals like bats, raccoons, skunks, and foxes are more common vectors.

• Humans and animals get infected by the virus through bites or scratches that break the skin and allow the virus to enter.
•  It's important to note that rabies cannot be transmitted through casual contact, such as petting an infected animal, or through contact with their fur, blood, urine, or feces. Additionally, rabies is not spread through the air.
• In rare cases, rabies can be transmitted through organ transplants from an infected donor, though this is extremely uncommon and typically only occurs when the donor's rabies status is unknown.

Explore All Women's Scrub

Symptoms of Rabies

The clinical course of rabies typically consists of five stages: incubation, prodrome, acute neurologic phase, coma, and death. Once symptoms of rabies appear, the disease is nearly always fatal, making early intervention through vaccination critical.

• Incubation Period: This phase can last anywhere from a few weeks to several months, with an average duration of 1-3 months. During this time, the virus is present in the body but is not yet causing symptoms. The length of the incubation period is influenced by factors such as the location of the bite (bites closer to the head and neck tend to result in shorter incubation periods) and the amount of virus introduced into the wound.

• Prodromal Phase: Early symptoms, which last 2-10 days, may mimic other illnesses. These include fever, headache, fatigue, nausea, vomiting, and pain or tingling at the site of the bite. These initial symptoms are non-specific, making it difficult to diagnose rabies at this stage without a known history of exposure.
• Acute Neurological Phase: Once the virus reaches the brain, neurological symptoms begin to manifest. This is when the classic signs of rabies appear, including agitation, confusion, hyperactivity, hallucinations, muscle spasms, seizures, and paralysis. Hydrophobia (fear of water) is a hallmark symptom, caused by spasms in the throat and larynx when attempting to swallow. This is one of the reasons why rabies is sometimes called "mad dog disease."
• Coma: As the disease progresses, patients fall into a coma. Respiratory failure often occurs as the brainstem is affected, leading to death if not supported by mechanical ventilation.
• Death: In the absence of advanced medical care, death typically occurs within days of the onset of neurological symptoms, either due to respiratory failure or widespread organ failure.

Diagnosis

Rabies can be difficult to diagnose in its early stages, as symptoms are non-specific. Once neurological symptoms appear, rabies can often be suspected based on clinical presentation and history of animal exposure. Laboratory tests can help confirm the diagnosis. These include:

• Direct Fluorescent Antibody (DFA) Test: This is the most widely used diagnostic test, which involves detecting viral antigens in tissue samples, usually taken from the skin, brain, or cornea.
• RT-PCR: Detecting viral RNA in saliva, cerebrospinal fluid, or tissues using reverse transcription polymerase chain reaction (RT-PCR) is another method of diagnosis.
• Histopathology: The presence of Negri bodies, which are characteristic inclusions in infected neurons, is pathognomonic of rabies.

Prevention

Rabies is a vaccine-preventable disease, and prevention strategies include both pre-exposure and post-exposure prophylaxis (PEP).

• Pre-exposure Vaccination: People at high risk of rabies exposure, such as veterinarians, laboratory workers, and travelers to areas with endemic rabies, can receive a series of rabies vaccinations to protect against the disease. These vaccines help build immunity before potential exposure to the virus.
• Post-exposure Prophylaxis (PEP): The most critical aspect of rabies prevention is the prompt administration of PEP following potential exposure. This involves immediate wound cleaning and a series of rabies vaccinations. If the patient has not been vaccinated before, rabies immunoglobulin (RIG) is also administered to provide immediate passive immunity.

PEP is highly effective when administered promptly. If given before the onset of symptoms, it nearly always prevents the development of rabies.

Challenges and Solutions in Rabies Control

The fight against rabies faces several challenges, particularly in low-resource settings. These include:

• Lack of Access to Vaccines: Many communities in rabies-endemic areas lack access to life-saving rabies vaccines, both for humans and animals. This issue is compounded by logistical challenges in maintaining cold chains for vaccine storage and transportation.
• Lack of Awareness: Public awareness of rabies and its prevention is often low in regions where the disease is most prevalent. Many people may not seek medical attention after a bite or may be unaware that PEP is available.
• Stray Dog Populations: In many developing countries, large populations of stray dogs contribute to the spread of rabies. Controlling these populations through vaccination and sterilization programs is essential for reducing the incidence of rabies.

Shop the Best Lab Coats from Here!