Key points:
- Rabies is a viral encephalitis that is almost always fatal.
- The rabies virus can be transmitted from animals to humans through bites, scratches, or licking of a wound, broken skin, or mucous membrane.
- There is no longer terrestrial rabies in France, but it still exists on all continents.
- In case of potential exposure to rabies, it is advisable to seek urgent medical attention in order to carry out a curative vaccination protocol that will prevent the development of the disease.
- It is recommended to avoid all contact with animals while travelling and to get vaccinated preventively.
What is rage?
Rabies is a zoonotic infectious disease (transmitted from animals to humans), caused by the rabies virus, which belongs to the genus Lyssavirus and the family of RhabdoviridaeThe virus, present in the saliva of infected mammals, is transmitted through bites, scratches, or licks on a wound, skin lesion, or mucous membrane. Once the central nervous system is affected, the disease is almost always fatal. Although the reservoir is primarily dogs (98% of human rabies cases are due to canine viruses), rabies also affects bats, cats, potentially any wild animal (fox, wolf, raccoon, skunk, mongoose, jackal, coyote, etc.), and livestock.
Rage in the world
Rabies is present on every continent, particularly in Africa, Asia, and Latin America. It is estimated that approximately 60000 people die from rabies each year, with 35% of these deaths occurring in Africa and 60% in Asia. However, this figure is very likely an underestimate due to massive underreporting by the most affected countries and a lack of access to diagnostic methods. Canine rabies disappeared from Western and Central Europe during the first half of the 20th century, but it still exists in Eastern Europe, where data is extremely scarce. In France, it has been officially declared eradicated since 200. It has become primarily an imported disease, with only about twenty cases recorded since 1970.
The symptoms of rabies
The rabies virus is a neurotropic virus that invades the nervous system, first peripherally (from the virus's entry point) and then centrally, where it causes acute encephalitis. The incubation period is highly variable (from a few days to several years) depending on the viral load and the type of lesion, but on average, it is 1 to 2 months. Before the onset of the main neurological signs, there may be prodromal symptoms, which are inconsistent and nonspecific, such as neuropathic pain or paresthesia at the site of inoculation (1/3 of patients). The disease then manifests in two main forms, which are also variable:
- Furious rage (2/3 of cases): combining altered consciousness, phobic spasms, spontaneous inspiratory spasms, autonomic nervous system dysfunction, superficial and deep sensory deficits and decreased osteotendinous reflexes.
- Paralytic rabies (1/3 of cases): also associated with sensory deficit and areflexia, phobic spasms in half of the cases, but above all an ascending motor deficit predominantly affecting the proximal segments and face, urinary incontinence, and abnormal muscle relaxation (deltoids and intercostals). Consciousness remains normal until the final phase.
Finally, both of these conditions end in coma and death within 5 to 11 days.
Diagnosing rabies
There is no diagnostic test available for humans following an animal bite (or scratch or lick). Diagnosis can be made once symptoms have appeared by detecting the virus using PCR in saliva and skin biopsies (possibly in cerebrospinal fluid and serum, but this is less reliable) or post-mortem on brain and skin biopsies. These virological analyses can only be performed in a reference laboratory. In France, this is the National Reference Center for Rabies (CNR Rabies) at the Pasteur Institute in Paris.
Treatment of rabies
There is no treatment for rabiesHowever, and fortunately, a human bitten by a rabid animal is not inevitably doomed, as the slow development of the virus can be used to good effect. After potential exposure to the rabies virus, it is recommended to immediately clean the wound with soapy water for 15 minutes and disinfect it, then seek urgent medical attention within 48 hours. Depending on the type of wound, the animal involved, and the geographical area where the incident occurred, a post-exposure curative rabies protocol A preventive rabies vaccination (PPE) program will be implemented, including vaccination and possibly the injection of rabies immunoglobulins (antibodies) to neutralize the virus more quickly. In France, PPE can only be administered at an approved rabies treatment center (CAR). Implementing a preventive rabies vaccination protocol reduces the time to treatment and the duration of the curative protocol (see next chapter). It is also important to verify tetanus vaccination status and, if necessary, administer antibiotic therapy.
Rabies prevention
Prevention for travelers relies primarily on avoiding all contact with animals, regardless of their behavior, even if they are familiar or appear healthy (animals can shed the virus in their saliva two weeks before the onset of symptoms). It should be noted that rabies is not transmitted through the blood, urine, or feces of an infected animal. However, it is recommended to avoid all contact with these substances, as they can carry other diseases. Every traveler should know what to do in case of potential exposure to the rabies virus (bite, scratch, and/or licking of a lesion or mucous membrane), regardless of their vaccination status (local treatment and emergency consultation for appropriate post-exposure prophylaxis). A [specific type of treatment/treatment] may be offered. pre-exposure vaccination Pre-exposure vaccination is recommended for all travelers, especially those staying for extended periods, in isolated areas, in areas of high disease endemicity, or who are engaged in high-risk activities. Preventive vaccination is particularly recommended for young children who are old enough to walk, due to their size being similar to that of animals, their lower level of wariness towards them, and the risk that they may not report even minimal contact. Pre-exposure vaccination consists of two or three doses of vaccine (days 0-7, plus or minus days 21 or 28). Following this protocol allows exposed travelers a 7-day window to seek medical attention (versus 48 hours for unvaccinated individuals) and enables them to benefit from a faster post-exposure protocol: two doses of vaccine administered three days apart. Three doses of pre-exposure vaccination are also recommended for exposed professionals (veterinarians, laboratory personnel, chiropterologists, etc.), with booster doses as needed based on individual circumstances and serological testing.
FAQ
Rabies is transmitted from animals to humans through the saliva of an infected animal, usually during a bite. It can also be transmitted through a scratch, or by licking an open wound or mucous membrane.
After being bitten, scratched, or licked on a wound by a suspected animal, it is essential to consult a doctor for prompt treatment and possible post-exposure vaccination. There is no diagnostic method available at this stage.
No, terrestrial rabies has been eradicated and France has been declared rabies-free by the WHO since 2001. There is a potential risk in case of contact with a bat.
There is no cure for rabies. However, it can be controlled if treated promptly. under 48 hours after infection, with the administration of the rabies vaccine or rabies serotherapy.
Louis Pasteur discovered the rabies vaccine by isolating and attenuating the virus, then successfully testing this vaccine on animals and humans. His work not only saved lives but also marked a turning point in preventive medicine.
