What are the symptoms of rabies?

THE Reims University Hospital confirmed Thursday October 12, 2023 THE death of a woman contaminated with rabies. She was returning from a trip to a Maghreb country where she had been injured by a cat. Upon taking charge, “the medical team identified that the patient presented compatible clinical signs with a suspected diagnosis of rabies” specifies the press release detailed by Le Figaro. This is a very rare case in France. Rage is a viral diseasecaused by viruses of the family lyssavirus. It’s about a zoonosis, it is therefore a disease transmitted to humans by animals but which is not transmitted between humans. THE first signs appear on average after an incubation of one to two months.

Definition: what is rabies?

Rage is a viral disease, caused by viruses of the lyssavirus family. It is a zoonosis, therefore it is a disease transmitted to humans by animals. Rabies causes encephalitis, a serious infection and inflammation of the brain. “Rabies is almost always fatal once the first symptoms appear”adds Dr. Perrine Parize, deputy head of the National Rabies Reference Center at the Pasteur Institute.

What are the symptoms of rabies?

After contamination by a rabid animal, first signs of the disease appear on average after a period of 1 to 2 months which corresponds to the incubation period. This period is variable and can last just a few days after the bite or several months. At first :

• common signs like fever
• pain, tingling, itching or burning sensations at the site of the injury.

Rabies then affects the brain and causes encephalitis (infection of the nervous system central). The main symptoms are:

• Anxiety, restlessness
• Mental confusion
• Hallucinations
• Hydrophobia (intense fear of water and difficulty drinking due to muscle spasms in the throat)
• Aerophobia (fear of drafts or fresh air)
• Photophobia (sensitivity to light)
• Sneck muscle spasms
• Partial or total paralysis, especially of the muscles of the throat and face
• Hypersalivation (often associated with difficulty swallowing)
• Voltage anomalies,
• Pupil abnormalities, hyper-salivation notably. This sign is also very characteristic in dog rabies.

After the appearance of the first symptoms, the progression is rapid and death generally occurs within a few days. specifies Perrine Parize. THE patients fall into a deep comafollowed by deathgenerally due to respiratory failure.

The WHO estimates that 99% of human rabies deaths are linked to a dog bite. “The disease is transmitted to humans by direct contact with a rabid animal (via its saliva)either by bite, by scratch, or by licking of a wound or mucous membrane. Most deaths occur in countries where dogs and certain wild mammals can be rabid, and where access to preventative treatments for the disease is not available to the most vulnerable populations. Africa and Asia bear the brunt of human rabies mortality“says the specialist. “There is no risk of transmission of rabies from humans to humans apart from extremely rare cases of contamination following organ or tissue transplants,” specifies the scientist. Rabies is not transmitted by petting an animal.

What are the diagnostic tests for rabies?

The diagnosis can be carried out in animals if the veterinarian suspects this disease (in an animal illegally imported from a country where rabies still circulates in dogs for example). In humans, there is no no diagnostic test for the disease before the appearance of encephalitis symptoms. In France, rabies diagnoses are often suspected by intensivists or infectious disease specialists in hospitals. “The disease is suspected because the clinical symptoms and patient history are suggestive. Has he been exposed to animals by bite or scratch abroad or exposed to a bat or an animal illegally imported into France? When all these elements are combined, the only laboratory in France authorized for human diagnosis is the CNR for rabies at the Pasteur Institute. Diagnosis is made by PCR on saliva and skin biopsy samples”, explains Dr. Parize.

What are the treatments for rabies?

There does not exist no treatment to treat rabies. We only have preventive treatments. “The only preventive treatment for rabies is post-exposure prophylaxis Who must be started as quickly as possible after the bite of an animal suspected of rabies. The vaccine is 100% effective in preventing infection. In France, we find rabies centers in almost every department, where we treat patients bitten or scratched by an animal suspected of rabies. Only these centers are authorized to deliver post-exposure prophylaxis. The treatment consists of a series of 4 or 5 vaccine injections and sometimes the injection of anti-rabies immunoglobulins, i.e. antibodies, directed directly against rabies”, lists the specialist. These treatments should be administered in the days following the bite or scratch, during the incubation period and before symptoms appear.

Who should get vaccinated against rabies?

The vaccine against rabies Pasteur® rabies vaccine it’s not mandatory In France. It is recommended :

• after exposure to a suspicious animal
• during a stay in a country at risk “especially in children“explains Perrine Parize.
• when you present an occupational risk of exposure to rabies (veterinarians, laboratory personnel who diagnose rabies or produce vaccines or chiropterologists who are in contact with bats)

The specialist advises discussing it with your doctor – all doctors can vaccinate against rabies as a preventative measure – or going to an international vaccination center where doctors specializing in traveler’s illnesses inform the public.

The situation most at risk for French nationals is a exposure to an animal in a country where terrestrial mammal rabies is still present (everywhere in the world except Western Europe, Japan, Australia, etc.) on the occasion of a journey. To protect yourself, during a stay abroad in a country at risk, do not touch an unknown animal and not bring it back with you. The animal can become infected with rabies and transmit the disease to people or other animals.

To travel with your pet, preliminary steps are required (non-compliance is subject to criminal sanctions):

• contact your veterinarian early enough before departure (1 to 4 months depending on the destination);
• your animal must be identified and accompanied by its up-to-date passport;
• your pet’s vaccinations must be up to date, particularly against rabies;
• a blood test for serum titration of anti-rabies antibodies is necessary before traveling to certain countries at risk of rabies.

In the event of exposure by bite, scratch or lick in France with a bat or an illegally imported animal or in the event of exposure with an animal abroad, it is appropriate to contact a rabies center immediately. “And when you travel, I advise you to find out about the risks before departure from your doctor or to go to an International Vaccination Center”adds Perrine Parize.

Which countries are at risk of rabies?

The list of countries at risk of rabies was updated in March 2022 by the The Minister of Agriculture. Among them :

• Afghanistan
• South Africa
• Algeria
• Angola
• Saudi Arabia
• Argentina
• Armenia
• Azerbaijan
• Bangladesh
• Belize
• Benign
• Bhutan
• Belarus
• Bolivia
• Botswana
• Brazil
• Burkina Faso
• Burundi
• Cambodia
• Cameroon
• Canada
• Chile
• China (People’s Republic of)
• Colombia
• Costa Rica
• Cuba
• Egypt
• United States of America
• Hungary
• India
• Madagascar
• Morocco
• Mexico
• Norway
• Poland
• Russia
• Thailand
• Tunisia
• Ukraine
• Venezuela
• Vietnam

Thanks to Dr. Perrine Parize, deputy head of the National Reference Center (CNR) for rabies at the Pasteur Institute. Comments collected in March 2021.