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In the last year, in particular in the Małopolskie Voivodeship, an increased number of rabies was recorded among wild animals. Rabies has also been found among “semi-wild” domestic animals, mainly in cats. During walks in the forest, and not only, you can come across boards informing about the area at risk of rabies. The warning should not be taken lightly, as rabies, despite medical advances, is still 100% deadly and incurable disease.
Rabies is a classic zoonosis (zoonotic disease) and is an acute viral infectious disease that damages the central nervous system.
The causative agent of rabies
Rabies is caused by viruses belonging to the family Rhabdoviridae kind lyssaviruses and we distinguish here: the classic rabies virus and related viruses – which can also cause the disease. Due to the antigenic diversity of viruses, there are 8 genotypes that occur in specific regions of the world and are characteristic for specific species of animals. The most popular is genotype 1, which includes the classic rabies virus.
Rabies virus remains viable for a long time, especially in a humid environment, in carcasses and is resistant to low temperatures, while it is sensitive to drying out, disinfectants and UV radiation.
Rabies virus is a typical neurotrophic virus, which means that it spreads and multiplies in the nervous system.
Rabies epidemiology
Rabies occurs all over the world and, depending on the source of infection, there are two epidemiological forms: urban and forest.
Forest rabies dominates in Europe and the Americas, where foxes are the main reservoir of the virus. The sources of rabies can also be raccoon dogs, martens, weasels, wild boars and bats. In contrast, urban rabies is characteristic in Asian countries, primarily in India and the Far East, where dogs and cats are the main reservoir of the disease, but the role of monkeys in transmitting the virus is also increasingly emphasized.
In Poland, the most common threats are wild animals and stray dogs and cats.
Fortunately, due to the commonness of vaccinating animals against rabies, sporadic cases of rabies in humans are reported. In our country in the years 1985 – 2006 there were 3 cases of the disease.
Ways of rabies infection
The primary route of rabies virus infection is the biting or slurping of damaged skin or mucous membranes by a diseased animal. The virus is excreted in large amounts with saliva. The possibility of infection as a result of inhaling the virus suspended in the air in caves inhabited by bats is also emphasized. The virus then enters the nervous system via the olfactory endings in the nose.
There are also reports of rabies as a result of corneal transplantation taken from deceased persons with undiagnosed rabies.
Rabies in humans
Symptoms of the disease appear 4-8 weeks after infection and the disease is divided into two or three stages:
- the teaser phase – malaise, headaches, insomnia or increased drowsiness, fever, numbness and burning sensation at the bite, restlessness, irritability – this phase lasts from 2 to 5 days
- paralysis phase – associated with encephalitis: disturbances of consciousness, visual and auditory hallucinations, convulsions; a characteristic symptom is hydrophobia (hydrophobia), which is manifested by a sudden contraction of the diaphragm and respiratory muscles, triggered by drinking fluids (reluctance to drink fluids; reaction to running water); circulatory and respiratory arrest may occur during an attack; most patients die in this phase of the disease
- coma phase – fatal
The classic symptoms that indicate a diagnosis of rabies are: hydrophobia and a feeling of numbness or burning (paraesthesia) at the site of the bite. After about 10 days of the disease, the person dies.
Rabies in animals
In animals, the disease lasts from 1 to 8 days and is mainly characterized by a change in behavior. Until now animals that have been calm become aggressive and vice versa. Wild animals feel a natural fear of people. Additionally, there are paresis and paralysis of the limbs, swallowing disorders, and saliva leakage. After this period, the animals die.
Diagnosis and treatment of rabies
The diagnosis of the disease is in most cases made posthumously based on the detection of the virus in the brain. It is also possible to detect the virus in sick humans and animals in saliva, the cerebrospinal fluid or in the brain biopsy.
The mortality of the disease is due to the lack of specific treatment. The patient requires compulsory hospitalization as part of intensive care. A sick person is potentially dangerous to the environment, because the patient’s saliva contains a large amount of the virus.
Rabies prevention
Due to the lack of effective treatment, the basic action comes down to extensive prophylactic methods.
The basic methods of prevention are aimed at the elimination of rabies virus reservoirs in the environment by:
– elimination of sick and suspected rabies animals
– vaccination of domestic and wild animals (especially foxes); periodic vaccine dropping actions
– rabies prevention in humans
– preventive preventive vaccinations (so-called pre-exposure vaccinations) are recommended in:
– people professionally exposed to rabies
– people going for a longer period to the countries of South-East Asia due to the high risk of rabies in cavers.
The vaccination schedule includes 3 basic doses on days 0 – 7 – 21 and a booster dose after one year. The protective period for vaccination is approx. 3 years. Vaccination is carried out on the following days: 0 (qualifying day for vaccination) – 3 – 7 – 14 – 30.
The vaccine doses are identical for children and adults. The vaccine is administered intramuscularly in the arm or in the thighs of children.
Passive immunization – in some situations, e.g. extensive bite or large salivation by a wild or domestic animal suspected of rabies, it is necessary to additionally administer a specific human anti-rabies serum
Does every person need to be vaccinated after contact with an animal:
YES – in case of being bitten or drooled by a wild animal – a wild animal not afraid of people should always be suspected of rabies
YES – in case of being bitten by a bat
YES – in the case of being bitten or drooled by a pet, “half-wild”, stray
YES – when bitten by a pet whose anti-rabies vaccination status is unknown
Domestic animals, possibly semi-wild (if caught), should be subjected to veterinary observation for a period of about 10-15 days. If rabies has been ruled out in the observed animal, the continuation of vaccinations that have already begun may be discontinued.
IMPORTANT TO REMEMBER
– avoid direct contact with wild animals
– do not touch the found dead animals – this fact should be reported to the police, municipal police or veterinary services
– systematically vaccinate your own dogs and cats
– do not release cats and dogs without the possibility of their control
– after biting or slicing on the wound, thoroughly rinse the wound several times with soap and water and disinfect
– it is imperative to see a doctor in order to assess the qualifications to start vaccination against rabies and to assess any additional vaccination against tetanus.
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