Rabies – symptoms, vaccine

Proven content

Rabies is a serious infectious disease caused by being bitten by a predatory or domestic animal that carries it. Infection occurs by transmission of the virus with saliva to a usually bitten wound.

The causes of rabies

Rabies is caused by RNA-virus from the rhabdovirus family, which is a specific example of a neurotrophic virus, i.e. a virus that spreads and multiplies in the nervous system. In addition to Australia and island countries such as Japan or England, rabies is present in other continents. A reservoir for the germ (depending on the continent) there are predators, e.g. foxes, hedgehogs, squirrels, bats, dogs, sometimes other wild or domesticated animals, unexpectedly infected with rabies (e.g. cows, deer, dogs, cats). It should be mentioned that small rodents are not involved in the transport of rabies to humans, therefore biting by a rat, hamster or mouse is not an indication for rabies vaccination.

Rabies – the route of infection

Rabies infection occurs through the transmission of the virus with saliva to the wound, most often bitten (damaged skin, mucous membranes, conjunctiva). On the other hand, the contact of the virus that causes rabies with intact human skin does not pose a risk of infection. A person suffering from rabies also secretes viruses with saliva. So far, there is no evidence of the possibility of infection by direct contact with a human suffering from rabies. Similarly, drinking milk from cows that have contracted rabies does not pose the risk of transmission of rabies.

Once transferred to the wound, the virus travels along the nerve fibers from the periphery, i.e. the bite site, to the central nervous system (CNS), where it causes specific inflammation of the nervous tissue, after which its centrifugal spread along all nerve fibers takes place.

Sensitivity to rabies infection is almost universal, but the disease depends on the number of viruses that penetrated the saliva of the infected animal, i.e. the depth or extent of the wound caused by them, and the bite site in terms of its innervation and proximity to the central nervous system. The infection is the more dangerous, and the ailments develop the faster, the closer to the head the rabies virus has been bitten and placed. For this reason, the bite and infection of the nasal mucosa, face or neck are particularly dangerous, because the virus penetrates quickly, and the central nervous system is very close.

The symptoms of rabies

The symptoms of rabies are related to its incubation period, which in humans is 3 to 12 weeks, but it can be shorter or much longer, in some cases reaching even a year. Symptoms can develop very quickly if the head, face, neck or neck are stung (as mentioned).

Initially, there is hyperemia, pain and hyperesthesia of tissues at the site of the bite, as well as tingling, burning or numbness. Often observed:

1. low-grade fever,
2. headaches (located mainly in the occipital area),
3. bad mood,
4. nausea and vomiting.

After this initial period, the full clinical picture of rabies begins to develop, including high sensitivity to light and sound, psychomotor agitation, skin hyperesthesia, visual and auditory hallucinations, body temperature, lacrimation and drooling. She finally shows up the most characteristic feature of rabies, which is hydrophobia, which is characterized by very painful muscle spasms in the mouth, throat and larynx that occur initially only when drinking, then at the mere sight of water, making it impossible to quench your thirst. In addition, respiratory muscle spasms, tremors and convulsions may also occur. The patient’s breathing becomes tiring and facial cyanosis appears. Most people infected with rabies die already when they are agitated, most often during a seizure. Some people experience a period of flaccid paralysis and coma after the agitation period.

Attention! Rabies is an incurable disease (it is only possible to alleviate its symptoms in a hospital setting), because so far no preparations that could cure the patient have been discovered.

Rabies – preventive treatment

Prophylaxis in people who are bitten and suspected of being infected with rabies consists in:

1. adequate protection of the wound,
2. quick reporting to the doctor,
3. examining the health of an animal that has bitten a human.

The wounds or even minor abrasions to the epidermis resulting from biting the animal by the animal should be washed for 10-15 minutes with hot water with soap (preferably a 20% solution) or other detergent. You can also use antiseptics. Inhibition of wound bleeding is contraindicated, except when a large arterial vessel is damaged and the haemorrhage is very intense. Finally, the wound should be treated with a sterile dressing and immediately see a doctor who will decide on further treatment.

Regardless of the bite, even shallow cuts or abrasions to the epidermis, scratches or open wounds are contaminated with potentially infectious material, as they may contain rabies viruses (saliva, brain, cerebrospinal fluid), and may also become a source and gateway of infection, although such exposure rarely causes rabies infection in humans. Therefore, it should be remembered that even minor wounds do not eliminate the need for thorough, individual assessment in terms of preventive treatment.

The contact of a human with a sick animal, consisting in stroking or even contact with its blood, urine or feces, does not constitute a risk of infection, if the human has not been injured and has not been in contact with the saliva of the sick animal. The mildness of wild animals may give rise to a suspicion that there is a disease in them and the danger of a subsequent bite and infection with rabies.

Rabies – diagnosis

In any case of biting a human, the possibility of infection with rabies from the biting animal should be eliminated.

Persons who may have become infected as a result of:

1. bitten by a wild animal,
2. bites by a rabid pet or an animal suspected of rabies,
3. contamination of mucous membranes or damaged skin with saliva or the brain substance of an angry or suspected rabies animal, because the animal has viruses in the saliva 2 weeks before the onset of the disease symptoms,
4. bitten by an animal of unknown origin (or even a domestic animal) that is missing.

In many cases, two major mistakes are made:

1. You touch free-living animals that you can easily approach and catch because they are sick, most often from rabies, and behavioral changes may be the first symptom of a developing disease.
2. A dog or a cat is killed in the event of aggressiveness and biting of a human by this animal, which makes it impossible to observe it and determine its health condition by veterinary medicine. Each rabid animal dies five days after the onset of the disease, so surviving 14 days from the bite shows that the animal was healthy at the time of biting and there were no germs in its saliva, so vaccination is unnecessary. Even if they are implemented, it is unnecessary after this period. On the other hand, in the case of killing an animal, the results of veterinary examinations, especially of its head, are often impossible or late, and in each such case, a properly initiated vaccination must necessarily be continued until the end.

Rabies – vaccine

Active immunization against rabies is the administration of a vaccine, which consists of inactivated rabies viruses.

Passive immunization it is used in every case of bite by an animal with confirmed rabies, as well as in the case of numerous and dangerous wounds due to their location. The anti-rabies serum or horse gamma globulin is then used.

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