Rabies: prevention measures, bite tactics and rules for keeping pets

p>Rabies is an extremely dangerous viral disease. It severely affects the spinal cord and brain, often leading to death. Rabies occurs naturally among all mammals and is transmitted through biological fluids (mainly saliva). People can become infected with it by being bitten by infected animals - most often cats, dogs, raccoons, rabbits, foxes, wolves, ferrets, bats, etc.

At the initial stage of the disease, the patient begins to experience increased salivation coupled with a fear of water. This is accompanied by a depressed state, followed by attacks of excitement and aggression. Those people who are at risk of developing this disease need to be vaccinated.

Symptoms of rabies in humans

As a rule, people infected with rabies do not develop any symptoms until the last stage of the disease, when it can no longer be cured. The incubation period itself can range from a week to a year and lasts 20-90 days on average. At the same time, the signs of rabies themselves often appear only a few days before the death of the patient:

• before the main symptoms appear, the bite site may become red, swollen, and begin to itch;
• fever;
• malaise and headache;
• loss of appetite, vomiting, diarrhea, nausea;
• depression;
• sleep disturbances, general restlessness;
• sensitivity to visual and auditory stimuli increases;
• apathy, anxiety and a depressed state of consciousness in the patient are replaced by attacks of aggression, anxiety and agitation. During attacks of excitement, a person’s heart rate and breathing become more frequent;
• swallowing and breathing disorders;
• fear of water or hydrophobia (when talking about water or trying to drink it, the patient experiences horror, he begins to experience spasms of the larynx and pharynx, which are accompanied by painful sensations);
• intense salivation;
• convulsions;
• partial paralysis;
• hallucinations.

Rabies is an extremely dangerous viral disease characterized by severe damage to the brain and spinal cord. It often ends in death.

Rabies occurs in all mammals and is transmitted through body fluids, mainly saliva. A person, as a rule, becomes infected with it as a result of the bite of an infected animal, most often a dog, cat, rabbit, ferret, fox, wolf, raccoon, bat, etc.

At the initial stage, the disease is manifested by increased salivation and fear of water, as well as a depressed state, which is replaced by attacks of aggression and excitement.

People at risk of developing rabies should be vaccinated.

Unfortunately, the appearance of symptoms of the disease inevitably ends in death, so treatment only involves alleviating the patient’s condition.

Synonyms Russian

Rabies, hydrophobia, hydrophobia.

English synonyms

Rabies, Hydrophobia, Canine madness, Lyssa, Madnessan.

Symptoms

Rabies usually does not cause any symptoms until the last stage of the disease, when treatment is no longer possible. The incubation period (from infection to the onset of symptoms) ranges from 7 days to 1 year, with an average of 20-90 days. Signs of the disease often appear several days before the patient’s death:

• before the main symptoms appear, swelling, redness, itching may occur at the site of the bite,
• fever,
• headache, malaise,
• loss of appetite, nausea, vomiting, diarrhea,
• anxiety, sleep disturbances,
• depression,
• increased sensitivity to auditory and visual stimuli,
• a depressed state of consciousness, anxiety, and apathy are replaced by attacks of excitement, restlessness, and aggression. Attacks of excitement are accompanied by increased breathing and heart rate,
• breathing and swallowing disorders,
• hydrophobia - fear of water (when talking about it or trying to drink, the patient experiences horror, he experiences painful spasms of the pharynx and larynx),
• excessive salivation
• hallucinations,
• convulsions,
• partial paralysis

General information about the disease

Rabies is a dangerous viral disease that is characterized by severe damage to the central nervous system (brain and spinal cord). At the initial stage it is asymptomatic, symptoms appear at a later stage, when treatment is no longer possible.

The prevalence of rabies depends on the level of vaccination of domestic animals. It is most common in rural areas and occurs more often in the summer.

Rabies can affect all mammals and is transmitted through body fluids, mainly saliva. In humans, rabies infection usually occurs as a result of a bite from an infected animal, or contact with the saliva of an infected animal on damaged skin, mucous membranes of the mouth, nose, and eyes. Rabies is transmitted much less frequently by eating infected meat. The disease does not spread from person to person; infection through organ transplantation from infected donors can occur extremely rarely.

Most often, a person becomes infected from domestic animals - dogs, cats, rabbits, horses, ferrets, less often - from wild ones - foxes, raccoon dogs, wolves, raccoons, bats, etc. Wild animals, in turn, infect domestic animals with rabies.

After the virus enters the body through the skin or mucous membrane, it reaches the spinal cord and brain along nerve fibers, where it is fixed and begins to divide. Encephalitis occurs - inflammation of the brain. This leads to increased reflex excitability and the development of paralysis. The virus then spreads along the nerve fibers in the opposite direction, entering the liver, kidneys, adrenal glands, skin, heart, salivary glands, skeleton, causing disruption of the nervous system and dysfunction of various organs.

The rate of spread of the virus depends on the location of the bite (for bites of the head or hands it will be high), its depth, the number of pathogens that have entered the wound, the activity of microorganisms, and the immune status of the infected person.

The incubation period of the disease averages 20-90 days, but can vary from a week to one year. Once symptoms appear, death is usually inevitable.

Death usually occurs as a result of damage to the respiratory center, which entails respiratory arrest.

Who is at risk?

• Those who have been bitten by domestic or wild animals.
• Residents of rural areas who keep animals at home that are not vaccinated against rabies.
• Traveling to developing countries (Africa, Southeast Asia).
• Traveling into nature and coming into contact with wild animals (foxes, raccoons, bats, etc.)
• Hunters, trappers.
• Employees of zoos, nurseries, animal shelters.
• Veterinarians.
• Working with the rabies virus in the laboratory.

Diagnostics

The diagnosis of rabies is assumed when symptoms of the disease are present after an animal bite and is confirmed by examining a skin sample from the back of the head and isolating the virus from saliva, lacrimal and cerebrospinal fluid.

Laboratory research

• Complete blood count (without leukocyte formula and ESR). The white blood cell count may be elevated.
• General urine analysis. With rabies, there may be a significant increase in the number of leukocytes in the urine in the absence of bacterial inflammation.
• A blood test aimed at determining antibodies to the rabies pathogen. The analysis uses special immunofluorescence staining to detect the presence in the blood of molecules produced by the immune system in response to the rabies virus entering the body. The diagnosis is confirmed by a significant (4 or more times) increase in the number (titer) of antibodies to the rabies virus in patients who have not been vaccinated.

• Determination of the causative agent of rabies in biological fluids and body tissues. Study of biopsy samples (tissue fragments) of the skin of the back of the head, imprints of the cornea. Labeled antibodies (molecules that specifically bind to the rabies virus molecule) are added to the resulting material. Under the influence of ultraviolet radiation, a complex of viruses “glued” with antibodies gives a characteristic greenish glow, which indicates the presence of the rabies virus in the taken material. This analysis is most reliable during the first week of the disease.
• Study of the genetic material of the virus using the polymerase chain reaction (PCR). Saliva, blood, cerebrospinal fluid, and affected tissue can be used. The reliability of the results is close to 100%.
• Examination of brain tissue using electron microscopy. A section of brain tissue is taken (biopsy), which is then specially stained and examined under an electron microscope, which allows for a very high degree of magnification. In this case, in the cells of the nervous tissue affected by the rabies virus, special inclusions are released or the virus itself is detected.

Other research methods

• Electroencephalography (EEG) is a method that evaluates the electrical potentials of the brain.

Treatment

There is no specific treatment for rabies. As a rule, the disease is incurable and leads to death.

When bitten by a wild animal, the wound is washed, thoroughly examined for foreign bodies (for example, broken teeth), and debridement is performed. Then immunoglobulins – special cells of the immune system – are urgently introduced. Next, the patient is vaccinated over the course of two weeks (a total of 5 vaccines are used). This is the only way to prevent the disease.

After a bite, the pet must be observed for approximately 10 days and if symptoms of rabies appear, immediately consult a doctor to take measures to immunize the patient. The source of rabies - a sick animal - must be isolated.

Treatment of rabies is aimed at alleviating its symptoms - relieving seizures and reducing pain. For this purpose, anticonvulsant, analgesic, and sedative medications are used, respectively.

To reduce contact with potential irritants, the patient is placed in a special ward.

Loss of fluid and minerals are replenished; artificial ventilation is performed.

Prevention

• People at risk of developing rabies should be vaccinated.
• After being bitten by a wild animal, you must thoroughly wash the wound with soap and water and immediately consult a doctor to undergo a course of immunization and vaccination against rabies.
• Preventive vaccination of domestic animals.
• Pets should be kept indoors and supervised when outside. Cages and closed pens can be used for this purpose. This will help avoid infection of domestic animals from wild ones. Special attention should be paid to rabbits, guinea pigs, hamsters and other small pets, as they cannot be vaccinated against rabies. Often a domestic animal becomes infected outside the city, where it has the opportunity to come into contact with wild animals, for example cats, dogs can run into the forest and come into contact with infected rodents and foxes there.
• You should follow the rules of communication when meeting stray animals - do not touch them or pet them to avoid being bitten.
• Avoid contact with wild animals (eg foxes, raccoons). Healthy wild animals themselves avoid people, so an animal that is not afraid of people and does not try to escape should arouse suspicion.
• A bite from a pet can also be a reason to see a doctor, for example, if you don’t know whether it could be infected with rabies, and even more so if the animal died within a few days after the bite.

Recommended tests

• General blood analysis
• General urine analysis

Literature

• Dan L. Longo, Dennis L. Kasper, J. Larry Jameson, Anthony S. Fauci, Harrison's principles of internal medicine (18th ed.). New York: McGraw-Hill Medical Publishing Division, 2011.
• Manning SE, Rupprecht CE, Fishbein D, et al. Human rabies prevention—United States, 2008: recommendations of the Advisory Committee on Immunization Practices. MMWR Recomm Rep. May 23 2008;57:1-28.
• Hemachudha T. Human rabies: clinical aspects, pathogenesis, and potential therapy. Curr Top Microbiol Immunol. 1994;187:121-43.
• Gerald L. Mandell. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases: Expert Consult Premium Edition. Churchill Livingstone, 2009.

Who is at risk?

• People who have been bitten by wild or domestic animals;
• People living in rural areas and keeping animals at home that have not been vaccinated against rabies;
• People who travel to developing countries (Southeast Asia, Africa);
• People who go outdoors and come into contact with wild animals (raccoons, foxes, bats, etc.);
• Trappers and hunters;
• Veterinarians;
• People who work in nurseries, zoos, animal shelters;
• People who work with the rabies virus in the laboratory.

Diagnosis of rabies

This diagnosis can be made when symptoms of the disease appear after an animal bite. Rabies is confirmed by examining a skin sample taken from the back of the head and isolating the virus from tear, cerebrospinal fluid, and saliva.

Laboratory tests required to diagnose rabies:

• general blood test (excluding ESR and leukocyte formula);
• general urine analysis;
• a blood test to determine antibodies to the rabies pathogen;
• Determination of the causative agent of rabies through examination of tissues and biological fluids of the body:

— examination of fragments of skin tissue on the back of the head, cornea imprints;

— study of the genetic material of the virus using PCR;

- examination of brain tissue using electron microscopy.

Other research methods used to diagnose rabies:

• EEG or electroencephalography is a method that allows you to evaluate the electrical potentials of the brain.

Forms

There are three forms of rabies in animals:

1. Violent form

   We discussed the violent form of rabies in cats in detail in the section on symptoms and signs, since it is the most common form of rabies in cats, but there may be exceptions. The main difference between this form and the others is that the animal turns from a gentle domestic animal to wild and aggressive. This happens due to severe damage to the brain; we can say that the virus controls the animal and forces it to bite others, thus spreading through saliva.

2. Silent form

   With this form of flow, excitation is not expressed at all or is weakly expressed. Sometimes rabies in kittens can manifest itself in this way. Paralysis progresses quite quickly, swallowing becomes difficult, and profuse, foamy salivation is observed. The animal's gaze is expressionless, indifferent, directed as if into emptiness. There may be prolapse of the third eyelid, strabismus, and different pupil sizes. Death occurs even faster than with the violent form, on the 2-4th day.

3. Atypical form

   This form of flow is extremely rare. Refusal to eat, exhaustion of the animal, inflammatory processes in the gastrointestinal tract, and hemorrhagic diarrhea are noted. No aggression is observed. This form can last up to 3 months or longer.

Treatment of rabies in humans

Unfortunately, if symptoms of this disease do appear, it most often leads to death. Treatment in most cases can only alleviate the patient's condition.

After a bite from a wild animal, the wound must be washed, carefully examined for the presence of any foreign bodies (for example, broken teeth) and surgically treated. After this, the patient is immediately injected with immunoglobulins - special cells of the immune system. The patient undergoes vaccination over the next two weeks (5 injections in total). The disease can only be prevented in this way.

If a pet is bitten, it should be observed for approximately 10 days and if symptoms of rabies are noticed, immediately consult a doctor so that he can take measures to immunize the bitten person. A sick animal that has become a source of rabies must be isolated.

Treatment of rabies can also alleviate its symptoms - reduce pain, relieve seizures. For this, appropriate medications are used, and the patient is placed in a special ward.

Prevention of rabies

• People who are at risk of developing this disease must be vaccinated;
• If a person is bitten by a wild animal, he needs to thoroughly wash the wound with soap and then immediately consult a doctor;
• Pets are vaccinated to prevent rabies;
• Pets must be kept indoors and supervised when outside. This will avoid their infection from wild ones;
• Do not pet or touch stray animals to avoid being bitten;
• Avoid contact with wild animals. Usually healthy wild animals avoid people on their own, so if you see an animal that is not trying to run away from you and is not afraid, it should arouse suspicion;
• Contact your doctor even if you are bitten by a pet (especially if it dies a few days after the bite).

How to recognize a sick cat?

To protect yourself from contracting rabies, it is important to understand how to recognize a sick cat. Let us immediately note that animals with rabies are very irritable, so it is not recommended to approach them. If you suspect that the animal’s behavior is inappropriate, without turning your back, slowly move away from it to a safe distance.

With the standard development of the clinical picture, symptoms occur in the following order:

• Sudden behavioral changes - unsociable cats are drawn to people, playful active animals become apathetic.
• Slight increase in temperature.
• Poor appetite.
• Discomfort at the site of bites or scratches through which the virus entered the body.
• Severe irritation to sounds.
• Fear of light and water.