Is there a cure for rabies? Drugs used to prevent rabies. What to do if you are bitten by a rabid animal or a stray dog

Rabies is an acute infectious disease caused by a virus that enters the human body when bitten by a sick animal or gets its saliva on the skin. Clinically characterized by severe damage to the nervous system. It is one of the most dangerous infectious diseases. Without specific treatment - the introduction of a rabies vaccine - the disease is fatal. The sooner a person seeks medical help after a bite, the less likely they are to get sick. Let's get acquainted with the causes and signs of rabies in people, talk about the principles of its diagnosis and treatment, as well as how to avoid this dangerous disease.

Historical facts

Rabies existed on planet Earth even before our era, and to this day humanity has not come up with a way to destroy the circulation of the pathogen in nature. The name of the disease comes from the word “demon.” This is exactly how the clinical symptoms of the disease were interpreted in ancient times, believing that a demon was possessing a person. There are some countries where rabies is not recorded: Great Britain, Norway, Sweden, Japan, Finland, Spain, Portugal, New Zealand, Cyprus (mostly island states). Until July 6, 1886, all cases of the disease were 100% fatal. It was on this day that a specific anti-rabies vaccine (Rabies - rabies in Latin), created by the French scientist Louis Pasteur, was first used. Since then, the fight against the disease began to end in victory (recovery).

Causes

Rabies is a viral infection caused by Neuroiyctes rabid from the Rhabdovirus family. The pathogen is destroyed by boiling for two minutes, inactivated by alkaline solutions, chloramine, 3-5% carbolic acid. Direct sunlight and drying are harmful to the virus. But freezing, exposure to antibiotics and phenols do not affect the virus.

In nature, the virus circulates among warm-blooded animals and birds. The source of infection is any (!) animal with rabies. Most often, humans become infected from dogs, cats, wolves, foxes, bats, crows, and cattle. Typically, such animals and birds behave inappropriately, attack people and other animals, biting them and thus infecting them. It is believed that a person with rabies, if he bites another, can also be a source of infection. The virus is transmitted through saliva: through a bite or even just contact of saliva on the skin and mucous membranes (due to the possible presence of microdamages in these places that are not noticeable to the eye).

The incubation period (the time from the moment the pathogen enters the body until the first symptoms appear) lasts on average from 10 days to 3-4 months. Isolated cases of the disease have been recorded with an incubation period of about a year. The timing of the appearance of the first symptoms depends on many factors: the location of the bite (the most dangerous are the head, genitals, hands), the amount of virus that has entered the body, and the state of the immune system. Even the type of animal plays a role in this case. You should be aware that any animal bite is considered a potential risk of rabies and medical attention should be sought immediately.

How does rabies develop?

The virus enters the nerve endings through damage to the skin and mucous membranes. Penetrates the nerves and moves towards the brain, multiplying in parallel. The speed of movement of viral particles is 3 mm/h, which is why bites to the head, face and hands (very close to the central nervous system) are so dangerous. Penetrating into the brain, the virus destroys cells of the cerebral cortex, cerebellum, subcortical formations, cranial nerve nuclei, and medulla oblongata. At the same time, the virus rushes back along the nerve trunks, now in a downward direction. Thus, the entire human nervous system is affected.

As a result of the accumulation of the virus in brain cells, specific conglomerates are formed: Babes-Negri bodies. They are found in the brain after autopsy of people who died of rabies.

Symptoms

In total, there are three stages of rabies, differing from each other by different symptoms:

initial stage (precursor period, prodromal period) – lasts 1-3 days;
stage of excitement (high heat, hydrophobia) – lasts 1-4 days;
the period of paralysis (the stage of “ominous calm”) lasts from 1 to 8 days according to various sources (very rarely 10-12 days).

initial stage

The patient experiences painful and unpleasant sensations in the area of the bite site, even if by this time the wound has completely healed. If there was no bite as such, then similar sensations appear at the site of contact with the saliva of a sick animal. A person feels a burning sensation, pulling and aching pain towards the center (along the nerve trunks up to the brain). The bite site itches, has increased sensitivity, and may even become swollen and red.

Body temperature rises to subfebrile levels: 37-37.3°C. Feeling worse, you may experience headaches, sleep and appetite disturbances, and general weakness. Along with these symptoms, mental disorders appear: causeless anxiety, fears, melancholy, and indifference to everything that happens. The person withdraws into himself. Sometimes there may be periods of irritation. If the bite was in the facial area, the patient may be bothered by visual and olfactory hallucinations: foreign odors are felt everywhere, objects or phenomena appear to be that are not actually there. Nightmarish dreams are typical.

Gradually, the pulse and breathing quicken, and anxiety increases.

Excitation stage

Characterized by increased sensitivity to all environmental influences: light, sounds, smells, touches. Particularly characteristic is the fear of water: hydrophobia. When you try to take a sip of water, a convulsive painful contraction of the muscles of the pharynx and respiratory muscles occurs, up to vomiting. Then spasms occur even from the sound of pouring water or the sight of it. The excitability of the nervous system reaches such a limit that any external irritants provoke convulsions. Patients begin to be afraid of light, noise, and breath of air, as all this provokes painful muscle contractions, painful for the patient.

The tone of the sympathetic nervous system increases. The pupils dilate sharply, the eyes seem to protrude forward (exophthalmos), the gaze is fixed at one point. Blood pressure rises, heart rate increases, and pulse increases sharply. Breathing becomes rapid. Profuse sweating and pronounced drooling appear (the saliva contains the rabies virus, which means it is contagious).

Periodically, attacks of severe psychomotor agitation occur, during which consciousness is impaired and the person cannot control himself. Patients become aggressive, attack others, tear their clothes to shreds, bang their heads against walls and floors, scream in a voice that is not their own, spit, and may bite. During an attack, they are haunted by hallucinations of a threatening nature. Cardiac and respiratory disorders increase, breathing and heartbeat may stop, followed by death.

Between attacks, the patient regains consciousness and behavior becomes adequate. In the end, one of the attacks of excitement ends in the formation of paralysis, and the last stage of rabies begins.

Stage of paralysis

Immobility of the limbs, tongue, eye muscles, muscles of the pharynx and larynx develops. The patient seems to calm down. The convulsions stop, the fear of water disappears. The patient no longer reacts violently to light and sounds.

Body temperature rises sharply to 40-42°C. Blood pressure drops and heart rate increases. Death occurs against the background of damage to the respiratory and cardiovascular centers.

Occasionally, rabies occurs in an atypical manner: there are no symptoms of hydrophobia or motor agitation, and paralysis immediately forms. In such cases, rabies is not recognized, only Babes-Negri bodies are found at autopsy, which confirms the diagnosis.

Diagnostic principles

The diagnosis is established on the basis of anamnesis (bite of a sick animal) and clinical manifestations.

Diagnosis is based on medical history: an animal bite or salivation of the skin. Then specific signs of rabies play a role: fear of hydrophobia, increased sensitivity to irritants (sounds, light, drafts), excessive salivation, attacks of psychomotor agitation with convulsions (even in response to the slightest movement of air).

Laboratory methods include the detection of rabies virus antigens in imprints from the surface of the cornea. A blood test reveals leukocytosis due to an increase in the content of lymphocytes. After the death of the patient, an autopsy reveals Babes-Negri bodies in the brain.

Principles of treatment

There are no statistically reliable treatments for rabies. If the patient has already developed initial symptoms, then the disease is incurable. You can help the patient only during the incubation period, and the sooner the better. To do this, a rabies vaccine is administered, but this measure is considered preventive.

When a patient has already shown signs of rabies, so-called symptomatic treatment is usually carried out to alleviate his condition. For this, the person is placed in a separate room, isolated from light, noise, and drafts (so as not to provoke convulsions). Medications include narcotic substances, anticonvulsants, and muscle relaxants. If there are severe respiratory disorders, the patient is connected to a ventilator. These manipulations prolong the patient’s life by several hours or even days, but the outcome is still unfavorable: the person dies. Administration of rabies immunoglobulin and vaccine when symptoms of rabies have already appeared is not effective!

Since 2005, several cases of recovery from rabies without the use of rabies vaccine have been reported worldwide. In 2005, a 15-year-old girl in the United States survived after being placed in an induced coma after showing signs of rabies. While she was in a coma, she was given drugs that stimulate the immune system. This treatment was based on the assumption that the human body simply does not have time to produce antibodies against the rabies virus, and if the nervous system is “turned off” for a while, there is hope for healing. A miracle happened - and the girl recovered. This treatment method was called the “Milwaukee protocol.” Later, this protocol was tried to be applied to other cases of rabies: out of 24 attempts, only one was successful, the remaining 23 people died.

In 2008, a 15-year-old boy from Brazil was rescued. He was treated using the Milwaukee Protocol, antivirals, sedatives and anesthesia. In 2011, an 8-year-old child survived, and in 2012, 5 more people survived. In all cases, treatment was carried out according to the protocol. Scientists still have not agreed on what exactly helped these patients avoid death. It is assumed that the main role was played by an unusually strong immune system and, possibly, a weakened form of the virus that caused the disease.

In 2009, a case of recovery was reported in the United States in an antisocial woman with rabies symptoms believed to have arisen after a bat bite. This episode prompted scientists to believe that abortive forms of rabies can occur in humans, by analogy with animals. After all, it is known that from 1% to 8% of animals that were bitten by a known sick animal do not develop rabies.

Prevention

Despite the described cases of recovery, today rabies is considered an incurable disease. It can be prevented in only one way: timely vaccination.

After an animal bite, you must wash the wound as quickly as possible using laundry soap, treat it with 70-degree alcohol or 5% iodine solution (if possible) and seek medical help.

In a medical institution, local treatment of the wound is carried out, and stitches are applied if necessary. Then specific prevention is carried out by administering rabies vaccine and/or rabies immunoglobulin.

Rabies vaccine is a laboratory-developed strain of the rabies virus. Its administration stimulates the production of antibodies. The vaccine cannot cause rabies. The ampoule with the vaccine is opened, the contents are mixed with 1 ml of water for injection and injected intramuscularly into the shoulder area (for children under 5 years old - into the thigh). Within 30 minutes after the injection, the patient is under medical supervision, as an allergic reaction is possible. The vaccination course is as follows: the first administration is carried out on the day of treatment, then on the 3rd, 7th, 14th, 30th and 90th day. During the entire period of vaccination, as well as 6 months after it (i.e., a total of 9 months), the patient is strictly contraindicated in drinking alcohol. Overheating, hypothermia and overwork should be avoided. The course of treatment with the vaccine is prescribed regardless of the period when the person was bitten. Even if seeking medical help occurs several months after the bite, a full course of vaccination is still carried out.

In some cases, along with the vaccine, anti-rabies immunoglobulin is also used (for bites of the head, neck, face, hands, genitals, for multiple bites or very deep single bites, for salivation of the mucous membranes, for any damage caused by wild predatory animals, bats and rodents). Rabies immunoglobulin is used at a rate of 40 IU/kg (horse) or 20 IU/kg (human). You should try to inject the entire dose into the tissue around the bite site. If this is not possible, then the remaining part of the drug is injected intramuscularly into the shoulder or thigh. In the latter case, immunoglobulin must be administered at sites other than the vaccine administration. If more than 3 days have passed since contact with the animal, then rabies immunoglobulin is not used.

When is the vaccine used:

with single superficial bites, scratches, abrasions caused by wild and domestic animals;
with multiple bites or a single deep bite caused by wild and domestic animals;
in case of salivation of intact skin or mucous membranes by wild and domestic animals.

Moreover, if it is possible to observe the animal that caused the damage, and it remains healthy for 10 days, then only the first three injections of the rabies vaccine are given. If it is impossible to monitor the animal for any reason, the complete course of vaccination is carried out.

This rabies prevention scheme saves a person from the disease almost 100%.

Taking the vaccine may have side effects. Locally, slight swelling, redness and itching may occur. Nearby lymph nodes may become enlarged. Common symptoms include headache, general weakness, and a slight increase in body temperature. To eliminate these symptoms, antipyretic and antiallergic drugs are used.

For people who are forced by the nature of their work to more often encounter the rabies virus, mandatory preventive vaccination against rabies is indicated. This category includes veterinarians, hunters, foresters, slaughterhouse workers, and persons performing work to catch stray animals. This contingent is administered the vaccine 1 ml in the first month 3 times (1, 7, 30 days), then once every year, and then once every three years.

General methods for preventing rabies include vaccinating domestic animals against rabies, catching stray dogs and cats, and regulating the density of wild animals (in Russia, the latter concerns foxes). Unvaccinated dogs should not be allowed to hunt wild animals.

Rabies is a deadly disease caused by the bite of a sick animal. Today, there is only one sure way to avoid the disease: in case of a bite, immediately seek medical help and undergo a course of vaccination with an anti-rabies vaccine.

Rabies is an acute infectious (viral) disease of humans and animals, characterized by damage to the brain: when infected, an inflammatory process (encephalitis) develops.

Despite the fact that rabies is one of the oldest infections, there is no downward trend to date, and no effective treatments have been developed. Rabies remains a deadly disease.

The symptoms of the disease are specific, but quite a long time can pass between infection and the first manifestations of the disease. In this article we will talk about the treatment and prevention of rabies in people, because it is very important to know how to protect yourself and your children from a dangerous disease.

The widespread prevalence of rabies among many species of warm-blooded animals poses a risk of infection for people, including children. Most often, infection occurs, but it is also possible to get the disease from wild animals.

Cause of the disease

Infection occurs through the bite of an animal with rabies.

The source of infection is sick animals. Both wild animals (foxes, wolves, bats), and domestic animals (cats, horses, dogs, pigs, cattle), etc. suffer from rabies. In this regard, a distinction is made between urban and forest types of rabies.

Rare cases of infection with the virus from a sick person have also been reported.

A person receives the virus through bites from a sick animal or through salivation of the skin and mucous membranes. The possibility of infection by airborne droplets has now been proven.

This is how people can become infected by inhaling air in caves with large numbers of bats. The rabies virus can be acquired through food (). We cannot rule out a contact route of infection through things that have come into contact with the saliva of a sick animal.

Children aged 5-7 to 14-15 (usually boys) are most susceptible to the disease: it is at this age that children fearlessly come into contact with animals and strive for such contact, including stray cats and dogs.

The group at high occupational risk of infection includes hunters, foresters, veterinary workers, and workers catching stray animals. They can also become infected from dead animals. Cases of infection through any microtrauma to the hands during skinning or cutting up the carcass of a sick animal are often recorded.

The seasonality of the disease is noted: from May to September. During this period, people (including children) spend more time outside than in winter. Rural residents get sick more often, as they have more opportunities to come into contact with different animals.

Natural foci of rabies are everywhere! Wild animals with rabies often run into nearby populated areas, where they can attack people.

Animals are infectious already 10 days before they show signs of rabies, but the greatest danger of infection occurs during the period when the disease manifests itself.

Not every bite from an infected animal results in rabies. About 30% of sick dog bites and about 45% of wolf attacks are infectious to humans. The risk of infection is higher with bites on the face and head, neck, perineum, fingers of the upper and lower extremities. Deep and lacerated wounds are very dangerous.

Infection can occur even in cases where there is no bite as such, there is just a scratch-mark from the teeth or only drooling of the skin and mucous membranes. The virus enters the body through the skin and mucous membranes.

Symptoms

The incubation period for rabies is long, from 1 to 6 months. With extensive wounds and massive infection, the incubation period can be reduced to 9 days. For bites of the face, head and neck, the latent period is short, for bites of the lower extremities it is longer. Cases of the development of rabies a year or more after being bitten have been described.

In the rabies clinic, there are 3 periods of the disease:

premonitory;
period of excitement;
period of paralysis.

IN prodromal period illness, aching pain appears in the area of salivation or bite, even if the wound has already healed. Redness of the scar, itching and burning may occur.

The child's temperature rises to within 38°C, worries him, and vomiting may occur. The child refuses food, his sleep is disturbed (insomnia appears). If the baby does fall asleep, then he sees frightening dreams.

During this period, the child is withdrawn, indifferent to what is happening, the mood is depressed and anxious. The facial expression is sad. The teenager is worried about an unfounded feeling of fear, heaviness in the chest, accompanied by breathing.

The duration of the prodromal period is 2-3 days (can extend up to 7 days). Subsequently, mental disorders intensify, depression and indifference are replaced by anxiety.

IN period of excitement The most characteristic symptom of rabies appears: hydrophobia (or hydrophobia). When a patient tries to swallow any liquid, even saliva, a muscle spasm of the larynx and pharynx occurs.

The sight and even the sound of pouring water, and even talking about water, causes a feeling of fear and the development of such a spasm. When trying to give the patient something to drink, he pushes the cup away, bends over, and throws his head back.

At the same time, the patient’s face turns blue and expresses fear: the eyes are somewhat bulging, the pupil is dilated, the gaze is directed at one point, breathing is difficult, sweating increases. Although the attacks of convulsive muscle contraction are short-lived (lasting a few seconds), they are often repeated.

An attack can be triggered not only by the sight of a liquid, but also by a stream of air, a loud knock or sound, or a bright light. Therefore, the patient develops not only hydrophobia (hydrophobia), but also aerophobia, acoustic phobia, and photophobia.

In addition to increased sweating, there is abundant formation and secretion of saliva. Psychomotor agitation and manifestations of aggression and rage occur. Patients can bite, they spit, they can hit, they can tear their clothes.

It is precisely this kind of inappropriate violent and aggressive behavior that is meant when people say: “behaves like mad.”

During an attack, there is confusion and frightening visual and auditory hallucinations. Between attacks, consciousness may become clearer.

Vomiting, sweating and drooling, and the inability to take fluids lead to dehydration (this is especially pronounced in children) and weight loss. The temperature may remain elevated.

The period of excitation lasts 2 or 3 days, less often up to 5 days. At the height of any of the attacks, respiratory and cardiac arrest may occur, that is, death.

In rare cases, the patient may survive until the third period of the disease - period of paralysis. The attacks stop at this stage, the patient can already drink and swallow food. Hydrophobia disappears. Consciousness during this period is clear.

But this is an imaginary improvement. Body temperature rises above 40°C. Pulse quickened. Excitement gives way to lethargy. Depression and apathy are increasing.

Then the function of the pelvic organs is disrupted, and paralysis of the limbs and cranial nerves develops. Death occurs as a result of paralysis of the respiratory and cardiac centers.

In addition to the typical form, there is also atypical form rabies. With this form there is no clear manifestation of periods of the disease; convulsive attacks of hydrophobia and a period of agitation may not develop. Clinical manifestations of the disease are reduced to a depressive, drowsy state with the subsequent development of paralysis.

Rabies baby V early age has some distinctive features:

the disease develops after a short incubation period;
hydrophobia is not noted;
the period of excitement is sometimes absent;
The death of the baby can occur on the very first day of the development of the disease.

In children over 2-3 years of age, the clinical manifestations of rabies are the same as in adults.

Diagnostics

The diagnosis of rabies is made clinically. Even in highly developed countries, it is difficult to confirm the diagnosis during life. As a rule, it is confirmed after the death of the patient.

The reference symptoms for clinical diagnosis are:

the fact of an animal biting or salivating on the patient’s skin;
pain at the site of the bite after the wound has healed;
hydrophobia;
photophobia;
aerophobia;
acoustic phobia;
psychomotor agitation;
swallowing and breathing disorders;
mental disorders;
paralysis.

Due to the lack of intravital laboratory diagnostics, atypical forms of the disease in the absence of agitation and hydrophobia are practically not diagnosed. Diagnosis of rabies in children is especially difficult, because It is not always possible to establish the fact of a child’s contact with a sick animal.

In 2008, French scientists managed to develop and offer for intravital diagnosis a biopsy study of the skin of the neck (at the border with hair growth) using the ELISA method.

The method is highly specific (98%) and highly sensitive (100%) from the very first day of the disease. The study allows you to detect the virus antigen in the nerve endings near the hair follicle.

If possible, the fluorescent antibody method examines corneal prints to detect the virus antigen.

When deciding on the need for immunoprophylaxis, it is necessary to diagnose rabies in the animal that caused the bite. This study is carried out as early as possible after the patient’s bite (if the animal’s corpse is available for taking biological tissue samples). In this case, the virus can be detected in the cells of the brain and cornea of the eyes or sections of animal skin using serological reactions and the method of fluorescent antibodies.

Treatment

Treatment of a patient with rabies is carried out only in a hospital. The patient's conditions should exclude exposure to bright light (room with darkened windows), loud noise stimuli and air currents.

Effective therapy for rabies has not been developed. Anti-rabies immunoglobulin, anti-rabies serum and large doses have a weak therapeutic effect.

Symptomatic treatment is carried out:

painkillers to reduce pain;
anticonvulsants;
sleeping pills for sleep disorders;
administration of solutions to normalize water-salt balance;
medications to stimulate the heart and respiratory system;
treatment in a pressure chamber (hyperbaric oxygenation);
cerebral hypothermia (ice pack on head);
connection of an artificial respiration device (according to indications).

The outcome of the disease is unfavorable, patients die. Isolated cases of recovery of children throughout the world have been described.

Prevention

In our country, specific and nonspecific rabies prevention is carried out.

Nonspecific prevention provides for the following measures:

catching and isolating stray animals;
identification of rabid animals by the veterinary service with their subsequent euthanasia;
extermination of predatory animals near populated areas;
quarantine measures and laboratory diagnostics at the source of infection;
sanitary educational work among the population.

Specific prevention is carried out by conducting a course of combined administration of rabies vaccine and rabies immunoglobulin after being bitten or salivated by an animal. After a bite, you should treat the wound and consult a surgeon.

Wound treatment is carried out as follows:

wash the wound generously with boiled soapy water or hydrogen peroxide;
treat the wound with 70° alcohol;
suturing the wound, as well as excision of its edges, is contraindicated;
Anti-rabies immunoglobulin is injected around the wound and into the wound itself;
after 24 hours, anti-rabies serum is injected.

The first two points of treatment should be carried out at home, even before visiting the doctor; the rest is carried out by the surgeon.

Considering the destructive effect of high temperature on the virus, in the field you can use the ancient method of treating wounds after an animal bite: cauterizing the bite wound with a hot iron.

To destroy the virus, you can put a crystal of permanganate or carbolic acid in the wound.

In the case of a bite by a pet, the doctor clarifies under what circumstances the bite was received, whether it was provoked by the patient’s behavior, whether it was vaccinated against rabies, and where the animal is now located. If the bitten animal is healthy (there is a certificate of vaccination), then vaccination is not carried out.

If the animal disappears after being bitten, or if the patient is bitten by a wild animal, vaccination is carried out with an anti-rabies vaccine and anti-rabies immunoglobulin.

The vaccination schedule is selected for the patient (especially a child) by the doctor individually: depending on the depth and location of the bite, the age of the bite, the animal that inflicted the bite and whether it is possible to observe it.

If after a 10-day observation of a pet that has bitten a person, it remains healthy, then the vaccine is canceled after 3 injections already received (if drooling or a shallow single bite has occurred).

But if the bite was inflicted in dangerous places (listed above), as well as in the absence of the opportunity to observe or examine the animal, the vaccine continues to be administered until the end of the prescribed regimen.

salivation of mucous membranes;
bites (of any depth and quantity) to the dangerous places listed above;
deep single or multiple bites caused by domestic animals;
any damage or salivation by wild animals or rodents.

The rabies vaccine is administered intramuscularly into the shoulder area, and into the upper third of the anterolateral surface of the thigh for children under 5 years of age. The vaccine cannot be administered into the buttocks. The vaccine has a preventive effect even in the case of multiple severe bites.

Persons at occupational risk of infection are given primary prophylaxis with an anti-rabies vaccine. Prophylactic administration of the vaccine is also recommended for young children, given that they may not tell about the contact with the animal.

Preliminary prevention can also be carried out for children when planning vacations in rural areas or in a health summer camp.

The vaccine is administered 1 ml intramuscularly 3 times: 7 and 28 days after the first administration. Persons at risk of infection are given revaccination every 3 years. After vaccination, adults and children should avoid overheating and avoid overwork. When carrying out vaccination and for six months after it, it is necessary to categorically exclude the use of any types and doses. Otherwise, complications from the central nervous system may occur.

Summary for parents

Considering that rabies is almost impossible to cure, all measures must be taken to prevent the child from becoming infected. The dangers of contact with stray cats and dogs should be explained to children from an early age. Small children should not be left unattended to prevent attacks and bites from animals.

A person is constantly exposed to all sorts of diseases that are transmitted in various ways from person to person. The most dangerous diseases are diseases carried by animals. These include rabies in humans, the symptoms, diagnosis and treatment of which we will discuss in this article.

So, rabies in humans (hydrophobia or hydrophobia) is an acute infectious disease that affects the central nervous system of a person, causing irreversible changes in his behavior, and in case of delay in seeking medical attention, death from its symptoms.

Until 1886, this disease was considered incurable, and the mortality rate was 100%. Studying this disease, the French scientist L. Pasteur created a specific vaccine against this disease, which was called the anti-rabies vaccine (from the Latin Anti - against, Rabides - rabies).

What is rabies and why is the disease called hydrophobia? Very simply, since ancient times, it was by this sign that the presence of a disease in a patient was determined. A person is pathologically afraid of everything connected with water - splash, noise, falling drops, etc. Undoubtedly, this is not its only sign. But one of the most memorable.

Mad Animal Habitat Map

The virus itself is carried by wild and domestic animals. Naturally, a person can become infected from both those and others. Approximately 25–30% of infections occur in domestic dogs, 28% in wild or stray dogs, and 10% in cats, remaining in the wild.

Among wild animals, the leading place is occupied by foxes, whose population in the post-Soviet space is steadily growing. In addition, the causative agent of the disease is well tolerated by hedgehogs, wolves, bears and even crows (although human infection by a crow is rather an exception to the rule, such exceptions have occurred).

Causes of rabies in humans

As it became clear that the causative agents of the rabies virus are carried by animals, infection can be caused by contact of infected saliva on human skin (if there are microtraumas and microcracks on the skin). But the most common method of infection is a bite. Moreover, the higher the place of the bite on the hand, neck, head, the faster the disease will progress. In turn, the lower, the longer a person will not feel any disturbing symptoms.

The disease is caused by the necrosyrtes rabid virus. The incubation period lasts from two weeks to several months (as mentioned earlier, depending on the location of the bite, as well as the amount of infection that has entered the body). There have been cases of longer incubation periods - up to a year.

The rate of development of the disease is directly affected by the size of the animal with which contact occurred (bite, scratch, saliva entering the wound), as well as the depth of the bite.

It is not for nothing that the site of the bite plays an important role in the development of the disease, since the virus gradually moves towards the brain and multiplies along the way. Movement to the brain occurs through nerve cells. Having reached the head, the infection affects the cortex, medulla oblongata, cerebellum, etc. After which the infection begins to move in the opposite direction.

Symptoms and signs of rabies in humans

The main symptom by which the presence of the virus in the body was previously determined is hydrophobia. Why are infected people afraid of water? It's all about the action of the virus, which, affecting the human nervous system, causes a pathological fear of everything connected with water on an instinctive level. But these problems do not appear immediately, but after some time.

How the virus spreads

The immediate development of the disease can be divided into three stages, excluding the incubation period, during which a person does not feel any changes in the body.

Stages of rabies:

Initial stage.
Excitement stage.
Stage of paralysis.

initial stage

The first signs of infection after a bite can appear within three days and are directly related to the site of the bite. A person feels itching in the area of the wound, it swells, nagging pain may occur at the site of its localization, and redness. Even though the wound has already healed.

headache;
nausea;
vomit;
weakness;
sleep disturbance (possible nightmares);
poor appetite;
insomnia;
body temperature is not higher than 37.3 and not lower than 37 degrees.

Particular attention should be paid to the patient’s condition when a bite is inflicted on the neck or head; in this case, the following are added to the symptoms described above:

Hallucinations are visual or olfactory.
Apathy.
Excessive irritability.
Development of various phobias.

A person feels a nagging pain from the site of a bite or contact with the saliva of a sick animal towards the brain, exactly as the infection spreads. The duration of this stage is up to 3 days, after which the excitation stage begins to develop.

Excitation stage

How does the disease manifest itself in the second stage? It is at this stage that the patient’s characteristic fear of water and attacks of uncontrolled behavior begin to appear, during which the infected person can cause harm to himself and others.

Outbursts of rage are replaced by an adequate state, and can be repeated for quite a long time.

The true reason for this behavior of the patient lies in the hallucinations that haunt him, during which he experiences uncontrollable horror and thus tries to protect himself. Without being aware of his actions, he can unknowingly harm people who love him.

As for the fear of water, it manifests itself in the form of convulsive states. For example, when trying to take a sip of water, a patient may experience a cramp in the throat; the same reaction occurs at the sound of falling water, its splash, and even at the sight. Convulsions affect not only the swallowing system, but also the respiratory system.

In addition, the body reacts with convulsive contractions to any irritants, including:

Bright light.
Loud noise.
Gusts of wind.

Among other things, the second stage also responds to the patient’s visual system. So, the patient experiences dilation of the pupils and protrusion of the eyeballs. An infected person is often observed to focus on one point.

In addition, the stage of excitation is characterized by:
sweating profusely

Cardiopalmus.
Rapid pulse.
Increased salivation.

On average, this stage lasts no more than three days, after which, if no measures have been taken, the stage of paralysis occurs.

Stage of paralysis

The patient's salivation increases due to paralysis of the facial muscles. Also, the patient is forced to constantly spit out accumulated saliva due to its excessive amount. The jaw drops and the shoulders also seem to drop.

At this stage, everything ends for the patient and he dies. The stage of paralysis is characterized by immobilization of the patient as a result of muscle paralysis. In addition to the inability to move, the patient experiences spasms inside the body, namely in the cardiovascular and respiratory systems. It is for this reason that death occurs.

In addition, there is a sharp rise in the patient’s body temperature, up to 42 degrees, and a decrease in blood pressure. The duration of this stage does not exceed a day.

We can say that if no measures are taken, then after the incubation period the last seven days of the patient’s life will begin, since this is exactly how long the three stages of the disease last. And even when treatment begins at one of the above stages, doctors will not be able to do anything - only alleviate the patient’s plight. Therefore, the standard question of how long a patient can die implies a disappointing answer - approximately seven days from the initial stage.

Diagnosis of rabies in humans

Determining the presence of a virus in the body is quite difficult. For example, a blood test cannot always show whether a patient has a given infection. That is why the basis of diagnostic procedures is the study of the patient’s medical history and symptoms.

So, the doctor questions the patient about the fact of contact with the animal (bite, saliva on the skin, etc.).

After this, the victim’s skin is examined for lacerations or bite wounds, or areas of redness. The external condition of the patient and his well-being are analyzed.

As for such a research method as laboratory diagnostics, it is carried out in the following form.

Samples of infection from saliva (of course, if they are found there) are taken and experimental animals are infected with them. If the rabies virus is present in the saliva, the animal dies.

The most accurate analysis is the collection of brain particles, however, this procedure is carried out after the death of the patient and can do little to help the victim.

Treatment of rabies in humans

Is there a cure for this disease? Despite the seriousness of the infection, rabies treatment is carried out and is quite successful, another question is when it was started. After all, the later a person turns to a specialist, the higher the chance of death for a person.

The basis of therapy is the complete isolation of the patient from others, since contact with the saliva of an infected person can lead to infection, and given the inadequate nature of the patient’s actions, this fact cannot be excluded.

To alleviate the patient's suffering, he is prescribed a sleeping pill, which calms the nervous system. The presence of bright light, noise and drafts is excluded in the ward, so as not to provoke the occurrence of spasms and convulsions.

In the later stages, when cure is no longer possible, narcotic drugs are used to relieve pain, artificial ventilation devices, etc. can be used. This treatment is symptomatic and only prolongs the patient’s life for a while (by several hours or even days).

Undoubtedly, there is also effective emergency treatment - this is the administration of a post-exposure vaccine, and in especially serious cases, rabies immunoglobulin.

Post-exposure vaccine

A post-exposure vaccine is a medicine that is administered in a course and, if applied early, in most cases leads to the patient’s recovery.

The vaccine is administered into the deltoid muscle in adults and into the inner thigh in children. Injection of this drug into the buttock is extremely contraindicated.

The course is as follows: 1st day 3rd, 7th, 14th, 30th day in some cases it is possible to administer the vaccine on the 90th day.

After the course, immunity lasts for a year. However, if you see a doctor more than 14 days after exposure to a potential infection, the vaccine may not be effective.

It should be remembered that alcohol consumption is contraindicated during the entire course. It is better to consult your doctor about other contraindications.

The main thing is that there are no contraindications for administering the vaccine due to pregnancy or breastfeeding, as the disease can be fatal.

Anti-rabies immunoglobulin

In addition to the post-exposure vaccine, in particularly difficult cases (multiple bites, deep bites or bites on the upper surface of the body), rabies immunoglobulin may be prescribed. This medicine is administered along with the 3rd shot of the vaccine. The procedure involves injecting the bite site with half the dose, and the other half is injected intramuscularly (injection into the gluteal muscle is allowed).

It should be understood that rabies immunoglobulin cannot be administered with the same syringe as the vaccine - this is dangerous.

Home conditions

Treating rabies at home with traditional methods is extremely unwise and can be fatal. After a bite, it is recommended not to tempt fate by using various grandmother’s recipes, but to immediately seek qualified medical help.

Prevention of rabies in humans

Prevention of rabies is divided into the following types:

Non-specific.
Specific.

Non-specific prevention includes the extermination of rabid animals that can infect humans, as well as the burning of their corpses. This prevention is carried out regularly, but due to its inhumane nature it causes a lot of criticism from animal rights activists.

Specific prevention includes precisely vaccinating an infected person using the methods indicated above.

In which cases is infection unlikely and a vaccine is not required:

salivation of areas of skin that have not had any damage;
bite through tissue when no damage is recorded;
drinking milk from an animal infected with rabies;
bite from a vaccinated pet (only if the bites are not localized to the upper body).

In any case, an animal that has bitten or salivated a person is monitored for 10 days, and if during this time there are no changes in its behavior, vaccination is not necessary.

If the animal ran away before the end of the 10-day observation or the bite was made by a wild animal, it is carried out immediately.

So, rabies in humans is a serious and fatal disease that requires an immediate visit to the doctor. You should not flatter yourself with the hope that this or that animal was not sick. It is better to see a doctor and find out that everything is fine with you than to leave everything as is and end up in the hospital for another reason. Take care of yourself and your loved ones.

Rabies is an acute infectious disease of humans and animals that affects the central nervous system. Its cause is viruses that have a tropism for the tissues of the nervous system, where, after biting a sick animal, they move at a speed of 3 mm per hour. After replication and accumulation in the tissues of the central nervous system, viruses spread through neurogenic pathways to other organs, most often to the salivary glands.

The incidence of the disease depends on the location and severity of the bite. In 90% of cases, the disease develops with bites on the neck and face, in 63% - in the hands, in 23% - in the shoulder. The signs and symptoms of rabies at all stages of the disease are highly specific. There are no effective treatments for the disease. The disease is usually fatal. Timely vaccination against rabies is the most effective prevention of the disease. The rabies vaccine was first obtained in 1885 by the French microbiologist Louis Pasteur. And in 1892, Victor Babes and in 1903 A. Negri described specific inclusions in the neurons of the brain of animals that died from rabies (Babes-Negri bodies).

Rice. 1. The photo shows rabies viruses.

Rabies virus

The filterable rabies virus is a member of the genus Lyssavirus(from the Greek lyssa, which means rabies, demon) family Rhabdoviridae.

The rabies virus has a tropism for nervous tissue.

Rabies viruses are heat sensitive. They are quickly inactivated when exposed to solutions of alkalis, iodine, detergents (surfactant synthetic substances), and disinfectants (Lysol, chloramine, carbolic and hydrochloric acids).
Viruses are sensitive to ultraviolet irradiation, die quickly when dried, and die within 2 minutes when boiled.
At low temperatures and freezing, rabies viruses persist for a long time. They can be stored in animal corpses for up to 4 months.

Viruses are transmitted to humans through bites with saliva or through damaged skin that contains saliva from a sick animal. Damage to the central nervous system inevitably leads to the death of the patient. The presence of viruses in the central nervous system is indicated by the detection of “Babes-Negri bodies” in ganglion cells.

Rice. 2. The photo shows rabies viruses that resemble a bullet in appearance. One end is rounded, the other is flat. The synthesis of viral particles occurs in the cytoplasm of neurons.

Rice. 3. The photo shows the rabies virus. The virion is surrounded by a double shell. On the outer shell of viral particles there are spikes (protrusions) with knobby swellings at the ends. Inside the virions there is an internal component, which is a thread-like formation. The photo clearly shows transverse stripes representing a nucleoprotein.

Taurus Babesha-Negri

In 1892, V. Babes and in 1903, A. Negri, described specific inclusions in the cytoplasm of neurons in the brains of animals that died from rabies. They are called Babesh-Negri bodies. Large neurons of the ammon's horn, pyramidal cells of the cerebral hemispheres, Purkinje cells of the cerebellum, neurons of the thalamus optic, cells of the medulla oblongata and ganglia of the spinal cord are areas of the nervous system where Babes-Negri bodies are most often found.

Cytoplasmic inclusions are strictly specific for rabies disease

Babes Negri bodies are detected in the neurons of the brain of dogs that died from rabies in 90 - 95% of cases, in humans - in 70% of cases.

According to a number of researchers, Babes Negri bodies are:

places where virions replicate
places where the production and accumulation of the specific antigen of the rabies pathogen occurs,
The internal granularity of Babes-Negri bodies represents viral particles associated with cellular elements.

Rice. 4. The photo shows nerve cells with cytoplasmic inclusions. Babes Negri bodies have different shapes - round, oval, spherical, amoeboid and fusiform.

Rice. 5. The photo shows the Babesh-Negri body. The internal granularity of the inclusions represents viral particles associated with cellular elements.

Rice. 6. The photo shows the Babes-Negri body in the light of a conventional microscope. They are surrounded by a light rim.

Replication of viral particles in rabies is always accompanied by the formation of specific inclusions - Babes-Negri bodies.

Epidemiology

Articles in the "Rabies" sectionMost popular

Rabies(Latin - Lyssa; English - Rabies; hydrophobia, hydrophobia) is a particularly dangerous acute zooanthroponotic disease of warm-blooded animals of all species and humans, characterized by severe damage to the central nervous system, unusual behavior, aggressiveness, paralysis and death.

Historical background, distribution, degree of danger and damage. The disease was described about 5000 thousand years ago. There are messages about it in the code of laws of Babylon, the works of the ancient Greeks, in particular Aristotle. Even the names “Rabies” and “Lyssa” reflect the main clinical sign of the disease and are translated as fury, insane rage. Ancient doctors were able to determine the transmission of the disease through the saliva of “mad” dogs. Back in the 2nd century. n. e. Doctors used surgical removal of tissue at the site of the bite and cauterization of wounds with a hot iron as a preventive measure against rabies.
The period of L. Pasteur's discoveries is the next stage in the history of the study of rabies (1881-1903). Pasteur discovered the viral etiology of rabies. In 1890, Pasteur's students E. Roux and E. Nocard established that the saliva of sick animals becomes infectious 3-8 days before the clinical manifestation of the disease. L. Pasteur proved the possibility of reproducing the disease by intracerebral injection of material, and during such passages through the brain of rabbits the biological properties of the virus can be changed. In 1885, the first vaccinations were made to people, which became the crown of all L. Pasteur’s efforts to save humanity from rabies. The introduction of Pasteur vaccinations into practice led to a decrease in mortality from rabies by 10 times or more.

Currently, rabies is registered in most countries of the world. According to WHO, despite the fact that every year more than 5 million people and tens of millions of animals are vaccinated against rabies in the world, about 50 thousand cases of death from this disease are recorded annually, and the total number of sick productive animals is hundreds of thousands.

Despite the successes achieved, the problem of rabies is far from being solved; it has become very urgent due to the progressive spread of the disease among wild animals - the so-called natural rabies. Epizootics among wild animals have led to an increase in the incidence of disease in farm animals, primarily cattle.

The causative agent of the disease. Rabies is caused by a bullet-shaped RNA virus of the family Rhabdoviridae, genus Lyssavirus.

Rice. 1 - rabies virus model:
a - decreasing turns of the nucleocapsid; b - relative position of the spines and the underlying micellar protein (top view); c - spikes; g - micellar protein; d - inner membrane-like layer; e - a section of the virion showing the ratio of lipids to the micellar layer; the spine threads can extend deeper into the shell. The spineless part of the shell can form voids inside the nucleoprotein helix.

Previously, all strains of the rabies virus were considered antigenically the same. It has now been established that the rabies virus has four serotypes: the 1st serotype virus has been isolated in different parts of the world; virus serotype 2 was isolated from the bone marrow of a bat in Nigeria; serotype 3 virus was isolated from shrews and humans; serotype 4 virus has been isolated from horses, mosquitoes and mosquitoes in Nigeria and has not yet been classified. All variants of the virus are immunologically related.

The central nervous system is the selective site of the rabies pathogen. The highest titer of the virus was found in the brain (horns of ammon, cerebellum and medulla oblongata). After damage to the central nervous system, the pathogen penetrates all internal organs and blood, except the omentum, spleen and gall bladder. The virus is constantly found in the salivary glands and eye tissues. Cultivated by intracerebral passages in rabbits and white mice and in a number of cell cultures.

In terms of resistance to chemical disinfectants, the rabies pathogen is classified as resistant (second group). Low temperatures preserve the virus, and throughout the winter it persists in the brains of animal corpses buried in the ground. The virus is thermolabile: at 60°C it is inactivated after 10 minutes, and at 100°C it is inactivated instantly. Ultraviolet rays kill it in 5-10 minutes. It remains in rotting material for 2-3 weeks. Autolytic processes and putrefaction cause the death of the pathogen in the brain of corpses, depending on the temperature, after 5-90 days.
The following disinfectants are most effective: 2% solutions of chloramine, alkalis or formaldehyde, 1% iodine, 4% hydrogen peroxide solution, Virkon S 1:200, etc. They quickly inactivate the virus.

Epizootology. Basic epidemiological data of rabies:

Susceptible animal species: warm-blooded animals of all kinds. The most sensitive are fox, coyote, jackal, wolf, marsupial cotton rat, and vole. Highly sensitive animals include hamster, gopher, skunk, raccoon, domestic cat, bat, lynx, mongoose, guinea pig and other rodents, as well as rabbit.
The sensitivity to the rabies virus in humans, dogs, sheep, horses, and cattle is considered moderate, and in birds - weak.
Young animals are more susceptible to the virus than older animals.

Sources and reservoirs of the infectious agent. The reservoir and main sources of the rabies pathogen are wild predators, dogs and cats, and in some countries of the world, bats. In urban epizootics, the main spreaders of the disease are stray and street dogs, and in natural epizootics, wild predators (fox, raccoon dog, arctic fox, wolf, corsac fox, jackal).

Method of infection and mechanism of transmission of the pathogen. Infection of humans and animals occurs through direct contact with sources of the rabies pathogen as a result of a bite or salivation of damaged skin or mucous membranes.

Rice. 2. Spread of the virus in animals and humans

It is possible to become infected with rabies through the mucous membranes of the eyes and nose, nutritionally and aerogenously, as well as transmissibly.
The aerogenic mechanism of infection transmission to foxes and other wild carnivores in caves where millions of bats were observed was observed under experimental conditions. Carnivores were infected with a bat virus using an aerosol generator. Aerosol-infected wild animals kept in separate rooms and isolated cages infected foxes and other animals: over the course of more than 6 months, 37 foxes and other carnivores died from rabies. These experiments confirmed the respiratory transmission of rabies infection among wild carnivores. It was possible to isolate the rabies virus from the air of the observed caves by intercerebral infection of mice (Winkler, 1968). Constantine (1967) also noted that two orderlies developed hydrophobia as a result of supposed aerogenic contamination in a cave center of bats. Winkler et al. (1972) in a laboratory colony of coyotes, foxes, and raccoons identified an outbreak of rabies, probably as a result of aerogenic transmission of a virus adapted to bats. It should be noted that the aerogenic mechanism of infection transmission is reproduced mainly with the rabies virus maintained by bats.
In mice, hamsters, bats, rabbits, and skunks, rabies was reproduced under experimental conditions when infected through the intranasal route.

The intensity of manifestation of the epizootic process. At a high population density of foxes, corsacs, raccoon dogs, wolves, jackals, and arctic foxes, the disease spreads quickly; at an average population density, rabies manifests itself in isolated cases. When the population density of wild carnivores is low, the epizootic dies out.

Seasonality of disease manifestation, frequency. The maximum increase in incidence is in the fall and winter-spring period. A three- to four-year cycle of rabies has been established, which is associated with the population dynamics of the main reservoirs.

Factors contributing to the occurrence and spread of rabies. The presence of stray dogs and cats, as well as
sick wild animals.

Morbidity, mortality. The morbidity rate among unvaccinated animals bitten by rabid dogs is 30-35%, mortality is 100%.

According to the epizootological classification, the causative agent of rabies is included in the group of natural focal infections.

There are currently three types of rabies infection in Russia:

Arctic (reservoir - arctic foxes);
natural focal forest-steppe (reservoir - foxes);
anthropourgic (reservoir - cats, dogs).

Taking into account the nature of the pathogen reservoir, rabies epizootics are distinguished between urban and natural types. In urban epizootics, the main sources of the pathogen and spreaders of the disease are stray and stray dogs. The scale of the epizootic depends on their numbers. In natural epizootics, the disease is spread mainly by wild predators. The localization of natural foci of the disease corresponds to the distribution patterns of foxes, corsac foxes, raccoon dogs, wolves, jackals, and arctic foxes. They are very sensitive to the virus, aggressive, often prone to long-distance migrations, and when sick, they intensively secrete the virus in their saliva. These circumstances, along with the significant population density of some predators (fox, raccoon dog), the rapid change of their generations and the length of the incubation period for rabies, ensure the continuity of the epizootic process, despite the relatively rapid death of each individual diseased animal.

Pathogenesis. The possibility of developing a rabies infection, the causative agent of which is usually transmitted by a bite, depends on the amount of virus that has entered the body, its virulence and other biological properties, as well as the location and nature of the damage caused by the rabid animal. The richer the tissue in the area of the infection gate is with nerve endings, the greater the possibility of developing the disease. The degree of natural resistance of the body, depending on the type and age of the animal, is also important. Basically, the virus enters the animal’s body through damaged skin or mucous membrane.

The appearance of the virus in the blood is often observed before clinical signs of the disease appear and coincides with an increase in body temperature.

The pathogenesis of the disease can be divided into three main phases:

I - extraneural, without visible replication of the virus at the site of inoculation (up to 2 weeks),
II - intraneural, centripetal spread of infection,
III - dissemination of the virus throughout the body, accompanied by the appearance of symptoms of the disease and, as a rule, the death of the animal.

Reproduction of the virus in the gray matter of the brain causes the development of diffuse non-purulent encephalitis. From the brain, along centrifugal nerve pathways, the virus enters the salivary glands, where it multiplies in the cells of the nerve ganglia and, after their degeneration, enters the ducts of the glands, infecting saliva. Isolation of the virus in saliva begins 10 days before the onset of clinical signs. During the incubation period, the virus is also transported from the brain via a neurogenic route to the lacrimal glands, retina and cornea, and to the adrenal glands, where it apparently also reproduces. The impact of the pathogen initially causes irritation of the cells of the most important parts of the central nervous system, which leads to an increase in reflex excitability and aggressiveness of the sick animal, causing muscle cramps. Then degeneration of nerve cells occurs. Death occurs due to paralysis of the respiratory muscles.

Course and clinical manifestation of rabies symptoms. The incubation period varies from several days to 1 year and averages 3-6 weeks. Its duration depends on the type, age, resistance of the animal, the amount of virus that has penetrated and its virulence, the location and nature of the wound. The closer the wound is to the brain, the faster the symptoms of rabies appear.

The disease is often acute. The clinical picture is similar in all animal species, but has been better studied in dogs. Rabies usually manifests itself in two forms: violent and silent.

At violent rage There are three periods: prodromal, excitement and paralysis.
Prodromal period (precursor stage) lasts from 12 hours to 3 days. This period begins with a slight change in behavior. Sick animals become apathetic, boring, avoid people, try to hide in a dark place, and are reluctant to respond to the owner’s call. In other cases, the dog becomes affectionate towards its owner and acquaintances, and tries to lick its hands and face. Then anxiety and excitability gradually increase. The animal often lies down and jumps up, barks for no reason, there is increased reflex excitability (to light, noise, rustling, touch, etc.), shortness of breath appears, and the pupils are dilated. Sometimes severe itching occurs at the site of the bite; the animal licks, scratches, and gnaws the area. As the disease progresses, a perverted appetite often appears. The dog eats inedible objects (stones, glass, wood, earth, its own feces, etc.). During this period, paresis of the pharyngeal muscles develops. Difficulty swallowing is noted (it seems that the dog has choked on something), drooling, hoarse and abrupt barking, an unsteady gait, and sometimes squint.

The second period - excitement - lasts 3-4 days and is characterized by an intensification of the symptoms described above. Aggression increases, the dog can bite another animal or person, even its owner, without a reason; it gnaws iron, sticks, the ground, often breaking its teeth and sometimes its lower jaw. Sick dogs have an increased desire to break free and run away; within a day, a rabid dog runs tens of kilometers, biting and infecting other dogs and people along the way. It is typical that the dog silently runs up to animals and people and bites them. Bouts of violence, lasting several hours, are followed by periods of oppression. Paralysis of individual muscle groups gradually develops. The change in the dog's voice is especially noticeable due to paralysis of the laryngeal muscles. The bark sounds hoarse, reminiscent of a howl. This sign has diagnostic value. The lower jaw is completely paralyzed and droops. The oral cavity is open all the time, the tongue falls out halfway, and there is profuse salivation. At the same time, paralysis of the swallowing muscles and tongue muscles occurs, as a result of which the animals cannot eat food. Strabismus appears.

The third period - paralytic - lasts 1-4 days. In addition to paralysis of the lower jaw, the hind limbs, the muscles of the tail, bladder and rectum are paralyzed, then the muscles of the trunk and forelimbs. The body temperature in the excited stage rises to 40-41°C, and in the paralytic stage it decreases below normal. Polymorphonuclear leukocytosis is noted in the blood, the number of leukocytes is reduced, and the sugar content in the urine is increased to 3%. The total duration of the disease is 8-10 days, but often death can occur after 3-4 days.

At silent (paralytic) form of rabies(more often observed when dogs are infected from foxes) excitement is weakly expressed or not expressed at all. In the complete absence of aggressiveness, the animal experiences severe drooling and difficulty swallowing. In ignorant people, these phenomena often cause an attempt to remove a non-existent bone, and in doing so they can become infected with rabies. Then the dogs experience paralysis of the lower jaw, muscles of the limbs and torso. The illness lasts 2-4 days.

Atypical form of rabies does not have an arousal stage. Muscle wasting and atrophy are noted. Cases of rabies have been recorded that occurred only with symptoms of hemorrhagic gastroenteritis: vomiting, semi-liquid feces containing bloody mucous masses. Even less common are the abortive course of the disease, which ends with recovery, and recurrent rabies (after apparent recovery, clinical signs of the disease develop again).

For rabies in cats clinical signs are basically the same as in dogs, the disease proceeds mainly in a violent form. Often an infected animal tries to hide in a quiet, dark place. Sick cats are highly aggressive towards people and dogs. They cause deep damage by digging in with their claws, trying to bite into the face. Their voice changes. In the stage of excitement, cats, like dogs, tend to run away from home. Paralysis of the pharynx and limbs subsequently develops. Death occurs 2-5 days after the onset of clinical signs. In paralytic rabies, aggressiveness is weakly expressed.

Foxes when sick, they are alarmed by unusual behavior: they lose their sense of fear, attack dogs, farm animals, and people. Sick animals quickly lose weight, and itching often occurs in the area of infection.

For rabies in cattle the incubation period is more than 2 months, most often from 15 to 24 days. In some cases, 1-3 years may pass from the moment of the bite until the first signs of the disease appear. Rabies occurs mainly in two forms: violent and silent. In the violent form, the disease begins with excitement. The animal often lies down, jumps up, beats its tail, stomps, throws itself at the wall, and strikes with its horns. Aggression is especially pronounced towards dogs and cats. Salivation, sweating, frequent urge to urinate and defecate, and sexual arousal are noted. After 2-3 days, paralysis of the muscles of the pharynx (impossibility of swallowing), lower jaw (salivation), hind and fore limbs develops. Death occurs on the 3-6th day of illness.
In the quiet form, signs of excitement are weak or absent. Depression and refusal of food are observed. Cows stop producing milk and chewing cud. Then paralysis of the larynx, pharynx, lower jaw appears (hoarse mooing, drooling, inability to swallow), and then the hind and fore limbs. Death occurs on the 2-4th day.

U sheep and goats the symptoms are the same as in cattle: aggressiveness, especially towards dogs, increased sexual excitability. Paralysis develops quickly, and on the 3-5th day the animals die. In the paralytic form of rabies, agitation and aggressiveness are not noted.

Rabies in horses At first it manifests itself as anxiety, fearfulness, and excitability. Itching is often possible at the site of the bite. Aggressiveness is shown towards animals, and sometimes towards people. During periods of excitement, horses throw themselves at the wall, break their heads, gnaw feeders, doors, and sometimes, on the contrary, fall into a state of depression, resting their heads against the wall. There are muscle spasms of the lips, cheeks, neck, and chest. With further development of the disease, paralysis of the swallowing muscles and then the limbs develops. The animal dies on the 3-4th day of illness. But sometimes death occurs within 1 day. In the paralytic form of rabies, the excitation stage is eliminated.

Rabies in pigs often occurs acutely and violently. Pigs rush around in the pen, refuse food, gnaw at feeders, partitions, and the bite site. There is severe salivation. Aggression towards other animals and people appears. Sows attack their own piglets. Paralysis soon develops, and the animals die 1-2 days after their appearance. The duration of the illness is no more than 6 days.
In the paralytic form of rabies (rarely recorded), depression, refusal of food and water, slight drooling, constipation, and rapidly progressing paralysis are noted. Animals die 5-6 days after signs of the disease appear.

Pathological signs. Pathological changes are generally nonspecific. When examining the corpses, exhaustion, bite marks and scratches, damage to the lips, tongue, and teeth are noted. Visible mucous membranes are cyanotic. At autopsy, they establish cyanosis and dryness of the serous covers and mucous membranes, congestive plethora of internal organs; the blood is dark, thick, tarry, poorly coagulated; dark red muscles. The stomach is often empty or contains various inedible objects: pieces of wood, stones, rags, bedding, etc. The mucous membrane of the stomach is usually hyperemic, swollen, with minor hemorrhages. The dura mater is tense. Blood vessels are injected. The brain and its soft membrane are edematous, often with pinpoint hemorrhages, localized mainly in the cerebellum and medulla oblongata. The cerebral convolutions are smoothed, the brain tissue is flabby.
Histological changes are characterized by the development of disseminated non-purulent polyencephalomyelitis of the lymphocytic type.

An important diagnostic value for rabies is the formation in the cytoplasm of ganglion cells of specific Babes-Negri inclusion bodies of round or oval shape, containing basophilic granular formations of viral nucleocapsids of various structures.

Diagnosis and differential diagnosis of rabies. The diagnosis of rabies is made on the basis of a complex of epizootic, clinical, pathological and anatomical data and laboratory test results (final diagnosis).
To test for rabies, a fresh corpse or head is sent to the laboratory; for large animals, the head is sent. Material for laboratory research must be taken and sent in accordance with the Instructions on measures to combat animal rabies.

The general scheme for diagnosing the disease is presented in Figure 3:

In recent years, new methods for diagnosing rabies have been developed: radioimmunoassay, enzyme-linked immunosorbent assay (ELISA), enzyme-linked immunosorbent assay (ELISA), virus identification using monoclonal antibodies, PCR.

In differential diagnosis, it is necessary to exclude Aujeszky's disease, listeriosis, and botulism. In dogs - a nervous form of plague, in horses - infectious encephalomyelitis, in cattle - malignant catarrhal fever. Suspicion of rabies can also arise from poisoning, colic, severe forms of ketosis and other non-communicable diseases, as well as the presence of foreign bodies in the oral cavity or pharynx, or blockage of the esophagus.

Immunity, specific prevention. Animals vaccinated against rabies produce virus-neutralizing, complement-binding, precipitating, antihemagglutinating and lytic (destroying cells infected with the virus in the presence of complement) antibodies. The mechanism of post-vaccination immunity has not been fully deciphered. It is believed that vaccination causes biochemical changes that reduce the sensitivity of nerve cells to the virus. The essence of artificial immunization for rabies comes down to the active production of antibodies that neutralize the virus at the point of entry into the body before penetration into the nerve elements or, during forced immunization, neutralize the virus on its way to the central nervous system. T-lymphocytes responsible for the production of interferon are also activated. Therefore, for this disease, post-infectious vaccination is possible: the vaccine strain, penetrating nerve cells earlier than the field strain, causes them to produce interferon, which inactivates the wild rabies virus, and antibodies that block specific cell receptors.

In veterinary practice, both live tissue and culture vaccines and inactivated rabies vaccines (rabies vaccines) are currently used - up to 84 varieties of rabies vaccines in 41 countries of the world.

Rabies vaccines are classified into three groups: brain vaccines, which are made from the brain tissue of animals infected with a fixed rabies virus; embryonic, in which the virus-containing component is tissue from chicken and duck embryos; cultural rabies vaccines made from the rabies virus reproduced in primary trypsinized or transplanted BHK-21/13 cells.

In the Russian Federation, an inactivated rabies vaccine has been developed from the Shchelkovo-51 strain, reproduced in VNK-21 cell culture, which has high immunizing activity.
For preventive and forced vaccinations of large and small ruminants, horses, pigs liquid cultured (“Rabikov”) anti-rabies vaccine is used.
For preventive vaccinations for dogs and cats dry cultured rabies inactivated vaccine from the Shchelkovo-51 strain (“Rabican”) is used. A universal vaccine has been developed - for cattle, horses, sheep, pigs, dogs, cats.
Imported vaccines are widely represented on the Russian market. Veterinarians use anti-rabies vaccines Nobivak Rabies, Nobivak RL, Defensor-3, Rabizin, Rabigen Mono and others.
For oral vaccination of wild and stray animals, vaccination methods have been developed based on the animals eating various baits with the vaccine “Lisvulpen”, “Sinrab”, etc. Currently, work is underway on the creation of genetically engineered (recombinant) vaccines.

Prevention. In order to prevent rabies, they carry out registration of dogs owned by the population, control over compliance with the rules for keeping domestic animals, catching stray dogs and cats, annual preventive vaccination of dogs, and, if necessary, cats. Unvaccinated dogs are prohibited from being used for hunting or to guard farms and herds.
Forestry and hunting officials are required to report suspected rabies in wild animals, deliver their carcasses for examination, and carry out measures to reduce the number of wild predators in areas unaffected and threatened by rabies. Prevention of rabies in farm animals is carried out by protecting them from attacks by predators, as well as preventive vaccination in infected areas.
The sale, purchase, and transportation of dogs to other cities or regions is permitted only if there is a veterinary certificate indicating that the dog has been vaccinated against rabies no more than 12 months and no less than 30 days before export.

Treatment of rabies. There are no effective treatments. Sick animals are immediately isolated and killed, since their overexposure is associated with the risk of infecting people.

Control measures. When organizing measures to combat rabies, one should distinguish between an epizootic focus, an unfavorable point and a threatened zone.
Epizootic foci of rabies are apartments, residential buildings, private farmsteads of citizens, livestock buildings, livestock farms, summer camps, areas of pastures, forests and other objects where animals with rabies are found.
An area unaffected by rabies is a populated area or part of a large populated area, a separate livestock farm, a farm, a pasture, a forest area, on the territory of which an epizootic focus of rabies has been identified.
The threatened zone includes populated areas, livestock farms, pastures and other areas where there is a threat of rabies introduction or activation of natural foci of the disease.

Activities to eliminate rabies are presented in Figure 4:

Measures to protect people from rabies infection. Persons who are constantly at risk of infection (laboratory personnel working with the rabies virus, dog breeders, etc.) should be immunized prophylactically.

All people bitten, scratched, slobbered by any animal, even apparently healthy ones, are considered suspected of being infected with rabies.

After exposure, the development of infection can be prevented by prompt wound care and appropriate prophylactic treatment of the victim. The injured person should wait a while for a small amount of blood to flow out of the wound. Then it is recommended to wash the wound abundantly with soap and water, treat it with alcohol, tincture or an aqueous solution of iodine and apply a bandage. Wash the wound carefully to avoid further tissue damage. Local treatment of wounds is most beneficial if done immediately after an animal attack (within 1 hour if possible). The victim is sent to a medical center and given a course of therapeutic and prophylactic immunization with anti-rabies gamma globulin and anti-rabies vaccine. Persons with rabies are hospitalized.