Rabies is a dangerous disease. What happens? Facts about rabies

Over the past 3 years, 60 cases of human rabies infection have been recorded in Russia. Largest number Similar cases are registered in the Central, Volga, North Caucasus and Southern federal districts, as well as in the Republic of Tatarstan and the Chelyabinsk region. IN Nizhny Novgorod region Today quarantine has been declared in 50 settlements. These municipal districts are recognized as unfavorable in terms of the spread of rabies, and among the sick there are both wild and domestic animals.

In September 2015, a quarantine was declared in 6 Moscow veterinary clinics due to the occurrence of rabies in domestic animals. If rabies was found in domestic animals, this is the most dangerous, since their contact with humans is likely.

Is rabies a fatal disease?

The rabies virus affects the central nervous system of animals and humans. Climbing up nerve pathways, it reaches the brain and causes inflammation (specific encephalitis). Until 2005, rabies was considered a fatal infection for humans. There are only a few known cases of people being cured of this terrible infectious disease. However, a timely vaccination or certain measures, which will be discussed later, can save the patient’s life.

The main carriers of the rabies virus are:

1. Wild animals (wolves, foxes, wild cats, lynx, the bats, hedgehogs, rodents)
2. Farm animals
3. Pets

Statistics of rabies incidence in Russia by type of animal carrier for 1997 - 2007

The diagrams show that the main sources of rabies are wild animals. IN Lately due to the spread of rabies among wild animals, the virus penetrates simultaneously into several biological species. For example, it is transmitted from a wolf to a fox or marten. Therefore, you need to be especially careful and attentive in the forest. We have previously written about.

Approximately half of all cases of rabies infection occur in domestic and farm animals that come into contact with wild animals. The most dangerous wild animals in terms of rabies infection are foxes (first diagram). Moreover, you can meet mad foxes both in the forest and in the city. When infected with rabies, foxes can manifest themselves in two ways. Some may behave aggressively and attack people. Others, on the contrary, are drawn to people and show affection, like domestic cats. This behavior is not typical for a healthy fox.

If you encounter such a fox, you must immediately leave the forest or area in which it is located. Under no circumstances should you pick them up.

How can a person become infected with rabies?

A person usually becomes infected with rabies when an animal attacks him and then bites him. When analyzing the bulletin on rabies, it was revealed that it is the street type of rabies that occurs on the territory of our country. 99% of people who died from rabies (WHO) were infected from street stray dogs. It is also possible to become infected with rabies when animal saliva comes into contact with damaged human skin. But such cases occur quite rarely. Rabies cannot be contracted through urine, eating berries in the forest or smelling flowers.

The second source of human infection is forest foxes, we wrote about them above. In addition, humans can be infected by pets that have been bitten by rabid wild animals.

Symptoms of rabies in animals

Once a dog or cat is infected with rabies, it usually takes about 15 days before the animal begins to behave aggressively.

The most common symptoms dogs exhibit are:

1. Starts gnawing or licking the bite site.
2. The dog's pupils dilate, and it begins to behave aggressively and even runs away from the house.
3. While maintaining an appetite, the dog can swallow inedible things.
4. The animal may have severe salivation with foam and vomiting (doctors consider this to be the main symptom of rabies).
5. Hydrophobia (may not manifest itself).

After these signs appear, as a rule, on the third day, paralysis of all muscles and death of the animal occurs.

In cats The most common symptoms are salivation and intense agitation.

In cows limbs are paralyzed and death occurs.

Symptoms of rabies in humans

For rabies incubation period ranges from 8 days to 1 year. Most often, the disease does not manifest itself in any way for 40 days.

The duration of the incubation period and the course of the disease directly depend on the location of the bite on the body, the age of the victim, the depth of the wound and the penetration of the virus, quick application vaccines.

It is believed that the shortest incubation period for a person when bitten by a wolf. As for the location of the bite, the most dangerous are the injuries to the head, face and arms during an animal attack, since the rabies virus infects nerve fibers and human cells, then moving along the spinal cord to the brain.

Death occurs due to suffocation and cardiac arrest

Symptoms of rabies in humans:

1. TO primary symptoms rabies include: low-grade fever body (above 37, but below 38 degrees), malaise, convulsions during breathing and the desire to swallow food, headache, nausea, lack of air. The bite site turns red, and increased salivation is observed.
2. Nervous agitation, irritability, anxiety, headache, insomnia, depression appear, poor appetite. All this lasts approximately 1-3 days.
3. Then a characteristic symptom of rabies appears - “foaming at the mouth”; excitement is accompanied by muscle cramps, which can occur even from bright light. Patients may become aggressive, scream, tear their clothes, use force, and break furniture. Body temperature rises to 39-41 degrees, tachycardia, increased lacrimation, salivation, and sweating are observed.
4. Subsequently, hydrophobia and severe breathing spasms appear. Most often at this moment the pupils dilate, and convulsions can distort the face.
5. Then the face turns blue. On last stage illness, hallucinations with changes in mood and attacks of anger are possible, which are very dangerous. During a rage, a sick person may even bite others.

It's worth knowing that there is " quiet fury" When a person’s illness can be practically asymptomatic, he does not show agitation. It is most often transmitted by the bite of humans by bats found in South America.

What to do if you are bitten by a rabid animal or a stray dog?

1. At the first symptoms of rabies, it is almost impossible to save a person. Therefore, if you are bitten by a forest or stray animal, or by an unvaccinated pet, you should immediately seek medical help.
2. If the rabid animal is domestic, then it must be tied up and isolated.
3. Before the ambulance arrives, wash the wound with water and laundry soap and cause profuse bleeding from the wound, as there is a possibility that the virus will come out of it in the blood (virus penetration is 3 mm per hour)
4. You cannot stitch the wound, treat it with alcohol, iodine, or any other antiseptic.
5. You should not drink alcohol after a bite.
6. Animals that have bitten people should be examined by a veterinarian.
7. If the animal is aggressive and there is no way to tie it up, then it is necessary, without touching it, to call the sanitary service through the rescue telephone number 112.

Prevention of rabies

In the prevention of rabies it is very important role The owner’s compliance with the rules for keeping pets plays a role. The very first thing you need to do when you decide to take an animal into your home is to find out if it is vaccinated against rabies. Preventive vaccination using rabies vaccines for pets is mandatory in our country, and in any city or town, even a small one, they are required to do it free of charge in state veterinary clinics. The rabies vaccination is given in early age. Repeated vaccinations must be carried out every year.

If you suspect your pet has rabies, you should immediately take it to a veterinarian for examination and testing. If an animal is not vaccinated, then it should not be allowed to participate in exhibitions and livestock farms, or go hunting with it in the forest.

If you want to sell, buy or transport dogs, you must obtain a veterinary certificate indicating that the animal was vaccinated against rabies no more than 11 months and no less than 30 days before the trip.

If your pet has been bitten by wild animals or stray dogs, you must immediately report this to the veterinary services so that it can be examined by a doctor.

The material was prepared with the participation of a veterinary paramedic

Text: Maria Pletnyova

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 it as preventive measure against rabies surgical removal tissue at the site of the bite and cauterization of the wounds with a hot iron.
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 - internal 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 being found in salivary glands ah 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. Ultra-violet rays kill him 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 are most effective disinfectants: 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 include the 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 stray dogs, and in epizootics natural type- 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:

1. Arctic (reservoir - arctic foxes);
2. natural focal forest-steppe (reservoir - foxes);
3. 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 nerve endings tissue in the area of ​​the infection gate, 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 manifestation clinical signs disease 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 gray matter 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 occurs nerve cells. 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 at the site of the bite there is severe itching, the animal licks, combs, gnaws this place. 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 is choking on something), drooling, hoarse and abrupt barking, unsure gait, sometimes strabismus.

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. Beyond paralysis lower jaw paralyzed hind limbs, tail muscles, Bladder and rectum, 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. They note drooling, sweating, frequent urge to urination and defecation, sexual arousal. 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, edematous, with minor hemorrhages. Solid meninges tense. Blood vessels 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 of specific round or round Babes-Negri inclusion bodies in the cytoplasm of ganglion cells. 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 results laboratory research(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 last years new methods for diagnosing rabies have been developed: radioimmune method, linked immunosorbent assay(ELISA), enzyme-linked immunosorbent assay (ELISA), virus identification using monoclonal antibodies, PCR.

At 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 in the presence foreign bodies V oral cavity or pharynx, 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 use dry cultural anti-rabies inactivated vaccine from the Shchelkovo-51 strain (“Rabikan”). A universal vaccine has been developed - for cattle, horses, sheep, pigs, dogs, cats.
Imported vaccines are widely available in Russian market. Veterinarians anti-rabies vaccines Nobivak Rabies, Nobivak RL, Defensor-3, Rabizin, Rabigen Mono and others are used.
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 in necessary cases and 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 areas of infection.
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. Effective means there is no therapy. 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, personal farmsteads of citizens, livestock premises, cattle farms, summer camps, pasture areas, forest areas and other objects where animals with rabies were found.
A locality unaffected by rabies is a populated area or part of a large populated area, a separate livestock farm, farming enterprise, pasture, forest area, on the territory of which an epizootic focus of rabies has been identified.
The threatened area includes settlements, 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.

Following exposure, infection can be prevented by prompt wound care and appropriate preventive treatment 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 wound treatment brings greatest benefit, if it is carried out immediately after an animal attack (if possible within 1 hour). The victim is sent to a medical center and undergoes a course of treatment preventive immunization anti-rabies gamma globulin and anti-rabies vaccine. Persons with rabies are hospitalized.

Every year, tens of thousands of people around the world die from rabies. The disease is common in more than 150 countries.

Synonyms for the name of the disease are “rabies”, “hydrophobia”, “hydrophobia”.

This disease has been known since ancient times. Cases of human rabies infection from animals (wild or domestic) were described in ancient manuscripts. Until the end of the 19th century, a person infected with rabies was doomed to inevitable death. It wasn't until 1885 that Louis Pasteur invented the rabies vaccine, which has since saved the lives of millions of people.

Facts about rabies:

• There is still no specific treatment for rabies.
• According to the World Health Organization (WHO), more than 40% of infected people are children and adolescents. And in more than 95% of cases, the source of infection is domestic animals - dogs and cats.
• The incubation period usually lasts from several months to one year. Cases have been described in which the clinical picture of rabies developed two to three weeks after infection, and even several years later.
• Basically, the duration of the incubation period directly depends on the location of the source of virus penetration (site of bite, salivation, etc.). Thus, with a bite to the face and head, signs of the disease develop faster than with damage to the extremities, especially the lower ones.

CAUSES

The causative agent of the disease is the rabies virus, which belongs to the Rhabdovirus family.

Facts about the rabies pathogen:

• The virion is bullet-shaped and contains ribonucleic acid in its genome.
• The rabies virus is heat sensitive. Thus, elimination of the pathogen at a temperature of 56 degrees occurs in one hour, and at 80-100 degrees - in one minute.
• Alkali solutions, iodine, most antiseptics and ultraviolet radiation are also detrimental to this virus.
• The virus is neurotropic, that is affects mainly the nervous system.
• After the virus invades the body of a warm-blooded animal or person, the mechanisms of its active replication are launched in the muscle tissue surrounding the site of penetration. Further, along the axons of nerve cells, the pathogen enters the structures of the central nervous system, and from there again moves to the periphery, which causes damage to almost the entire nervous system in this pathology.
• The speed of movement of the rabies virus through the structures of the nervous system is quite high - approximately 3 mm per hour. That is why the duration of the incubation period for rabies is very dependent on the localization of the site of infection and its distance from the brain and spinal cord.

Ways of infection with the Rabies virus:

• The circulation and preservation of the rabies pathogen in natural conditions occurs in a variety of warm-blooded animals. Moreover, some of them (for example, bats) have rabies may remain asymptomatic for a long time.
• The most susceptible to infection are some members of the canine family (for example, wolves, dogs, foxes), felines - lynxes, cats, as well as raccoons, badgers and other species of animals.
• Humans are infected when infected animal saliva comes into contact with damaged skin or mucous membranes. Most often it is a bite or salivation of scratches, abrasions and other external injuries.
• Infection from humans is extremely rare and is disputed by some scientists.

CLASSIFICATION

Rabies is classified according to several criteria.

By type of infection:

• Urban.
• Natural.

Clinical stages of the disease:

• Initial (depression).
• Excitation.
• Paralysis.

The duration of each stage is usually from one to three to five days.

According to clinical forms:

• Bulbarnaya.
• Meningoencephalitic.
• Cerebellar.
• Paralytic.

SYMPTOMS

The rate of development of the disease depends on the location of the bite and the amount of virus that has penetrated.

Main manifestations of rabies:

• The first symptoms of the disease are unusual sensations in a bite wound(even if it has already healed): tingling, burning, itching, hyperesthesia, etc.
• Body temperature rises, headache appears, nausea often occurs, and repeated vomiting. Muscle and throat pain and a dry cough may appear.
• Feelings of melancholy and fear are expressed. The patient appetite and sleep disturbances, which manifests itself as insomnia or nightmares. Apathy sets in.
• After a few days, apathy is replaced by sudden excitement and anxiety.
• Most characteristic manifestation The disease at the second stage is hydrophobia (phobia of water). When trying to drink, the patient experiences convulsive spasms of the pharyngeal muscles. Subsequently, such muscle spasm occurs even at the mention of water.
• Convulsions can also occur when the face is exposed to a stream of air, a sudden bright light or a loud sound.
• The patient's gaze is fixed on one point, the pupils are dilated. Painful salivation (sialorrhea) is often detected.
• Characteristic is the occurrence of violent mental and motor excitement, accompanied by attacks unmotivated aggression, riot and rage. At the same time, the patient rushes about in bed and may hit or bite someone around him for no reason. A clouding of consciousness occurs, accompanied by visual or auditory hallucinations, which are often frightening in nature.
• At the third stage, widespread paralysis of the muscles of the limbs, face, pharyngeal muscles, tongue, etc. Death usually occurs within one to two days as a result of cardiorespiratory arrest.

The duration of the disease is usually 6-8 days. There are also cases of a short course of the disease - from one to three days.

Sometimes an atypical course of the disease occurs, especially in children. In this case, there may be no period of excitation, and muscle paralysis spreads to the entire body gradually, starting from the site of the bite.

DIAGNOSTICS

Diagnostic measures for suspected rabies include several approaches.

Diagnostic criteria:

• The history contains indications of a violation of the integrity of the skin and/or mucous membranes with the ingress of saliva from an animal with suspected rabies.
• Specific clinical manifestations diseases.
• Positive test results for rabies in the suspected animal (if possible) and in the infected person.

When carrying out general clinical research methods, pathognomonic signs of the disease are not detected. Various specific laboratory tests are used to confirm the diagnosis.

Principles of laboratory diagnosis of rabies:

• To confirm the diagnosis intravitally, skin biopsies (usually from the back of the head and back of the neck), smears of the cornea, smears of saliva and cerebrospinal fluid are examined.
• Apply laboratory methods, based on the isolation of the virus itself, determination of its RNA and antigen.
• Several tests are necessary to confirm the diagnosis.
• In post-mortem diagnostics it is mainly used histological examination brain biopsy. In this case, characteristic Babes-Negri bodies are revealed. Sometimes other immunological tests are required.

Methods for laboratory confirmation of rabies:

• Immunofluorescence reaction (RIF). Used for rapid rabies analysis.
• Enzyme-linked immunosorbent assay (ELISA).
• Diffusion precipitation reaction. It is used less frequently due to lower specificity compared to ELISA and RIF.
• Polymerase chain reaction (PCR). Used to determine pathogen RNA in biological material. A modern and highly sensitive diagnostic method.
• Methods for isolating the virus (bioassay on white mice and cell culture) are now used very rarely.

TREATMENT of rabies

Specific there is no therapy for the disease. Unfortunately, all patients with clinical symptoms rabies die.

If manifestations of the disease occur, it is only possible to carry out symptomatic treatment: the use of anesthetics, anticonvulsants and so on.

If, within the shortest possible time after the suspected infection, a course of preventive measures, then the development of the disease in most cases can be avoided.

COMPLICATIONS

As manifestations of the disease develop, death is inevitable due to the lack of effective treatment. Death occurs from paralytic arrest of respiratory and cardiac activity.

PREVENTION

If you come into contact (bite or salivate) with an animal showing signs of rabies, you should immediately seek medical attention. medical care to any nearest health care facility.

In this case, if possible, such an animal should be monitored for ten days. To do this, the suspicious animal is taken to a veterinarian, who reports the results of the observation to the medical institution that vaccinates the affected person.

Areas of preventive measures:

• Non-specific. Local treatment of the wound - immediate washing with soap and water, detergents, disinfectant solutions, etc. The duration of such treatment should be at least 15 minutes.
• Specific. The use of rabies vaccine and specific immunoglobulin as an immunization.

Indications for vaccination:

• Contact with obviously sick, suspicious, unknown or wild animals.
• For any injury caused by objects containing particles of saliva or medulla such animals.
• Contact with an apparently healthy animal at that time, which during the ten-day control period became ill, died or disappeared.
• In case of salivation or injury to the skin and/or mucous membranes caused by a sick person.

The rabies vaccine is administered immediately on the day of the bite and then five injections are given according to a certain schedule over four weeks. WHO recommends an additional injection of the vaccine three months after the start of specific vaccination.

Rabies immunoglobulin is used according to indications. As a rule, its solution is applied to the bite site.

Another area of ​​specific prevention is vaccination of people at risk: hunters, veterinarians, speleologists, etc.

Pets must undergo rabies vaccination in accordance with the veterinary calendar.

PROGNOSIS FOR RECOVERY

Prognosis for the development of a typical clinical picture of rabies always unfavorable. Death probable in virtually all cases.

With timely and correct use of preventive measures after suspected infection, it is almost always possible to avoid progression of the disease.

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Rabies(other names: rabies (lat. rabies), obsolete - hydrophobia, hydrophobia) is an acute infectious disease that occurs after the bite of an infected animal, occurs with severe damage to the nervous system and usually ends in death.

Rabies was known to people long before our era and is described in various ancient books. Already in Egyptian papyri, Indian sacred books Vedas, Greek and Roman written sources, and then in the Bible, rabies was told about rabies, which is transmitted to people from enraged animals (wild and domestic). The dangers of this disease were written about in the Middle Ages, the Renaissance and later.

All kinds of recommendations for the prevention and treatment of rabies - the destruction of enraged animals, cauterization of bite sites in people with a hot iron - did not produce any effect. Almost every person bitten by a rabid animal was doomed to death. Until the 80s of the nineteenth century, people did not have a reliable means of protection against this terrible disease.

The great French scientist Louis Pasteur has the honor of creating a vaccine against rabies (rabies vaccine, from the word Rabies - rabies), successfully used for the first time on July 6, 1885. Then, thanks to vaccination, a boy was saved, bitten by a rabid dog. And some time later, in a French village, children playing were attacked by a rabid dog. Defending them, fifteen-year-old shepherd Jean Jupille accomplished a real feat. He managed to tie the dog's face with a belt whip and kill it with his wooden shoe. But the boy's entire body was covered with wounds. Jean, barely alive, was brought to Paris. Pasteur saved the hero.

Occurrence of the disease Rabies

Rabies agent- Neuroiyctes rabid virus, belongs to the group of myxoviruses of the genus Lyssavirus of the Rhabdovtridae family. It has the shape of a rifle bullet, sizes from 90-170 to 110-200 nm, contains single-stranded RNA.

The virus is resistant to phenol, freezing, and antibiotics. Destroyed by acids, alkalis, heating (at 56°C it is inactivated within 15 minutes, when boiling - within 2 minutes. Sensitive to ultraviolet and direct sunlight, to ethanol to drying. Quickly inactivated by sublimate (1:1000), lysol (1- 2%), carbolic acid (3-5%), chloramine (2-3%).

The virus is pathogenic for most warm-blooded animals and birds. There are street rabies viruses (circulating in nature) and fixed rabies viruses maintained in laboratories. The fixed virus is not excreted in saliva and cannot be transmitted during a bite. It reproduces in various tissue cultures (primarily trypsinized and transplanted, in cultures of human diploid cells or hamster embryo fibroblasts), and after adaptation - on chicken and duck embryos, which is used in the production of rabies vaccines. The mechanism of viral persistence in cell cultures associated with the formation and accumulation of Di-particles. Penetration of the virus into cells occurs through adsorption endocytosis - virions are detected in the form of inclusions surrounded by a membrane, adsorbed on microtubules and as part of lysosomes.

Sources of infection 60% of people with rabies are dogs, 24% are foxes, 10% are cats, 3% are wolves and 3% are other animals. The animal becomes contagious 3-10 days before signs of the disease appear and remains contagious throughout the entire period of the disease. Rabies occurs in almost all countries of the world, with the exception of island countries (Great Britain, Japan, Cyprus, Australia, etc.), as well as a number of countries in the north (Norway, Sweden) and south of Europe (Spain, Portugal).

Human infection occurs through the bite or salivation of an animal with rabies. The rabies virus is transmitted through saliva. Bites to the head and hands are especially dangerous.

Human illnesses are mainly associated with the late seeking of medical care by those who have been bitten, with violation of the schedule during vaccinations or with the incompleteness of their course. Most of the sick did not go to medical institutions after contact with a sick animal. A quarter of the cases are children aged 4-14 years. Sick people, as a rule, had contact with sick animals in rural areas during the spring and summer months.

Course of the disease Rabies

After penetration through damaged skin, the rabies virus spreads centripetally along the nerve trunks, reaches the central nervous system, and then, again along the nerve trunks, centrifugally moves to the periphery, affecting almost the entire nervous system. In the same perineural route, the virus enters the salivary glands, excreted in the patient’s saliva.

The neurogenic spread of the virus is proven by experiments with ligation of nerve trunks, which prevents the development of the disease. The same method is used to prove the centrifugal spread of the virus in the second phase of the disease. The speed of spread of the virus along the nerve trunks is about 3 mm/h.

One hypothesis explains the spread of the rabies virus through the axoplasm peripheral nerves to the central nervous system by the influence of the body's electromagnetic field on negatively charged virions. In experiments on mice it is possible to achieve therapeutic effect, exposing animals to an electric field created by fixing a negative electrode on the head and a positive electrode on the paw. When the electrodes are positioned in the opposite direction, infection is stimulated.

The role of the hematogenous and lymphogenous route of spread of the virus in the body cannot be denied. Interestingly, the amino acid sequence of the rabies virus glycoprotein is similar to that of the snake venom neurotoxin, which selectively binds to acetylcholine receptors. Perhaps this determines the neutrotropic nature of the rabies virus, and its binding to specific neurotransmitter receptors or other neuronal molecules explains the development of autoimmune reactions and selective damage to certain groups of neurons.

By multiplying in nervous tissue (brain and spinal cord, sympathetic ganglia, nerve ganglia of the adrenal glands and salivary glands), the virus causes in it characteristic changes(swelling, hemorrhages, degenerative and necrotic changes in nerve cells). Neuronal destruction is observed in the cerebral and cerebellar cortex, in the optic thalamus, subthalamic region, in the substantia nigra, cranial nerve nuclei, in the midbrain, basal ganglia and in the pons of the brain. However, the maximum changes are in the medulla oblongata, especially in the area of ​​the bottom of the fourth ventricle. Lymphocytic infiltrates (rabbit nodules) appear around the areas of affected cells. In the cytoplasm of the cells of the affected brain (usually in the neurons of the ammon's horn), oxyphilic inclusions (Babes-Negri bodies) are formed, which are sites of production and accumulation of rabies virions.

Symptoms of the disease Rabies

Incubation period lasts on average from 1 to 3 months (fluctuations are possible from 12 days to 1 year or more). The duration of the incubation period is influenced by the location of the bite. The shortest incubation is observed with a bite to the face, head, then the upper extremities, and the longest incubation is observed with a bite to the lower extremities.

There are 3 stages of the disease: I - initial (depression), II - excitement, III - paralysis.

Stage I of rabies. The disease begins with the appearance of unpleasant sensations in the bite area (burning, nagging pain with irradiation to the center, itching, hyperesthesia of the skin), although the wound may already be completely healed. Sometimes local inflammation appears again, the scar becomes red and swells. When bitten in the face, olfactory and visual hallucinations are observed. Body temperature becomes subfebrile - usually 37.2-37.3°C. At the same time, the first symptoms of mental disorder appear: inexplicable fear, melancholy, anxiety, depression, less often - increased irritability. The patient is withdrawn, apathetic, refuses to eat, sleeps poorly, and his sleep is accompanied by frightening dreams. The initial stage lasts 1-3 days. Then apathy and depression are replaced by anxiety, the pulse and breathing quicken, and a feeling of tightness in the chest arises.

Stage II of rabies- excitation is characterized by increased reflex excitability and severe sympathicotonia. The most striking clinical symptom of rabies is fear of hydrophobia: when trying to drink, painful, spastic contractions of the swallowing muscles and auxiliary respiratory muscles occur. These phenomena increase in intensity so that one reminder of water or the sound of pouring liquid causes spasms of the muscles of the pharynx and larynx. Breathing becomes noisy in the form of short, convulsive breaths.

At this time, reactions to any irritants sharply worsen. An attack of seizures can be triggered by blowing a stream of air into the face (aerophobia), bright light (photophobia), or loud sound(acousticophobia). The patient's pupils are greatly dilated, exophthalmos occurs, and the gaze is directed to one point. The pulse is sharply accelerated, profuse, painful salivation (sialorrhea), and sweating appear. At the height of the attack, a violent psychomotor agitation(attacks of violence, rage) with violent and aggressive actions. Patients can hit, bite others, spit, and tear their clothes. Consciousness darkens, auditory and visual hallucinations of a frightening nature develop. Cardiac and respiratory arrest is possible. During the interictal interval, consciousness usually clears up, patients can correctly assess the situation and answer questions intelligently. After 2-3 days, excitement, if death does not occur at the height of one of the attacks, is replaced by paralysis of the muscles of the limbs, tongue, and face.

Period of rabies paralysis associated with loss of activity of the cerebral cortex and subcortical formations, characterized by a pronounced decrease in motor and sensory functions. Convulsions and attacks of hydrophobia stop. People around them often mistakenly take this condition for an improvement in the patient’s condition, but in reality it is a sign near death. Body temperature rises to 40-42°C, tachycardia and hypotension increase. Death occurs within 12-20 hours from cardiac paralysis or respiratory center. The total duration of the disease is 5-8 days, rarely slightly longer.

Sometimes the disease without warning immediately begins with the stage of excitement or the appearance of paralysis. Rabies in children has a shorter incubation period. Attacks of hydrophobia and severe agitation may be absent. The disease manifests itself as depression, drowsiness, development of paralysis and collapse. Death can occur within a day after the onset of the disease. Variants of the course include bulbar, paralytic (Landry type), meningoencephalitic and cerebellar forms of the disease.

Diagnosis of the disease Rabies

Recognition of the disease is based on epidemiological (bite or salivation of the skin, mucous membranes of a sick person by animals suspected of rabies) and clinical data (characteristic signs initial period alternating with agitation with symptoms such as hydrophobia, aerophobia, drooling, delirium and hallucinations). IN general analysis blood, lymphocytic leukocytosis is noted with aneosinophilia. It is possible to detect the rabies virus antigen in prints from the surface of the cornea. In case of death of patients, the ammon's horn is examined (histologically and by immunofluorescent method), in which Babes-Negri bodies can be detected.

It is necessary to differentiate from tetanus, encephalitis, hysteroneurosis, poisoning with atropine and strychnine, and attacks of delirium tremens. Tetanus is characterized by tetanic convulsions, trismus, “sardonic smile”, absence of disturbances of consciousness and normal psyche sick.

In encephalitis (lethargic, poliomyelitis, etc.), before the development of the paralytic phase, there is no stage of excitation, combined with hydrophobia, aerophobia and severe sympathicotonia.

The picture of false rabies in hysteroneurosis is characterized by a confused history (often bitten animals are healthy), an abundance of subjective complaints, a lack of objective signs (no breathing disorders, tachycardia, dilated pupils) and a long course.

Drug poisoning is excluded on the basis of a carefully collected medical history and the absence of a characteristic cyclical nature of the disease. Attacks of delirium tremens are not accompanied by hydrophobia or convulsions.

Treatment of the disease Rabies

Urgent Care

If signs of illness appear in a person bitten by an animal, it is necessary to immediately seek medical help.

There are no effective treatments. Held symptomatic therapy to reduce the patient's suffering. The patient is placed in a darkened, noise-free, warm room. Injected into large doses morphine, pantopon, aminazine, diphenhydramine, chloral hydrate in enemas. Administration of curare-like drugs, transfer of the patient to artificial ventilation lungs can prolong his life. The use of rabies immunoglobulin in the presence of clinical symptoms of the disease is ineffective.

Treatment using induced coma "Milwaukee protocol"

In 2005, there were reports that a 15-year-old girl from the United States, Gina Gies, was able to survive infection with the rabies virus without vaccination, when treatment was started after the appearance of clinical symptoms. During treatment, Gis was put into an artificial coma, and then she was given drugs that stimulate the body's immune activity. The method was based on the assumption that the rabies virus does not cause irreversible damage to the central nervous system, but causes only a temporary disruption of its functions, and thus, if you temporarily “turn off” most of the brain functions, the body will gradually be able to produce sufficient quantity antibodies to defeat the virus. After a week in a coma and subsequent treatment, Gis was discharged from the hospital several months later without signs of being affected by the rabies virus.

However, all subsequent attempts to use the same method on other patients were unsuccessful. There is still ongoing debate among doctors about why Gina Gies recovered. Some indicate she may have been infected with a severely weakened form of the virus or had an unusually strong immune response.

The third confirmed case in the world of a person recovering from rabies without using a vaccine is the recovery of a 15-year-old boy hospitalized with rabies symptoms in Brazil. The teenager, whose name has not yet been revealed, contracted rabies after being bitten by a bat in the Brazilian state of Pernambuco. For unknown reasons, the boy was not vaccinated to avoid the development of the disease. In October, the child developed nervous system symptoms consistent with rabies and was admitted to the Oswaldo Cruz University Hospital in Recife, the capital of Pernambuco state. To treat the boy, doctors used a combination antiviral drugs, sedatives and injectable anesthetics. According to the attending doctors, a month after the start of treatment, the virus was absent in the boy’s blood. The child is currently recovering.

Forecast always unfavorable. Descriptions available isolated cases recovery of patients who received full course immunization with rabies vaccine and sick people after its completion.

Prevention of Rabies Disease

Measures to prevent rabies in animals include regulating the density of wild animals; catching stray dogs and cats; compliance with the rules for keeping domestic dogs (registration, use of muzzles, keeping them on a leash, etc.); mandatory annual preventive immunization against rabies in dogs.

A course of preventive immunization is carried out for persons professionally associated with the risk of contracting rabies (dog catchers, commercial hunters, veterinarians, etc.).

Dogs, cats and other animals that have bitten people or animals must be immediately delivered by the owner to the nearest veterinary hospital for examination and quarantine under the supervision of specialists for 10 days. The results of such observation of animals are reported in writing to the medical institution where the affected person is vaccinated. If the animal does not die during the observation period, then it is probably healthy.

Nonspecific prevention

The best preventative measure is local wound treatment. The bite area should be immediately thoroughly cleaned with a 20% solution of mild medical soap. Deep bite wounds are washed with a jet soapy water using a catheter. Cauterization of the wound or suturing is not recommended.

Specific prevention (immunoglobulin + vaccine)

The best specific prevention is passive immunization with rabies immunoglobulin or rabies serum followed by active immunization (vaccination). Passive and active immunization are carried out simultaneously, but different drugs cannot be injected into the same place.

Indications for rabies vaccination

General secondary prevention(vaccine prophylaxis) begin immediately when:

All bites, scratches, salivation of the skin and mucous membranes caused by clearly rabid, suspected rabid or unknown animals;

In case of injury by objects contaminated with saliva or brain of rabid or suspected rabid animals;

When bitten through clothing if it is damaged by teeth;

When bitten through thin or knitted clothing;

When biting, salivating or scratching a healthy animal at the time of contact, if it became ill, died or disappeared during a 10-day observation;

When bitten by wild rodents;

In case of obvious salivation or damage to the skin of a person with rabies.

When is the rabies vaccine not necessary?

Vaccinations are not carried out:

In case of bites through intact thick or multi-layered clothing;

When injured by non-birds of prey

When bitten by domestic mice or rats in areas where rabies has not been recorded in the last 2 years;

In case of accidental consumption of thermally processed meat and milk of rabid animals;

If the animal remains healthy within 10 days after the bite.

When bitten by an animal 10 days or more before their illness;

In case of salivation and bites of mild and moderate severity caused by animals that were healthy at the time of the bite, with favorable data (rabies is not found in the area, the animal is kept in isolation, the bite was provoked by the victim himself, the dog is vaccinated against rabies). However, in this case, the animal is subject to 10-day veterinary observation in order to begin vaccinations if it shows signs of rabies, as well as death or disappearance;

In case of provoked salivation of intact skin by an unknown domestic animal in rabies-free areas;

In cases of contact with a person with rabies, if there was no obvious salivation of the mucous membranes or damage to the skin.

Rabies vaccination procedure

Active immunization begins immediately. The vaccine is administered intramuscularly, 1 ml 5 times: on the day of infection, then on the 3rd, 7th, 14th and 28th day). With this scheme, satisfactory immunity is always created, so routine serological test Not recommended. WHO also recommends a 6th injection 90 days after the first.

Adverse reactions of the rabies vaccine

There may be mild reactions at the injection site such as soreness, swelling and induration. In some cases, these reactions may be more severe. In addition, there may be an increase in temperature to 38 degrees Celsius or higher, enlarged lymph nodes, arthritis and dyspeptic disorders. Sometimes headache, general malaise, chills, myalgia and allergic reactions are observed.

special instructions

Vaccinations against rabies are carried out both on an outpatient and inpatient basis. Persons with severe bites living in rural areas are subject to hospitalization; re-vaccinated; persons with diseases of the nervous system or allergic diseases; pregnant women, as well as persons vaccinated with other drugs during the previous two months.

Corticosteroids and immunosuppressants may suppress the immune response to the vaccine. Therefore, if vaccination is necessary while taking these drugs, determining the level of antibodies is mandatory to decide on an additional course of treatment

During vaccinations, it is necessary to monitor the patient's health status. If there are complaints of deterioration of the condition, hospitalization is necessary, and vaccinations are temporarily suspended. The victim should be examined by a neurologist and therapist. The issue of continuing or stopping vaccinations is decided in consultation with a neurologist, radiologist and therapist.

In order to ensure proper immunity and prevent post-vaccination complications, the use of any alcoholic beverages during the vaccination course and for 6 months after its completion is contraindicated for those vaccinated. It is necessary that during the vaccination period the patient does not overwork and avoid hypothermia and overheating. In some cases, it is recommended to transfer to more light work or issuing sick leave.

The use of other vaccines simultaneously with rabies is not allowed. However, if necessary, emergency tetanus prophylaxis can be carried out. People with rabies are not vaccinated.

Northwestern State Medical University named after I.I. Mechnikov

Department of Infectious Diseases

Head of the department: Professor Lobzin Yu.V.

Teacher: Associate Professor Romanova E.S.

Abstract on the topic:

Rabies

Completed by: Student 546 gr.LF

Ukhatova A.A.

St. Petersburg, 2014

Rabies – a viral zoonotic natural focal infectious disease with a contact mechanism of transmission of the pathogen through the saliva of an infected animal, characterized by severe damage to the central nervous system with a fatal outcome.

Etiology:

The causative agent is an RNA genomic virus of the genus Lissavirus of the Rhabdoviridae family. It is rod-shaped or bullet-shaped and contains two antigens: soluble S-Ag, common to all lyssaviruses, and surface V-Ag, responsible for the development of antiviral immune reactions. There are two known variants of the virus: street (wild), circulating in nature among animals, and fixed, used for the manufacture of vaccines against rabies. The variants are similar in antigenic structure, so vaccination with a fixed strain creates immunity to the street virus.

The virus is unstable in external environment- dies when heated to 56 0 C in 15 minutes, when boiled in 2 minutes. Sensitive to ultraviolet and direct sunlight, ethanol and many disinfectants. However, it is resistant to low temperatures, phenol, and antibiotics.

Epidemiology:

Sources and reservoir of infection – The source of the rabies virus is both wild and domestic animals. Wild animals include wolves, foxes, jackals, raccoons, badgers, skunks, bats, rodents, and domestic animals include dogs, cats, horses, pigs, small and cattle. However, the greatest danger to humans is represented by foxes and stray dogs outside the city in the spring and summer. The mechanism of transmission is contact; human infection usually occurs through bites, less often through salivation by animals with rabies. In recent years, it has been proven that in addition to contact, aerogenic (in caves inhabited by bats, intra-laboratory infections), alimentary and transplacental routes of transmission of the virus are possible.

The natural susceptibility of people is not universal and is largely determined by the severity of the damage caused and the location of the bite.

Pathogenesis:

When the virus enters through damaged skin, it begins to move along the nerve trunks to the central nervous system, then centrifugally to the periphery, and the entire nervous system is damaged. Once in the salivary glands, the virus is released in saliva.

When it enters nervous tissue, the rabies virus causes swelling, necrotic and degenerative changes, and hemorrhages of nerve cells. Neurons are destroyed in the cortex and pons of the brain. The virus is able to selectively bind to acetylcholine receptors, which explains the selective damage to certain groups of neurons and leads to an increase in reflex excitability, and then to the development of paralysis. Edema, hemorrhages, degenerative and necrotic changes form in the brain. The process involves the cerebral cortex, cerebellum, optic thalamus, subcutaneous region, and cranial nerve nuclei. Similar changes develop in the midbrain, basal ganglia and pons. Maximum lesions are observed in the region of the fourth ventricle. Changes in the central nervous system are associated with convulsive contractions of the respiratory and swallowing muscles, increased secretion of saliva and sweat, respiratory and cardiovascular disorders. Eosinophilic inclusions (Babes-Negri bodies) are found in the cytoplasm of brain cells. Subsequently, the virus enters various organs and systems from the central nervous system: skeletal muscles, heart, lungs, liver, kidneys, adrenal glands. Penetrating the salivary glands, it is released with saliva.

Clinical picture:

The duration of the incubation period for rabies usually varies and ranges from 7-10 days to 1-2 years. This depends on the age of the victim, his reactivity and state of the nervous system, localization, depth and multiplicity of bites, the abundance of nerve endings in the affected areas, and the timeliness of the use of therapeutic vaccination. It is shorter in children, with deep bites and injuries to the face and head, as well as fingers and nail beds, especially caused by wild rabid animals; lengthens in vaccinated people if the bites are not very severe and are localized in the lower extremities.

There are three periods in the clinical picture:

1.Initial period (depression period)

It is characterized by exacerbation of local phenomena in the area of ​​the bite, changes in the patient's behavior and neurological disorders. From the very beginning, paresthesia appears in the area of ​​the bite and often along the nerve trunks in the form of a burning sensation or, conversely, coldness, crawling and itching lasting from several hours to many days. The scar in the area of ​​the bite turns red again and swelling, anesthesia or hypoesthesia occur, and around the scar there is hyperesthesia and pain resumes.

The patient's character traits and behavior change(unexplained fears and anxiety, sadness, leading to depressed mood, deep depression, melancholy). Possible nausea, vomiting, belching, constipation, dry mouth. Patients complain of headaches, ringing in the ears, and persistent insomnia. The temperature rises from 37°C to 38°C, appetite disappears. The condition is periodically alarming due to a painful sensation of constriction in the chest, which is accompanied by rapid, spasmodic breathing and mental and sensory agitation. From the cardiovascular system, tachycardia, arrhythmia, and hypotension are observed.

2. Period of excitement (stage of the height of the disease)

It begins with signs pathognomonic for rabies: hydrophobia, aerophobia against the background of hyperexcitability and violent attacks. They are caused not so much by difficulty swallowing and breathing due to spasm of the pharynx and larynx as a result of the lesion medulla oblongata how much fear, excitement and anxiety patients have before, during or after attempting to swallow. In the first days of this stage, patients are still able to swallow solid food and suck on a wet towel or sponge.

Hydrophobia, or fear of water, is manifested by an unbearable disgust for a glass of water brought close to the patient’s lips, causing sharply painful spasms of the muscles of the larynx and pharynx, a feeling of suffocation, and at the height of paroxysm - cardiac and respiratory arrest with a feeling of imminent death. Attacks of hydrophobia are caused not only by the sight, but also by the noise of water flowing from the tap, and even the mention of it or any irritant reminiscent of water, the shine of a mirror (mirror sign).

Aerophobia (fear of air)- a consequence of a laryngeal-pharyngeal spasm that occurs in a patient from a blowing stream of air, especially cold air directed at his face. The attack may begin when sudden opening doors and windows, airing bed linen near the patient, when he himself moves from one room to another, that is, during any action accompanied by air movement (aerophobia). It can be caused by sound stimuli (akusophobia), exposure to bright light (photophobia).

Laryngopharyngeal spasms accompanied by severe shortness of breath, reach the highest degree, generalized clonic-tonic convulsions and muscle contractures appear. In some cases, suddenly, in others, the attack of violence gradually passes, consciousness is restored, but the background of increased excitement of the patient remains, which may be the cause of a repeated paroxysm of even greater force. During the “calm down” period, the patient’s fatigue is evident, and he answers questions adequately. Due to the fact that the patient cannot swallow either food or water, signs of dehydration and emaciation quickly develop, and he is exhausted.

Towards the end of the period of excitement, when sympathicotonia gives way to vagotonia, salivation sharply increases and saliva thins. IN in rare cases uncontrollable vomiting is possible, sometimes with bloody masses. Despite extreme fatigue and exhaustion, the patient does not sleep, shudders all the time when exposed to external irritations, and his barely open eyes are red. The features of the cyanotic face are sharply pointed, the eyes are sunken, the pupils are dilated and sluggishly react to light. Body temperature remains high. From the cardiovascular system - tachycardia (140-160 per 1 min), pulse of satisfactory filling. With the cessation of convulsions and agitation, the patient can swallow, drink, eat, and his breathing is calm.

3. Paralytic period.

characterized by a decrease in general excitability and the development of flaccid (peripheral) paralysis, which often begins in the area of ​​the bitten limb or in the form of paraplegia. Paralysis of the bladder occurs. Paralysis spreads from bottom to top, similar to Landry's palsy, including the cranial nerves. But sometimes paresis or paralysis of the cranial nerves may appear earlier, which is associated with the localization of bites on the head.

At this stage, body temperature rises to 38-39°C, before death to 42-43°C. The phenomena of exicosis are increasing due to ongoing profuse sialorrhea and sudden sweating. The patient loses weight sharply. He lies motionless with his eyes half open due to ptosis of both eyelids.

Paralytic period may be absent or last from several hours to 2-3 days. The total duration of the disease from the moment of the onset of hydro- and aerophobia is usually 1-3 days, less often - 3-6 and very rarely 7-8 days or more.

May rarely be observed paralytic form of rabies. It is characterized by short duration, weak excitability and mildly expressed attacks of violence or their absence. Cardinal symptoms of rabies (hydrophobia, aerophobia, agitation) are either absent or mild.

Rabies in children has a shorter incubation period and a “quiet” form of the disease. General symptoms in the prodrome and melancholy include drowsiness or mild anxiety with signs of aerophobia and violent attacks. Then paralysis and death occur due to symptoms of collapse.

Rabies in vaccinated people may be atypical with the absence of such cardinal signs as hydro- and aerophobia. The disease may manifest itself as meningoencephalitis or paralytic forms. In such cases, the diagnosis is usually made posthumously.

Rabies due to chronic alcoholism characterized by pronounced hallucinations along with smoothing of hydrophobia.

Differential diagnosis: Rabies should be distinguished from polio, tetanus, encephalitis, botulism, and hysteria.

Diagnostics:

Clinical diagnosis of rabies during the period of precursors or in atypical cases it is difficult, but in the midst of a typical illness, when such cardinal signs as hydro- and aerophobia are expressed, against the background of increased excitability with bouts of violence, it does not cause difficulties.

Laboratory diagnosis of rabies in both humans and animals, includes studies of cadaveric brain tissue. Brain prints stained by Sellers can detect Babes Negri bodies using light microscopy within 2-4 hours, which reliably confirms the diagnosis of rabies. The most valuable method for the rapid diagnosis of rabies is the method of fluorescent specific antibodies (MFA), which is strictly specific and in its sensitivity exceeds the method for detecting Babes-Negri bodies, coinciding with the results of a bioassay.

A biological test is usually performed if the results are negative. histological examination of the brain. The results of the bioassay (for young animals are obtained after 1-3 weeks, and for newborns - after 6-7 days) should be compared with clinical and morphological indicators.

Treatment:

Patients with rabies must be hospitalized in intensive care units of infectious diseases hospitals or infectious diseases departments of psychiatric hospitals. They are placed in dark, warm isolation wards or separate rooms without unnecessary objects, where the maximum gentle regime should be created (rest, protection from noise, bright light, cold air movement) and individual care should be provided. For safety reasons, personnel must work in masks, goggles, gloves and thoroughly wash their hands with H. Discharge from patients is disinfected.

Already in the emergency room, symptomatic medications are prescribed to reduce the patient’s suffering to eliminate restlessness, anxiety, attacks of hydro-aerophobia and associated pain - relaxants, sedatives, hypnotics and other drugs. Pantopon is administered 2-3 times a day in combination with enemas with chloral hydrate. I recommend it for relieving cramps! seduxen, relanium, droperidol, aminazine, hexenal, drip enemas with amytal sodium (2-3 times a day).

To provide nutrition and maintain water-salt balance, pour in a 40% glucose solution 20-40 ml 2 times a day intravenously, intravenously drip - rheopolyglucin, hemodez, 5% glucose, saline solutions with the simultaneous administration of diuretics, blood and plasma transfusions are indicated. The total volume of injected liquid is at least 2 liters.

In the paralytic stage, cardiovascular drugs (korglykon, strophanthin K) and respiratory stimulation with the use of artificial respiration devices are important.

Prevention:

The fight against rabies consists of comprehensive measures aimed at eliminating it among animals, providing assistance to victims of rabid or suspected rabid animals, and specific prevention. Elimination of rabies among animals. Due to the fact that the main source of rabies are predatory animals and in modern conditions epizootics of this disease are widespread throughout the globe, the following measures are of great importance in their elimination:

control over animal population density;

identification and destruction of all sick and suspected rabies wild and domestic animals;

systematic catching and destruction of all homeless and stray dogs; - destruction of all dogs and cats that have been in contact with rabid animals or bitten by them;

isolation and vaccination of livestock exposed to rabid animals;

burning the corpses of animals killed by rabies.

Animals that have bitten people are quarantined for 10 days of observation. The corpses of suspicious animals are sent for laboratory and diagnostic testing. All remaining dogs and cats are vaccinated and revaccinated.

Specific immunization occupies one of the leading positions in the fight against rabies.

Therapeutic immunization carried out after the expected penetration of the rabies virus into the human body or at the beginning of the incubation period. It should be preceded by local treatment of a wound or scratch caused by an animal with rabies, if primary treatment is not carried out before seeking medical help. Help is provided at trauma centers.

In those vaccinated with the rabies vaccine, immunity to the rabies virus appears 5-6 weeks after the start of vaccination. As is known, with bites of dangerous localization (to the face, head, neck, fingers) and multiple bites of the body inflicted by wild animals, especially wolves, the incubation period is short - from 7 to 45 days. In such cases, to quickly create immunity to rabies, the vaccine is combined with anti-rabies gamma globulin (passive immunization).

Bibliography:

1. Textbook of infectious diseases and epidemiology, V.I. Pokrovsky, GEOTAR-Media, M. 2009

2. Textbook for students: Infectious diseases, Yu.V. Lobzin. St. Petersburg, 2013

3. Textbook Infectious diseases, V.N Timchenko, SpetsLit, St. Petersburg, 2006.