Rabies in humans and animals. Rabies: incubation period in humans, symptoms and diagnosis Rabies develops

Rabies (rabies) is an acute zoonotic disease of viral etiology that develops after a person is bitten by an infected animal. The disease is caused by RNA viruses (rhabdoviruses).

The disease manifests itself as severe damage to the central nervous system and death. There is no cure for rabies. The rabies vaccine is the only chance for a person bitten by a sick animal to survive. Therefore, vaccination should be carried out immediately.

Most cases of rabies development in patients are caused by late seeking specialized help, as well as by violation of the recommended regimen during the period of preventive vaccination or by failure to complete the course of specific immunization.

In most cases, the incubation period for rhabdoviruses ranges from one to 3 months. However, in some cases, this period may be reduced to one week. The maximum incubation period for the rabies virus does not exceed one year.

Due to the fact that the incubation period may be shortened in some patients, vaccine prophylaxis and serotherapy should be performed urgently, immediately after a rabid animal has bitten or salivated an area of the patient’s injured skin.

If possible, the animal that bit the patient should be examined. The animal's condition is monitored for ten days. At the same time, laboratory tests are carried out to identify rhabdoviruses in the animal.

If negative test answers are received and the animal remains healthy within ten days of observation, rabies prophylaxis for the bitten person is stopped.

In this situation, the start of the introduction of anti-rabies vaccines before receiving the results of the study is justified by the fact that a cure for rabies has not yet been developed. The disease is characterized by absolute lethality. All treatment, when symptoms of rabies appear in a person, is reduced only to alleviating his condition until death.

Prevention of rabies in humans, through emergency administration of rabies vaccine, is the only way to prevent the development of this disease and its consequences.

How can you become infected?

Infection with rhabdoviruses occurs after a person is bitten by an infected animal. Also, infection can occur as a result of infected saliva coming into contact with areas of affected skin.

In most cases, urban residents become infected after a dog bite. Cases of infection after cat bites are much less common.

Susceptibility to the rabies virus is high among all warm-blooded animals. Therefore, you can become infected after the bite of any infected animal (bat, rat, squirrel, horse, fox, wolf, etc.).

Based on the causes of rabies, it is divided into urban and natural rabies.

Rural rabies accounts for 2/3 of all cases. This is due to the fact that residents of rural areas have a higher risk of being bitten by a rabid animal than a city resident.

The most common causes of urban rabies are bites from dogs, bats and cats. Outbreaks of natural rabies are usually associated with attacks by foxes and wolves.

After a bite to the hand, the incidence of rabies is about seventy percent. The maximum probability of infection and rapid development of the disease with a minimum incubation period occurs with bites to the neck and face (the probability of infection is more than 95%).

Rabies is more common in children than in adults. This is because children often play with stray animals and may receive minor bites that they do not report to adults. Bats are particularly dangerous at the moment. In this regard, it is strictly not recommended to try to catch a mouse with your bare hands that has flown into an apartment or onto a balcony.

It should be noted that in states where there are strict restrictions on the import of animals and mandatory vaccinations have been introduced for them, there is practically no rabies. Such preventive measures are common in Japan, Great Britain, etc.

Is rabies transmitted from person to person?

The rabies virus is transmitted to humans only from an infected animal.

Upon contact with a bitten person, transmission of the virus does not occur. There have been isolated cases of infection following a cornea transplant from a person who died of rabies.

In theory, transmission of the virus from a person with terminal rabies to another person is possible. However, to do this, the sick patient must not only bite another person, but also bite through the skin. Or, a large amount of saliva from a patient in the terminal stage of rabies should come into contact with the affected area of the skin (open wounds).

In practice, people with rabies do not pose an epidemiological danger.

The rabies virus is not transmitted from person to person by airborne droplets or kissing.

According to recent studies, an aerogenic transmission mechanism (extremely rare) is only possible when visiting caves with a huge number of bats.

Can you get rabies without a bite?

In addition to a bite, infection can occur after contact with the saliva of a sick animal on open lesions of the skin or mucous membranes. Infection does not occur if the animal’s saliva gets on intact skin, for example, the animal was unable to bite through a thick sleeve of a coat, trousers, etc., but the fabric became saturated with saliva that got on the skin.

Examination of the animal and a course of prevention (injections against rabies to humans) after a bite or salivation of open wounds is mandatory.

In isolated cases, vertical transmission of the virus from a mother bitten by an animal to a child is possible.

How does rabies develop?

The rabies virus appears in saliva eight to ten days before the animal shows signs of illness. Therefore, even after being bitten by a seemingly normal, healthy animal, you should urgently treat the wound with laundry soap and consult a doctor for preventative measures.

If possible, the animal should also be taken to a doctor for further observation and examination.

There are two types of rabies virus:

street (wild variants of the virus common among animals);
fixed (this type of rabies virus is used to create vaccines).

Both viruses have a similar antigenic nature, therefore, after administration of a vaccine made from a fixed strain, immunity to the wild virus also develops.

Once infected, rhabdovirus spreads along nerve fibers. Hematogenous and lymphogenous spread of the virus is also possible.

The virus is characterized by its tropism for acetylcholine receptors, which contributes to the damage of many groups of neurons, the development of reflex-type hyperexcitability and, subsequently, the formation of paralysis.

The brain of an infected person is affected by swelling, hemorrhage and severe necrotic and degenerative changes. Rabies causes damage to all brain structures. The area of the fourth ventricle is subject to the most severe degenerative changes.

Signs of rabies in humans

Severe damage to the central nervous system leads to:

development of convulsive contractions of the respiratory and swallowing muscles;
a sharp increase in salivation (secretion of saliva and profuse sweating;
severe disorders of the respiratory and cardiovascular systems.

Further migration of the rabies virus throughout the body is accompanied by its penetration into all organs and the development of multiple organ failure.

The first signs of rabies in humans are the appearance of a scar phenomenon, unclear fears, and depression. Subsequently, the addition of paroxysms of rabies and various phobias is noted.

The scar phenomenon consists of a strong burning sensation, as well as nagging and aching pain at the site of the bite. The pain spreads along the nerve fibers located at the site of the bite. Severe redness and swelling of the scar is also noted.

Paroxysms of rabies are called a specific reaction of the patient to the action of any irritants. The patients shudder, stretch their trembling arms forward (the body also goes through a slight trembling) and throw their heads back. The appearance of inspiratory dyspnea (inability to take a full breath) is also characteristic.

The most indicative phobias (fears) with rabies will be the occurrence of hydrophobia (fear of water), aerophobia (fear of air), acousticophobia (fear of various sounds), photophobia (fear of light).

Classification of rabies

Based on the nature of its occurrence, the disease is divided into epizootic urban and natural rabies.

Clinical forms include bulbar, meningoencephalitic, cerebellar and paralytic forms.

The periods of the disease are divided into three stages:

harbingers (first stage);
excitement (2);
paralysis (3).

I also distinguish two forms of the disease: violent and paralytic.

The first symptoms of rabies in humans

The first signs of rabies in humans can appear as early as a week after the bite, however, more often the incubation period of the virus ends one to three months after the bite.

In patients, the temperature rises (as a rule, low-grade fever is characteristic), the phenomenon of a scar develops, complaints of general malaise, the occurrence of inexplicable anxiety, and depression appear. There are sleep disturbances, possibly both nightmares and insomnia.

Patients also complain of severe dry mouth, poor appetite, headaches, shortness of breath, and tachycardia.

The first stage of rabies lasts from one to three days.

The second stage is accompanied by pronounced excitement. One of the most specific signs of rabies appears - severe hydrophobia. The fear of water is so strong that an attempt to bring a glass of water to the patient’s lips causes a painful spasm of the larynx and an attack of suffocation.

Patients reject water, despite severe dehydration and extreme thirst. Specifically, stretching forward of trembling hands and small twitching of the facial muscles. Such symptoms appear not only when the patient sees water, but also when he hears its sound (an open tap).

Aerophobia is manifested by the development of an attack from a breath of fresh air. In some cases, the attack may be accompanied by pronounced aggressiveness; patients try to attack hospital staff. Periods of aggression and violence are accompanied by pronounced salivation.

There is a sharpening of facial features, sunken eyes, and dilated pupils.

After periods of violence, the patient comes to his senses and is fully aware of what is happening. Also, patients fully remember everything that happened.

After the development of hydrophobia, patients live for several days (rarely more than six days).

The patient's descent into an “ominous tranquility” is a sign of imminent death. The cause of death is paralysis of the cardiac and respiratory muscles.

In isolated cases, variants of silent rabies are possible (usually after an attack by vampire bats). The disease occurs with clinical paralysis without the stage of excitation.

The total duration of rabies is from five to eight days. A longer course of the disease is extremely rare.

Diagnosis of rabies in humans

To make a diagnosis of rabies, a medical history (animal bite) is extremely important. If possible, the animal should be captured and examined.

The specific symptoms of the disease are also taken into account. Diagnosis of rabies is divided into intravital and postmortem.

Test for rabies in humans

Intravital is carried out by carrying out:

virological examination of biological material (saliva, cerebrospinal fluid);
PCR, ELISA, RIF;
study of corneal imprints.

For post-mortem diagnosis, electron microscopy of frozen brain tissue, immunohistochemical examination of the brain, as well as MFA or PFA are used.

All work with the rabies virus is carried out only in specialized laboratories in compliance with the strictest safety measures and protocols for working with especially dangerous infections.

Treatment of rabies in humans

There is no cure. All treatment comes down to creating the most gentle conditions for the patient and alleviating his condition until death. After death, the body undergoes mandatory cremation.

Attempts have been made to treat with rabies gamma globulins, but there is no data on their effectiveness.

To date, only six cases of rabies survival have been reported. The most famous patient is Gina Gies, who was treated according to the Milwaukee Protocol.

This is an experimental treatment developed by Dr. Rodney Willoughby. Therapy consists of putting the patient into an induced coma (to protect the central nervous system until the body produces antibodies to the virus) and using antiviral drugs.

The patient spent seven days in a coma. In total, the treatment took 31 days. Subsequent studies showed that her brain was not damaged. Mental and cognitive functions were completely preserved.

Prevention and vaccination against rabies in humans

After animal bites, you must immediately thoroughly wash the wound with laundry soap and running water, treat it with alcohol and iodine. It is strictly forbidden to cauterize or excise the wound, as this contributes to the spread of the virus.

After treatment in the hospital, the wound is sprinkled with powder containing anti-rabies gamma globulins.

They no longer give 40 rabies injections in the stomach. This method is outdated.

A person should be vaccinated against rabies no later than two weeks from the moment of the bite. After the specified period, it is practically ineffective.

Rabies vaccination schedule

At the moment, the following rabies vaccination schedule for humans is used: 1 milliliter of vaccine five times on the day of the bite. The drug is injected into the shoulder or thigh. Next, the rabies vaccine is administered on the third, seventh, fourteenth, twenty-eighth (or thirtieth) and ninetieth day after the bite.

The injection is given on the 28th or 30th day, depending on the vaccine manufacturer.

In case of severe bites or late treatment (10 days from the moment of the bite), anti-rabies gamma globulins are administered in addition to the vaccine.

Preventive vaccinations are recommended for people working with animals, hunters, researchers, veterinarians, etc. The rabies vaccine is valid for about a year. Therefore, for patients bitten by an animal within a year after a full course of vaccinations, vaccination is indicated only on the day of the bite + on the third and seventh days.

Preventive vaccinations are carried out upon application, as well as on the seventh and thirtieth day. A year later, the first revaccination is indicated (one administration), with further administration of the vaccine every three years (single administration of the vaccine).

Compatibility of rabies vaccination in humans and alcohol

Alcoholic beverages should not be drunk for six months after rabies vaccination and throughout the entire course of vaccination.

Drinking alcohol increases the risk of developing adverse reactions to the rabies vaccine.

The use of glucocorticosteroid drugs and immunosuppressants is also contraindicated.

Is it possible to wet the rabies vaccine?

The instructions for vaccines do not contain information about the prohibition of getting the vaccine wet. However, it is not recommended to actively rub the grafting site while swimming. Also, it is advisable to refrain from visiting the sauna (overheating is contraindicated).

During the course of preventive vaccination, overheating, hypothermia or excessive physical activity should be avoided.

Side effects of rabies vaccination in humans

Side effects of the vaccine can be manifested by the development of swelling at the injection site, pain, fever, gastrointestinal disorders of a dyspeptic nature, arthritis, and enlarged lymph nodes.

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 consider 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 asks 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 characterized by severe damage to the central nervous system and, in the absence of timely vaccination, leads to death. This disease has been known to mankind for a long time. Back in the 1st century AD. Cornelius Celsus described a case of rabies in humans. And now rabies is found everywhere. Doctors managed to make a significant breakthrough: at the end of the 19th century, Louis Pasteur invented an anti-rabies vaccine, which saved the lives of many people. But in the 21st century, a cure for rabies has not yet been developed and people continue to die from this disease.

According to the Global Alliance for Rabies Control (GARC), approximately 160 people die from rabies every day! Most of the victims are residents of developing countries, where there are no vaccines or government programs to eliminate rabies among animals.

Causes

The causative agent of the disease is a virus of the Rabdoviridae family, genus Lyssavirus. This is a zoonotic infection. A person becomes ill when bitten or salivated on damaged skin or mucous membranes by an infected animal. From the site of introduction, the virus spreads along nerve fibers and reaches the brain, where it is fixed in the medulla oblongata and hippocampus. Here the microorganism begins to multiply, causing the development of characteristic changes: the appearance of tissue edema, hemorrhages, degenerative and necrotic foci. Then the virus spreads throughout the body through the bloodstream and enters the salivary glands, heart, lungs, kidneys, and adrenal glands.

It is noteworthy that a sick animal becomes infectious already in the last ten days of the incubation period, that is, before the first clinical signs of the disease appear. Thus, an animal that is adequate and healthy at first glance can be a potential source of rabies.

Sources of infection are sick foxes, dogs, cats, wolves, raccoon dogs, jackals, and bats. The highest incidence of rabies is observed in the summer-autumn period.

Many people are interested in whether it is possible to become infected with rabies from a sick person if he attacks and bites a healthy person? Theoretically this is possible. In fact, not a single similar case has been recorded in history.

The incubation period can be as short as twelve days or as long as one year. But on average, this period for rabies is one to three months. The duration of the incubation period is primarily influenced by which part of the body the sick animal bit. Thus, the shortest duration of the incubation period is recorded for bites in the area of the head, neck, upper extremities, and the longest - for a bite localized in the area of the lower extremities. A short incubation period is observed in children. No less important are the state of the body’s immune system, the depth of the wound, and the amount of pathogen that has entered the wound.

There are three stages of the disease:

Initial (depression);
Excitement;
Paralytic.

initial stage

The first signs of the disease are the appearance of twitching, itching, burning, and nagging pain in the bite area, even if the wound has already completely healed. Sometimes the wound can become inflamed again, and the skin in this area becomes swollen and red.

The victim notes general malaise and may experience a headache. The temperature rises to 37-37.5 degrees and remains at this level.

At this time, signs of damage to the nervous system already appear: the person becomes depressed, anxiety, fear, and, less often, irritability appear. Such a person withdraws into himself, refuses communication, food, and does not sleep well. The duration of the initial stage is only one to three days. After this period, apathy gives way to excitability, increased heart rate and breathing, and the appearance of compressive pain in the chest area.

The patient becomes more and more restless. At this stage, the most characteristic sign of the disease already appears - hydrophobia. When trying to swallow water, a person experiences painful spasms of the swallowing and auxiliary respiratory muscles. Therefore, even at the sound of running water from the tap, a person becomes restless, breathes noisily, taking short breaths.

The central nervous system gradually becomes susceptible to any irritants. Muscle cramps can be triggered by a puff of air (aerophobia), a loud sound (acousticophobia) or a bright light (photophobia).

Noteworthy are the sharply dilated pupils, the patient's gaze is fixed on one point. The pulse is greatly increased, and there is increased salivation and sweating. The patient is not able to swallow such a large amount of saliva, and therefore constantly spits or saliva flows down the chin.

At the height of the attack, psychomotor agitation occurs, the patient becomes aggressive, tears his clothes, rushes around the ward, and attacks people. At the same time, consciousness becomes darkened and the patient suffers from hallucinations of a frightening nature. During periods between attacks, consciousness can clear up and then the patient is even able to react adequately and answer the questions posed. The duration of this period is two to three days.

At this stage, convulsions and hydrophobia stop. People around often perceive such changes as an improvement in the patient’s condition, but in fact this indicates imminent death.

During this period, body temperature rises to critical levels: 40-42 degrees. There is a rapid heartbeat and a drop in blood pressure. Death usually occurs within 12-20 hours from paralysis of the respiratory center or heart.

On average, the illness lasts five to eight days. The classic version of the course of the disease is described above, but not in all cases rabies occurs in this way. Thus, sometimes the disease immediately manifests itself as agitation or paralysis, without an initial period. Some patients may have no attacks of psychomotor agitation or hydrophobia at all.

Diagnostics

The diagnosis of rabies is based on epidemiological (bite by a suspicious animal) and clinical data (attacks of psychomotor agitation with hydrophobia, drooling, hallucinations). Clinical diagnostic tests are of secondary importance. Lymphocytic leukocytosis and a decrease (absence) of eosinophils are noted in the blood.

In addition, the virus can be detected in saliva and cerebrospinal fluid. The selected material is seeded into cell culture or infected mice.

An accurate diagnosis of rabies is possible only after the death of the patient. Pathologists perform a histological examination of the brain to detect disease-specific inclusions - Babes-Negri bodies.

Also a very informative method is histological examination of the brain of the biting animal. Of course, this is possible when the animal can be isolated.

As already stated, there are no effective treatments for rabies. If a person has already developed symptoms of rabies, it will inevitably lead to death. The only method of preventing death is timely vaccination. Administration of rabies immunoglobulin in the presence of rabies symptoms is no longer effective.

In treating a patient, all possible methods are used to alleviate the patient's suffering. The person is placed in a noise-isolated, darkened room to prevent irritation of the nervous system by loud sounds and bright light.

The patient is administered morphine, aminazine, diphenhydramine, and chloral hydrate in large doses. If signs of respiratory failure develop, the patient may be transferred to mechanical ventilation.

Prevention

Prevention, first of all, consists of combating the source of the disease and preventing human infection. For this purpose, domestic animals are registered and vaccinated against rabies. If your pet is not vaccinated but still goes outside occasionally, there is always the possibility of contracting rabies. In addition, a person always needs to remember the likelihood of infection and avoid contact with stray animals. Unfortunately, people get rabies not only from bites from obviously sick wild animals, such as foxes, but also from contact with street kittens and puppies.

What to do if an animal does bite a person?

You should immediately wash the wound thoroughly with soap. Abundant washing of the wound can reduce the amount of virus ingested;
Treat the edges of the wound with 70% alcohol;
Apply a bandage. No need to tie a tourniquet;
Go to the nearest emergency room.

At the emergency room, the surgeon again washes the wound with soapy water, treats the edges of the wound with alcohol-containing preparations, washes the wound itself with an antiseptic and applies an antiseptic bandage to it. The edges of the bite wound are not sutured. After these manipulations, immunoprophylaxis begins. There are absolute and relative indications for vaccination. The risks of infection can be correctly predicted by a doctor, and it is he who decides whether vaccination is necessary.

The times when the bitten person was given forty injections in the stomach have sunk into oblivion. Currently, the rabies vaccine administration regimen consists of six injections. The first vaccine is given on the day of the bite (day 0), then on the 3rd, 7th, 14th, 30th and finally 90th day. For severe and moderate bites, or for bites of any severity and a person’s late (after ten days) treatment, an additional one-time injection of rabies immunoglobulin is administered.

Remember: Only timely vaccination can prevent the death of rabies. If an animal is bitten, you should go to the emergency room the same day.

Upon a person’s visit to the emergency room, the surgeon fills out an emergency notification about an animal bite, which is transmitted to the sanitary and epidemiological service. Having received the notification, epidemiologists begin to investigate the case. An animal that has bitten, even if it appears healthy at first glance, is isolated for ten days. If the specified period has passed, and the animal has not shown signs of illness, it can be said that it is healthy.

If during this time the animal shows obvious signs of illness, it is killed by veterinarians, biomaterial is collected and sent for research.

How can you tell if an animal is sick based on external signs? At the initial stage of the disease, the animal’s behavior changes, it becomes apathetic, avoids people, does not eat, or, on the contrary, can become very affectionate and sociable. There is increased salivation. After a couple of days, the animal becomes aggressive, chews on inedible objects, tries to escape, attacks people and bites.

Due to paralysis of the laryngeal muscles, the animal's jaw is drooping, its tongue is protruding, foamy saliva flows from the mouth, and the animal does not drink water. Dogs' barking becomes hoarse. During this period, cats often become timid and run into secluded places, where they die. At the last stage, the animal is tormented by cramps of the limbs and torso.

– an infectious zoonosis of viral etiology, characterized by predominantly severe damage to the central nervous system, threatening death. A person becomes infected with rabies through an animal bite. Spreading along nerve fibers, the rabies virus first increases their excitability and then causes the development of paralysis. Penetrating into the tissues of the spinal cord and brain, the virus causes severe disturbances in the functioning of the central nervous system, clinically manifested by various phobias, attacks of aggressive agitation, and hallucinatory syndrome. Rabies remains an incurable disease. For this reason, it is difficult to overestimate the importance of preventive rabies vaccination given to the patient in the event of an animal bite.

ICD-10

A82

General information

Characteristics of the pathogen

Rabies is caused by an RNA-containing rhabdovirus, which is bullet-shaped and has two specific antigens: soluble AgS and surface AgV&. During the replication process, the virus promotes the appearance of specific inclusions in neurons - eosinophilic Babes-Negri bodies. The rabies virus is quite resistant to cooling and freezing, but is easily inactivated by boiling, exposure to ultraviolet radiation, and disinfection with various chemical reagents (Lysol, chloramine, carboxylic acid, sublimate, etc.).

The reservoir and source of rabies are carnivores (dogs, wolves, cats, some rodents, horses and livestock). Animals excrete the virus in saliva, the contagious period begins 8-10 days before the development of clinical signs. Sick people are not a significant source of infection. Rabies is transmitted parenterally, usually when a person is bitten by a sick animal (saliva containing the pathogen enters the wound and the virus penetrates the vascular bed). Currently, there is evidence of the possibility of aerogenic, alimentary and transplacental routes of infection.

Humans have limited natural susceptibility to rabies; the likelihood of developing infection if infected depends on the location of the bite and the depth of the injury and ranges from 23% of cases for bites of the extremities (proximal parts) to 90% for bites to the face and neck. In a third of cases, infection occurs through the bite of wild animals; in other cases, domestic animals and livestock are responsible for human rabies. If you seek medical help in a timely manner and carry out preventive measures, rabies will not develop in infected individuals.

Pathogenesis of rabies

The rabies virus enters the body through damaged skin and spreads along the fibers of nerve cells, to which it has a pronounced tropism. In addition, the virus can spread throughout the body through the blood and lymph. The main role in the pathogenesis of the disease is played by the ability of the virus to bind acetylcholine receptors of nerve cells and increase reflex excitability, and subsequently cause paralysis. Penetration of the virus into the cells of the brain and spinal cord leads to gross organic and functional disorders of the central nervous system. Patients develop hemorrhages and swelling of the brain, necrosis and degeneration of its tissue.

The pathological process involves cells of the cerebral cortex, cerebellum, thalamus opticus and subtubercular region, as well as the nuclei of the cranial nerves. Microscopy reveals eosinophilic formations (Babes-Negri bodies) inside brain neurons. Pathological degeneration of cells leads to functional disorders of organs and systems due to impaired innervation. From the central nervous system, the virus spreads to other organs and tissues (lungs, kidneys, liver and endocrine glands, etc.). Its entry into the salivary glands leads to the release of the pathogen in saliva.

Symptoms of rabies

The incubation period for rabies can range from a couple of weeks when the bite is localized on the face or neck to several months (1-3) when the pathogen is introduced into the extremities. In rare cases, the incubation period lasted up to a year.

Rabies occurs in a succession of three periods. In the initial period (depression), there is a gradual change in the patient’s behavior. In rare cases, depression is preceded by general malaise, low-grade fever, pain in the area of infection (usually a wound that has already healed at the onset of the disease). Sometimes (extremely rarely) the site of entry of the pathogen becomes inflamed again. Usually during this period, the clinic is limited to manifestations from the central nervous system (headaches, sleep disorders, loss of appetite) and the psyche (apathy, depression, irritability, depression and attacks of fear). Sometimes patients may feel chest discomfort (tightness) and suffer from indigestion (usually constipation).

The height of the disease (excitement stage) occurs 2-3 days after the first signs of depression appear, and is characterized by the development of various phobias: fear of water, air, sounds and light. Hydrophobia - fear of water - prevents patients from drinking. Characteristic behavior is when a glass of water is offered, the patient happily takes it, but an attempt to drink the liquid causes an attack of paralyzing fear, a pause in breathing, and the patient throws the glass. However, rabies is not always accompanied by hydrophobia, which can make diagnosis difficult. As the disease progresses, patients suffer from severe thirst, but due to the formed reflex, even the sight and sound of water causes spasms of the respiratory muscles.

Aerophobia is characterized by attacks of suffocation due to air movement; with acoustophobia and photophobia, such a reaction is observed to noise and bright light. Attacks of suffocation are short-lived (a few seconds), they are accompanied by spasms and convulsions of the facial muscles, the pupils are dilated, patients are excited, experience panic, scream, throw their heads back. There is trembling of the hands. Breathing during paroxysms is intermittent, whistling, and inhalations are noisy. The muscles of the shoulder girdle are involved in breathing. During this period, patients are in an aggressive, excited state, scream a lot, and are prone to unsystematic aggressive activity (they rush around, they can hit or bite). Hypersalivation is characteristic.

As the disease progresses, attacks of agitation become more frequent. There is weight loss, excessive sweating, and hallucinations (auditory, visual and olfactory). The duration of the excitation period is 2-3 days, less often it extends to 6 days.

The terminal stage of the disease is paralytic. During this period, patients become apathetic, their movements are limited, and sensitivity is reduced. Due to the subsidence of phobic paroxysms, a false impression arises that the patient has become better, but at this time the body temperature quickly rises, tachycardia and arterial hypotension develop, and paralysis of the limbs and, subsequently, of the cranial nerves occurs. Damage to the respiratory and vasomotor centers causes cardiac and respiratory arrest and death. The paralytic period can last from one to three days.

Diagnosis of rabies

There are ways to isolate the rabies virus from cerebrospinal fluid and saliva; in addition, there is the possibility of diagnosis using the reaction of fluorescent antibodies on dermal biopsies and corneal imprints. But due to labor intensity and economic inexpediency, these methods are not used in widespread clinical practice.

Diagnosis is mainly carried out on the basis of the clinical picture and epidemiological history data. Diagnostic methods that are intravital in nature also include bioassays on laboratory animals (newborn mice). When they are infected with a virus isolated from saliva, cerebrospinal fluid or tear fluid, mice die after 6-7 days. Histological analysis of the brain tissue of a deceased patient makes it possible to definitively confirm the diagnosis if Babes-Negri bodies are detected in the cells.

Treatment of rabies

Currently, rabies is an incurable disease; therapeutic measures are palliative in nature and aimed at alleviating the patient’s condition. Patients are hospitalized in a darkened, soundproofed room, they are prescribed symptomatic drugs: sleeping pills and anticonvulsants, painkillers, tranquilizers. Nutrition and rehydration measures are carried out parenterally.

Now there is active testing of new treatment regimens using specific immunoglobulins, immunomodulators, cerebral hypothermia and intensive care techniques. However, rabies is still a fatal disease: death occurs in 100% of cases of clinical symptoms.

Prevention of rabies

Rabies prevention is primarily aimed at reducing morbidity among animals and limiting the likelihood of stray and wild animals biting humans. Domestic animals are required to undergo routine vaccination against rabies; designated categories of citizens (veterinary workers, dog catchers, hunters, etc.) are immunized with an anti-rabies vaccine (triple intramuscular injection). A year later, revaccination is carried out and in the future, if the risk of infection remains high, repeat immunization is recommended every three years.

In the event of an animal bite, a set of measures must be taken to prevent rabies: the wound is washed with medical alcohol, treated with antiseptics, an aseptic bandage is applied, after which you should immediately contact a trauma center (or a surgeon or paramedic at the FAP). A course of preventive rabies vaccination (dry inactivated vaccine) and passive immunization (rabies immunoglobulin) is carried out as soon as possible. The schedule of preventive injections depends on the location of the bite, the depth of the wound and the degree of contamination with saliva.