Rabies In Humans - Signs And Symptoms, Rabies Vaccination In Humans

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-07 17:49

Human rabies

Content:

• Etiology and routes of transmission of rabies
• The structure of patients with clinical manifestations
• Diagnosis of rabies in humans
• Human rabies symptoms
• Treatment of rabies in humans
• Rabies prevention
• Which doctor should I go to?

Etiology and routes of transmission of rabies

The virus is extremely dangerous for birds and animals by its ability to cause various pathologies in them. It exists due to circulation in nature, spreading with the help of living warm-blooded organisms. A person becomes infected most often from dogs (both domestic and wandering), and they are from wild animals. Directly from representatives of wild fauna, people become infected in no more than 28% of cases. Cats become a source of infection in 10% of cases.

Infection occurs by contact with the saliva of a sick animal, most often by a bite. Trauma to the head and hands is especially dangerous in this regard. The more bites, the higher the risk of infection. The peak incidence occurs in the spring and summer. Theoretically, a person is a source of danger during the development of symptoms of the disease, especially at a time when he ceases to control his own behavior.

In the Russian Federation, in 2012, 950 people were infected. 52 percent of patients live in the Central Federal District, even less in the Volga (17%) and Ural (8%), in the South and Siberian - 7% each.

The carrier of the disease is considered to be foxes, whose population is large in the country. So, for every 10 square kilometers there are up to 10 individuals. In order to prevent the spread of the disease, no more than one animal should fall on the same area.

In addition, the population of wolves and raccoon dogs is growing, they spread the infection no less actively than foxes. Hedgehogs, moose, lynxes, bears can also get sick, although this is not typical for them. Cases of attacks on people by rabid crows are also recorded.

This is why rabies vaccination for pets is so important. There are frequent cases of export of unvaccinated dogs to nature, where they attack infected hedgehogs. After some time, their behavior becomes inadequate, they go to dark places and die.

In the past, the vaccine was administered to humans only 10 days later. At this time, they watched the animal that attacked him. If it did not die during this time, then the victim was not vaccinated. However, if a person does not see a doctor within 4 days after the first symptoms appear, there is a 50% chance that they will survive. If a person began to undergo a course of vaccination only on the 20th day, the probability of his death is 100%.

And if, after a bite, you promptly seek medical help and undergo a course of vaccination, then any consequences can be avoided in at least 96-98% of cases.

The incubation period of rabies in humans

The incubation period of this disease can be either short (9 days) or long - up to 40 days. The disease will progress faster if the virus enters the body through a bite on the face and neck. Bites on the hands are also extremely dangerous - in this case, the incubation period can be reduced to 5 days. So the virus, moving along the nerve pathways, enters the spinal cord and brain, causing cell death. If the infection occurred through the legs, then the incubation period increases significantly. There were cases when the virus did not appear for a year or more. It should be noted that the disease develops faster in children than in adults.

The structure of patients with clinical manifestations of rabies

Since the modern vaccine allows you to save the patient from the disease, patients arriving with obvious clinical signs of rabies are a very rare occurrence. The onset of the disease may be due to the following factors:

• Long-term absence of medical care;
• Violation of the vaccination regime;
• Independent early completion of vaccination.

In most cases, the cause of the disease is the lack of necessary knowledge in people, as well as neglect of their own health. A person often does not attach due importance to the fact that he was bitten. He refers to this wound as an ordinary scratch, which in fact carries a direct threat to life. While you need to seek help not only after a bite, but even after saliva gets on the skin, the integrity of which is violated.

In the body, after infection, the following processes occur: the virus enters the spinal cord and brain, destroying its cells. The death of the nervous system causes a number of symptoms and is fatal.

Diagnosis of rabies in humans

In order to make a diagnosis, the doctor will need to find out the fact of a bite or ingestion of animal saliva on a person. The clinic for all patients is the same. The level of lymphocytes in the blood rises, eosinophils are completely absent. A print smear taken from the surface of the cornea indicates the presence of antibodies produced against an infection that has entered the body.

Human rabies symptoms

The virus can remain asymptomatic in the body for 30 to 90 days. Less often, the incubation period is reduced to 10 days, even less often it increases to a year. The duration mainly depends on the location of the injury. The longer the virus has to get to the brain, the longer the person will remain outwardly healthy. In medicine, cases have been described when the disease manifested itself even 4 years after the bite of an infected cow.

The disease goes through three stages of development, each of which manifests itself with different symptoms.

The first signs of rabies in humans

The initial stage, which lasts from 24 hours to 3 days, is characterized by the following symptoms:

• The first to disturb the patient is the wound. Even if the bite has already healed by this time, the person begins to feel it. The damaged area hurts, the sensations are pulling in nature, localized in the center of the injury. The skin becomes more sensitive and itchy. The scar becomes inflamed and swollen.
• The body temperature does not exceed 37.3 ° C, but it also does not fall below 37 (subfebrile condition).
• Headaches occur, weakness appears. The patient may vomit and vomit.
• When a bite is applied to the face, the person often develops hallucinations, both olfactory and visual. The victim begins to be haunted by smells that are actually absent, non-existent images appear.
• Mental abnormalities appear: the patient becomes depressed, he is pursued by causeless fear. Sometimes increased anxiety is replaced by excessive irritability. A person experiences apathy for everything, becomes withdrawn.
• Appetite disappears. Night rest is disrupted, and nightmares replace normal dreams.

Symptoms of the second stage of rabies in humans

The next stage lasts 2 to 3 days and is called the arousal stage. It is characterized by:

• Due to damage to the nervous system, there is an increase in the excitability of the nervous reflex system. The tone of the autonomic nervous system prevails.
• A striking symptom of the progression of the disease is the development of hydrophobia. An infected person has a spasm when trying to take a sip of liquid. The respiratory and swallowing muscles are exposed to it, up to the occurrence of vomiting. As the disease progresses, a similar spasm will occur in response to the sound of flowing water and even to its appearance.
• The patient's breathing becomes rare and convulsive.
• Facial cramps appear. Any external stimuli cause an acute reaction of the nervous system.
• Convulsions become a response to even insignificant stimuli for a healthy person: bright light, wind or draft, sharp sound. This causes fear in the patient.
• The pupils dilate, the eyeballs protrude (exophthalmos), the gaze is fixed at one point. The pulse quickens, profuse sweat appears, saliva flows continuously, its volume increases significantly.
• Mental disorders progress, the patient is overly excited, becomes violent. He is a threat to himself and those around him, behaves aggressively and even violently. Infected people rush at others, fight and bite, tear their belongings, hair, bang against walls. In fact, a person during such an attack suffers terribly from haunting creepy images and sounds. During the peak of the seizure, a person may stop breathing as well as stop their heartbeat.
• When the attack passes, people behave adequately, non-aggressively, their speech is logical and correct.

Stage III symptoms

The final phase of the disease is the stage of paralysis. It lasts no more than a day, and is characterized by the extinction of motor function. The patient's sensitivity is disturbed, convulsions and hallucinations no longer pursue him. Various muscle groups and organs are paralyzed. Outwardly, the person looks calm. In this case, a significant jump in temperature occurs. It rises to 42 ° C, the heart rate increases, and the blood pressure drops. A person dies due to paralysis of the heart muscle or the respiratory center.

From the onset of symptoms of the disease to the moment of death of the patient, it takes from 3 days to a week. Sometimes rabies is characterized by rapid progression and blurred clinical picture. In this case, the victim may die during the first day, after the first meager symptoms appear.

Treatment of rabies in humans

After the symptoms first manifest themselves, the disease becomes incurable. All actions of doctors will be reduced only to the relief of a person's well-being. They try to isolate him from external stimuli, administer opioid analgesics, and perform supportive therapy. Artificial ventilation of the lungs helps to prolong life, however, death is inevitable.

Postexposure vaccine

Providing first aid to the victim is the responsibility of a surgeon who works at the rabies care center. The patient receives an injection on the same day he asks for help.

If earlier up to 30 vaccinations were injected into the abdomen, under the skin, then starting in 1993, such a scheme for the prevention of the disease was abandoned. A modern vaccine (COCAV) is now in use. It is purified and makes it possible to significantly reduce the course of treatment, as well as to reduce the dosage administered once.

The vaccine is not injected into the buttock! For children it is placed in the thigh (in the outer surface), and for adults and adolescents in the deltoid muscle. The standard dosage is 1 ml. The effect of the injected vaccine reaches 98%, however, it is important to make the first injection no later than two weeks after the injury or bite.

At the first visit of the patient, even months after a dangerous contact, he will be shown a treatment course.

After the vaccination has been made, the first antibodies to the virus will appear after 14 days, their maximum concentration will come in a month. When there is a risk of shortening the incubation period, the patient is administered rabies immunoglobulin.

When the course is completed, the person will develop immunity, which will begin to work 14 days after the last injection.

The formed protection will operate throughout the year.

Despite existing vaccines and immunoglobulin, people continue to die from the virus. This happens as a result of their low awareness of the dangers of the disease and because of not going to the doctor. Some victims refuse to provide medical care and in 75% of cases die due to the fact of infection. Sometimes the blame for the death of such patients lies with the doctors, who incorrectly assessed the degree of threat to human health (up to 12.5%). Some patients (up to 12.5%) die due to interruption of the course or violation of the vaccination regimen.

It is strictly forbidden for patients undergoing treatment, as well as 6 months after its completion: to consume any alcoholic beverages, excessive physical fatigue, being in a bath and a sauna, hypothermia. This is due to a decrease in the production of antibodies, a deterioration in immunity. If the patient is receiving concurrent treatment with immunosuppressants or corticosteroids, control of antibodies to the virus is necessary. If they are produced in insufficient quantities, then additional therapy is needed.

As a rule, most people do not experience any side effects after receiving the vaccine. It is most often well tolerated. Minor allergic manifestations are noted in no more than 0.03% of cases.

There are no contraindications for the administration of the rabies vaccine, due to the lethal threat of a sick person.

Injections are administered to women carrying a child and to patients with acute pathologies.

When should you not be vaccinated?

• When the saliva of an animal gets in or when it touches the whole skin;
• If an animal has bitten a person through a tissue that is thick and not damaged;
• When a bird's beak or claw has been wounded;
• When bitten by domestic animals, if they were vaccinated against the virus and showed no signs of illness for a year.

As for pets, a person is not vaccinated if he has not been bitten on the neck, face, fingers or hands, as well as if the bite is single. When the injury is localized in a dangerous place or is multiple in nature, a person is given 3 vaccinations. This is necessary due to the fact that even vaccinated pets can carry the virus.

The injured animal should be monitored, if it shows signs of illness, then vaccination should be started immediately.

If the infection is likely to have occurred. The vaccine must be done if an injury (bite, scratch, saliva on damaged skin) has been received from a wild animal. If it is possible to track him, then the person is given only 3 injections.

Prophylaxis is stopped if the animal remains healthy for 10 days after the injury.

Also, 3 vaccines are enough if the animal was killed and no rabies virus was found in its brain.

The course is carried out completely if:

• The fate of the animal is unknown;
• It had contact with representatives of wild fauna.

If an injured person was vaccinated with a full course earlier, and 365 days have not passed since that time, then he is given three vaccines (first, 3 and 7 days). If the year has already passed, then you must complete the full therapeutic course.

Rabies immunoglobulin

Therapy using immunoglobulin is necessary for implementation within 24 hours after injury. This period should not exceed 3 days after a possible infection and before the 3rd vaccine was administered. The dose is 20 IU / kg of immunoglobulin.

One half of the calculated dose is injected around the damaged tissue (the wound can be irrigated). The rest is injected into the muscle (into the thigh - into its upper third or into the buttock). The vaccine and immunoglobulin are not injected with the same syringe!

They can be combined with the following indications:

• The bite is deep, bleeding is observed;
• There are multiple bites;
• Injuries sustained in hazardous areas.

It should be remembered that the virus is deadly. Seek medical attention immediately after an injury or a risk of infection.

Rabies prevention

It is important to know that with even a minor bite, a person needs to seek medical help. The further course of therapy will be determined by the doctor. He implements emergency treatment by administering either active or passive rabies immunoglobulin vaccine.

It is important to rinse the injured area with running water immediately after the bite. In addition, the prophylactic vaccine can be administered to persons with occupational risks, for example, trainers, hunters, veterinarians.

The vaccine is administered immediately after the affected person goes to the hospital. It is performed on the first day, then on days 3 and 7, and then on days 14 and 28. The World Health Organization recommends vaccination 3 months later, after the last injection was injected, it is injected into the muscle. This is a sufficient scheme to generate an immune response.

The vaccine is administered if:

• There was a bite by wild rodents;
• There was a contact of saliva on the skin, there was a bite or scratch of an animal that is accurately carrying a virus, or even if it is suspected of being present;
• The bite occurred through a thin layer of tissue after being wounded by any object soiled with the saliva of an infected animal.

The vaccine is not given if:

• A bird (not a predator) injury occurred;
• A bite occurred, without damaging the skin (through dense tissue);
• When ingested milk or meat of an infected animal that has undergone heat treatment;
• Domestic rodent bite;
• A rodent bite occurred in the area where the disease has not been recorded for 2 years;
• There was contact with an infected person without damaging the skin or getting his saliva on the mucous membranes;
• Contact occurred, but the animal did not die 10 days after contact (the measure is not relevant).

The vaccine has fewer adverse reactions compared to possible illness. In some cases, allergic reactions appear, the injection site may swell, harden or hurt. Sometimes there is an increase in body temperature (no more than 38 ° C), chills and headaches appear. Lymph nodes may swell.

Which doctor should I go to?

Primary rabies care is provided by a surgeon (traumatologist) of the rabies care center (according to the order of the Ministry of Health No. 297 of 7.10.1997). The rabies vaccine is given on the first day of visiting the trauma center.

Author of the article: Danilova Tatyana Vyacheslavovna | Infectionist

Education: in 2008 received a diploma in General Medicine (General Medicine) at the Pirogov Russian Research Medical University. Immediately passed an internship and received a diploma of a therapist