Enterovirus infection: types of enteroviruses, symptoms, treatment. Viral diarrhea (rotavirus, norovirus, enterovirus) Video: enterovirus infection, “Live Healthy”

Viral bowel diseases are similar in their manifestations. How to distinguish rotavirus infection from enterovirus. Features of treatment in pregnant women.

Rotavirus can only infect the human gastrointestinal tract, which is its main difference from enterovirus.

The incubation period of infection is from one to four days. Fever begins to subside 1-2 days after infection, but diarrhea can last up to 7 days.

Enterovirus infection

This microorganism is able to affect not only the intestines, but also other human organs - for example, eyes, central nervous system, liver, heart. The incubation period of enterovirus is 1-10 days. This is another difference from rotavirus.

Symptoms:

1. Rapid and acute development of the disease;
2. Increase in body temperature up to 40˚С;
3. General malaise, weakness;
4. Diarrhea, but less frequent than with rotavirus infection;
5. Attacks of nausea and vomiting;
6. The disappearance of symptoms immediately after a decrease in body temperature;
7. puffiness;
8. Redness of the eyeball, palate;
9. Small rash all over the body;
10. Muscle pain;
11. Torsing pains in the abdomen;
12. Enlarged lymph glands;
13. Discharge of icy sweat and chilliness.

From the foregoing, it follows that there is a difference between rotavirus and enterovirus. Moreover, enterovirus infection is more dangerous than rotavirus.

Methods of treatment and diagnostics

It is already known how rotavirus differs from enterovirus, but the treatment for these infections is the same. The main methods of treatment include:

• Plentiful drink. Due to dehydration, all subsequent problems occur, so both diseases often end in the hospitalization of a child or adult. You can drink plain water, but it is better to use specialized solutions that help replenish the water balance in the body. One such tool is Ringer. The medicine can be used in small amounts, but often (every 15-20 minutes).
• Starvation. The first 3-4 days of illness the patient is on complete starvation, but these days he will not experience hunger, because the appetite completely disappears. Viruses carry out vital processes due to the intake of nutrients into the body. If food is not supplied, then, accordingly, microorganisms will begin to die due to the created unfavorable environment.
• Medicines. There are no specialized medicines for enterovirus, but there are broad-spectrum drugs that have a detrimental effect on these microorganisms. Such medicines include Enterofuril, Stopdiar, Levomycetin, etc.
• Sorbents and probiotics. To restore the normal functioning of the gastrointestinal tract, experts prescribe agents containing strains of bifidobacteria and lactobacilli. They will help normalize the destroyed intestinal flora and help digestion. These drugs include Bifidumbacterin, Acipol, Linex, etc. From the very beginning of the disease, adsorbents (activated carbon, smecta, enterosgel, polysorb, filtrum) should be used. They "collect" harmful substances on themselves, and leave the body naturally.
• Concomitant medications. In case of impaired functioning of the gastrointestinal tract, specialists prescribe medications containing natural enzymes, for example, Mezim or Pancreatin.

At elevated temperatures (above 38˚C), viruses are inactivated. This means that with a tolerable state of health, it is not recommended to bring down the temperature. If a small child is sick, then you need to bring down the temperature after 38.5 ° C, using Nurofen, Paracetamol, Cefecon, Panadol, etc.

Infection during pregnancy

During pregnancy, the risk of infection with these types of viruses is especially increased, so contact with sick people should be avoided. If a loved one falls ill, then it is advisable to isolate him from the future mother. Symptoms of diseases are the same as described above.

Depending on the gestational age, entero- and rotavirus can cause irreparable harm to the fetus:

1. At an early stage of pregnancy, fetal death and spontaneous abortion (miscarriage) are possible;
2. In the later stages, polyhydramnios, placental insufficiency, delayed development of the child in the womb are possible.

The risks of the formation of malformations of organs and systems in a baby increase, and the risks are higher in shorter periods. There is also a risk of premature birth and, as a result, the birth of small children.

An increased risk of infection of the baby in women who are carriers of the virus and in girls who first encountered the disease. In the former, infection occurs with the help of circulating blood, and in the latter due to the lack of antibodies and immunity to viruses.

Similar to normal. This is a plentiful drink, taking probiotics, antiseptics, vitamins. Treatment and dosage prescribed by a doctor.

Antipyretics are used in extreme cases - if the expectant mother feels very unwell. You can drink Ibuprofen or Paracetamol, but there is a risk of miscarriage or premature birth (depending on the gestational age).

Most often, the infected are placed in a hospital, because enterovirus during pregnancy is very dangerous.

Disease prevention

For pregnant women, specific prophylaxis has not been developed and no vaccines are provided. Other people and children are recommended to be vaccinated against these viruses, thereby reducing the risk of infection by several times.

But nonspecific prophylaxis is the same for all patients:

• Compliance with personal hygiene;
• Regular walks and ventilation of the premises;
• Refusal to be in crowded places;
• Processing children's toys, furniture and other items with disinfectants.

This disease is not fatal if timely measures are taken. Be healthy and don't get sick!

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Rotavirus and enterovirus, when viewed through a microscope, are significantly different from each other, although their component in both examples is ribonucleic acid (RNA). Enteroviruses do not have an outer fatty membrane (membrane). The size of the virus is 25 nm. Rotavirus gets its name from its appearance. In a microscope with multiple magnification, wheels with hubs are clearly visible. The double-stranded group of ribonucleic acid molecules is covered with a protein shell. The diameter of viral wheel particles is 65-75 nm.

In this article you will learn:

What is common between enterovirus and rotavirus infections

Rotavirus and enterovirus infectious diseases have a common nature of infection - viral. These viruses are usually picked up by young children while interacting with other children in the kindergarten or in the yard in the sandbox. Enterovirus infection and rotavirus infection have a number of common symptoms - diarrhea, fever. Often, respiratory pathologies occur simultaneously with intestinal upset.

Both contagious diseases are spread mainly by the oral-fecal route, although airborne transmission is also possible. Rotavirus and enterovirus are transmitted only from person to person, although food, household items that have been in the hands of the virus carrier, and water can serve as transmission factors.

Their high resistance to the external environment complicates the prevention of infection.

Features of rotavirus

Rotavirus infection has become quite widespread, and most intestinal disorders with diarrhea in children are due to rotavirus. Symptoms are similar to gastroenteritis and enteritis. Rotavirus and enterovirus infections have similar symptoms. Sometimes, against the background of intestinal disorders at the onset of the disease, a respiratory syndrome is manifested, resembling SARS. It is noticed that rotavirus infection often accompanies influenza. All these factors led to the fact that the infection was called intestinal flu, although rotavirus has nothing to do with this infection.

In both cases, there is indigestion.

Rotavirus is not as harmless as it might seem at first glance. Every year, up to 25 million people are infected. Of this number, 2.5-3.6 percent of patients die. The list of the dead includes people with weakened immune systems and health conditions. About 2 million patients end up in hospitals. The share of rotavirus accounts for up to 50 percent of all diseases in children, accompanied by diarrhea.

A patient's stool contains up to 10 trillion viral components per gram. For infection, 100 particles are enough, which are not even visible to the naked eye, these viruses are so microscopic. Young children under 5 years of age acquire this infection in nurseries and kindergartens.

A three-layer shell of protein compounds ensures the stability of a microorganism that has entered the acidic environment of the stomach and invulnerability to intestinal digestive enzymes. Once in the intestines, rotaviruses duplicate, ensuring their reproduction. At the same time, epithelial villus cells are damaged, causing their damage and death. Structural and functional changes in the epithelium provoke diarrhea.

Rotavirus infection begins with vomiting and a sharp increase in temperature. In this case, there may be a runny nose and redness in the throat. The stools are gray-yellow in color and have a clay-like consistency.

Each infection strengthens the immune system to that type of virus, so the disease is much easier with subsequent infection.

Enterovirus Features

Enteroviruses got their name from the place of localization (in the small intestine), but they rarely lead to enteritis. Reproducing in the intestines, viruses penetrate into the blood, into the internal organs, into the nervous system. Hence such a variety of pathologies generated by these viruses. The difference between rotavirus and enterovirus lies in the variety of strains of the latter.

At the moment, 67 types of enterovirus are known:

• polioviruses - causative agents of poliomyelitis;
• A and B;
• ECHO viruses.

Enteroviruses are highly resistant to acids and esters. At a pH of 3 to 10, viruses are able to reproduce. Resistant to a wide range of detergents. They die only at temperatures above 400 ° C. They are afraid of drying, ultraviolet radiation.

Polioviruses

Polioviruses are the causative agents of the severe disease poliomyelitis. The very name of the disease, if translated from ancient Greek, suggests that it affects the spinal gray matter. Pathology covers the part of the nervous system responsible for the motor function of certain parts of the body. Hippocrates also mentioned this disease.

There are 3 types of pathogens of this insidious disease:

1. The Brungind serotype is the most pathogenic for humans, has the highest neurovirulence, and more often than other types provides paralytic forms of the pathology.
2. Lansing serotype, less pathogenic. In experiments conducted on cotton rats, it produced 1 acute case per 1000-10000 asymptomatic forms.
3. The Leon serotype is less common than other forms and is the least pathogenic for humans and monkeys.

The World Health Organization has set itself the goal of eradicating poliomyelitis by the year 2000, but has not achieved success in this regard.

This video covers the most common enterovirus infections:

How to distinguish rotavirus infection from enterovirus

At first glance, rotavirus and enterovirus infections are similar, but they have distinctive features. Laboratory diagnostics, which is carried out in the hospital, will also help identify groups of viruses. What is the difference between enterovirus and rotavirus, the following table will show.

Rotavirus and enterovirus are the causative agents of intestinal infections (“intestinal flu”) affecting both adults and children. However, despite the fact that one and the other pathology is accompanied by nausea, vomiting, diarrhea and a significant deterioration in well-being, they differ significantly from each other.

Comparative characteristics

The onset of the disease in both cases resembles the usual acute respiratory infections or SARS. And only after diarrhea and vomiting appear, it is possible to speak with confidence about the "intestinal flu". But what is the difference between rotavirus and enterovirus?

Rotaviruses

Rotavirus infection accounts for more than half of the cases of diarrhea, the treatment of which requires the patient to be admitted to a hospital. This is explained by the fact that a significant increase and thinning of the stool, as well as frequent vomiting, lead to severe dehydration of the body (especially in children).

The disease affects the gastrointestinal tract, and its symptoms include:

• nausea and vomiting from the first day of the development of pathology;
• increased stool up to twenty times a day from the second day of the disease;
• acute onset;
• increase in body temperature up to 38-40C;
• loss of strength, headache, drowsiness;
• white coating on the tongue.

The incubation period of the disease ranges from one to four days. The fever does not last long, and then the temperature gradually decreases. Disorders of the stool last for five or six days (even after the temperature returns to normal).

Attention! Stool with rotavirus infection in the first days is liquid, yellow, in the subsequent days - clay-like, gray-yellow

Enteroviruses

The incubation period of the disease ranges from one to ten days, and it itself affects not only the gastrointestinal tract, but also other organs and systems. The pathological process involves the liver, organs of vision, heart, central nervous system, which affects the general condition of a person and determines the manifestations of pathology.

Characteristic signs of an enterovirus infection include:

• acute onset;
• an increase in body temperature to 38-40C (observed from three to five days);
• a sharp deterioration in well-being;
• diarrhea (however, stool frequency is less than with rotavirus infection);
• nausea and vomiting;
• disappearance of symptoms together with a drop in temperature;
• muscle pain;
• soreness in the abdomen;
• swollen lymph nodes;
• cold sweat.

Attention! Stool with enterovirus infection has a yellowish-brownish tint and does not include extraneous organic impurities (foam, blood inclusions, mucus)

In addition, there are specific signs that develop against the background of damage to certain organs and systems.

When an enterovirus affects the mucous membranes of the oral cavity and throat, enteroviral tonsillitis develops. Pathology is accompanied by a rise in body temperature to high values, loss of strength, drowsiness. Bubbles with liquid contents appear on the affected mucous membranes, opening up over time and leaving behind ulcers covered with a white coating. After recovery, the mucous membranes are completely restored.

When an enterovirus affects the organs of vision, conjunctivitis develops, affecting one or both eyes - their conjunctiva swells and acquires a reddish tint. The patient experiences severe pain in the eyes in bright light, he has lacrimation. In some cases, hemorrhages in the sclera are observed.

When the enterovirus affects the muscles, myositis is observed, which is manifested by severe pain in the lower and upper limbs, back, and chest. The complication is accompanied by an increase in body temperature.

When the enterovirus affects the muscular layer of the heart, myocarditis develops, and when the heart valves are involved in the pathological process, endocarditis develops. These complications are manifested by a breakdown, weakness, chest pain, and a decrease in blood pressure.

When exposed to enterovirus on the central nervous system, meningitis or encephalitis develops. Neurological complications are accompanied by severe headache, fever, nausea and vomiting, loss of consciousness. With untimely treatment, muscle paralysis is possible.

When an enterovirus affects the liver, acute hepatitis develops, accompanied by an increase in the size of the organ, pain and heaviness in the right hypochondrium.

When an enterovirus affects the skin, a red rash appears on the arms, chest and head.

When an enterovirus affects the testicles in boys, their inflammation (orchitis) develops.

Thus, the answer to the question: "Enterovirus and rotavirus - what is the difference?" It will be clear. The main difference between one disease and another is the presence / absence of damage to other organs and systems, except for the digestive tract.

Rotavirus treatment

There is no drug that can kill rotavirus. If the manifestations of the disease are obvious, the therapy is directed to the elimination of certain of its manifestations, i.e. is symptomatic. For example:

1. Pain and spasms of the intestines are relieved with the help of No-shpa;
2. The temperature is reduced by any antipyretic;
3. Intoxication is eliminated by drinking plenty of water and taking sorbents that absorb toxins and remove them from the body (for example, use Smecta);
4. Dehydration is prevented by taking rehydro solutions (as a rule, Regidron is used for this purpose).

Enterovirus treatment

Therapy for enterovirus infection is complex and includes both etiotropic (aimed at destroying the pathogen) and symptomatic treatment.

Antiviral therapy in this case includes:

• interferons;
• immunoglobulins (prescribed in especially severe cases).

Symptomatic therapy includes:

• antiemetics;
• antihistamines;
• antipyretics;
• drugs that promote intestinal detoxification (sorbents);
• frequent drinking (five to ten milliliters every five minutes) - this will avoid dehydration;
• bed rest;
• diet.

The diet for enterovirus infection involves the exclusion from the diet of dairy products (except kefir), fatty, fried, spicy and salty. You can replace them with fruits and vegetables, steamed or stewed in water.

Food should be fractional, but high-calorie. It is advisable for patients to offer food in small portions every two to three hours.

Prevention of rotavirus

Prevention of rotavirus infection consists, first of all, in observing the simplest hygiene standards:

1. Regular hand washing (mandatory before eating);
2. Boiling water (with the exception of bottled water);
3. Thorough washing of fruits, vegetables and berries.

In the vast majority of cases, these recommendations allow avoiding the development of the disease in adults. However, it is quite difficult to monitor the observance of the rules by the child. Babies in this case are recommended to be vaccinated with RoTatec or Rotarix.

Attention! The effect of vaccination occurs only in children under the age of two years.

Enterovirus prevention

Prevention of enterovirus infection includes:

• quarantine of sick people, disinfection of their personal belongings and hygienic items;
• following the rules of personal hygiene;
• boiling water before drinking (with the exception of bottled water);
• washing fruits, vegetables and berries before eating;
• protection of food from insects and rodents;
• using different knives and cutting boards for raw and non-cooked foods;
• preventing the purchase of food products in places of unauthorized trade, as well as swimming in prohibited places.

Immunoglobulins and interferons can be prescribed to people who have come into contact with patients for prophylactic purposes.

Enterovirus, unlike rotavirus, affects not only the gastrointestinal tract. The disease is longer, more severe, has a longer incubation period. With rotavirus infection, the condition stabilizes after 2-3 days.

Young children are most susceptible to various infectious diseases. And it is rare to find a child who has never picked up the so-called intestinal flu. This popular name was given to rotavirus and enterovirus - it is thanks to them that children suddenly begin to vilify, have a temperature and complain of feeling unwell. And taking into account the fact that both viruses have a high virulence, some of the people in contact with a sick child fall ill, mainly children 3-4 years old. At an older age, the body can already cope with the infection, so cases of the disease are extremely rare.

The situation is aggravated by the fact that microorganisms have good resistance and survivability even in an unfavorable environment - simple washing of hands with soap does not always help. Well, you can not talk about using the same toys, utensils or educational materials. In addition, these viruses can be transmitted not only by household contact, but also by airborne droplets.

Periodic outbreaks of rotavirus or enterovirus infection are not uncommon in any locality where there is a kindergarten or other institution that is attended by a large number of young children.

All unpleasant symptoms can be caused by both microorganisms, in both cases the onset of the disease can be easily confused with SARS, acute respiratory infections or other diseases that can be caused by adenoviruses. And only after intestinal disorders appear, we can confidently talk about the "intestinal flu". How is one microorganism different from another?

Rotaviruses

They account for about half of cases of diarrhea that require hospitalization. This is explained by the fact that the child begins to vilify often, abundantly. Naturally, this leads to severe dehydration of the body, and this condition already requires urgent hospitalization.

Typical complaints with rotavirus infection:

• nausea from the first day, vomiting is possible;
• profuse diarrhea up to 20 times a day from the 2nd day of illness;
• acute onset;
• temperature rise to 38-40 degrees;
• general deterioration of the condition: weakness, drowsiness, headache;
• white coating on the tongue, "geographic tongue".

Rotavirus infection affects only the gastrointestinal tract of a child, this is also its difference from enterovirus.

The incubation period for rotavirus is 1 to 4 days. The high temperature does not last long, about 2 days, then it starts to decrease. However, diarrhea continues even after the temperature returns to normal, on average this period lasts 5 or 6 days.

Enteroviruses

The incubation period for infection with this microorganism may be longer. It is from 1 to 10 days. Another significant difference: the virus affects not only the gastrointestinal tract, but also other organs. The eyes, heart, liver, nervous system suffer, which naturally affects the child's well-being and determines the typical symptoms of the disease.

Characteristic manifestations of enterovirus infection:

• acute onset;
• high fever that lasts from 3 to 5 days;
• deterioration of well-being;
• not as frequent diarrhea as with rotavirus;
• nausea, vomiting;
• symptoms disappear simultaneously with the normalization of temperature;
• swelling;
• redness of the eyes and soft palate;
• rash on the body;
• muscle pain;
• pain in the abdomen;
• enlarged lymph nodes;
• cold sweat.

Thus, a feature of an infection caused by enteroviruses is the presence of not only symptoms of indigestion, but also manifestations that indicate damage to other organs and systems.

Treatment

There is a difference in the symptoms of the two viral pathologies, but in all cases the treatment is the same. Its basis is a plentiful drink - it is necessary to restore the water balance in the body. It is dehydration, and not the disease itself, that leads to most of the complications, in some cases even to placement in intensive care.

The best option for replenishing the lost fluid are special solutions, for example, Ringer's. They can be drunk little by little, but often, every 15 minutes. As mentioned above, in half of the cases with rotavirus, hospitalization is required, since simply drinking plenty of water is not enough, intravenous administration of glucose-salt solution is necessary.

The second basis of treatment is hunger. The first three days the patient is on a starvation diet. This is due to the fact that enteroviruses and rotaviruses multiply when a nutrient medium appears in the intestine, and since food does not enter the body, this medium does not exist. In fairness, it should be said that the first days the patient does not experience hunger, completely losing his appetite.

As for drug treatment, there are no specific drugs against infections.

Patients, in addition to drinking plenty of water, are prescribed probiotics - preparations containing bifidus and lactobacilli to normalize the intestinal microflora. Their reception begins after the relative stabilization of the condition and the appearance of appetite.

Without fail, enterosorbents are immediately prescribed: activated carbon, Enterosgel, Smecta, Polysorb or others. They are necessary for the speedy removal of the virus and decay products from the body.

If there is a violation of digestion, which happens often, enzymes can be prescribed: Mezim, Pancreatin.

As for lowering the temperature, the viruses are inactivated just at rates above 38 degrees. And when there is no significant deterioration in well-being, the temperature should not be brought down if it is slightly above 38. Naturally, this does not apply to children under one year old - Panadol or Nurofen is always prescribed for infants.

Prevention

High virulence, the possibility of infection by airborne droplets or household contact, the resistance of viruses in the environment - all this makes prevention difficult. During an outbreak, specific vaccines are recommended - this is the only effective method to prevent infection.

As for non-specific methods, they are standard: personal hygiene, food processing. In children's institutions, it is necessary to regularly disinfect toys, furniture, household items, utensils.

Viruses are classified according to their morphology. rod-shaped(for example, the causative agent of Ebola), bullet-shaped(rabies virus) spherical(herpesviruses), oval(pox virus), as well as bacteriophages that have a complex shape (Fig.

2 –1 ). With all the variety of configurations, sizes and functional characteristics, viruses have some common features. Generally mature viral particle (virion) made up of nucleic acid, proteins and lipids, or it contains only nucleic acids and proteins.

Y Layout, Drawing 02–01

2 –1 . Sizes and morphology of the main causative agents of human viral infections.

Nucleic acids

For example, smallpox, herpes simplex, Epstein-Barr viruses are DNA-containing, and togaviruses, picornaviruses are RNA-containing. The genome of the viral particle is haploid. The simplest viral genome encodes 3-4 proteins, the most complex - more than 50 polypeptides.

Nucleic acids are represented by single-stranded RNA molecules (excluding reoviruses, in which the genome is formed by two strands of RNA) or double-stranded DNA molecules (excluding parvoviruses, in which the genome is formed by one strand of DNA). In the hepatitis B virus, the strands of the double-stranded DNA molecule are unequal in length.

Viral DNA form circular, covalently linked supercoiled (for example, in papovaviruses) or linear double-stranded structures (for example, in herpes and adenoviruses).

Their molecular weight is 10–100 times less than that of bacterial DNA. Transcription of viral DNA (mRNA synthesis) is carried out in the nucleus of a virus-infected cell. In viral DNA, at the ends of the molecule, there are straight or inverted (turned by 180°) repeating nucleotide sequences. Their presence ensures the ability of the DNA molecule to close into a ring.

These sequences, present in single- and double-stranded DNA molecules, are unique markers of viral DNA.

Viral RNA represented by single- or double-stranded molecules. Single-stranded molecules can be segmented, from two segments in arenaviruses to 11 segments in rotaviruses. The presence of segments leads to an increase in the coding capacity of the genome.

Viral RNAs are divided into the following groups: plus-strand RNA (+RNA), minus-strand RNA (-RNA). In various viruses, the genome can form strands of +RNA or -RNA, as well as double strands, one of which is RNA, the other (complementary to it) - +RNA.

A plus—strands of RNA are represented by single chains with characteristic endings (“caps”) for ribosome recognition.

This group includes RNAs that can directly translate genetic information on the ribosomes of a virus-infected cell, that is, perform the functions of mRNA. Plus strands perform the following functions: they serve as mRNA for the synthesis of structural proteins, as a template for RNA replication, and they are packaged into a capsid to form a daughter population.

Minus—strands of RNA they are not able to translate genetic information directly on ribosomes, that is, they cannot function as mRNA.

However, such RNAs serve as templates for mRNA synthesis.

Infectivity of nucleic acids. Many viral nucleic acids are infectious in themselves, as they contain all the genetic information necessary for the synthesis of new viral particles.

This information is realized after the penetration of the virion into the sensitive cell. Nucleic acids of most +RNA- and DNA-containing viruses exhibit infectious properties.

Double-stranded RNAs and most -RNAs do not show infectious properties.

capsid

The genetic material of viruses is "packed" in a special symmetrical "case" - capsid[from lat. capsa, case]. The capsid is a protein shell consisting of repeating subunits.

Main capsid functions- protection of the viral genome from external influences, ensuring the adsorption of the virion to the cell, its penetration into the cell by interacting with cell receptors. Capsids form subunits of the same structure - capsomeres, organized into one or two layers according to two types of symmetry - cubic or spiral. The symmetry of the capsid is due to the fact that a large number of capsomeres is required for genome packaging, and their compact connection is possible only if the subunits are symmetrically arranged.

The formation of a capsid resembles the process of crystallization and proceeds according to the principle of self-assembly. The number of capsomeres is strictly specific for each species and depends on the size and morphology of the virions. Capsomeres (morphological units of viruses) form protein molecules - protomers(structural units). Protomers can be monomeric (comprising one polypeptide) or polymeric (comprising several polypeptides).

Nucleocapsid

The complex of the capsid and the viral genome is called the nucleocapsid.

It repeats the symmetry of the capsid, that is, it has spiral or cubic symmetry, respectively (Fig. 2 –2 ).

Y Layout, Drawing 02—02

Rice. 2 –2 . Main types of symmetry of viruses. BUT- "naked", cubic symmetry.

B- “dressed”, cubic symmetry. AT- "bare", spiral symmetry. G- "dressed", spiral symmetry.

Spiral symmetry.

In the nucleocapsid, the interaction of nucleic acid and protein is carried out along one axis of rotation. Each virus with helical symmetry has a characteristic length, width, and periodicity of the nucleocapsid. Nucleocapsids of most human pathogenic viruses have helical symmetry (for example, coronaviruses, rhabdoviruses, para- and orthomyxoviruses, bunyaviruses and arenaviruses). This group also includes the tobacco mosaic virus. The helical symmetry organization gives viruses a rod-like shape..

With helical symmetry, the protein sheath protects hereditary information better, but requires a large amount of protein, since the sheath consists of relatively large blocks.

cubic symmetry. In such viruses, the nucleic acid is surrounded by capsomeres that form a figure icosahedron- a polyhedron with 12 vertices, 20 triangular faces and 30 corners.

Viruses with a similar structure include adenoviruses, reoviruses, iridoviruses, herpesviruses, and picornaviruses. Organization according to the principle of cubic symmetry gives viruses a spherical shape.. The principle of cubic symmetry is the most economical for the formation of a closed capsid, since relatively small protein blocks are used for its organization, forming a large internal space in which the nucleic acid freely fits.

double symmetry.

Some bacteriophages (bacterial viruses) have double symmetry: the head is organized according to the principle of cubic symmetry, the process - according to the principle of spiral symmetry.

Lack of permanent symmetry. Larger viruses (for example, poxviruses) are characterized by the absence of permanent symmetry.

The nucleocapsids also contain internal proteins, which ensure the correct packaging of the genome, and also perform structural and enzymatic functions.

Viral enzymes are divided into virion and virus—induced. The former are part of virions and are involved in transcription and replication (for example, reverse transcriptase), the latter are encoded in the viral genome (for example, ortho- and paramyxovirus RNA polymerase or herpesvirus DNA polymerase). Virion enzymes are also divided into two functional groups: enzymes of the first group ensure the penetration of viral nucleic acids into the cell and the exit of daughter populations; enzymes of the second group are involved in the processes of replication and transcription of the viral genome.

Enzymes of both groups can be present in capsids.

Supercapsid

« dressed up» viruses. Some viruses may contain a special shell on top of the capsid - supercapsid, organized by a double layer of lipids and specific viral proteins, most often forming outgrowths-thorns penetrating the lipid bilayer.

Such viruses are called "clothed". Supercapsid formation occurs at the late stages of the reproductive cycle, usually during the budding of daughter populations.

Lipids.

The main function of lipids is to stabilize the structure of viruses. Degradation or loss of lipids leads to the loss of infectious properties, since such viral particles lose the stability of their composition and, accordingly, the ability to infect cells.

The composition of lipids usually depends on the nature of the "budding" of the viral particle. For example, in the influenza virus, the composition of the lipid bilayer is similar to that in cell membranes. Herpesviruses bud through the nuclear membrane, so the lipid profile of the supercapsid reflects the lipid composition of the nuclear membrane.

Glycoproteins are part of the surface structures of the supercapsid (for example, "thorns").

The sugars that make up glycoproteins usually originate from the host cell.

The surface proteins of naked viruses ensure the interaction of viruses with cell receptors and subsequent penetration into the cell by endocytosis. Most "clothed" viruses have surface special F-proteins [from lat. fusio, fusion], which ensure the fusion of viral supercapsids and cell membranes. Surface proteins are an important component that facilitates the penetration of viruses into sensitive cells.

Their characteristic property is the ability to bind to receptors on the surface of red blood cells and agglutinate them. The ability to hemagglutinate is widely used to determine the number of viruses..

« Naked» viruses. Viruses that do not have a supercapsid are called naked. As a rule, they are resistant to the action of ether and more resistant to denaturation.

M proteins

Non-glycosylated matrix proteins (M-proteins) form a structural layer on the inner surface of the supercapsid and facilitate its interaction with nucleocapsid proteins, which is important at the final stages of virion self-assembly (see Fig.

chapter 5 ).

Virus reproduction

Viruses are not capable of self-replication. The synthesis of viral proteins and the reproduction of copies of the viral genome - the necessary conditions for the emergence of a daughter population - provide the biosynthetic processes of the host cell. In this case, protein macromolecules and nucleic acids are formed separately, after which the daughter populations are assembled. In other words, viruses are characterized disjunctive(uncoupled) reproduction type carried out during the interaction of the virus with the infected cell.

The implementation of the reproductive cycle largely depends on the type of infection of the cell and the nature of the interaction of the virus with a sensitive (possible to be infected) cell.

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How can you distinguish rotavirus from poisoning

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Every day we are confronted with pathogenic microorganisms that cause all kinds of diseases, and because human organs are much fewer in number than the types of infectious agents, some diseases have clinical similarities.

Sometimes only an experienced specialist with a whole laboratory arsenal can understand the cause of the disease, and sometimes it is enough to know the basic differences between the symptoms in order to independently recognize the diagnosis and even recover. How rotavirus disease differs from intestinal infection and poisoning will be discussed in this article.

Rotavirus infection is a very common disease, almost every child has it before adolescence.

According to statistics, 6% of all deaths among children under 5 years of age occur precisely from rotavirus infection. These data indicate the need to teach the population about early diagnosis in order to timely seek medical help.

Rotavirus got its name not from the word "mouth", but due to the structure of the capsid, which resembles a wheel with spokes in shape (the wheel in Latin sounds like "rota"), which is why rotovirus is an incorrect spelling of the name of the pathogen.

It belongs to RNA-containing viruses that mainly affect the gastrointestinal tract, their main group is Norfolk virus, reovirus, enterovirus and rotavirus. It is often not possible to distinguish them without laboratory tests, however, due to the similarity of the therapy of any of them, this is usually not required.

Rotaviruses have the ability to recombine their own genes, which gives them the ability to mutate, creating new strains.

The source of infection is an exceptionally sick person who excretes the virus with feces.

The main transmission mechanism is fecal-oral, however, recently there are data describing the transmission of the pathogen and airborne droplets.

Due to its high resistance to changes in the acid-base balance of the environment, viruses easily overcome the gastric juice and penetrate into the small intestine, where their intensive reproduction begins.

Damage to the intestinal villi is the cause of the diarrheal component of the disease. Additionally, a syndrome of malabsorption (impaired parietal digestion of food) develops, due to which diarrhea is supplemented by bloating, rumbling and flatulence. All other symptoms are due to the penetration of the virus into the circulatory system.

Differential Diagnosis

The treatment of all viral intestinal infections is similar, like two drops of water, the question is how to distinguish rotavirus from poisoning or a bacterial infection of the intestine, because it depends on whether you will flush the stomach, enemas, take antibiotics or antiviral drugs.

The history of the onset of the disease will always tell you poisoning or rotavirus in front of you through the connection with the use of low-quality food or contact with a sick person.

To know how to distinguish poisoning, it is not necessary to be a doctor. In the case of the viral nature of the disease, most often one member of the family falls ill first, and then all those who have been in contact with him join him. High body temperature, catarrhal phenomena and repeated vomiting will also testify not in favor of food poisoning.

Also, food poisoning often occurs in the summer, and a viral infection has a pronounced autumn-winter seasonality.

Intestinal infections of a bacterial nature will differ from rotavirus in the absence of pathology from the nasopharynx, as well as a different nature of the stool.

Salmonellosis is characterized by abundant and very fetid stools of a dirty green color, dysentery has a pathognomonic symptom in the form of tenesmus, cholera does not hurt the stomach, and feces resemble rice water - this is its main difference, the difference between escherichiosis in yellowish stools.

Does not change with bacterial diseases and the color of urine.

Symptoms of rotavirus infection

This disease is characterized by a standard set of symptoms:

• acute onset of the disease with a sharp rise in temperature to febrile;
• fever, headache, joint pain;
• intoxication, which is manifested by weakness, nausea and recurrent vomiting;
• diarrhea that causes dehydration, accompanied by flatulence and strong rumbling in the stomach;
• signs of catarrh of the upper respiratory tract in the form of redness and sore throat, dry cough, runny nose and sneezing;
• darkening of urine with the acquisition of an ammonia smell.

The infectious process in adults is much easier than in children, this virus is dangerous for the life of an adult only in the case of existing disorders in the immune status (hereditary immunodeficiencies, HIV infection or bone marrow transplantation).

The danger for young children is the rapid dehydration of their body and changes in blood pH, which leads to severe intoxication, convulsive conditions and disruption of the cardiovascular system. High body temperature can also provoke febrile convulsions, which can later be complicated by epileptoid conditions.

Rotavirus infection in children also has a feature in the form of a wave-like change of symptoms, at first signs of SARS predominate, and then after 1-2 days vomiting and diarrhea join, while in older people everything happens at once.

Treatment of the disease

Regardless of the rotavirus infection or poisoning before us, the basis is the restoration of the body's water and electrolyte balance and acid-base balance.

With a disease of mild and moderate severity, oral rehydration is acceptable in a daily volume of at least 2-3 liters. It is better to carry it out with the help of special solutions, such as Regidron, Re-Sol, Electral or Orsol. In severe conditions with severe dehydration, treatment in a hospital must be carried out, where electrolyte solutions will be infused intravenously in individually calculated dosages.

The diet relieves the symptoms of the disease and should exclude all dairy, fatty and spicy foods.

Irritation of the intestines by extractive products will cause additional discomfort, and dairy dishes will increase gas formation. Enzyme medicines somewhat help to eliminate discomfort, therefore their appointment can be called reasoned even for children under one year old.

If it is impossible to eat food through the mouth due to intense vomiting, parenteral nutrition is prescribed for the duration of treatment, followed by a smooth transfer of the patient to soups and decoctions of cereals.

Antiviral drugs are most effective on the first day of their appointment, when you start taking them later than on the second day, their use will no longer affect the severity of symptoms, but it may somewhat speed up the recovery process.

Interferon inducers can be prescribed for severe infections, but you can often do without them.

Antipyretics will help to cope with hyperthermia, Paracetamol and Ibuprofen remain the drugs of choice for children, in case of intractable fever, it is possible to use a lytic mixture of Analgin with Diphenhydramine in age dosages.

In no case should you take antibacterial agents if you suspect a viral etiology of the disease.

Not only will this not help in its treatment, but it will also make the diarrhea worse with a prolongation of the body's recovery after it.

Enterovirus infection: types of enteroviruses, symptoms, treatment

To restore the intestinal microflora, after clinical recovery, it is recommended to use probiotics or prebiotics for 1-2 months.

Prevention

Prevention comes down to observing the basic rules of personal hygiene and limiting contact with sick people, as with any other intestinal infections. To date, there are oral and recombinant vaccines that protect against rotavirus infection.

They are quite effective and are successfully applied in many countries of the world. And although they are not included in the mandatory vaccination schedule, if desired, you can vaccinate a child and thereby virtually eliminate the risk of such a serious illness.

A correct diagnosis is a big part of proper treatment, and high-quality prevention is the key to long-term health, keeping this in mind, rotavirus should not bring serious consequences for you and your family.

Mazmuna

• 1 ITIS
  • 1.1 ITIS aurularynyn belgileri
  • 1.2 AIV-tyn taralu zholdary
  • 1.3 Zhalpymemlekettik sharalar
  • 1.4 Zheke adamnyn saktanu sharalary
  • 1.5 Tagy karanyz
  • 1.6 Derekkozder

ITIS

ITIS-immunity tapshylygyn iemdengen syndrome, alones taratatyn virus 1986 zhyly AIV (adam immunotapshylyk viruses) bollyp ataldy viruses.

Ohan algash 1938-1939 zhyldars american Robet Gallo men frenchman galim Luc Montagnier sipattama berdi.

Enteroviruses, rotaviruses

1981 Zhyly AҚSh-tyn California stateynda algash ret esirtke paydalanatyndardan ITIS auruy tirkeldi. Americandyk galymdar bul aurdyn kozdyrgyshyn taratatyn virustar Afrikadagy adamdardan tapty. Dal osygan ұқsas virus keyinnen chimpanzee maymylynyn қanynan and tabyldy.

ITIS aurularynyn belgileri

Aurudyn algashky kezeninde denede bezgek auruyna ұқsas diril payda bolady. Lymph tuyinderі іsіnedі. Teri bortip, berte-birte zharaga ainalada. Virustyn aserinen adam azady, day temperaturesy koteriledі, іsh өtedі.

Kanazdyk baykalyp, adam sharshaydy, buyny syrgyrap, basses auyrady. Okpe kabynady, teride payda bulgan zharalar katerlі іsіkke ainaluy mүmkin.

AIV-tyn taralu zholdary

ITIS auruy kobіne zhynystyқ katynas arkyly taralada: birіnshіden-ITIS auruymen auyrgandarmen zhynystyқ қatynas kezіnde, ekіnshіden -AIV-tyң қozdyrgyshy bar

AIV-tyn taraluy kan arkyly da zhuredi. Bul kobine kan kuyu, ulpalar men mүshelerdі auystyryp salgan kezde taralada. AIV pelvis emes medicinelyk құraldardy paidalanganda zhұғada. Mundai zhagday kobіne esіrtkі paydalanushylar arasynda zhiі kezdesedі. AIV zhezoksheler arkyly keninen taralada. Virustyn zhalpy taraluynyn 40% wasps zholmen zhuzege asada. Afrikada 90% zhezoksheler arkyly taralada.

AIV Anasy arkyly balasyna ұryktyn damu kezinde, tuganda kanmen, emizgende sutpen taralada. AIV zhötelgende, tushkirgende aua arkyly taralmaydy. Kүndelikti kol alyp, құshaқtasyp amandasu kezinde, monshaғa tuskende virus zhұқpaida. Bunaqdeneliler shaqqan kezde taralmaidy. ITIS auruy қazirgі kezde dүnie zhүzіnde өte қarkқyndy taralyp zhatқan іndet. Duniezhuzilik densaulyk saktau uyymynyn malimetі boyinsha kazir Africada-2.5 million, America-2 million, Eurofall-500 myn, Asia men mukhit araldarynda 100 myn adam AIV-yn zhұқtyrgan.

Dunie zhuzinde kүnine ITIS auruymen auyrgandardyn 7000 omіrimen koshtasady, al 16000 adam AIV-yn zhұқtyrady. Kazakhstan nakty derekter boyinsha 2004 zhylga deyin 4000-nan astam adam ITIS auruymen auyrgan. Olardyn 24-14 zhaska deyingi balalar.

Elimizde ITIS auruinan 123 adam dunieden ozdy.

Zhalpymemlekettik sharalar

1. Kan beretin adamdardy zhane aғzaғa құyylatyn қandy mұқiyat tekseruden өtkіzu.
2. Esirtkіge zhane zhezokshelіkke қarsy kүrestі lady kүsheytu.
3. Emdeu mekemelerinde sanitary erezhelerdi kataң turde saktau.
4. Turgyndardy zhүyelі turde meditsinalyқ tekseruden өtkіzіp tұru.
5. Kөpshilik arasynda sanitary үgіt-nasikhat zhұmystaryna erekshe kҩңіl bөlu.

Zheke adamnyn saktanu sharalary

1. Arbir adam ozinin zheke basyn hygienic erezhelerin saktau.
2. Salauatty Omir suru saltyn ustanu.
3. Anda-sanda қan tapsyryp, tekseruden өtіp tұru.

Tagy Karanyz

1. Immunity

Derekkozder

1. Biology, 8 sons, 2012 life

ITIS Turaly Akparat

ITIS
ITIS

ITIS Turaly Video

ITIS Siz karap zhatyrsyz.

ITIS degenimiz not, ITIS kim, ITIS sipattamasy

There are excerpts from wikipedia on this article and video

Enteroviruses, rotaviruses

Most acute intestinal infections (AII) are caused by viruses. More than 120 viruses are known to cause AII, among them are enteroviruses, rotaviruses, coronaviruses, caliciviruses, astroviruses and others.

Family Picornaviridae unites four genera - Enterovirus, Cardiovirus, Rhinovirus, Aphtovirus.

These are small “naked” viruses with icosahedral (cubic) symmetry. The genome is formed by unsegmented positive RNA. RNA replication and virus assembly are carried out in the cytoplasm, the release of the virus is accompanied by cell lysis. Replication of vRNA is carried out according to the scheme: vRNA-> cRNA-> vRNA. The name of the family comes from pico (lat. - small) and RNA (RNA), i.e. small RNA viruses. Of the genus of aphthoviruses, the foot-and-mouth disease virus is of the greatest importance. Representatives of the genus of rhinoviruses (more than 100 serotypes) are the causative agents of acute respiratory infections.

Enterovirus genus .

The genus combines several groups of viruses: polioviruses (1 - 3 types), Coxsackie A viruses (24 serovars), Coxsackie B viruses (6 serovars) and ECHO (34 serovars), as well as unclassified viruses (viruses 68 - 72).

Enterovirus 72 is the causative agent of hepatitis A.

All enteroviruses are acid-resistant (they can survive in the acidic environment of the stomach), the absence of an envelope makes them resistant to the action of fatty solvents and bile acids (polioviruses are especially resistant). Pathogenic species affect the gastrointestinal tract. They are characterized by: fecal-oral mechanism of infection, summer-autumn seasonality, isolation of viruses from the intestines, nasopharynx, cerebrospinal fluid and blood, detection in wastewater, widespread carriage, predominantly affecting the child population.

Polioviruses.

Polioviruses cause polio- an acute infection with damage to the neurons of the medulla oblongata and anterior horns of the spinal cord.

The most important biological property of polioviruses is tropism for the motor cells of the gray matter of the spinal cord (polios - gray, myelitis - inflammation of the spinal cord).

The virion capsid is formed by four proteins that form the outer (VP1, VP2, VP3) and inner (VP4) surfaces of the capsid. Envelope proteins are important in recognition and attachment to cell receptors, release of virion RNA inside the cell, development of paralysis.

According to antigenic properties Polioviruses are divided into three types, with type 1 polioviruses having the highest virulence and epidemic activity.

The pathogenesis of lesions.

The entry gates for polioviruses are the mucous membranes of the pharynx, stomach, and small intestine. After reproduction in epithelial cells, the virus penetrates into the regional lymph nodes, then into the blood (primary viremia). These first stages characterize a “minor illness”, which can be almost asymptomatic (mild malaise, short-term fever) and end with the formation of post-infection immunity and recovery, which happens in most cases.

If the poliovirus overcomes the blood-brain barrier and infects the neurons of the anterior horns of the spinal cord, the medulla oblongata and the pons, which carry poliovirus receptors, a “big disease” develops - paralytic forms (spinal poliomyelitis usually with asymmetric lesions of the lower extremities, bulbar poliomyelitis in some cases with lesions of the centers that control the respiratory muscles, as well as combined spinal-bulbar lesions.

Laboratory diagnostics is of particular importance, especially in erased forms, since many entero - and herpetoviruses are capable of causing similar lesions.

Enterovirus infection in children and adults: signs, treatment

Therefore, studies must be carried out simultaneously for all these groups of viruses.

1. Virological diagnostics includes the isolation of the virus in various cell cultures or (in some cases, Coxsackie A) in newborn white mice, followed by identification by cytopathic effect, in RN, RTGA, RSK with reference sera.

Serological diagnosis carried out in various reactions (currently - ELISA), it is necessary to study in paired sera, to identify specific IgM - antibodies.

Immunity and specific prophylaxis.

Immunity to polioviruses is strong, due to virus-neutralizing antibodies and immune memory cells.

For specific prophylaxis, killed (Salk vaccine) and live (Sabin vaccine) attenuated vaccines (contain attenuated strains of poliovirus types 1, 2 and 3) are used. There are mass immunization programs against poliomyelitis and programs for the complete eradication of this infection.

Against the backdrop of a sharp decline and elimination of poliomyelitis, poliomyelitis-like diseases are observed, caused mainly by viruses. coxsackie and ECHO.

Coxsackie viruses.

They form a group close to polioviruses.

Coxsackieviruses of groups A and B, unlike polioviruses, are pathogenic for newborn mice, differing from each other in the nature of the lesions they cause (group A - predominant lesions of the skeletal muscles, group B - predominant lesions of the central nervous system).

Antigenic structure.

Coxsackieviruses do not cross serological reactions with polioviruses, group A has 24 serovars, group B has 6 serovars. Serovars do not contain a group-specific antigen, but have some cross-reactivity. The presence of type-specific antigens in pathogens determines the synthesis of type-specific antibodies. Coxsackie B serovars and some Coxsackie A serovars, unlike polioviruses, have hemagglutinating properties.

Clinical manifestations.

Among all enteroviruses, Coxsackieviruses (especially group B) have the greatest cardiotropism, causing myocarditis.

Most often they affect children, in most cases they cause mild forms, mainly with “cold” symptoms. Along with poliomyelitis-like diseases (flaccid paralysis) and myocarditis, viruses of this group can cause acute respiratory infections, gastroenteritis, herpangina, and pemphigus of the mouth and extremities.

Laboratory diagnostics like all enteroviruses.

Belonging to serovars is determined in RSK or RN with type-specific sera.

effective methods specific prevention and antiviral therapy not developed.

ECHO - viruses got their name from the words E nteric (intestinal) C ytopathogenic (cytopathogenic) H uman (human) O rphan (orphan) viruses. They were isolated from the human intestine, in a number of ways they turned out to be similar to polioviruses and Coxsackieviruses, but initially they were not associated with any diseases (i.e.

turned out to be "orphans").

Classification and antigenic structure.

Currently, the intestinal group of ECHO viruses includes 34 serovars. The division is based on the type specificity of the viral capsid antigens. Some antigens are cross-reactive, 12 serotypes are capable of hemagglutination.

Pathogenesis diseases caused by ECHO viruses is similar to the pathogenesis of poliomyelitis.

Infection occurs mainly by the fecal-oral route. Reproduction of viruses occurs in the epithelial cells of the mucous membranes, as well as in the lymphoid tissue. Able to cause "colds" (like SARS), some serotypes (11, 18 and especially 19) - intestinal dyspepsia, more rarely - meningitis, ascending paralysis and encephalitis, individual serotypes - hepatitis, conjunctivitis, uveitis (serotypes 11 and 19) .

A group of unclassified enteroviruses.

Of this group, the most important enterovirus 72 —hepatitis A virus(the causative agent of Botkin's disease) - HAV (hepatitisAvirus).

Viral hepatitis is a large, heterogeneous in etiology, but similar in clinical manifestations, a group of severe (in terms of consequences) diseases that are widespread in the world.

Hepatitis A virus - enterovirus 72, B - hepadnovirus, C and G - togaviruses of the genus Flavivirus, D - unclassified virus, E - calicivirus. Of these, hepatitis A and E viruses are characterized mainly by the fecal-oral transmission mechanism, B, C and G - parenteral (blood contact), D (delta) - is a defective virus - a satellite of the hepatitis B virus, transmitted parenterally and vertically (from mother to fetus).

The hepatitis A virus has a “bare” capsid with a cubic symmetry type - an icosahedron.

The genome is made up of a single-stranded positive RNA molecule. The protein shell (capsid) contains 4 structural proteins - VP1, VP2, VP3, VP4. HAV is one of the most persistent viruses in the environment.

Antigenic structure.

The virus has one antigenic type and contains the main antigen (NA Ag), the development of an immune response to which provides strong lifelong immunity.

The pathogenesis of lesions.

The virus enters the body as a result of the implementation of the fecal-oral infection mechanism, replicates in the epithelium of the small intestine mucosa and regional lymph nodes, then enters the blood (the highest titers of the virus in the blood are at the end of the incubation period and in the preicteric period), is excreted with feces.

Then the pathogen penetrates the liver and causes acute diffuse hepatitis associated with damage to hepatocytes (the main target for reproduction and cytopathogenic action of the virus) and reticulo-endothelial elements of the liver. This is accompanied by a decrease in the barrier and detoxification functions of the liver, disorders of protein, carbohydrate and pigment metabolism, an increase in the level of aldolase and hepatic (destruction of hepatocytes) aminotransferases (alanine - and aspartate - aminotransferases), bilirubin in the blood serum.

Clinical Features.

The most typical acute icteric cyclic form, however, mild anicteric and asymptomatic forms predominate.

This infection is characterized by a relatively mild course, the virtual absence of virus carriers and chronic forms of the disease.

Laboratory diagnostics

1. Determination of bile pigments and aminotransferases in blood serum.

2. ELISA to detect virus antigens and IgM antibodies to it. HAV antigens in faeces can only be detected at the end of incubation before clinical manifestations appear. The most reliable diagnostic method is the detection of early anti-HAV - IgM antibodies.

They are detected in almost all patients, regardless of the form of the disease, and indicate the presence of a current or recent infection.

Specific prophylaxis.

Use inactivated vaccines against hepatitis A virus of domestic "Hep-A invac") and foreign ("Havriks 1400" company "Smith Klein Beecham") production. Three times (at birth, at 1 and 6 months) vaccination forms protective immunity in 99% of children.

Hepatitis E virus

General characteristics.

Hepatitis E is an infection epidemiologically similar to hepatitis A, formerly known as non-A, non-B hepatitis with fecal-oral transmission.

The causative agent, hepatitis E virus (HEV), belongs to the family caliciviruses However, this has been questioned in recent years. It has a spherical shape, the diameter of the virion is about 30 nm, it does not have a supercapsid. The genome is represented by single-stranded non-fragmented positive RNA. It has no antigenic relationship with HAV, it is less virulent for humans.

Representatives of the calicivirus family are similar to picornaviruses in a number of ways. They got their name from lat. calix is ​​a bowl due to the presence of bowl-shaped depressions on the surface of the capsid.

Among the members of the family are the causative agents of animal gastroenteritis (for example, Norfolk virus), hepatitis E virus.

Epidemiology.

The virus has a fecal-oral mechanism of spread, realized mainly by drinking contaminated water.

Widespread in countries with a hot climate and poor water supply, when using poor-quality water (from ditches, irrigation canals, groundwater pollution, etc.), infection occurs. Outbreaks are observed in South - East Asia, Africa, South America. The infection is common in the Central Asian region of the former USSR. The peculiarity is the high lethality of HEV infection in pregnant women in the second half of pregnancy.

Laboratory diagnostics.

ELISA and immunoblot test systems have been developed to detect IgM and IgG classes of anti-HEV antibodies, suitable for diagnosis in the acute stage of the disease and during convalescence.

HEV prevention- non-specific.

Immunity- durable, due to virus-neutralizing antibodies and memory cells.

Rotaviruses.

The reovirus family includes the genera reoviruses, rotaviruses, and orbiviruses. The name of reoviruses comes from respiratory enteric orphan - "reo", i.e.

respiratory intestinal viruses. These viruses have a double-stranded, fragmented RNA surrounded by a bilayered capsid (outer and inner capsid). Reovirus infection is characterized by damage to the respiratory and intestinal tracts. The main route of transmission is airborne, but alimentary is also important, since these viruses are widespread not only in humans, but also in many animal species, people can get these viruses in the alimentary way - with food.

Rotaviruses got its name in connection with the peculiarity of the morphology of the virus (lat.

rota - wheel). For the first time, rotaviruses were detected in children with acute gastroenteritis of their epithelial cells of the duodenal mucosa. Virions in electron - microscopic examination have the form of wheels with a diameter of 70 nm with a circular rim around the periphery and "spokes" extending inward.

They have an outer and inner capsid, inside which contains a double-stranded fragmented RNA. Calf (Nebraska) and monkey rotavirus are serologically related to human rotaviruses, which are easier to cultivate in cell cultures and are used as antigenic preparations for serodiagnosis of rotavirus infection in humans.

Human rotavirus is a fecal-oral virus. It causes gastroenteritis in newborns (nosocomial outbreaks), preschoolers, and younger schoolchildren. In the world, up to several million deaths of rotavirus gastroenteritis in children are recorded annually. The most dangerous patients in the first 3-5 days of the disease due to the intensive release of the virus in the feces. Laboratory diagnostics is based on the detection of the virus antigen in faeces (ELISA, coagglutination reaction, immunofluorescent analysis, RNA probes, immune electron microscopy), serological methods (RSC, RTGA, ELISA), isolation in cell cultures.

Orbiviruses are viruses of ticks and insects (for example, the Kemerovo virus).