Viral hepatitis

Infectionists estimated that for economic damage each case of viral hepatitis is second only to influenza and ARI.The incidence remains high, despite the detailed study of hepatotropic viruses, the achievement of gene and molecular engineering, progress in diagnostic methods.

Viral hepatitis is an inflammatory liver damage caused by the ingress of viruses into the human body. The disease is characterized by the selective action of pathogens on the hepatic cells, a violation of all functions of the organ, transformation into cirrhosis and cancer. Early detection and treatment can reduce the danger to people, prevent infection of others.

What are the signs of hepatitis dividing into species?

In the group of infectious hepatitis, diseases of a viral origin occupy overwhelming position. Classification of viral hepatitis depends on the method of infection, the clinical course of the disease, the specific features of the structure of the pathogen.

For practical work of doctors it is convenient to use the division according to clinical signs and results of laboratory tests:

• for acute form - the disease lasts up to 3 months;
• protracted - up to 6 months;
• chronic - 6 months or more.

The icteric and jaundiced forms are also distinguished depending on the degree of increase in the bilirubin content in the patient's blood. Microbiological studies have revealed the difference in the composition of the genotype of viruses. They are called the letters of the English alphabet. Currently known: hepatitis A, viral hepatitis B, C, D, E, G, new little-known viruses TTV, SEN.

Depending on the pathways of infection, all forms are divided into enteral( the causative agent is entered with dirty hands, food, water, begins its action from the intestine) and parenteral( the disease is transmitted bypassing the intestine).

Fecal-oral transmission mechanism is typical for viral hepatitis E and A. They are fairly stable in the external environment, transmitted through contaminated water, products, by contact with a sick person. They are widespread, recorded as outbreaks and epidemics that swept entire territories.

. Hepatitis C, B, D and G differ parenterally through transmission. Their activity is much lower than virus A. Penetrated into the patient through the blood and its components during transfusion, medical manipulations, intravenous procedures, surgical interventions. Infection is important against the background of minor injuries in the manufacture of manicure, tattooing, in the dentistry of

These types of viruses can be sexually transmitted, especially with perverted sexual intercourse in adults, pass through the placenta from mother to fetus. Infectious hepatitis, caused by parenteral transmission, is characterized by a prolonged chronic course, increased viremia( a virus in the blood), a tendency to covert flow, a transition to a virus carrier.

Prevalence of viral hepatitis

The last decade is characterized by an increase in the prevalence of all types of viral hepatitis in Russia. Epidemiologists associate this with the worsening of social conditions for the population, which supports the way of infection. It was found that the ratio of hidden forms to those with clinical signs was 2.2: 1 for hepatitis B, 5: 1 for hepatitis C.

In the general structure of the lesion, parenteral hepatitis accounts for 84% of cases. The prevalence of hepatitis A is 3 times less. This form is more typical for children. Of the parenteral species among them, hepatitis B( 2-fold compared with C) is more common.

Changes in liver cells and reflection in symptoms of

The defeat of the hepatic structures by viruses is manifested by typical cytolytic, cholestagic and immunoinflammatory syndromes. The process of cytolysis( destruction of hepatocytes) is caused by direct exposure to the virus or formed antibodies.

When entering the liver cells, viruses disrupt all metabolic processes, oppress antioxidant systems. As a result, the envelope of hepatocytes becomes permeable, enzymes and potassium leave the cells through it. They are replaced by sodium and calcium.

This promotes water retention, cell swelling, disrupts the acid-base balance, stops the biochemical process of energy production. Termination of the activity of enzyme systems leads to the violation of all types of metabolism, disrupts the work on the removal of intoxication by incoming toxic substances.

The growth of such intracellular enzymes as alanine aminotransferase( ALT), cholinesterase, aspartate aminotransferase( ASAT), arginase, serum iron is considered markers of the cytolysis process. The extent of the violation of pigmental metabolism and secretory function is judged by the amount of free bilirubin.

Normally, hepatocytes capture free bilirubin, "bind" it and remove it to bile. To suppress the synthesis function indicates hypoalbuminemia( low protein content in the blood).

Infection contributes to the disruption of the formation of clotting factors, especially in the case of prothrombin, substances that affect coagulation and fibrinolysis.

Therefore, infectious hepatitis is accompanied by a hemorrhagic syndrome with massive hemorrhages and bleeding. In severe cytolysis, lysosomes die in hepatocytes, which are a container of proteolytic enzymes. Therefore, with a massive exit from the hydrolase cells, self-destruction and destruction occur.

The result is acute liver failure. Bile stasis( cholestasis) reflects a decrease in secretory function and cytolysis. In the blood go, besides bilirubin, bile acids, cholesterol, copper, enzymes alkaline phosphatase and gamma-glutamyl transpeptidase.

The severity of intoxication does not always increase in proportion to the level of bilirubin:

• The initial( pre-jaundiced) period reflects the phase of the spread and accumulation of the virus in the blood. It is manifested by fever, general signs of malaise.
• At the height of the disease, the main role is assigned to the process of cytolysis with a violation of counteracting intoxication. Clinically, this is indicated by nausea, loss of appetite, vomiting, lethargy.
• The connection of acute liver failure is indicated by specific impairments in the functioning of the central nervous system in the form of hepatic encephalopathy.

Features of the manifestation of viral hepatitis

Symptoms of viral hepatitis may depend on the type of pathogen, the severity of the lesion. Before the manifestation of the initial signs of the disease there are different periods: for hepatitis A - it takes from 2 weeks to a month, up to six months - for hepatitis B, up to 26 weeks - for hepatitis C.

For hepatitis A, there is a rapid rise in temperature, headache, nausea,appetite, aches in the joints. Clinically, in the jaundiced period, the disease resembles the flu. Types B and C start more gradually, there is no sharp rise in temperature. The presence of the virus B is manifested by a slight increase, skin rashes, joint pain.

A week later, the appetite disappears, patients are worried about dull pain in the hypochondrium to the right, nausea( especially on the smell of food), vomiting, noticeable darkening of urine, feces become gray. When examined in this period the doctor discovers an increase in the liver, rarely a spleen.

In the blood test, the level of bilirubin, liver enzymes( 8-10 times) increases, specific immunological markers of viruses appear. Often with yellowing of the skin and mucous, the patients feel better. In a more difficult situation, patients with hepatitis C, chronic alcoholics and drug addicts.

Depending on the clinical course, the following are distinguished:

• is an easy form;
• of moderate severity;
• heavy;
• lightning fast( fulminant).

With the latter develops rapid massive necrosis of hepatic cells, the outcome is lethal. The transition to a chronic course is a dangerous consequence. It is characteristic only in case of hepatitis B, C, D. Signs of viral hepatitis of chronic form are manifested by increased fatigue, weakness, and disability.

This is especially true for physical activity. Patients have nausea, a feeling of heaviness in the hypochondrium to the right, a disorder of the stool, pain in the muscles and joints. Because of the inconsistency of symptoms, people are slow to consult a doctor.

When jaundice of the skin appears, itching, weight loss, gum bleeding, vascular "stars", darkening of urine and discoloration of feces, the process is considered already neglected. Cytolysis leads to the destruction of the liver parenchyma. Complete restoration of organ functions is impossible. We should expect a transition to cirrhosis with replacement of scar tissue.

Features of

viruses The microorganism is coated with a protein coat. Sometimes still a fatty layer. Inside is the most specific part - the genetic material, which provides the function of reproduction and transmission of the properties necessary for human infection.

The genome consists of chains of amino acids combined in DNA and RNA.The virus necessarily allocates the products of vital activity. They consist of foreign to humans proteins, lipids, polysaccharides, which serve as antigens in the immune response.

After entering the blood, antigens are produced antibodies. By biochemical composition, they are constructed from two types of immunoglobulins:

• with the ability to circulate freely through the bloodstream;
• is strongly associated with B-lymphocytes.

The main role of antibodies is to retain, destroy and remove from the blood of foreign antigens. For hepatitis B, a factor that exacerbates viral damage has been identified. It is called a delta agent. It is a concomitant minute antigen, manifested only with the help of an "assistant".

are established. It is established that it is able to reproduce only in an organism infected with the hepatitis B virus. For the patient this can be regarded as a superinfection. The hepatitis C virus differs from others in a variety of strains by gene composition. They are called genotypes. In total, more than 9 varieties are identified, but each of them is subdivided into internal subtypes.

So # 1 is divided into genotype 1a, genotype 1b and c;genotype number 2 has 4 forms. The danger of genotyping is caused by the propensity to mutations. It is not possible to achieve recovery and persistent immunity if the patient has one of the subtypes. The best result of treatment in patients with the disease, confirmed immediately by all genotypes.

How is the diagnosis performed?

The study of viruses allowed the development of a diagnostic system based on the characteristic antigenic properties, the typical composition of DNA and RNA in nuclear structures. In a normal clinical laboratory, it is impossible to detect a virus. For this purpose there are specialized virological institutions. They are engaged in the study of properties, the search for methods for detecting viruses in infectious diseases.

Hepatitis viruses are visible only under the electron microscope, the smear is specially treated with a solution of phosphoric-tungstic acid and antibodies. Contours of the virus differ in the "whisk" from immune complexes.

To identify the presence of a microorganism, the most accessible immunological methods based on recording the response to specific immunoglobulins or antibodies. By their presence, they judge the type of virus, the degree of activity.

RNA chain. Types of immunological assays.

. Typical antigens or antibodies are considered as evidence base or markers of viral hepatitis. They are detected:

• in the serum;
• feces patient;
• biopsy samples from the liver.

And also in contaminated products, water. The antigenic composition varies depending on the period after infection, the duration of the incubation period, the phase of the disease. In the course of an immunological study, known antigens or antibodies are used, and appropriate antibodies or antigens suitably formulated for them are used. Methods include modifications.

The primary analysis for viral hepatitis is the determination of total antibodies. Immunoglobulins( Ig) of type G, M, E are most important. In addition to them, there are A, D. When obtaining a figure of total height, it makes sense to investigate each type separately.

Immunoenzyme assay( ELISA)

Method essence: connection of blood serum of a patient with hepatitis with a solution of standard antibodies, with labeled enzymes. If there are antigenic structures in the serum, they are connected by an antibody protein.

For quantitative analysis, a colorant is added to the mixture. It was found that the color change is proportional to the number of molecules of the bound antigen. The calculated indicator allows to reveal the viral load in a particular case. The interpretation of the result is fixed in international units( IU / ml):

• high figure is 800 IU / ml or more;
• low - less than 800.

The method of immunoblotting

It is considered more sensitive than ELISA, since it combines with electrophoresis. Previously, the blood plasma of a patient with probable antigens is separated by electrophoresis in a gel medium, then transferred to a special paper containing the activating agent. Serum is added and electrophoresis is performed again.

Study depending on the task is divided:

• for protein-blotting;
• RNA-blotting;
• DNA blotting.

Radioimmunological analysis( RIA)

The main difference is the use of isotopes as a means of labeling the components of a biochemical reaction( standard antigens or antibodies).The amount of isotope is known in advance, so it is possible to calculate the mass of antibodies by radiometry. The technique is considered highly sensitive.

Express methods

Express strips impregnated with a standard antibody solution, allow for a preventive examination of a large number of contact persons to see a qualitative response to hepatitis markers. It is enough to apply a drop of blood from the finger to the strip.

Experts consider them sufficiently reliable to detect suspicion of an icteric form, an easy current, a virus carrier. It takes 15 minutes to get the result. A positive test reveals people who need a more thorough analysis.

Other studies on hepatitis

In addition to immunological diagnosis, clinics use other direct or indirect diagnostic confirmation capabilities.

Technique of polymerase chain reaction( PCR)

The expediency of using the method is caused by an unclear interpretation of the results of the analyzes, differential diagnostics. This method is not immunological. It is based on the property of replication( duplication, copying) of DNA and RNA sites in the nucleus of the virus.

virus. Clinical and biochemical studies of

. Clinical and biochemical studies are used to detect the extent of liver cell damage and organ function disorder:

• general blood test - typical increase in ESR, hemoglobin;
• urobilin urine - positive;
• transferase( alanine and aspartic) grow at times, indicate cytolysis.

The disrupted enzyme composition confirms the fall in all liver functions. Determine:

• alkaline phosphatase;
• sorbitol dehydrogenase;
• lactate dehydrogenase;
• gamma glutamntranspeptidase;
• gamma glutamyl transferase;
• fructose-1-phosphataldolase( P-1-FA).

Patients undergo a detailed coagulogram examination, which allows to determine the defeat of the coagulation system. In addition, some biochemical tests show the degree of disruption of functions. These include:

• thymol sample;
• ratio of protein albumins and globulins;
• indicators of fat metabolism( cholesterol, triglycerides, lipoproteins);
• bilirubin;
• prothrombin index, fibrinogen.

Dynamics of indicators with active viral hepatitis:

• increases the aminotransferase( alanine stronger than aspartic), F-1-FA, thymol assay, cholesterol, triglycerides, bilirubin is detected;
• in the urine appears bilirubin and urobilin;
• decreased albumin, prothrombin index.

Treatment of

Treatment of viral hepatitis includes the mandatory use of antiviral agents. Doctors of infectious diseases around the world use the recommendations of one of the leading American experts Jay Sanford.

physicians is published. They are set out in a special manual for practical practitioners and include recommendations for the therapy of AIDS and viral hepatitis. S.N.Sorinson, a professor from the Medical University of Nizhny Novgorod, devoted a lot of work to the study of viral hepatitis, diagnosis, treatment and problems of polyclinic practice.

It matters in the choice of treatment methods to date. Includes recommendations on diet, treatment of virus carriers, examination rules, monitoring of convalescents( who underwent hepatitis).In drug therapy, Sorinson requires you to abandon any drugs that are unnecessary for emergency care( hypnotics, sedatives, diuretics).

To remove intoxication proposed a solution of glucose 5%, Haemodesum, electrolyte standard compounds( Trisol, Quartazol, Lactosol).To support the regenerative function of the hepatic tissue are recommended:

• complex vitamins;
• Heptral intravenously;
• betaine citrate in tablets;
• corticosteroids( restricted).

In the organizational work on medical care for servicemen who become ill with chronic viral hepatitis in the army, they are instructed by the GVMU( Main Military Medical Directorate - "Ministry of Health" for military doctors).

Complications of

About recovery from an acute form of hepatitis or remission of a chronic doctor judged by immune tests and biochemical tests. Complications include:

• functional and inflammatory diseases of the biliary tract;
• acute liver failure with the development of coma( gives a lethal outcome in 90% of cases);
• transition to a chronic course( mainly hepatitis C, occurs in 70% of patients) followed by the development of cirrhosis or cancer;
• Cirrhosis of the liver is formed in 1/5 of all patients other than hepatitis C, hepatitis B in combination with D or isolated can lead to it.

Severe types of damage to the body in connection with the exclusion of liver work cause serious anxiety and require the prompt detection of viral hepatitis with full treatment. Reduce prevalence can only be through preventive measures nationwide scale.