Epidemiology, diagnosis and prevention of viral hepatitis are important issues in practical medicine. Tens of millions of people are affected by these infections every year. According to WHO data, at present there are at least 2 billion patients infected with hepatitis B virus alone. In Russia, a high incidence rate and an increasing frequency of adverse outcomes (transition of the disease into a chronic form and death) remain, which determines the high importance of studying the clinic, diagnosing and treatment of viral hepatitis by practitioners and medical students.
What causes hepatitis
From the moment of infection to the appearance of the first symptoms of the disease, it takes from two to four weeks for hepatitis A to two to four (or even six) months for hepatitis B. During thisperiod, the virus multiplies and adapts in the body, and then begins to manifest itself. Before the skin and mucous membranes acquire a characteristic yellow tint, the urine darkens, and the feces become colorless, losing bile, hepatitis resembles the common flu. The patient has a fever, headache, body aches, general malaise. With hepatitis B and C, the temperature may not rise, but the virus is manifested by pain in the joints, sometimes rashes appear. Initial symptoms of hepatitis C may be limited to loss of appetite and weakness. With asymptomatic course, the diagnosis of viral hepatitis is difficult.
Change in clinical picture
After a few days, the clinical picture changes. There are pains in the hypochondrium on the right, nausea and vomiting, appetite disappears, urine darkens, feces become discolored, doctors fix an increase in the size of the liver, sometimes the spleen. At this stage, characteristic changes are detected in the blood and early diagnosis of viral hepatitis becomes possible: bilirubin increases, specific markers of viruses appear, liver tests increase eight to ten times. After the onset of jaundice, the general condition of the patient improves, but this does not happen in chronic drug addicts and alcoholics, regardless of the type of virus that caused the disease, as well as in hepatitis C. In the rest of the patients, symptoms develop in the opposite direction within a few weeks.
The clinical course can be mild, moderate and severe. The fulminant form of hepatitis is the most severe form, withwhich rapidly develops liver necrosis and usually ends in death. But the greatest danger is the chronic course of the disease, which is typical for hepatitis B, C and D. Characteristic symptoms are increased fatigue, decreased performance, inability to perform physical activity of the same intensity. Stool disorder, pain in the abdomen, muscles and joints, nausea can be caused by both the underlying disease and concomitant ones. Darkening of urine, spider veins, bleeding, enlargement of the spleen and liver, jaundice, weight loss is detected already at serious stages, when the diagnosis of viral hepatitis is not difficult.
Diagnostic features
The main methods for diagnosing chronic viral hepatitis or an acute form of the disease are laboratory tests: determining hepatitis markers, the nature of changes in blood biochemical parameters. Hepatitis A, B, D and E manifest relatively similar symptoms (pain in the right hypochondrium and stomach, increasing weakness, diarrhea, nausea and vomiting, yellowing of the skin and whites of the eyes, enlarged liver). Hepatitis G and C for many years can be manifested only by enduring fatigue. When diagnosing, a PCR analysis is required to detect enzymes of the genetic information of the virus, a biochemical blood test, an immunological study that determines the presence of antibodies to the virus, and the determination of the level of enzymes and bilirubin.
Radiation hepatitis,intoxication and autoimmune
Not only viruses can cause disease, but toxins of plant or synthetic origin. Various poisons and toxic substances contained in plants and fungi contribute to the death of liver cells. Diagnosis is carried out by detecting the level of prothrombin, enzymes, albumin and bilirubin. Radiation hepatitis is one of the manifestations of radiation sickness, which occurs due to radiation exposure. In clinical practice, the disease is rare, because the patient, in order to get into the risk zone, must receive high doses of radiation (more than 400 rad) for 3-4 months. The main diagnostic method is blood biochemistry and bilirubin analysis.
A rare form of hepatitis is autoimmune. Science still does not explain the causes of this disease. With autoimmune hepatitis, the body fails, its own cells begin to attack the liver. This form is often accompanied by other autoimmune diseases, but in rare cases it can manifest itself. Laboratory diagnostics is based on the study of the level of gamma globulins and antibodies (lgG, AST and ALT). The disease can be suspected if the IgG level is twice or more than normal.
Laboratory diagnostics
Viral hepatitis is much more common than other types of diseases, so it is worth dwelling on laboratory diagnostics in more detail. A blood test can give maximum information about the course of the disease. Instrumental methods, such as MRI, ultrasound or CT, are ineffective. These procedures make it possible to evaluatethe condition and structure of the liver, but will not give information about what kind of hepatitis the body is infected with, how long ago it happened. The analysis is prescribed for suspected infection with viral hepatitis, in the presence of symptoms and asymptomatic course, to control immunity after vaccination. Regular blood donation for screening is recommended for people at increased risk of infection: he althcare workers, children of infected parents, people who have not been vaccinated, pregnant women, people with immunodeficiency conditions.
Preparing for blood tests
Laboratory diagnosis of viral hepatitis involves taking venous blood from the inner surface of the elbow. To obtain reliable results, the patient needs to prepare in a certain way for the study. The rules for all blood tests are standard. A day before the sampling of biological material, fatty foods, alcohol, drugs and drugs should be excluded from the diet (only after consulting a doctor). Eliminate smoking, physical activity and stress 30 minutes before the examination. Blood is donated on an empty stomach (after the last meal, at least 8, preferably 12 hours should pass), you can only drink mineral water without gas. All tests are carried out before radiography, physiotherapy, ultrasound.
What can affect the result
A blood test is a simple diagnostic procedure that allows you to suspect or confirm many diseases. But sometimes you can getfalse negative or false positive results. Improper sampling, storage or transportation of venous blood, long-term storage of biological material before entering the laboratory, freezing or heat treatment of the patient's blood can affect the result of the study. Taking certain medications can distort the results of the diagnosis. False-positive results can be obtained in the presence of autoimmune diseases, in particular the presence of rheumatoid factor in the blood. The most common systemic diseases are insulin-dependent diabetes mellitus, vitiligo, psoriasis, ulcerative colitis, gluten intolerance, diffuse toxic goiter, AIDS\HIV.
Diagnosis of hepatitis A
The diagnosis is established on the basis of epidemiological data and questioning of the patient. A doctor can suspect hepatitis A if the patient had contact with a patient with jaundice about 7-50 days before the deterioration of he alth, the fact of drinking raw water, unwashed fruits and vegetables. Hepatitis A usually affects people between the ages of 15 and 29. Symptoms of the disease are assessed: a sharp deterioration in well-being with fever and gastrointestinal upset, jaundice, improvement against the background of yellowness of the skin and sclera of the eyes, an increase in the size of the spleen and liver.
Laboratory methods
Diagnosis of acute viral hepatitis A requires general and biochemical tests, analysis to determine the RNA of the virus, detection of antibodies to the virus. Forthis type of disease is characterized by a low level of leukocytes, high ESR, low bilirubin and albumin. Specific antibodies can be determined only at the beginning of the disease, that is, almost immediately after the end of the incubation period. The most reliable method for laboratory diagnosis of viral hepatitis A is PCR analysis, which allows detecting antibodies even at low concentrations. PCR provides information about when the infection occurred. This diagnostic method also makes it possible to identify virus RNA fragments. Laboratory tests should be performed twice to rule out the possibility of obtaining a false positive or false negative result.
Hepatitis B Diagnosis
In the differential diagnosis of viral hepatitis, indications for intravenous administration of narcotic drugs, surgical interventions, blood transfusions and other procedures associated with a violation of the integrity of the mucous or skin integuments, contact with people suffering from chronic liver diseases or patients with hepatitis in terms of six weeks to six months before deterioration, casual sex. Hepatitis B is characterized by a gradual onset, a long period with severe weakness, joint pain, digestive disorders, and skin rashes. With the appearance of yellowness of the skin, there is no improvement in well-being. The condition of some patients even worsens. The doctor may record an enlarged liver. Jaundice in hepatitis B does not appearimmediately, but gradually.
Combination with hepatitis D
When viral hepatitis type B and delta infection (hepatitis D) are combined, the disease is more severe, symptoms and laboratory changes are usually more pronounced. Specific reactions are of particular importance for diagnosis. The B virus contains three antigens, to each of which antibodies are produced during the infectious process. Therefore, enzyme immunoassay is of great practical importance among other methods of laboratory diagnosis of viral hepatitis. The DNA of the virus is determined in the patient's blood, and infection markers are evaluated in the results of PCR. The presence of antibodies to HB-core Ag may mean that the patient once had hepatitis B, because the antibodies persist for a long period after recovery. Sometimes antibodies persist throughout life.
Hepatitis C Diagnosis
To diagnose hepatitis C, the following instrumental and laboratory examinations are prescribed: ultrasound, blood for antibodies to the hepatitis virus, blood biochemistry, PCR analysis to determine the DNR virus, liver biopsy. Positive results may indicate a chronic infection or past illness. Another infectious viral process can cause changes in the blood. There is a possibility of getting a false positive result. At the first analysis, there may be a positive result, which in the future (with an in-depth study) is not confirmed. Such a reaction may be associated with various causes, but not with the virus.hepatitis.
Hepatitis E: diagnosis
Diagnosis of viral hepatitis E is based on a combination of symptoms of an acute form of the disease with the characteristics of infection (visiting specific regions for type E 2-8 weeks before the onset of signs of the disease, drinking untreated water, the presence of similar diseases in others). Hepatitis E can be suspected in the absence of hepatitis A and C markers in the blood. The diagnosis is confirmed in the presence of specific antibodies to the type E virus, which can be detected by ELISA analysis in the acute period of the disease. An additional diagnostic method is ultrasound of the liver. Treatment involves the fight against intoxication due to symptomatic therapy and liver damage. A sparing diet, hepatoprotectors, detoxification infusions are prescribed.
Differential Diagnosis
If antibodies are not detected in laboratory tests with symptoms of hepatitis, then serological tests and the determination of antibodies to the herpes simplex virus, toxoplasma, cytomegalovirus should be carried out. Laboratory parameters may change with any systemic viral infection that accompanies liver damage. With pain in the right hypochondrium, fever, jaundice, nausea and vomiting, an erroneous diagnosis is sometimes made: acute cholecystitis, ascending cholangitis, choledocholithiasis. In older people, it is required to differentiate hepatitis from obstructive jaundice caused by pancreatic cancer or choledocholithiasis. Hepatitis in pregnant women is often confused with liver disease (eclampsia, cholestasis of pregnancy,acute fatty degeneration of the liver). In some cases, it is necessary to exclude hereditary metabolic disorders.
Tests when prescribing therapy
When prescribing antiviral therapy, additional studies are required. Thus, the treatment and diagnosis of viral hepatitis are linked. A complete examination of the virus (viral load, genotype), a complete diagnosis of the liver (ultrasound with Doppler ultrasound, biochemistry reflecting the functional and structural state of the liver cells, assessment of the degree of fibrosis), tests to exclude contraindications for prescribing therapy (autoimmune antibodies, blood test, hormones, thyroid ultrasound). Patients over 40 years of age are prescribed an examination of the respiratory system, heart and blood vessels. If hepatitis B is diagnosed, then additionally, when prescribing therapy, an analysis is carried out for drug resistance, virus mutation, and delta virus.
