Epidemiology, diagnosis and prevention of viral hepatitis are important issues in practical medicine. Tens of millions of people get these infections every year. According to the WHO, at present there are at least 2 billion patients infected only with hepatitis B. In Russia, a high level of morbidity and an increasing frequency of adverse outcomes (the transition of the disease to a chronic form and fatal outcome) remain, which determines the high importance of studying the clinic, diagnosing and treatment of viral hepatitis by medical practitioners and medical students.
How does hepatitis begin?
From the moment of infection to the onset 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 this period, the virus multiplies and adapts in the body, and then begins to manifest itself. Before the skin and mucous membranes acquire a characteristic yellow hue, the urine darkens, and the feces, losing bile, become colorless, hepatitis resembles ordinary flu. The patient has a fever, a headache, body aches, and general malaise. With hepatitis B and C, the temperature may not increase, but the virus manifests itself as pain in the joints, sometimes rashes appear. The initial symptoms of hepatitis C may be limited to a decrease in appetite and weakness. With an asymptomatic course, the diagnosis of viral hepatitis is difficult.
Clinical Change
After a few days, the clinical picture is changing. Pain appears in the upper quadrant on the right, nausea and vomiting, appetite disappears, urine darkens, feces become discolored, doctors record 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 virus markers appear, and liver tests increase eight to ten times. After the appearance of jaundice, the general condition of the patient improves, but this does not occur in chronic drug addicts and alcoholics, regardless of the type of virus that caused the disease, as well as in hepatitis C. In other 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 difficult variety, in which liver necrosis rapidly develops and usually ends in death. But the chronic course of the disease is of great danger, which is typical for hepatitis B, C and D. The characteristic symptoms are increased fatigue, decreased working capacity, and the 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 its attendant. Darkening of urine, spider veins, bleeding, enlargement of the spleen and liver, jaundice, weight loss are already detected 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: determination of hepatitis markers, the nature of changes in blood biochemical parameters. Hepatitis A, B, D, and E are manifested with relatively identical symptoms (pain in the right hypochondrium and stomach, growing weakness, diarrhea, nausea and vomiting, yellowing of the skin and eye proteins, enlarged liver). Hepatitis G and C for many years can only manifest persistent fatigue. When diagnosing, a PCR analysis is required to identify enzymes of the genetic information of the virus, a biochemical blood test, an immunological test 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 the 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 by detecting the level of prothrombin, enzymes, albumin and bilirubin. Radiation hepatitis is one of the manifestations of radiation sickness, occurs due to radiation exposure. In clinical practice, the disease is rare, because the patient, in order to fall 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 analysis for bilirubin.
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 a study of the level of gamma globulins and antibodies (logG, AcT and Alt). The disease can be suspected if the level of IgG exceeds normal values twice or more.
Laboratory diagnostics
Viral hepatitis is much more widespread than other types of diseases, so it is worthwhile to dwell on laboratory diagnosis 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. Such procedures allow you to assess the condition and structure of the liver, but they will not give information about exactly what hepatitis infected the body, how long it happened. The analysis is prescribed for suspected infection with viral hepatitis, in the presence of symptoms and an asymptomatic course, to monitor immunity after vaccination. Regular blood donation for a screening test is recommended for people with an increased risk of infection: health workers, children of infected parents, people who have not been vaccinated, pregnant women, people with immunodeficiency.
Preparation for blood tests
Laboratory diagnosis of viral hepatitis involves the collection of venous blood from the inner surface of the elbow. To obtain reliable results, the patient needs to prepare for the study in a certain way. The rules for all blood tests are standard. The day before the collection of biological material from the diet, fatty foods, alcohol, drugs and drugs should be excluded (only after consulting a doctor). 30 minutes before the study, eliminate smoking, physical activity and stress. Blood is donated on an empty stomach (after an extreme meal should pass at least 8, preferably 12 hours), you can drink only mineral water without gas. All analyzes are carried out before radiography, physiotherapeutic procedures, ultrasound.
What may affect the result.
A blood test is a simple diagnostic procedure that allows you to suspect or confirm many diseases. But sometimes you can get false negative or false positive results. Incorrect sampling, storage or transportation of venous blood, long-term storage of biological material until admission to the laboratory, freezing or heat treatment of the patient’s blood can affect the result of the study. The use of certain medications can distort the results of 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 the questioning of the patient. A doctor may suspect hepatitis A, if the patient had contact with a patient with jaundice about 7-50 days before the state of health worsened, the fact of drinking raw water, unwashed fruits and vegetables. People aged 15 to 29 years are usually infected with hepatitis A. The symptoms of the disease are assessed: a sharp deterioration in well-being with an increase in body temperature and gastrointestinal upset, jaundice, improvement against jaundice 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 a general and biochemical analysis, analysis for the determination of virus RNA, and detection of antibodies to the virus. This type of disease is characterized by a low white blood cell count, 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 can detect antibodies even at low concentrations. PCR provides information about when an infection occurred. This diagnostic method also makes it possible to identify fragments of the RNA of the virus. Laboratory studies should be carried out twice to exclude the possibility of obtaining a false positive or false negative result.
Diagnosis of hepatitis B
In the differential diagnosis of viral hepatitis, indications of intravenous drug administration, surgical interventions, blood transfusions and other procedures related to the violation of the integrity of the mucous membranes or skin, contact with people suffering from chronic liver diseases or patients with hepatitis from six weeks to six months help to deterioration, accidental sexual intercourse. Hepatitis B is characterized by a gradual onset, a long period with severe weakness, joint pain, digestive disorders, skin rashes. With the appearance of yellowness of the skin, an improvement in well-being is not observed. The condition of some patients even worsens. The doctor may fix an enlarged liver. Jaundice with hepatitis B does not occur immediately, but gradually.
Combination with hepatitis D
With a combination of type B viral hepatitis and delta infection (hepatitis D), the disease is more severe, symptoms and laboratory changes are usually more pronounced. Of particular importance for diagnosis are specific reactions. Virus B contains three antigens, each of which produces antibodies during the infection 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, the markers of infection are evaluated in the results of PCR. The presence of antibodies to HB-core Ag may mean that once a patient has had hepatitis B, because antibodies persist for a long period after recovery. Sometimes antibodies persist throughout life.
Diagnosis of hepatitis C
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 DPR of the virus, liver biopsy. Positive results may indicate a chronic infection or a past illness. Another infectious viral process can cause changes in the blood. There is a chance of getting a false positive result. At the first analysis, there may be a positive result, which is not confirmed in the future (with an in-depth study). Such a reaction can be associated with various causes, but not with the hepatitis virus.
Hepatitis E: diagnosis
Diagnosis of viral hepatitis E is based on a combination of a symptom of an acute form of the disease with the characteristics of infection (visiting specific regions of 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 if there are no 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 in the acute period of the disease. An additional diagnostic method is an ultrasound of the liver. Treatment involves combating intoxication due to symptomatic therapy and liver damage. A sparing diet, hepatoprotectors, detoxification infusions are prescribed.
Differential diagnosis
If no antibodies are detected in the laboratory tests for hepatitis symptoms, then serological tests and determination of antibodies to the herpes simplex virus, toxoplasma, cytomegalovirus should be performed. Laboratory indicators may change with any systemic viral infection accompanying liver damage. For 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 necessary to differentiate hepatitis with obstructive jaundice caused by pancreatic cancer or choledocholithiasis. Hepatitis in pregnant women is often confused with liver diseases (eclampsia, pregnant cholestasis, acute fatty liver disease). In some cases, it is necessary to exclude hereditary metabolic disorders.
Assays for the appointment of therapy
When prescribing antiviral therapy, additional studies are necessarily carried out. Thus, the treatment and diagnosis of viral hepatitis are related. A complete examination of the virus (viral load, genotype), a complete diagnosis of the liver (ultrasound with dopplerography, biochemistry, reflecting the functional and structural state of the liver cells, an assessment of the degree of fibrosis), tests to eliminate contraindications for the appointment of therapy (autoimmune antibodies, blood tests, hormones, Ultrasound of the thyroid gland). 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, virus delta.