Hepatitis A virus, PCR-quality
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Why this test?
For early detection of viral hepatitis A.
For differential diagnosis of jaundice and hepatitis.
For examination of people who have been in contact with a patient with hepatitis A.
In what cases is it prescribed?
With symptoms of hepatitis.
With an increase in laboratory indicators of liver function.
If there is data on the patient's contact with a patient with viral hepatitis A (or if possible contact is suspected).
When examining people in centers of infection.
Information about the test
Hepatitis A virus (HAV) is the most common causative agent of viral hepatitis in the world. It belongs to enteroviruses and contains a single-stranded RNA strand inside a protein shell. The virus is resistant to exposure to chlorine, acids, freezing, but quickly dies during boiling and heat treatment. At a temperature of +4 ° C, it can be stored in the external environment for several months, at -20 ° C - for several years, at room temperature - for several weeks.
The source of infection is a sick person at the end of the incubation period, in the icteric and non-icteric periods, as well as during the asymptomatic course of the disease.
The disease is asymptomatic in 90% of cases in children and in 25-50% of cases in adults. The mechanism of virus transmission is fecal-oral. The infection is mainly spread through water, but there are also frequent cases of infection through food products, household items, from person to person through unwashed hands. Infection is possible with a blood transfusion taken in the last days of the incubation period. The number of patients increases in summer and autumn.
The incubation period of infection lasts from 15 to 50 days, on average 3-4 weeks.
At first, hepatitis is usually accompanied by an increase in temperature, weakness, headache, body aches, and indigestion. Often, during the jaundice-free period, the diagnosis of SARS or acute intestinal infection is mistakenly made. After 2-10 days, jaundice appears, laboratory indicators of liver function change, body temperature decreases, and the liver enlarges. During the jaundice period, the patient complains of heaviness in the right hypochondrium, nausea, lack of appetite, darkening of urine and grayish-white, clay stool.
On average, the disease lasts 2-3 weeks. Full recovery occurs within several weeks and may take up to 3-6 months.
In some people, hepatitis occurs without obvious symptoms and without a jaundiced period. The outcome of the disease is favorable, complications occur very rarely. After an infection, persistent immunity to it is formed.
The transition to a chronic form and carrying the virus is not characteristic of hepatitis.
With high specificity and sensitivity, the RNA of the virus can be detected in the blood by the PCR method 10-14 days after infection, 2 weeks before clinical manifestations and in the first 1-3 weeks of the acute phase of the disease.
The genetic material of the virus in the blood can be detected earlier than IgM to it, which makes it possible to start treatment in a timely manner and prevent further spread of the infection.