HCV Genotyping

Hepatitis C virus

Hepatitis C virus is an RNA-containing virus from the Flaviviridae family of the genus Hepacivirus. HCV is characterized by high genetic variability, which prevents its elimination from the body, contributes to the rapid formation of virus variants resistant to antiviral drugs, and complicates the development of effective specific prophylaxis methods. To date, eight major genotypes of the virus have been identified, of which genotypes 1a, 1b, 2 and 3a/3b are the most frequent in Russia. Genotype 1b is associated with a more severe course of the disease and a lower probability of successful antiviral treatment.

People infected with HCV, including those in the incubation period, act as the source of infection. The most significant is the parenteral route of transmission (during surgical interventions and cosmetic procedures, transfusion of blood and its components, use of intravenous narcotic drugs). Sexual and vertical routes of transmission are much less common.

The incubation period of viral hepatitis C varies from 2 to 26 weeks (6-8 weeks on average). The acute phase of the disease is asymptomatic in 70-80% of infected patients, and only 20-30% of patients have nonspecific symptoms such as general weakness, fatigue, decreased appetite, nausea, muscle and joint pain. Jaundice of the skin and mucous membranes rarely occurs. In most cases, the acute phase is followed by the development of chronic hepatitis, which can persist for a long time without marked clinical manifestations. The outcomes of chronic viral hepatitis C include the development of serious complications such as cirrhosis and hepatocellular carcinoma.

PCR assay has high sensitivity and specificity, enabling detection of HCV RNA as early as 1-2 weeks after infection. The presence of HCV RNA in the serological window phase (in the absence of HCV antibodies) is an important diagnostic criterion.

The course and effectiveness of HCV treatment depend on the virus genotype. Genotypes 1b and 4a with high replicative capacity are the most dangerous. Detection of HCV in blood plasma and serum and subsequent genotype identification are essential for clinical diagnosis and selection of antiviral therapy, as well as for ensuring safe blood storage and providing epidemiological information on HCV prevalence.