Hepatitis C

náhled|vpravo|450px|Světová prevalence virové hepatitidy typu C náhled|450px|vpravo|Zdroje nákazy hepatitidou C

The causative agent is HCV-RNA virus (Flaviviridae). Different genotypes and their subtypes are distinguished, it is easily subject to mutations. There are 6 types of viruses and a large number of subtypes (genotype 1b occurs most often in the Czech Republic). Spread parenterally (blood derivatives – hemophiliacs, i.v. drug addiction, hemodialysis, sexual transmission, perinatally from mother to fetus, transplant grafts),it is about 100 times less contagious than VHB.

Acute HCV has an ICD code of B171, chronic B182.

The course of infection
The incubation period is 15–160 (most often around 50) days.


 * 1) Acute infection (asymptomatic or icteric form), in 15% spontaneous elimination, in 85–90% it becomes chronic;
 * 2) chronic infection.

The infection is often asymptomatic, or it takes the form of vague dyspeptic problems. It is usually without jaundice. It may manifest itself clinically after years as liver cirrhosis (or its complications) or hepatocelullar carcinoma. Icterus occurs more often in the elderly. Hepatic failure is rare. The development of liver cirrhosis is slow, accelerated by HBV and alcohol. Asymptomatic carriers are rare.

Diagnostics
We determine serologically - anti-HCV antibody (not only in infected persons, but also in those who eliminated the virus spontaneously or by antiviral treatment). PCR detection of viral RNA is an indicator of active infection. Anti-HCV is demonstrable about 3 weeks after exposure, it has no preventive effect against reinfection.It is characterized by a small link between biochemistry and histology (even slightly increased ALT, large changes). For this reason, we have to resort to lliver biopsy more often.

Ig production may be delayed; if acute HCV is suspected, the test should be repeated. Chronic hepatitis C requires a biopsy with staging (advanced liver fibrosis) to show a risk of progression to liver cirrhosis. The virus cannot be grown on tissue cultures, so PCR or Ig anti-HCV is detected.

Therapy
We treat HCV infection with antivirals - a combination of IFN-α (pegylated) with ribavirin. The course lasts 6 or 12 months and negative PCR for viral RNA 24 weeks after the end of treatment is considered a criterion for curing the infection. IFNs are of two types - conventional and pegylated (bound to polyethylene glycol - they are released gradually, applied s.c. once a week).

Newer treatment from 2015 is possible with the so-called 3D combination of drugs: Sofosbuvir, Simeprevir, ledipasvir and others. This treatment may or may not be combined with Ribavirin or IFN alpha (according to the genotype of the virus) and the therapy lasts 12-24 weeks. The side effects are quite mild but the treatment is very expensive. Unlike previous therapy, there is a success rate of up to 97%. Another treatment method is liver transplantation.

Prophylaxis
There is no effective vaccine against HCV (due to the high variability of the virus), post-exposure Ig prophylaxis or antivirals does not make sense either.

Související články

 * Virové hepatitidy
 * Hepatitidy

Zdroje




Externí odkazy

 * Hepatitida C (česká wikipedie)

Použitá literatura