Etiology and transmission routes
The hepatitis C virus (HCV) belongs to the Flaviviridae family. It is a spherical, enveloped, RNA-containing virus. It is characterized by extremely high genetic variability: 6 main genotypes and more than 100 subtypes are known.
The source of infection is an infected person, who becomes contagious as early as the incubation period and remains so for up to 10 weeks after the onset of symptoms.
The main transmission route is parenteral (via blood). Sexual and vertical (mother-to-child) transmission routes are also possible, but they are much less common than in hepatitis B virus infection. Seasonality is not characteristic of this disease.
Pathogenesis and mechanisms of chronicity
The virus enters the liver via the bloodstream (hematogenously). The destruction of liver cells (hepatocytes) occurs in two ways: due to the direct cytopathic effect of the virus itself and as a result of an attack by the host's own immune system (immune cytolysis). At the same time, the severity of the condition directly depends on the level of viremia. Interestingly, HCV is also capable of replicating outside the liver—in cells of lymphoid and non-lymphoid tissue, disrupting their function.
Acute hepatitis C very frequently transitions into a chronic form. This is associated with three factors:
- "Escape" phenomenon: due to continuous genome mutations, the virus becomes invulnerable to the immune system.
- Cellular immunodeficiency: production of $\alpha$-interferon decreases and the balance of T cells is disrupted (T-suppressors predominate).
- Antigen masking: viral proteins bind into immune complexes.
Clinical presentation
The incubation period lasts 5–12 weeks. The development of the disease goes through several stages:
- Pre-icteric period: begins gradually. Astheno-dyspeptic syndrome predominates (weakness, nausea, decreased appetite). Low-grade fever and dull abdominal pain may occur. The liver enlarges and becomes tender.
- Icteric period: lasts 1–3 weeks. Its specific feature is that with the appearance of jaundice, intoxication symptoms do not disappear, but persist or intensify (unlike other types of viral hepatitis). Dark urine and acholic stools are observed (cholestasis syndrome). Some patients experience splenomegaly.
- Post-icteric period: well-being improves, liver size and enzyme levels return to normal.
Diagnostics and treatment
The diagnosis is established based on clinical findings (astheno-dyspeptic syndrome, hepatomegaly) and anamnesis data (medical or other blood-related interventions 1–6 weeks/months prior to illness). Laboratory tests reveal cytolysis syndrome—a sharp increase in ALT and AST by 5–15 times, as well as an elevation in direct bilirubin.
To precisely confirm the diagnosis, the following are used:
- ELISA: screening for antibodies to the virus (anti-HCV).
- PCR: detection of HCV RNA. PCR specifically determines active viral replication, allowing current infection to be distinguished from a past resolved infection.
Treatment is based on the same principles as for hepatitis B. In confirmed viral replication, antiviral therapy is prescribed (interferon preparations with ribavirin). This regimen is approved for children starting from 2 years of age.
Class and exam questions
Why does acute hepatitis C frequently progress to a chronic form?
This is due to the virus's ability to rapidly mutate (the "escape" phenomenon), suppression of cellular immunity, and the formation of immune complexes that mask viral antigens.
How does the icteric period in hepatitis C differ clinically?
With the onset of jaundice, intoxication syndrome (weakness, nausea) does not resolve, but persists or even worsens, which is atypical for other viral hepatitides.
Which test is the most important for confirming the diagnosis?
The determining test is PCR for detecting viral RNA. It demonstrates active replication of the pathogen in the body at the present time.
Is there a vaccine against hepatitis C?
No, a specific vaccine has not been developed. Prevention is limited solely to adherence to asepsis rules and the safe use of medical instruments.
What else to study on this topic
- Extrahepatic replication of the hepatitis C virus
- Differential diagnosis of hepatitis A, B, D, and E
- Classification of severity forms of acute hepatitis C
- Mechanisms of hepatocellular carcinoma formation during chronicity
- Specifics of interferon therapy in pediatric practice
Master the entire topic in the Pediatrics course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Acute viral hepatitis C" and 3,738 other pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 71 video lessons on the subject
Other topics from the section «Chapter 12. Infectious and parasitic diseases»
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.