[Hepatitis C epidemiology in the world]

Area of Science:

• Hepatology
• Virology
• Epidemiology

Background:

• Hepatitis C virus (HCV) screening tests facilitate epidemiological research on non-A, non-B hepatitis.
• Phylogenetic analysis identifies distinct HCV genotype distributions globally, with genotypes 1, 2, and 3 prevalent in developing nations and 4, 5, and 6 in other regions.
• Confirmed transmission routes include transfusion and addiction, yet sexual, intrafamilial, and mother-to-infant transmission require further investigation.

Purpose of the Study:

• To review current knowledge on hepatitis C virus epidemiology, transmission, and natural history.
• To highlight gaps in understanding regarding transmission routes and early disease stages.
• To emphasize the need for expanded global prevalence studies.

Main Methods:

• Phylogenetic analysis of HCV genotypes.
• Review of established and suspected HCV transmission routes.
• Assessment of current diagnostic limitations, including serological latency.
• Analysis of existing global prevalence data.

Main Results:

• HCV genotypes exhibit distinct geographical distributions.
• Transfusion and addiction are confirmed major transmission pathways.
• Serological latency poses challenges for post-transfusion screening.
• Knowledge of early disease stages and non-transfusion transmission routes is limited.
• Specific regions like Southern/Eastern Europe, Japan, and Sub-Saharan Africa show high prevalence (>1.5%).

Conclusions:

• Further research is crucial to elucidate HCV transmission dynamics, particularly non-traditional routes.
• Development of novel methods is needed to study early-stage HCV infection.
• Comprehensive global epidemiological studies are essential to accurately map HCV prevalence and inform public health strategies.