Background and Rationale
Hepatitis C virus (HCV) exhibits high structural variability; globally it is classified into eight genotypes and numerous subtypes. These genotypes and subtypes display distinct geographic, ethnic and risk-group distributions. In Hungary, screening for HCV infections has been in place since 1992. The Molecular Diagnostic Laboratory responsible for this nationwide series has conducted serotyping since 1996 and genotype/subtype analyses since 2000, providing a long-term dataset to assess temporal and demographic changes in circulating HCV variants.
Objective
The study aimed to analyse genotype and subtype distributions in a national cohort (n = 9,067) and to examine how these distributions vary by age, sex and geographic region, as well as how they evolved over three decades (1996–2026).
Methods
Specimen and period coverage
- The national sample comprised 9,067 patients collected between 1996 and 2026.
- Serotyping was performed between 1996 and 1999 (n = 175).
- Genotyping by hybridization was used from 2000 to 2016 (n = 4,844).
- Since 2016 genotyping has been performed by real-time reverse-transcription polymerase chain reaction (real-time RT-PCR) (n = 4,223).
Analytical scope
- The analyses categorized samples by genotype and subtype and correlated findings with patient age, sex and geographic region to identify demographic and spatial patterns and trends over time.
Results
Overall sample and dominant subtype
- Across the three decades, GT1b remained the dominant HCV subtype in the Hungarian sample.
- Despite persistent dominance, the relative frequency of GT1b decreased over time in comparison with GT1a and GT3.
Age and sex distribution
- The highest overall prevalence of HCV-positive samples occurred among younger males (under 40 years) and older females (over 60 years).
- Age under 40 years showed a statistically significant association with increased prevalence of GT3 and with non-GT1b genotypes more broadly.
Regional variation
- Regional differences were identified: GT3 was most commonly observed in the Southwest region of Hungary.
- Non-GT1b genotypes collectively showed the highest relative frequency in the Northeast region.
Temporal changes
- Over the study period there was a measurable shift in genotype/subtype composition, marked by rising detection of GT1a, GT3, and other non-GT1b genotypes relative to the long-standing predominance of GT1b.
Discussion
Comparison with international trends
- The observed increase in genetic diversity and changing genotype/subtype proportions align with international reports of evolving HCV epidemiology.
Drivers of change
- The authors attribute the evolving genotype landscape to factors including migration, increased international travel and a rising frequency of intravenous drug use, all of which can introduce and disseminate different HCV subtypes across populations.
Clinical and public-health implications
- Continued genotype monitoring is recommended for several reasons: early detection of rare or emerging subtypes; interpretation of unexpected therapeutic outcomes; targeted epidemiological investigations; and support for differentiating relapse from reinfection in treated individuals.
- Monitoring genotype distribution can also serve as an indirect indicator of changing population behaviors and infection routes, informing prevention and control strategies.
Limitations
- The summary provided in the source reports the methods and main findings but does not include detailed numerical breakdowns (for example, exact percentages per genotype over time) in the abstract. These granular data were not reported in the abstract available through the source.
Conclusions
- In this national Hungarian dataset spanning 1996–2026 (n = 9,067), GT1b remained the most frequently detected HCV subtype but its relative share decreased with rising representation of GT1a, GT3, and other non-GT1b genotypes.
- Younger age (<40 years) was significantly associated with GT3 and non-GT1b genotypes; regional patterns showed geographic clustering of specific genotypes.
- The findings support sustained, nationwide genotype surveillance to detect shifts in circulating HCV subtypes, guide interpretation of treatment responses, and inform public-health interventions.