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Distribution of hepatitis B virus genotypes in two different pediatric populations from Argentina
V A Mbayed1, J L López, P F Telenta
1Cátedra de Virología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
Insights
Hepatitis B virus (HBV) genotype distribution differs significantly between low-prevalence Buenos Aires and high-prevalence Gualeguay, Argentina. Phylogenetic analysis revealed distinct HBV genotypes in pediatric patients, highlighting geographic variations in viral populations.
Area of Science:
- Virology
- Epidemiology
- Genetics
Background:
- Hepatitis B virus (HBV) infection acquired in infancy has a high probability of becoming chronic.
- HBV pathogenesis and chronic carrier probability are age-dependent.
- Geographic location influences HBV prevalence and genotype distribution.
Purpose of the Study:
- To determine HBV genotypes in pediatric patients from two Argentinian areas with differing prevalence rates.
- To analyze phylogenetic differences in HBV genotypes between Buenos Aires and Gualeguay.
- To investigate the origins of HBV genotypes, particularly genotype F.
Main Methods:
- Phylogenetic analysis of HBV DNA sequences.
- Genotyping of HBV isolates from 22 pediatric patients.
- Comparison of genotype distribution in low-prevalence (Buenos Aires) and high-prevalence (Gualeguay) areas.
Main Results:
- Significant differences in HBV genotype distribution were observed between the two study areas.
- Buenos Aires showed genotypes A (36%), D (9%), and F (55%).
- Gualeguay exclusively presented genotype A isolates with low nucleotide divergence, suggesting a founder effect.
Conclusions:
- HBV genotype distribution in pediatric patients varies geographically in Argentina.
- The prevalence of genotype F in Buenos Aires aligns with its American origin.
- The findings suggest distinct HBV transmission dynamics in high- and low-prevalence regions.
Abstract:
Differences in pathogenesis and the probability of becoming a chronic carrier depend on the age at which hepatitis B virus (HBV) infection is acquired, ranging from 82% in infants less than 6 months of age to 15 to 30% in older children. HBV genotypes from 22 pediatric patients from two areas that differ in prevalence have been determined. Phylogenetic analysis shows a clear difference between the genotype distribution in Buenos Aires, a low-prevalence area, and that found in Gualeguay, Entre Ríos, a high-prevalence area. While the analysis allocated the sequences in the Buenos Aires group to genotypes A (36%), D (9%), and F (55%), the Gualeguay group presented exclusively genotype A isolates with very low nucleotide divergence, which suggests a strong founder viral population. The high prevalence of genotype F in the Buenos Aires group and its high intragroup heterogeneity agree with the American origin of this genotype.