Acute hepatitis A virus infection in Turkey

Area of Science:

• Virology
• Molecular Biology
• Hepatology

Background:

• Hepatitis A virus (HAV) infection is a significant public health concern.
• Genotyping and viral load assessment are crucial for understanding HAV epidemiology and pathogenesis.
• RT-PCR is a key molecular tool for detecting and characterizing viral RNA.

Purpose of the Study:

• To genotype HAV isolates from acute hepatitis A patients in Turkey.
• To compare the sensitivity of RT-PCR in different HAV genomic regions.
• To investigate the relationship between viral load, patient age, and transaminase levels.

Main Methods:

• Serum samples from anti-HAV IgM positive patients were tested for viral RNA using RT-PCR with primers from two HAV genomic regions (5'NCR and VP1-P2A).
• Phylogenetic analyses were performed on amplified PCR products for genotyping.
• Quantitative assessment of HAV RNA genome equivalents was done using real-time RT-PCR.
• Serum levels of AST and ALT were measured and compared between age groups.

Main Results:

• The majority of HAV isolates belonged to genotype IB, with close genetic relatedness among them.
• Two isolates were classified under genotype IA.
• RT-PCR targeting the 5'NCR region showed higher sensitivity than targeting the VP1-P2A region.
• Patients under 10 years of age exhibited higher mean AST and ALT levels compared to older patients.
• No association was found between viral load (genome equivalents) and elevated transaminase levels in younger patients.

Conclusions:

• Genotype IB is predominant in the studied Turkish population.
• The 5'NCR region is a more sensitive target for RT-PCR-based HAV RNA detection.
• Age-related differences in transaminase levels exist in acute hepatitis A, independent of viral load.