Molecular Characterization of Hepatitis a Virus Isolated from Patients with Acute Hepatitis Infections in Duhok City-Iraq
DOI:
https://doi.org/10.32007/jfacmedbaghdad3208Keywords:
Hepatitis A virus, IB genotype, phylogenetic analysis, VP1/2AAbstract
Background: Hepatitis A virus (HAV) is a major cause of acute viral hepatitis in Iraq and is common worldwide. A variety of HAV genomic areas have been used for genotyping in order to study the molecular HAV variations.
Objectives: To identify the prevalent circulating genotype and molecular characteristics of HAV in Duhok city of Iraq and determining its genetic relatedness to reference strains.
Methods: Blood samples were collected from 171 patients with acute viral hepatitis at pediatric and general teaching hospitals in Duhok from August 2020 to November 2021. Serum samples were tested for IgM anti-HAV antibodies using ELISA. Seropositive samples underwent standard nested reverse transcription-polymerase chain reaction (RT-PCR) targeting the VP1/2A region, followed by sequencing and submission to GenBank. Phylogenetic relatedness and sequence identity were analyzed for selected HAV samples.
Results: Of the 171 patients, 37 (21.6%) were positive for HAV-specific IgM antibodies. RT-PCR confirmed that all 37 samples were positive for the virus. Analysis of 12 sequenced samples submitted to GenBank revealed that genotype IB was the circulating strain. The selected HAVs exhibited a high level of sequence identity. While nucleotide substitutions were detected, only one sample differed from the reference strain, showing an arginine-to-lysine substitution at position 788 of the VP1-2A gene.
Conclusions: Genotype IB is the circulating strain causing acute hepatitis A in the locality studied. The amino acid sequence analysis revealed a K788R substitution (lysine to arginine) in one sample. Further investigation may be necessary to determine if this affects vaccine efficacy.
Received: 16 Feb. 2026, Revised:20 Sept. 2026, Accepted: 25 Sept. 2026, Published online: Oct. 2026
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