Prevalence of Hepatitis B genotypes worldwide and in Iran: A meta-analysis

Background. Chronic hepatitis B is associated with different long-term outcomes in various regions. One of the critical predictors of clinical outcomes is the genotype of Hepatitis B virus (HBV). The current study investigated the frequency of worldwide and Iranian national HBV genotypes. Methods. Electronic search was performed through Medline (via Ovid), Embase, Web of Science, and Persian databases. Furthermore, the references of eligible articles were manually checked. The quantitative synthesis was conducted using the 2nd version of comprehensive Meta-analysis software (CMA.2). Results. In total, 5817 records were retrieved, and after removing duplicate studies, 3701 were screened at the title/abstract level. A total of 350 eligible studies were identified in the end.D genotype had the highest frequency (43.50%; 95% CI: 39.60 to 47.50), and the H genotype had the lowest frequency (1.2%; 95% CI: 0.6 to 2.7) globally. In 29 studies conducted in Iran (97.0%), genotype D was identified. Genotype E was the most prevalent in the African Region, followed by A in the American Region, B and C in the South-East Asian Region, D in the European Region, and C in the Western Pacific Region. Conclusion. The most prevalent genotype of HCV worldwide and in Iran is D. Furthermore, HBV genotype frequencies vary according to WHO regions. A prediction of progression could be made based on these results. Practical Implications. 1.According to the results of the meta-analyses, the D genotype had the highest frequency (43.50%; 95% CI: 39.60 to 47.50) and the genotype H had the lowest frequency (1.2%; 95% CI: 0.6 to 2.7) globally. 2.In 29 studies conducted in Iran (97.0%), genotype D was identified. 3. Genotype E was the most prevalent in the African Region, followed by A in the American Region, B and C in the South-East Asian Region, D in the European Region, and C in the Western Pacific Region.