Background : Dengue fever, caused by the dengue virus (DENV), is a significant global health concern with more than 50 million cases being recorded annually worldwide. Tropical and subtropical regions bear most of the disease burden, with it being endemic in Bangladesh. To tackle this threat, comprehension of the circulating serotypes and genotypes of DENVs is essential to gain insights into the evolution, etiology, or emergence of newly imported viruses. Hence, the study aimed to identify the circulating serotypes and genotypes of DENVs among dengue-infected patients in Dhaka, Bangladesh, in 2022. Methods A total of 234 NS1-positive patients were enrolled in the study for serotyping of DENV via multiplex PCR. Sanger sequencing of a partial Capsid Premembrane (CPrM) region was subsequently used for genotyping. Results : Among the NS1-positive patients, DENV3 was detected in 231 (98.7%) cases, while 3 (1.3%) patients were DENV2-positive. Out of 38 samples that were sequenced, Genotype-Ⅰ was detected in all (36) DENV3-positive patients, and genotype-Ⅱ (cosmopolitan) was detected in all (2) DENV2-positive cases. Furthermore, phylogenetic analysis of DENV3 genotype-Ⅰ showed them clustering closely with other Bangladeshi strains, alongside strains from China and Myanmar. Cosmopolitan genotypes of DENV2 clustered closely to Bangladeshi cosmopolitan strains, alongside Chinese, Singaporean, and South Korean strains. Conclusions : DENV3 was predominant in Dhaka, Bangladesh in 2022, with DENV2 being in co-circulation. No other serotype was detected in this study. Consequently, a predominance of DENV2 or re-emergence of other serotypes may potentiate a larger outbreak in upcoming years, highlighting the necessity of these studies.
Khatun et al. (Mon,) studied this question.