Genomic epidemiology of early SARS-CoV-2 transmission dynamics in Bangladesh

Background: Genomic epidemiology has helped reconstruct the global and regional movement of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there is still a lack of understanding of SARS-CoV-2 spread in some of the world’s least developed countries (LDCs). Methods: To begin to address this disparity, we studied the transmission dynamics of the virus in Bangladesh during the country’s first COVID-19 wave by analysing case reports and whole-genome sequences from all eight divisions of the country. Results: We detected > 50 virus introductions to the country during the period, including during a period of national lockdown. Additionally, through discrete phylogeographic analyses, we identified that geographical distance and population -density and/or -size influenced virus spatial dispersal in Bangladesh. Conclusions: Overall, this study expands our knowledge of SARS-CoV-2 genomic epidemiology in Bangladesh, shedding light on crucial transmission characteristics within the country, while also acknowledging resemblances and differences to patterns observed in other nations.