AI Summary
This study focuses on the molecular epidemiology and evolutionary characteristics of dengue virus 2 in East Africa, particularly in Kenya. By analyzing genetic structures, phylogenies, and gene flow between Kenya and other countries, the study reveals two dengue-2 Cosmopolitan genotype lineages in Kenya, linked to recent outbreaks in coastal Kenya and Burkina Faso. Importation of dengue-2 from East and Southeast Asia into Kenya and other parts of Africa is identified as a driving factor behind the virus's circulation in the region.
Despite the increasing burden of dengue, the regional emergence of the virus in Kenya has not been examined. This study investigates the genetic structure and regional spread of dengue virus-2 in Kenya. Viral RNA from acutely ill patients in Kenya was enriched and sequenced. Six new dengue-2 genomes were combined with 349 publicly available genomes and phylogenies used to infer gene flow between Kenya and other countries. Analyses indicate two dengue-2 Cosmopolitan genotype lineages circulating in Kenya, linked to recent outbreaks in coastal Kenya and Burkina Faso. Lineages circulating in Western, Southern, and Eastern Africa exhibiting similar evolutionary features are also reported. Phylogeography suggests importation of dengue-2 into Kenya from East and Southeast Asia and bidirectional geneflow. Additional lineages circulating in Africa are also imported from East and Southeast Asia. These findings underscore how intermittent importations from East and Southeast Asia drive dengue-2 circulation in Kenya and Africa more broadly.
Dengue virus (DENV) is transmitted by mosquitoes and poses a significant public health risk, particularly in developing countries1,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2" title="Bhatt, S. et al. The global distribution and burden of dengue. Nature 496,