Phylogeographic analysis of dengue virus serotype 1 and Cosmopolitan serotype 2 in Africa
Published in International Journal of Infectious Diseases, 2023
Abstract
Background
The origin and spread of dengue virus (DENV) circulating in Africa remain poorly characterized, with African sequences representing <1% of global sequence data.
Methods
Whole genome sequencing was performed on serum samples (n=29) from an undifferentiated fever study in 2016 in the Democratic Republic of Congo (DRC), and from febrile travelers returning from Africa. The evolutionary history of the newly acquired African DENV-1 (n=1) and Cosmopolitan genotype DENV-2 (n=18) genomes, was reconstructed using a phylogeographic, time-scaled Bayesian analysis on a curated DENV panel including all known African sequences.
Results
A minimum of 10 and 8 introductions could be identified into Africa for respectively DENV-1 and Cosmopolitan DENV-2, almost all originating from Asia. Three introductions were previously unknown. The currently circulating virus comprises mainly recently introduced clades and one long-established, African clade. Robust geographical clustering suggests limited spread of DENV after each introduction. Our data identified the DRC as the source of the 2018 Angolan DENV-2 epidemic, and similarly, the 2013 Angolan DENV-1 outbreak as the origin of our DRC study.
Conclusion
Active genomic surveillance of DENV in Africa at the portals of entry might help early outbreak response, and limit sero- and genotype spread and human disease burden.