Molecular detection of dengue virus from febrile patients in Ghana

Viral hemorrhagic fevers (VHFs) belong to a group of viral infectious diseases that interfere with the blood's clotting mechanism. VHF has a wide host range, including bats, rodents, or arthropods such as mosquitoes and ticks. Most VHFs emerge suddenly as outbreaks, making it difficult to predict occurrence. To be responsive to such outbreaks, the Noguchi Memorial Institute for Medical Research (NMIMR) provides high-end molecular and genomic diagnostics capability for surveillance of suspected VHFs in samples collected from health facilities across the country.

Between January 2022 and December 2023, cross-sectional surveillance for viruses was conducted in patients with suspected VHF. During the period, 2586 serum or plasma samples were collected and transported under a cold chain to the NMIMR for testing. The samples were analyzed for potential VHF viruses including yellow fever, Ebola/Marburg, Lassa fever, and Dengue viruses using Real-Time Polymerase Chain Reaction Assay. Dengue positives were serotyped using the protocol of Johnson W.B et al.,2005. Whole genome sequencing was conducted using Illumina Next Generation Sequencing Technology. Using IQ-TREE, a maximum likelihood phylogenetic analysis was carried out.

Dengue virus (DENV) was detected in eight patient samples that subtyped to serotypes 1, 2, and 3. All dengue fever cases were resident in the Greater Accra region. The detection of serotype one increases the possibility of multiple infections in individuals and may have a worse or increased risk of severe dengue fever. Phylogenetic analysis revealed that the DENV-1 strain shared similarities to circulating strains in West Africa.

Until the emergence of recent cases, the circulating subtype has been serotyped as Dengue one. There is therefore the need to intensify surveillance and also to control the mosquito vectors which can transmit these DENV in Ghana.