Molecular Detection and Characterization of Dengue Virus Serotypes in Febrile Patients Presenting at Tertiary Hospitals in Plateau State

Dengue fever is an emerging arbovirosis in Nigeria with significant under-diagnosis due to its clinical resemblance to malaria and typhoid fever and the absence of routine molecular diagnostic services in most tertiary facilities. This prospective analytical study molecularly detected and characterized dengue virus serotypes among febrile patients presenting at Jos University Teaching Hospital, Plateau State, in the North Central geopolitical zone of Nigeria. Blood samples from 250 febrile patients who tested negative for malaria and typhoid by conventional diagnostics were processed. Dengue non-structural protein 1 (NS1) antigen was detected by ELISA, and dengue-positive samples underwent RT-PCR followed by serotype-specific PCR using established primers. Dengue seropositivity by NS1 antigen was 12.4 percent. RT-PCR confirmed dengue in 10.8 percent of enrolled patients. Dengue virus serotype 2 (DENV-2) was the most prevalent at 55.6 percent, followed by DENV-3 at 29.6 percent. Co-circulation of two serotypes was detected in 11.1 percent of positive cases. Clinical severity analysis revealed dengue hemorrhagic fever presentation in 22 percent of confirmed cases. Aedes aegypti density surveys conducted concurrently indicated high vector indices in Jos urban areas. These results confirm active multi-serotype dengue transmission in Plateau State and advocate for inclusion of dengue in differential diagnostics for febrile illness, enhanced Aedes control, and establishment of national dengue surveillance. Keywords: dengue virus, serotypes, febrile illness, Plateau State, molecular detection.