Dengue among febrile patients in Ghana: prevalence and facility-level variation in a multisite surveillance study

Introduction: Dengue is under-recognized in Ghana, where laboratory testing is limited. We estimated dengue NS1 and/or IgM positivity among febrile patients and described geographical, temporal, and demographic variation. Methodology: We conducted cross-sectional surveillance among consenting febrile patients aged ≥1 year at six public facilities in Greater Accra, Bono East, and Upper West between August 2023 and July 2025. We randomly selected one region within each of three ecological strata and selected facilities with high febrile-case volumes. We approached and recruited consecutive eligible patients. We tested serum for dengue NS1 antigen and IgM antibody by ELISA; positive NS1 samples underwent RT-PCR and serotyping. We estimated proportions with 95% confidence intervals (CI) and used logistic regression to examine adjusted associations. Results: Among 2,936 participants, 204 were NS1- and/or IgM-positive (6.95%; 95% CI, 6.05-7.93%): 31 were NS1-only, 161 IgM-only, and 12 dual-positive. Prevalence ranged from 3.88% (95% CI, 2.19-6.31%) at Kintampo to 12.32% (9.56-15.55%) at Atebubu, both in Bono East. Adjusted odds increased with age (aOR per five years, 1.09; 95% CI, 1.05-1.14). Eight of 43 NS1-positive samples contained dengue RNA: five DENV-1 from Bono East and three DENV-3 from Upper West. There was no clear rainy-dry season difference. Conclusions: Dengue NS1 and/or IgM were detected among febrile patients at all six facilities, and RT-PCR confirmed circulation of DENV-1 and DENV-3. These findings support including dengue in febrile illness evaluation and strengthening laboratory-supported surveillance in Ghana. Keywords: dengue, febrile illness, NS1 antigen, IgM, DENV-1, DENV-3, Ghana