Seroepidemiological Mapping of Arboviral Co-Infections (Dengue, Chikungunya, Zika) in Febrile Patients Across Six Geopolitical Zones of Nigeria

Arboviral infections caused by dengue virus, chikungunya virus, and Zika virus frequently co-circulate in tropical regions where Aedes mosquito vectors are endemic, yet the concurrent epidemiology of these three arboviruses across Nigeria's six geopolitical zones remains poorly characterised. This study constructs a seroepidemiological map of dengue, chikungunya, and Zika co-infections among febrile patients presenting at sentinel health facilities in one urban and one rural site per geopolitical zone. A cross-sectional multisite design will recruit 1,800 febrile patients over 18 months. Serum samples will be tested for dengue NS1 antigen, anti-dengue IgM and IgG, anti-chikungunya IgM and IgG, and anti-Zika IgM using validated ELISA platforms, with flavivirus cross-reactivity resolved through plaque reduction neutralisation testing. Entomological surveys will characterise Aedes vector density at each site, and geographic information system tools will be employed to map seropositivity clusters. This study addresses a critical evidence gap: most Nigerian arboviral serosurveys have examined single pathogens in single states, leaving co-circulation dynamics and geographic variation entirely unmapped. Multivariable logistic regression will identify demographic, environmental, and occupational predictors of each arboviral infection. Findings will provide a national arboviral co-infection baseline to guide the NCDC's Arboviral Reference Laboratory in developing integrated surveillance protocols and targeted vector control programmes. Keywords: dengue, chikungunya, Zika, co-infection, seroepidemiological mapping