Seroprevalence of Zika Virus Among Pregnant Women in Imo State

Zika virus (ZIKV), a flavivirus transmitted by Aedes mosquitoes, gained global attention following its association with microcephaly and congenital abnormalities during the 2015 to 2016 Brazilian epidemic. In Nigeria, where Aedes aegypti is hyperendemic and antenatal surveillance for arboviral infections is limited, the risk to pregnant women remains poorly quantified. This study determines the seroprevalence of anti-Zika IgG and IgM antibodies among pregnant women attending antenatal care at the Federal Medical Centre, Owerri, Imo State, South East Nigeria. A cross-sectional design will enrol 300 pregnant women in their first trimester over eight months. Serum samples will be tested using ZIKV-specific ELISA, with flavivirus cross-reactivity assessed through dengue IgG confirmatory testing. Demographic, obstetric, and mosquito exposure data will be collected via structured interview. Neonatal head circumference records will be reviewed for women delivering during the study period. Recent serological surveys from southern Nigeria have detected anti-ZIKV antibodies in 4 to 12 percent of sampled populations, suggesting ongoing low-level transmission. Findings will characterise ZIKV exposure in Imo State's antenatal population, informing obstetricians and public health authorities about the risk of congenital Zika syndrome and supporting the case for Zika surveillance integration into Nigeria's antenatal care package. Keywords: Zika virus, seroprevalence, pregnant women, Imo State, congenital syndrome