Schistosomiasis Seroprevalence among Children Aged 0–14 Years in Nigeria, 2018

Abstract

ABSTRACT. The first nationally representative, population-based study of schistosomiasis seroprevalence in Nigeria was conducted using blood samples and risk-factor data collected during the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). Schistosomiasis seroprevalence was estimated by analyzing samples for reactivity to schistosome soluble egg antigen (SEA) in a multiplex bead assay; NAIIS survey data were assessed to identify potential risk factors for seropositivity. The SEA antibody data were available for 31,459 children aged 0 to 14 years. Overall seroprevalence was 17.2% (95% CI: 16.3–18.1%). Seropositive children were identified in every age group, including children < 5 years, and seroprevalence increased with increasing age (P < 0.0001). Several factors were associated with increased odds of seropositivity, including being a boy (odds ratio [OR] = 1.34, 95% CI: 1.24–1.45), living in a rural area (OR = 2.2, 95% CI: 1.9–2.5), and animal ownership (OR = 1.67, 95% CI: 1.52–1.85). Access to improved sanitation and drinking water sources were associated with decreased odds of seropositivity (OR = 0.52, 95% CI: 0.47–0.58 and OR = 0.53, 95% CI: 0.47–0.60, respectively) regardless of whether the child lived in a rural (sanitation: adjusted odds ratio [aOR] = 0.7, 95% CI: 0.6–0.8; drinking water: aOR = 0.7, 95% CI: 0.6–0.8) or urban area (sanitation: aOR = 0.6, 95% CI: 0.5–0.7; drinking water: aOR = 0.5, 95% CI: 0.4–0.6), highlighting the importance of these factors for schistosomiasis prevention and control. These results identified additional risk populations (children < 5 years) and a new risk factor (animal ownership) and could be used to monitor the impact of control programs.