Description of the design of a mixed-methods study to assess the burden and determinants of malaria transmission for tailoring of interventions (microstratification) in Ibadan and Kano metropolis

Abstract Introduction : Rapid urbanization in Nigerian cities may likely result in small-scale variation in malaria transmission with a higher malaria burden in informal settlements and slums. However, data is unavailable to quantify city-level variations in transmission risk and to inform selection of appropriate interventions. We are conducting field studies to understand how malaria risk varies at the smallest administrative units (wards) in two major Nigerian cities – Ibadan and Kano – to inform tailoring of interventions for cities in Nigeria’s National Malaria Strategic Plan. Methods and Analysis: This is a mixed-method research design involving qualitative and quantitative research methods. We will carry out formative qualitative studies to inform sampling strategies for formal settlements, informal settlements and slums and the design of survey questionnaires. Cross-sectional surveys will be conducted in the wet and dry seasons across wards in the study cities and within different settlement types at the household and health facility levels to map all-age and under-five malaria prevalence and evaluate related risk factors. A 12-month longitudinal study among children under the age of 10 years will provide information on malaria seasonality in the two cities and related factors. Entomological surveys will be undertaken for six months (three months in each season) per city to assess local transmission risk in both cities. Descriptive and regression analysis will be applied to study data to assess malaria prevalence, seasonality and related factors. Mathematical models of malaria transmission for each study ward will be developed based on study data to inform assessment of the impact of various intervention scenarios specified by the NMEP on malaria transmission. Conclusion The combination of various study types provide in-depth information useful for subcity tailoring of interventions in Nigeria