Field assessment of the burden and determinants of malaria transmission to inform tailoring of interventions (microstratification) in Ibadan and Kano metropolis: Study protocol

Abstract

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 used to undertaken for eight months (four 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. Ethics and Dissemination This protocol has been approved by Nigeria’s National Health Research Committee and relevant institutional Ethical Review Committees. Study results will be disseminated to key stakeholders and study communities. Strength and Limitations Strengths Cross-sectional and longitudinal study sampling procedures and questionnaire design are enhanced by a strong formative research foundation Study design and site selection are informed by modeling and local knowledge The combination of human and vector studies will provide detailed information on malaria transmission risk and associated drivers Limitations Cross-sectional study may not be powered to measure all-age prevalence as sample size estimation is based on prevalence among children under the age of five years Study findings may not adequately measure transmission burden and risk factors in unsampled wards