A Practical Approach for Geographic Prioritization and Targeting of Insecticide-Treated Net Distribution Campaigns During a Public Health Emergency

Abstract BackgroundThe use of data in targeting of malaria control efforts is becoming increasingly adopted by national malaria control programmes and is essential for optimal use of resources. This is especially important during public health emergencies such as the COVID-19 pandemic which resulted in reallocation of funding towards containment efforts. This work provides a practical mechanism for prioritizing geographical areas for insecticide-treated net (ITN) distribution during a public health emergency or situations of limited resources. We adopt a GIS-based weighted approach to categorize and rank administrative units based on data inputs that are widely available and can be applied in various country contexts where Plasmodium falciparum transmission is reported. MethodsP. falciparum-specific intervention and prevailing risk factors were used to rank administrative units in Nigeria for prioritization during ITN distributions. Each factor was assigned a unique weight and was multiplied by a value, typically ranging from 1 to 4, based on natural groupings inherent in the data, or the presence or absence of a given intervention. Risk scores for each factor were then summated to generate a composite unique risk score for each administrative unit. This risk score was then translated into a prioritization map which ranks each administrative unit from low to high priority in terms of ITN distribution targeting in situations of limited resources. ResultsA major component that influenced the prioritization scheme was previous ITN depth of coverage, as obtained and spatially interpolated from DHS survey data. The geospatial heterogeneity found among input risk factors suggests that a range of variables and covariates — outside of those that characterize malaria transmission exclusively — should be considered when using data to inform ITN distributions. The approach resulted in identification of regions that should be prioritized in upcoming ITN distributions. ConclusionThe presented approach provides a tool for prioritizing regions for ITN distributions. It serves as a base upon which a wider range of vector control interventions could be targeted. Its value added can be found in its potential for application in multiple country contexts, expediated timeframe for producing outputs, and its use of systematically collected malaria indicators in informing prioritization.