Poverty and neglected tropical diseases in Nigeria: a quantitative geospatial assessment at the sub-national level.

Neglected tropical diseases (NTDs) and poverty are commonly associated in NTD literature despite not necessarily having quantifiable evidence of such an association. Quantifying the association at a sub-national level could lead to more informed and thus effective public health policy and disease intervention programming. Objectives:The objectives of this study were to spatially visualize and quantify the relationship between poverty and trachoma, lymphatic filiriasis (LF) and cumulative soil-transmitted helminth (STH) infection prevalence in Nigeria at the sub-national level. Methods:Poverty and NTD data were visualized using ArcMAP. ArcMAP was also employed to extract data from each spatial layer to tables then exported and analyzed in SAS. Multicollinearity was assessed for each model then multiple linear regression was performed for the association between poverty and LF and STH, while logistic regression was performed for poverty and trachoma. A two-sample t-test was also conducted for assessing the poverty-trachoma relationship. Results:A sub-national, geospatial assessment of the association between poverty and each NTD revealed positive estimates of association, however they were very imprecise and non-significant. The results of this analysis fail to reject the null hypothesis of no association between poverty and each NTD. Conclusions:There were many limitations to this analysis thus it is important not to interpret the results as confirmation of a null association. Limitations arose from incomplete and non-representative small area NTD data for Nigeria and highlighted the difficulties of performing spatial analysis in low-resource settings. These results also shed light on the importance of representative sub-national data for the investigation of intra-country variation in the relationship between poverty and NTD prevalence. Future work should include a reevaluation of the spatial infrastructure of NTD surveillance to include improved, temporally-relevant small area NTD surveillance. Improving small area NTD surveillance is necessary for characterizing, monitoring and intervening on NTD transmission.