Supporting elimination of lymphatic filariasis in Samoa by predicting locations of residual infection using machine learning and geostatistics.
The global elimination of lymphatic filariasis (LF) is a major focus of the World Health Organization. One key challenge is locating residual infections that can perpetuate the transmission cycle. We show how a targeted sampling strategy using predictions from a geospatial model, combining random forests and geostatistics, can improve the sampling efficiency for identifying locations with high infection prevalence. Predictions were made based on the household locations of infected persons identified from previous surveys, and environmental variables relevant to mosquito density. Results show that targeting sampling using model predictions would have allowed 52% of infections to be identified by sampling just 17.7% of households. The odds ratio for identifying an infected individual in a household at a predicted high risk compared to a predicted low risk location was 10.2 (95% CI 4.2-22.8). This study provides evidence that a 'one size fits all' approach is unlikely to yield optimal results when making programmatic decisions based on model predictions. Instead, model assumptions and definitions should be tailored to each situation based on the objective of the surveillance program. When predictions are used in the context of the program objectives, they can result in a dramatic improvement in the efficiency of locating infected individuals.
Operational research to develop an M&E strategy to guide triple drug stopping decisions for lymphatic filariasis in Samoa
What is the indicator(s) and accompanying M&E strategy that enables country programs to determine when the risk of ongoing transmission of lymphatic filariasis (LF) has been reduced so that triple drug therapy with ivermectin, diethylcarbamazine, and albendazoe (IDA) can be stopped with little risk of resurgence of transmission?
To develop an M&E strategy that enables Samoa’s LF elimination program to determine when the risk of ongoing transmission of LF has been reduced so that IDA can be stopped with little risk of resurgence of transmission
What is the effectiveness of appropriately dosed IDA in clearing Mf from Mf positive people who (i) reported taking IDA in August 2018, and (ii) did not report recently taking IDA?