The First Biological Validation of Taenia solium Risk Assessment Tools

Taenia solium places substantial burden on communities in low and middle-income countries, where neurocysticercosis is a leading cause of preventable epilepsy. Current diagnostic tests for T. solium are not suited for low resource settings or perform poorly. Several risk-assessment tools have been developed to support countries in identifying areas for further T. solium investigation and intervention. These tools are based on risk, rather than disease data, and have yet to be validated against biological results.

Two national quantitative risk-assessment tools (LISA and MCDA), two local semi-quantitative tools (rapid and in-depth), and a local qualitative tool (workshop) had their performance assessed against biological T. solium taeniasis data from 28 villages. The final risk category, risk score and individual components of each tool were assessed independently against village T. solium status by logistic regression.

T. solium positive villages had higher odds of being high-risk villages for all tools, however, this was only significant for the LISA and workshop tools. For the LISA tool, the median risk score was also significantly greater in positive villages. A unit increase in LISA risk score led to a significant increase in the odds of a village being positive for T. solium. Other tools that calculated risk scores also showed similar results, however, were not statistically significant. All positive villages were hotspots for unimproved toilets by the LISA tool. The open defaecation component of the local rapid tool was the only component of any tool to demonstrate a significant relationship with positive T. solium villages.

This first biological validation of T. solium risk-assessment tools demonstrates that there are multiple tools that should be considered for further development. Supporting endemic countries to implement recently developed risk-assessment tools is consistent with the World Health Organization's goal of intensified control of T. solium in hyperendemic areas.