Soil-transmitted helminthiasis (STH)
About the disease
Soil-transmitted helminthiasis (STH) is a neglected tropical disease caused by parasitic intestinal worms. These parasites are spread through contact with soil contaminated with human feces, so STH commonly occurs in places with poor sanitation. As many as two billion people worldwide are at risk of infection, especially in Africa, Asia, and Central and South America. STH causes illness and malnutrition, and children with STH suffer from impaired growth and cognitive development.
Finding and fighting STH
STH can be controlled with mass drug administration for at-risk populations and prevention activities like improved sanitation and hygiene. Infection levels must be closely monitored to assess the impact of these interventions and guide control programs. However, current diagnostic methods are labor-intensive to perform in the field, and are not sensitive enough to detect low levels of infection, which will become more common as control efforts scale up.
Creating new diagnostics for STH
PATH is working with partners to accelerate the development of novel diagnostics to guide STH control programs. To date, we have:
- Collaborated with leading organizations in STH research and programming to develop target product profiles describing user needs and technical requirements for new diagnostics.
- Advanced development of highly sensitive, field-deployable nucleic acid amplification technology (NAAT)-based molecular diagnostic tool completed through alpha prototype, and an accompanying simple and affordable sample preparation protocol.
- Evaluated options such as recombinase polymerase amplification (RPA) and the potential of diagnosing STH through antigen detection in stool samples by assessing the feasibility of various biomarkers to detect STH.
- STH fact sheet
- STH business case
- STH diagnostic gap analysis
- STH target product profiles – MDA stopping decision use case
- General platforms
- Lateral flow test detecting antigen
- Field-deployable nucleic acid amplification test (NAAT)
Post-MDA surveillance use case
- Diagnostic tests to support late-stage control programs for schistosomiasis and soil-transmitted helminthiases
- Poster – Development of modified alkaline lysis-magnetic bead extraction of DNA for molecular diagnosis of soil-transmitted helminths from stool
- Poster – Recombinase polymerase amplification-based assays to diagnose soil-transmitted helminths in stool
This project is supported by grants from the Bill & Melinda Gates Foundation and the Department for International Development.
Tala de los Santos
Global Program Leader, Diagnostics