Changing the Landscape of Soil Transmitted Helminth Infections in India Using a One Health Approach

Christian Medical College, Vellore

Investigators

Abstract

PROJECT SUMMARY Soil transmitted helminths (STH) - hookworms (Ancylostoma duodenale and Necator americanus), Ascaris lumbricoides and Trichuris trichiura - are among the most widespread neglected tropical diseases (NTD) of humans worldwide, disproportionately affecting the poorest and most vulnerable communities. In rural, populations, intensive animal-human mixing with livestock and companion animals combined with poor hygiene and sanitation can lead to transmission of zoonotic infections as well as result in zoonotic sources of infection. It is estimated that 30% of households globally have domestic livestock animals, with south and southeast Asia and Africa contributing the largest proportion. These regions also have the highest burden of STH globally. Most epidemiological surveys and mathematical models of STH do not account for or measure the risk of infections acquired from zoonotic sources, either by direct contact with animals or animal feces or indirectly from the environment. The inability to interrupt transmission due to presence of zoonotic and environmental reservoirs of infection may prolong mass drug administration (MDA) campaigns and result in emergence of anthelmintic resistance. The overarching goal of this multi-disciplinary collaborative application is to use a One Health framework to examine the interconnected burden and transmission patterns between human, animal and environmental reservoirs of STH by integrating carefully collected epidemiological, environmental and qualitative research data with state-of-art molecular techniques to better inform monitoring and elimination strategies in endemic communities. We will leverage an ongoing randomized controlled trial on community wide MDA and an upcoming One Health project in two eco-epidemiologically and culturally distinct geographic regions of India (Tamil Nadu and Meghalaya) to: (1) comprehensively investigate the transmission dynamics of different STH species at individual, household and community levels; (2) ascertain the impact of community wide MDA on zoonotic STH transmission and screen for emergence of benzimidazole resistance markers; and (3) develop and validate field-ready, portable point-of-collection (POC) diagnostics for STH based on prevalent human and zoonotic species. The field and laboratory data will provide the key parameters to build species-specific STH transmission models and explore the impact of human, animal and environmental reservoirs on STH control measures, across a range of transmission scenarios. The One Health framework of this TMRC will provide much needed data for future planning of integrated STH control programs that combine community wide MDA with upgraded WASH, supported by POC molecular diagnostics. The center will provide a platform for early career investigators to conduct multi- disciplinary One Health research on STH as well as other zoonotic or helminth NTDs.