ZooTRIP. Zoonotic transmission of intestinal parasites: implications for control and elimination

Gut parasites, in particular parasitic worms, are extremely widespread in rural and poor urban areas of low and middle-income countries. Gut worms have chronic and often insidious effects on human health and child development including abdominal problems, anaemia, stunting and wasting. The spread of many gut worms involves a faecal-oral route: worm eggs are shed into the environment by human or animal defecation and individuals become infected through ingestion of these eggs, for example when children play in contaminated dirt. In other instances, infection occurs through ingestion of meat from infected animals. However, there is a poor understanding of the overall role played by animals in the spread of gut worms to humans. This information is very important in order to design effective and sustainable strategies for control of gut worms and ultimately to stop them infecting humans.

This project will take place in the Philippines where gut worm infections are widespread, particularly in rural communities. Backyard farming is extremely common, bringing people in close proximity to their livestock. In addition, the country has one of the highest rates of dog ownership in the world and there are many stray dogs and cats. Thus, there is likely significant transmission of gut worms from animals to people. The project will bring together a team of internationally respected researchers, with expertise in different disciplines, to assess the contribution of animals and environmental contamination to human gut worm infection in the Philippines. As a first step, a field study will be carried out in two distinct areas on the island of Mindanao to investigate gut worms circulating in humans, animals and the environment. For some gut worms it is difficult to determine whether they originated in animals or humans. Therefore DNA sequencing of gut worms collected in the Philippines will be carried out to identify genetic markers which can be used to distinguish between worms of human and animal origin and to detect their resistance to deworming drugs. This will allow genetic characterisation of gut worm samples collected during the field study. Mathematical models incorporating information from the field study and genetic data from the worm samples will then be developed to quantify the contribution of animals and environmental contamination to spread of gut worms to humans and predict the effects of different control strategies. Finally, an evaluation of the socio-economic and health impacts of gut worm infections in the Philippines will be conducted together with development of a set of recommendations for policy makers.

By embracing a One Health approach this project will shed new light on the epidemiology of gut worms in humans and animals in the Philippines and quantify the contribution of animals to human infection. Project findings will enable development of novel control strategies, leading to increased effectiveness and sustainability of gut worm control in the Philippines and worldwide, and ultimately to improvements in health in endemic areas. The assessment of socio-economic impacts of intestinal helminths in humans and animals will provide crucial evidence for policy-makers and funders.

This interdisciplinary project will assess the contribution of zoonotic transmission and environmental reservoirs to the burden of human intestinal helminth infection in the Philippines, and determine the most effective strategies for intestinal helminth control and elimination. Objective 1 will investigate the epidemiology of intestinal helminths circulating in humans, animals and the environment through a cross-sectional community-based field study, involving parasitological and molecular diagnosis of intestinal helminths in participants and their animals, detection of helminth eggs in soil and crop samples and a questionnaire to gather demographic, socio-economic and environmental data. Objective 2 will use genome sequencing to characterise Filipino helminth isolates, identify markers for molecular epidemiology and establish a multi-locus sequence typing scheme. Genotyping assays will be used to detect zoonotic transmission and anthelmintic resistance markers in samples collected during the field survey. Objective 3 will develop mathematical models to quantify the contribution of zoonotic transmission and environmental reservoirs to human infection risk and predict the effects of intervention strategies. Epidemiological and genetic data gathered under Objectives 1 and 2 will be used for model parameterisation. Objective 4 will formulate policy recommendations based on model outcomes and an evaluation of the socio-economic and health impacts of intestinal helminth infections in the Philippines. This will involve quantitative risks assessment, impact quantification and economic valuation of impacts. Overall the project will shed new light on the epidemiology of intestinal helminths in the Philippines and quantify the contribution of zoonotic transmission to human infection. Project findings will lead to increased effectiveness and sustainability of intestinal helminth control in the Philippines and worldwide, and ultimately to health improvements in endemic areas.

There will be a number of beneficiaries of this project:

Staff working on the project:
Project staff will have the opportunity to develop a range of scientific skills including epidemiological surveys, parasitological diagnosis, molecular diagnostics, genomics, bioinformatics, mathematical modelling, economic analysis. There will be significant strengthening of capacity in molecular biology at the Institute of Biological Sciences through establishment of a dedicated laboratory and provision of training in molecular biology and bioinformatics. In addition, staff will gain experience in logistics, project management, writing research publications and presenting research findings. There will be opportunities for student exchange between Philippines and the UK, and undergraduate and graduate students in the UK and Philippines will have their research projects affiliated with the project thereby introducing them first-hand to studies aimed at improving the welfare of humans and animals.

Public health officers and local health units:
During the course of the project, training and capacity development in control of intestinal helminths will be provided for public health officers and local health units. This will ultimately lead to improved control of intestinal helminths at a local level.

World Health Organization (WHO) and the Department of Health (DOH), Republic of the Philippines:
Through highlighting and recording the potential for zoonotic transmission and forecasting effective and cost-efficient management strategies, our findings will inform WHO and the DOH in development of national policies on control of intestinal helminths in the Philippines and, over the longer-term, in other countries. Possible changes to treatment and control policy could include improved hygiene and sanitation, improvements in livestock management practices and deworming of livestock and companion animals in endemic communities. This could ultimately lead to a reduction in the impact of intestinal helminthiasis worldwide.

People and animals in intestinal helminth-endemic communities in the Philippines/worldwide:
Study participants (humans and animals) will be examined for intestinal helminth infections and referred for treatment where appropriate. Information, engagement and feedback meetings will be held in the study communities to communicate the nature and purpose of the project, ongoing progress and research findings and to receive input and feedback from the communities. This will increase awareness of intestinal helminths, and provide a better road-to-health for such activated communities. Information, Education and Communication (IEC) materials will be developed based on feedback from local communities. More effective control of intestinal helminths will bring longer term benefits to their own future health and socio-economic status and that of others living in endemic communities.

ODA COMPLIANCE
Intestinal helminths are classified as neglected tropical diseases (NTDs), described as "poverty-promoting" due to their significant impacts on health, child development and agricultural productivity. Thus control of NTDs can improve economic development and welfare in endemic areas. In the Philippines >30 million children are infected with intestinal helminths. Through advances in understanding of intestinal parasite transmission dynamics and infection reservoirs and their socio-economic impacts, this project will provide a crucial evidence base for implementation of effective and sustainable parasite control. This will lead to improvements in human health and socio-economic development, particularly in poor and marginalized communities. At least half of the project will take place in the Philippines led by Filipino researchers. The project will involve a significant capacity-building component including training in cutting-edge laboratory and computational techniques.