Schistosomiasis, also known as Bilharzia, is a chronic, debilitating disease second only to malaria among human parasites in its socio-economic and public health importance. Over 206 million people are infected, of whom 97% live in Africa. The Schistosomiasis Control Initiative (SCI) was established in 2002 and capitalizing on Uganda'Âs already detailed national surveys, rolled out its first large-scale praziquantel (PZQ) treatment programme there in 2003.
My PhD research focused on the effect of PZQ on Schistosoma mansoni in natural and experimental settings in Uganda, starting in Oct 2003. Costs associated with PZQ-resistance were identified and parasite genetic and phenotypic variation in response to chemotherapy observed. After my PhD I carried out multi-locus genotyping on S. mansoni miracidia from Uganda, to analyse parasite diversity, heterozygosity and population structure and how they alter over time with PZQ exposure. Early research carried out during my PhD, contributed to the paper ÂDevelopment and application of an ethically and epidemiologically advantageous assay for the multi-locus microsatellite analysis of Schistosoma mansoniÂ which was awarded the 2007 parliamentary 3RÂs prize for the replacement, refinement and reduction of animals in research. It is this population genetics research which I am building and expanding on during my current Fellowship.
During my fellowship I have become more involved in diagnostic techniques for schistosomiasis and soil-transmitted helminths. This has resulted in a few papers recently published and some invited reviews. In addition, one of my BSc Global Health students from 2013 won a Global Health Innovation Award of £5000 to continue her work into LAMP based diagnositcs for S. mansoni.
During my current fellowship I have formed new collaborations with partners at the University of Khon Kaen, University of Mahidol and Phramongkutklao College of Medicine in Thailand to work on Opisthorchis viverrini. We are investigating the effect of geographic distribution on parasite population diversity in cercariae, and the effect parasite population genetic factors in association with host morbidity indicators.
From 2009 to 2012 I was a Research Associate in the Department of Infectious Disease Epidemiology working on a Wellcome Trust funded project investigating the effect of ÂDensity-dependent host choice by onchocerciasis vectorsÂ. With the World Health Organization (WHO) identifying some vector borne diseases (VBDs) as potentially eliminable / eradicable (e.g., onchocerciasis, lymphatic filariasis, schistosomiasis), it is timely to evaluate whether current transmission dynamics and control models for such diseases will usefully guide intervention programmes towards their projected endpoints. In order to attain their goals, interventions may have to implement vector control in addition to drug treatment. Our key aims are to quantify the effects that vector and host densities may have on vector host choice as measured by the proportion of human bloodmeals in transmission models of VBDs using field, laboratory, and theoretical approaches that will enhance understanding of VBD transmission dynamics.
Human onchocerciasis, commonly known as River Blindness is endemic in 34 countries, despite some control efforts now spanning into their fourth decade. My research activities currently involve extensive epidemiological field data and sample collection from five regions of Ghana and novel molecular techniques for the identification of the vector species, parasite infection and previous host bloodmeal species. We are using these data to help us understand density-dependent processes involved in the transmission dynamics of Onchocerca volvulus with the results being used to parameterise mathematical models of onchocerciasis transmission and control. These models will then inform us on the relative merits of complementing antiparasitic strategies with vector control and/or manipulation of alternative hosts abundance (zooprophylaxis).
The effect of mass drug administration on Schistosoma mansoni infections in Uganda, Royal Veterinary College, Hawkshead Campus, 2015
The effect of mass drug administration on S. mansoni phenotype and genotype, University of Khon Kaen, Thailand, 2015
Understanding the effects of on-going mass drug administration on neglected tropical diseases, University of Glasgow, UK, 2014
Using parasite population genetics to understand transmission dynamics in neglected tropical diseases, University of Oxford, UK, 2014
Using parasite population genetics to understand transmission dynamics in neglected tropical diseases, University of Warwick, UK, 2014
Onchocerciasis transmission with ivermectin treatment: How long is mass drug administration needed?, Liverpool School of Tropical Medicine, UK, 2013
The molecular epidemiology of schistosome species and the monitoring of genetic change under community based treatment., Launch of the London Centre for Neglected Tropical Disease Research, London School of Hygiene and Tropical Medicine, UK, 2013
Onchocerciasis transmission in Ghana: How long will treatment with ivermectin be needed?, Fiocruz Amazonas, Manaus, Brazil, 2012
Challenges for vector-borne disease mathematical models -density-dependent host choice by onchocerciasis vectors, British Society for Parasitology, Nottingham, 2011
Benefits of data sharing, Dryad UK: a repository for data linked to bioscience research articles, London, UK, 2010