The main focus of my research is utilising field epidemiological data, laboratory experiments and population genetics to understand population structure, transmission dynamics and effects of long term mass drug administration programmes on neglected tropical diseases (NTDs) such as schistosomiasis, soil-transmitted helminths, opisthorchiasis and onchocerciasis.
I am currently funded by a five year (2016-2021) European Research Council Starting Grant, held at The University of Glasgow, investigating ‘New approaches to characterise Schistosoma mansoni infections persisting despite mass drug administration’.
My research focuses on how best to optimise individual treatment success as well as how best to reduce transmission in high endemicity areas.
This research builds on the findings of my Research Fellowship, held at Imperial College London from 2012-2015, where I identifed hotspots of high Schistosoma mansoni transmission and infection levels in Uganda despite over a decade of mass drug administration. I aim to increase understanding of how to prevent or at least slow the spread of PZQ resistance, and maximise treatment sucess at individual and community levels.
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’s 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. I was supervised by Prof. Joanne P. Webster and Prof. Sir Roy M. Anderson and completed my PhD entitled ‘Adaptation and evolution of Schistosoma mansoni in response to chemotherapeutic pressures’ in 2007. 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 ‘Development and application of an ethically and epidemiologically advantageous assay for the multi-locus microsatellite analysis of Schistosoma mansoni’ which was awarded the 2007 parliamentary 3R’s prize for the replacement, refinement and reduction of animals in research. This population genetics research was expanded on during my Fellowship, and will continue to be incorporated in my current research on transmission hotspots. During my fellowship I became more involved in diagnostic techniques for schistosomiasis and soil-transmitted helminths and this is a key focus of my current research.
During my Fellowship, at Imperial College from 2012 - 2015 I 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 with Prof. Maria-Gloria Basáñez, with whom I still work closely, on a Wellcome Trust funded project investigating the effect of ‘Density-dependent host choice by onchocerciasis vectors’. 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).
Before starting my PhD at Imperial College London I worked as a research assistant at the Zoology Department of The University of Oxford, investigating the influence of anti-psychotic drugs on Toxoplasma gondii’s ability to alter its’ rodent hosts behaviour. Prior to this I completed my Biological Sciences undergraduate degree at Pembroke College, University of Oxford in 2002.
I have a keen interest in public outreach and have taken part in Science Uncovered, and Nature Live interviews at the Natural History Museum, London as well as giving talks at secondary schools and mentoring local school children.
I co-supervised a PhD student Dr Maya Kaushik whose thesis is entitled ‘The effect of parasites on host behaviour: studies on epidemiology, evolution and mechanisms of action’. Our research primarily focused on the parasite Toxoplasma gondii and the role of dopamine and/or therapeutic treatment on the parasites ability to affect host behaviour.
At the start of my Fellowship I took over the co-supervision of a PhD student, Ms Rita Oliveira, now in her third year, researching 'Age-distribution implications in dynamics and control of soil-transmitted helminths'. Rita's work incorporates data and sample collection field trips in collaboration with KEMRI in Kenya, and immunological analyses of blood samples with Chris Drakeley's group in the London School of Hygiene and Tropical Medicine.
I lecture on the MSC in Modern Epidemiology run by the School of Public Health and the Biology BSc module in Epidemiology run by the Department of Life Sciences. I also lecture on Imperial College’s short course, Introduction to Mathematical Models of the Epidemiology & Control of Infectious Diseases, a highly successful intensive 2 week course aimed at public health professionals, policy-makers and researchers.
I have co-supervised several student projects from the BSc Global Health course over the years and have superised three UROP summer placement students.
Lamberton PHL, Jourdan PM, 2015, Human Ascariasis: Diagnostics Update, Current Tropical Medicine Reports, Vol:2, ISSN:2196-3045, Pages:189-200
et al., 2015, Onchocerciasis Transmission in Ghana: Persistence under Different Control Strategies and the Role of the Simuliid Vectors, PLOS Neglected Tropical Diseases, Vol:9, ISSN:1935-2735
et al., 2015, Modelling the Effects of Mass Drug Administration on the Molecular Epidemiology of Schistosomes, Advances in Parasitology, Vol:87, ISSN:0065-308X, Pages:293-327
et al., 2014, Onchocerciasis transmission in Ghana: biting and parous rates of host-seeking sibling species of the Simulium damnosum complex, Parasites & Vectors, Vol:7, ISSN:1756-3305
et al., 2014, Sensitivity and Specificity of Multiple Kato-Katz Thick Smears and a Circulating Cathodic Antigen Test for Schistosoma mansoni Diagnosis Pre- and Post-repeated-Praziquantel Treatment, PLOS Neglected Tropical Diseases, Vol:8, ISSN:1935-2735
et al., 2010, In Vitro Praziquantel Test Capable of Detecting Reduced In Vivo Efficacy in Schistosoma mansoni Human Infections, American Journal of Tropical Medicine and Hygiene, Vol:83, ISSN:0002-9637, Pages:1340-1347
et al., 2009, Evaluation and application of potential schistosome-associated morbidity markers within large-scale mass chemotherapy programmes, Parasitology, Vol:136, ISSN:0031-1820, Pages:1789-1799