Alan Fenwick

• PhD
• Professor at Imperial College London

Background Soil-transmitted helminth (STH) control programs currently lack evidence-based recommendations for cost-efficient survey designs for monitoring and evaluation. Here, we present a framework to provide evidence-based recommendations, using a case study of therapeutic drug efficacy monitoring based on the examination of helminth eggs in sto...

Background: Soil-transmitted helminth (STH) control programs currently lack evidence-based recommendations for cost-efficient survey designs for monitoring and evaluation. Here, we present a framework to provide evidence-based recommendations, using a case study of therapeutic drug efficacy monitoring based on the examination of helminth eggs in st...

Background: Childhood anaemia affects 1.8 billion people globally. Little is known about the long-term impact of mass drug administration (MDA) for the control of soil-transmitted helminthiases (STH) on the spatiotemporal variation of anaemia prevalence and severity. We describe the long-term spatiotemporal impact of a 5-year STH MDA programme (20...

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

Background Schistosomiasis is a parasitic disease caused by trematode worms of the genus Schistosoma and belongs to the neglected tropical diseases. The disease has been reported in 78 countries, with around 290.8 million people in need of treatment in 2018. Schistosomiasis is predominantly considered a rural disease with a subsequent focus of rese...

The history of the neglected tropical disease movement is seen through the lens of authors who worked during the last 4 decades in different roles and in different settings, from Western-based laboratories to clinical roles in endemic countries and in critical policy roles in the World Health Organization (WHO). The authors seek to identify key pla...

Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinated a five-year study implemented in several countries, including Niger, to provide an evidence-base for programmatic decisions regarding cost-effective approaches to preventive chemotherapy for schistosomiasis control. Methods This was a cluster-rand...

Background: An accurate understanding of the geographical distributions of both soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and the hookworms Necator americanus and Ancylostoma duodenale) and schistosomes (SCH; Schistosoma mansoni and S. haematobium) is pivotal to be able to effectively design and implement mass dr...

[This corrects the article DOI: 10.1371/journal.pntd.0007025.].

Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinated a five-year study implemented in several countries, including Niger, to provide an evidence-base for programmatic decisions regarding cost-effective approaches to preventive chemotherapy for schistosomiasis control. Methods This was a cluster-rando...

This report summarizes the design and outcomes of randomized controlled operational research trials performed by the Bill & Melinda Gates Foundation-funded Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) from 2009 to 2019. Their goal was to define the effectiveness and test the limitations of current WHO-recommended schis...

Background: Schistosomiasis and infection by soil-transmitted helminths are some of the world's most prevalent neglected tropical diseases. Infection by more than one parasite (co-infection) is common and can contribute to clinical morbidity in children. Geostatistical analyses of parasite infection data are key for developing mass drug administra...

Background: The geographical distributions of both soil-transmitted helminths (STHs; Ascarislumbricoides, Trichuristrichiura, and the hookworms (Necatoramericanus and Ancylostomaduodenale) and schistosomes (SCH; Schistosomamansoni and S. haematobium) are pivotal to be able to effectively design and implement mass drug administration (MDA) programs....

Background : An accurate understanding of the geographical distributions of both soil-transmitted helminths (STHs; Ascaris lumbricoides , Trichuris trichiura , and the hookworms ( Necator americanus and Ancylostoma duodenale ) and schistosomes (SCH; Schistosoma mansoni and S. haematobium ) is pivotal to be able to effectively design and implement m...

Background: An accurate understanding of the geographical distributions of both soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and the hookworms (Necator americanus and Ancylostoma duodenale) and schistosomes (SCH; Schistosoma mansoni and S. haematobium) is pivotal to be able to effectively design and implement mass dr...

Background: An accurate understanding of the geographical distributions of both soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and the hookworms Necator americanus and Ancylostoma duodenale) and schistosomes (SCH; Schistosoma mansoni and S. haematobium) is pivotal to be able to effectively design and implement mass dru...

Background Schistosomiasis is a neglected tropical disease caused by Schistosoma parasites. Intervention relies on identifying high-risk regions, yet rapid Schistosoma diagnostics (Kato-Katz stool assays (KK) and circulating cathodic antigen urine assays (CCA)) yield different prevalence estimates. We mapped S. mansoni prevalence and delineated at-...

Background: Schistosomiasis is one of the neglected tropical diseases endemic to Mali. There has been insufficient investigation of the morbidity burden in highly endemic irrigated rice areas with the ongoing mass drug administration with praziquantel. In February 2005, a year after an initial mass drug administration in 2004, we performed the fir...

Soil-transmitted helminth (STH) infections are globally distributed intestinal parasite infections caused by Ascaris lumbricoides, Trichuris trichiura, and hookworms (Ancylostoma duodenale and Necator americanus). STH infection constitutes a major public health threat, with heavy burdens observed in many of the world’s tropical and subtropical regi...

Background A pioneering strategy developed by the World Health Organization (WHO) for the control of schistosomiasis was the concept of a height-based dose pole to determine praziquantel (PZQ) dosing in large-scale treatment campaigns. However, some recent studies have shown variable accuracy for the dose pole in terms of predicting correct mg/Kg d...

Background Kato-Katz examination of stool smears is the field-standard method for detecting Schistosoma mansoni infection. However, Kato-Katz misses many active infections, especially of light intensity. Point-of-care circulating cathodic antigen (CCA) is an alternative field diagnostic that is more sensitive than Kato-Katz when intensity is low, b...

Background: The results presented here are part of a five-year cluster-randomised intervention trial that was implemented to understand how best to gain and sustain control of schistosomiasis through different preventive chemotherapy strategies. This paper presents baseline data that were collected in ten districts of Cabo Delgado province, northe...

Background In Mozambique, schistosomiasis is highly endemic across the whole country. The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinates a five-year study that has been implemented in various African countries, including Mozambique. The overall goal of SCORE was to better understand how to best apply preventi...

Background The development of new diagnostics is an important tool in the fight against disease. Latent Class Analysis (LCA) is used to estimate the sensitivity and specificity of tests in the absence of a gold standard. The main field diagnostic for Schistosoma mansoni infection, Kato-Katz (KK), is not very sensitive at low infection intensities....

R2OpenBUGS code used to run the model. (DOCX)

Cote d’Ivoire data. (CSV)

Detailed methodology of Bayesian latent class analysis. (DOCX)

Infection category cross tab. CCA results by WHO Kato-Katz infection category in each country. (DOCX)

Participant flow diagram. (PDF)

Summary of S. haematobium infection rates for each study year and study arm (9-to-12-year-old cross section only). Village-level S. haematobium prevalence, prevalence of heavy infection, and mean intensity for each study year from baseline to Year 5, by study arm among 9-12-year old cross section only. (TIFF)

GEE logistic model to assess differences in prevalence and intensity of S. haematobium infection between four versus two rounds of treatment in 9-12-year olds. (TIFF)

Prevalence of S. haematobium by individual villages over time by study arm. Prevalence of S. haematobium by individual villages, shown by different coloured points, over time by study arm. The black line is the mean village prevalence, by study arm, at each year. In treatment holidays shown in Arms 3, 5 and 6, there was no data collected and theref...

Spatial clusters of high prevalence villages calculated in SatScan. Spatial clusters of high prevalence villages calculated in SatScan show a decrease in the number of disease clusters from baseline (Year 1) to Year 5, and the spatial extent of disease became less scattered over time. Each point represents an individual village whereby all communit...

GEE prevalence- and intensity-adjusted parameter estimates (9-12-year olds only). (TIFF)

GEE logistic model to assess differences in prevalence and intensity of S. haematobium infection in first-year students only. (TIFF)

Background In Mozambique, schistosomiasis is highly endemic across the whole country. The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinates a five-year study that has been implemented in various African countries, including Mozambique. The overall goal of SCORE was to better understand how to best apply preventi...

Information, behaviors, and technologies spread when people interact. Understanding these interactions is critical for achieving the greatest diffusion of public interventions. Yet, little is known about the performance of starting points (seed nodes) for diffusion. We track routine mass drug administration—the large-scale distribution of deworming...

Schistosomiasis, one of the 17 neglected tropical diseases listed by the World Health Organization, presents a substantial public health and economic burden. Of the 261 million people requiring preventive chemotherapy for schistosomiasis in 2013, 92% of them lived in sub-Saharan Africa and only 12.7% received preventive chemotherapy. Moreover, in 2...

Information, behaviours, and technologies spread when people interact. Understanding these interactions is critical for achieving the greatest diffusion of public interventions. Yet, little is known about the performance of starting points (seed nodes) for diffusion. We track routine mass drug administration—the large-scale distribution of dewormin...

Background Investigating the effect of successive annual deworming rounds on the spatiotemporal distribution of infection prevalence and numbers at risk for soil-transmitted helminths (STHs) can help identify communities nearing elimination and those needing further interventions. In this study, we aim to quantify the impact of an 8-year mass drug...

Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) focus is on randomized trials of different approaches to mass drug administration (MDA) in endemic countries in Africa. Because their studies provided an opportunity to evaluate the effects of mass treatment on Schistosoma-associated morbidity, nested cohort s...

More than a quarter of the world's population is at risk of infection with the soil-transmitted helminths Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), Trichuris trichiura, and Strongyloides stercoralis. Infected children and adults present with a range of medical and surgical conditions, and clinicians should consi...

Over 1.9 billion individuals require preventive chemotherapy through mass drug administration (MDA). Community-directed MDA relies on volunteer community medicine distributors (CMDs) and their achievement of high coverage and compliance. Yet, it is unknown if village social networks influence effective MDA implementation by CMDs. In Mayuge District...

Background The cornerstone of current schistosomiasis control programmes is delivery of praziquantel to at-risk populations. Such preventive chemotherapy requires accurate information on the geographic distribution of infection, yet the performance of alternative survey designs for estimating prevalence and converting this into treatment decisions...

Empirical survey data used in analysis. (DOCX)

Additional methods (incl. sample size calculations) for baseline mapping surveys. (DOCX)

Supplementary tables. (DOCX)

Supplementary figures. (DOCX)

Strobe check list. (DOC)

Over 1.9 billion individuals require preventive chemotherapy through mass drug administration (MDA). Community-directed MDA relies on volunteer community medicine distributors (CMDs) and their achievement of high coverage and compliance. Yet, it is unknown if village social networks influence effective MDA implementation by CMDs. In Mayuge District...

Following implementation of the national control program, a reassessment of Schistosoma mansoni prevalence was conducted in Burundi to determine the feasibility of moving toward elimination. A countrywide cluster-randomized cross-sectional study was performed in May 2014. At least 25 schools were sampled from each of five eco-epidemiological risk z...

Profound changes are occurring in the epidemiology of schistosomiasis, a neglected tropical disease caused by a chronic infection with parasitic helminths of the genus Schistosoma. Schistosomiasis currently affects 240 million people worldwide, mostly in sub-Saharan Africa. The advent and proliferation of mass drug administration (MDA) programmes u...

In 2001, the World Health Assembly (WHA) passed the landmark WHA 54.19 resolution for global scale-up of mass administration of anthelmintic drugs for morbidity control of schistosomiasis and soil-transmitted helminthiasis, which affect more than 1·5 billion of the world's poorest people. Since then, more than a decade of research and experience ha...

In 2001, the World Health Assembly (WHA) passed the landmark WHA 54.19 resolution for global scale-up of mass administration of anthelmintic drugs for morbidity control of schistosomiasis and soil-transmitted helminthiasis, which affect more than 1·5 billion of the world's poorest people. Since then, more than a decade of research and experience ha...

Schistosomiasis is a chronic and poverty-promoting disease that affects over 200 million people and inflicts a considerable public health burden across large parts of the developing world. Yet, schistosomiasis remains one of the so-called 'neglected tropical diseases' because it affects poor populations mostly in rural areas. The distribution of sc...

Background Soil-transmitted helminth (STH) infections are amongst the most prevalent infections in the world. Mass drug administration (MDA) programmes have become the most commonly used national interventions for endemic countries to achieve elimination. This paper aims to describe the effect of an 8-year MDA programme on the prevalence, intensity...

Several hundred cases of Hirmi Valley Liver Disease (HVLD), an often fatal liver injury, occurred from 2001 to 2011 in a cluster of rural villages in Tigray, Ethiopia. HVLD is principally caused by contamination of the food supply with plant derived pyrrolizidine alkaloids (PAs), with high exposure to the pesticide DDT among villagers increasing th...

Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was established in 2008 to answer strategic questions about schistosomiasis control. For programme managers, a high-priority question is: what are the most cost-effective strategies for delivering preventive chemotherapy (PCT) with praziquantel (PZQ)? This pap...

Schistosomiasis is a major public health problem in Gezira State, Sudan. The statewide prevalence survey among school children showed that the prevalence reached up to 82% in some districts and the reported mean intensity reached up to 223 eggs/gm of stool for S. mansoni and 28 eggs/10 ml of urine for S. haematobium. Based on this, a plan was estab...

Background: Repeated mass drug administration (MDA) with preventive chemotherapies (PCs) is the mainstay of morbidity control for schistosomiasis and soil-transmitted helminths. Yet, the World Health Organization (WHO) recently reported that less than one third of individuals who required PCs received treatment. Methods: Coverage of community-di...

Background: Biannual mass drug administration (MDA) with praziquantel and additional interventions to eliminate urogenital schistosomiasis has been implemented on the Zanzibar islands, United Republic of Tanzania, since 2012. We aimed to assess the coverage of school-based treatment (SBT) and community-wide treatment (CWT), to validate the coverag...

Background: The association of anaemia with intestinal schistosomiasis and hookworm infections are poorly explored in populations that are not limited to children or pregnant women. Methods: We sampled 1,832 individuals aged 5-90 years from 30 communities in Mayuge District, Uganda. Demographic, village, and parasitological data were collected....

Background: The last decade has seen an expansion of national schistosomiasis control programmes in Africa based on large-scale preventative chemotherapy. In many areas this has resulted in considerable reductions in infection and morbidity levels in treated individuals. In this paper, we quantify changes in the force of infection (FOI), defined h...