Center for Tropical and Infectious Diseases

Liverpool, United Kingdom

Center for Tropical and Infectious Diseases

Liverpool, United Kingdom
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Stothard J.R.,Center for Tropical and Infectious Diseases | Chiodini P.,Hospital for Tropical Diseases | Booth M.,Durham University
Parasitology | Year: 2011

Without realizing it perhaps, the research activities of many parasitologists are often focused upon the study of parasites most commonly found in children. Though there is little recognition of paediatric parasitology as a separate topic within medical parasitology, with the global interest in promotion of maternal and child health, alleviation of diseases associated with poverty and requirements of "child-sized" medicines, a more formal consideration is now timely. Recent research, for example, has highlighted that defining precisely the "first-age" at which parasites interfere with a child's health, or normal developmental processes, is being revised. Attention is now drawn towards ever younger subjects, for parasites have the capacity to also influence the health of the foetus within the in utero environment, altering immune-development. These subtle, yet evolutionary profound interactions perhaps manifest themselves as to why some children are more prone to infection(s), develop overt disease and sadly die while others do not. Here, we address the growing importance of paediatric parasitology and its applications within disease control strategies as highlighted in the 2010 Autumn Symposium of the British Society of Parasitology. Copyright © 2011 Cambridge University Press.


Sousa-Figueiredo J.C.,Collaborating Center for Schistosomiasis | Sousa-Figueiredo J.C.,London School of Hygiene and Tropical Medicine | Betson M.,Center for Tropical and Infectious Diseases | Kabatereine N.B.,Ministry of Health | And 2 more authors.
Parasitology | Year: 2011

Anaemia is a severe public health issue among African preschool-aged children, yet little effective progress has been made towards its amelioration, in part due to difficulties in unravelling its complex, multifactorial aetiology. To determine the current anaemia situation and assess the relative contribution of malaria, intestinal schistosomiasis and infection with soil-transmitted helminths, two separate cross-sectional epidemiological surveys were carried out in Uganda including 573 and 455 preschool-aged children (≤6 years) living along the shores of Lake Albert and on the islands in Lake Victoria, respectively. Anaemia was found to be a severe public health problem in Lake Albert, affecting 68.9% of children (ninety-five percent confidence intervals (95% CI) 64.9-72.7%), a statistically significant higher prevalence relative to the 27.3% detected in Lake Victoria (95% CI: 23.3-31.7%). After multivariate analysis (controlling for sex and age of the child), the only factor found to be significantly associated with increased odds of anaemia in both lake systems was malaria (Lake Albert, odds ratio (OR)=2.1, 95% CI: 1.4-3.2; Lake Victoria, OR=1.9, 95% CI: 1.2-2.9). Thus intervention strategies primarily focusing on very young children and combating malaria appear to represent the most appropriate use of human and financial resources for the prevention of anaemia in this age group and area. Looking to the future, these activities could be further emphasised within the National Child Health DaysPLUS agenda. Copyright © 2011 Cambridge University Press.


PubMed | MRC Unit The Gambia, Center for Tropical and Infectious Diseases, Birmingham Heartlands Hospital, Weatherall Institute of Molecular Medicine and University of Kelaniya
Type: | Journal: American journal of hematology | Year: 2016

Anemia affects over 800 million women and children globally. Measurement of hepcidin as an index of iron status shows promise, but its diagnostic performance where hemoglobinopathies are prevalent is unclear. We evaluated the performance of hepcidin as a diagnostic test of iron deficiency in adolescents across Sri Lanka. We selected 2273 samples from a nationally representative cross-sectional study of 7526 secondary schoolchildren across Sri Lanka and analyzed associations between hepcidin and participant characteristics, iron indices, inflammatory markers and hemoglobinopathy states. We evaluated the diagnostic accuracy of hepcidin as a test for iron deficiency with estimation of the AUC


Rollinson D.,Natural History Museum in London | Knopp S.,Swiss Tropical and Public Health Institute | Knopp S.,University of Basel | Levitz S.,Natural History Museum in London | And 13 more authors.
Acta Tropica | Year: 2013

It is time to raise global awareness to the possibility of schistosomiasis elimination and to support endemic countries in their quest to determine the most appropriate approaches to eliminate this persistent and debilitating disease. The main interventions for schistosomiasis control are reviewed, including preventive chemotherapy using praziquantel, snail control, sanitation, safe water supplies, and behaviour change strategies supported by information, education and communication (IEC) materials. Differences in the biology and transmission of the three main Schistosoma species (i.e. Schistosoma haematobium, S. mansoni and S. japonicum), which impact on control interventions, are considered. Sensitive diagnostic procedures to ensure adequate surveillance in areas attaining low endemicity are required. The importance of capacity building is highlighted. To achieve elimination, an intersectoral approach is necessary, with advocacy and action from local communities and the health community to foster cooperative ventures with engineers, the private sector, governments and non-governmental organizations specialized in water supply and sanitation. Examples of successful schistosomiasis control programmes are reviewed to highlight what has been learnt in terms of strategy for control and elimination. These include St. Lucia and other Caribbean islands, Brazil and Venezuela for S. mansoni; Saudi Arabia and Egypt for both S. mansoni and S. haematobium; Morocco, Tunisia, Algeria, Mauritius and the Islamic Republic of Iran for S. haematobium; Japan and the People's Republic of China for S. japonicum. Additional targets for elimination or even eradication could be the two minor human schistosome species S. guineenisis and S. intercalatum, which have a restricted distribution in West and Central Africa. The examples show that elimination of schistosomiasis is an achievable and desirable goal requiring full integration of preventive chemotherapy with the tools of transmission control. An agenda for the elimination of schistosomiasis would aim to identify the gaps in knowledge, and define the tools, strategies and guidelines that will help national control programmes move towards elimination, including an internationally accepted mechanism that allows verification/confirmation of elimination. © 2012 Elsevier B.V.


Sousa-Figueiredo J.C.,Center for Tropical and Infectious Diseases | Sousa-Figueiredo J.C.,London School of Hygiene and Tropical Medicine | Gamboa D.,Project Health Research Center in Angola | Pedro J.M.,Project Health Research Center in Angola | And 6 more authors.
PLoS ONE | Year: 2012

Background: Malaria, schistosomiasis and geohelminth infection are linked to maternal and child morbidity and mortality in sub-Saharan Africa. Knowing the prevalence levels of these infections is vital to guide governments towards the implementation of successful and cost-effective disease control initiatives. Methodology/Principal Findings: A cross-sectional study of 1,237 preschool children (0-5 year olds), 1,142 school-aged children (6-15 year olds) and 960 women (>15 year olds) was conducted to understand the distribution of malnutrition, anemia, malaria, schistosomiasis (intestinal and urinary) and geohelminths in a north-western province of Angola. We used a recent demographic surveillance system (DSS) database to select and recruit suitable households. Malnutrition was common among children (23.3% under-weight, 9.9% wasting and 32.2% stunting), and anemia was found to be a severe public health problem (i.e., >40%). Malaria prevalence was highest among preschool children reaching 20.2%. Micro-hematuria prevalence levels reached 10.0% of preschool children, 16.6% of school-aged children and 21.7% of mothers. Geohelminth infections were common, affecting 22.3% of preschool children, 31.6% of school-aged children and 28.0% of mothers. Conclusions: Here we report prevalence levels of malaria, schistosomiasis and geohelminths; all endemic in this poorly described area where a DSS has been recently established. Furthermore we found evidence that the studied infections are associated with the observed levels of anemia and malnutrition, which can justify the implementation of integrated interventions for the control of these diseases and morbidities. © 2012 Nery et al.


Vallieres C.,French National Center for Scientific Research | Fisher N.,Center for Tropical and Infectious Diseases | Fisher N.,Michigan State University | Antoine T.,Center for Tropical and Infectious Diseases | And 8 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2012

The mitochondrial bc 1 complex is a multisubunit enzyme that catalyzes the transfer of electrons from ubiquinol to cytochrome c coupled to the vectorial translocation of protons across the inner mitochondrial membrane. The complex contains two distinct quinone-binding sites, the quinol oxidation site of the bc1 complex (Q o) and the quinone reduction site (Q 1), located on opposite sides of the membrane within cytochrome b. Inhibitors of the Q o site such as atovaquone, active against the bc 1 complex of Plasmodium falciparum, have been developed and formulated as antimalarial drugs. Unfortunately, single point mutations in the Q o site can rapidly render atovaquone ineffective. The development of drugs that could circumvent cross-resistance with atovaquone is needed. Here, we report on the mode of action of a potent inhibitor of P. falciparum proliferation, 1-hydroxy-2-dode-cyl-4(1H)quinolone (HDQ). We show that the parasite bc1 complex - from both control and atovaquone-resistant strains - is inhibited by submicromolar concentrations of HDQ, indicating that the two drugs have different targets within the complex. The binding site of HDQ was then determined by using a yeast model. Introduction of point mutations into the Q i site, namely, G33A, H204Y, M221Q, and K228M, markedly decreased HDQ inhibition. In contrast, known inhibitor resistance mutations at the Q o site did not cause HDQ resistance. This study, using HDQ as a proof-of-principle inhibitor, indicates that the Q i site of the bc 1 complex is a viable target for antimalarial drug development. Copyright © 2012, American Society for Microbiology. All Rights Reserved.


DuVall A.S.,University of Michigan | Fairley J.K.,Emory University | Sutherland L.,Case Western Reserve University | Bustinduy A.L.,Center for Tropical and Infectious Diseases | And 5 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2014

To better delineate the impact of parasitic coinfection in coastal Kenya, we developed a novel specimen-sparing bead assay using multiplex flow immunoassay (MFI) technology to simultaneously measure serum or plasma immunoglobulin G4 (IgG4) against Brugia malayi antigen (BMA) and Schistosoma haematobium soluble worm antigen (SWAP). Properties of the bead assay were estimated by latent class analysis using data from S. haematobium egg counts/filarial rapid diagnostic cards (RDTs), parasite-specific enzyme-linked immunosorbent assays (ELISAs), and the multichannel IgG4 assay. For schistosomiasis, the bead assay had an estimated sensitivity of 81% and a specificity of 45%, and it was more sensitive than ELISA or urine egg counts for diagnosing infection. For filariasis, it had a sensitivity of 86% and a specificity of 39%, and it was more sensitive than ELISA or RDT. Measuring antibody by MFI is feasible and may provide more accurate epidemiological information than current parasitological tests, especially in the setting of low-intensity infections. Copyright © 2014 by The American Society of Tropical Medicine and Hygiene.


PubMed | Center for Tropical and Infectious Diseases
Type: Journal Article | Journal: PloS one | Year: 2012

Malaria, schistosomiasis and geohelminth infection are linked to maternal and child morbidity and mortality in sub-Saharan Africa. Knowing the prevalence levels of these infections is vital to guide governments towards the implementation of successful and cost-effective disease control initiatives.A cross-sectional study of 1,237 preschool children (0-5 year olds), 1,142 school-aged children (6-15 year olds) and 960 women (>15 year olds) was conducted to understand the distribution of malnutrition, anemia, malaria, schistosomiasis (intestinal and urinary) and geohelminths in a north-western province of Angola. We used a recent demographic surveillance system (DSS) database to select and recruit suitable households. Malnutrition was common among children (23.3% under-weight, 9.9% wasting and 32.2% stunting), and anemia was found to be a severe public health problem (i.e., >40%). Malaria prevalence was highest among preschool children reaching 20.2%. Micro-hematuria prevalence levels reached 10.0% of preschool children, 16.6% of school-aged children and 21.7% of mothers. Geohelminth infections were common, affecting 22.3% of preschool children, 31.6% of school-aged children and 28.0% of mothers.Here we report prevalence levels of malaria, schistosomiasis and geohelminths; all endemic in this poorly described area where a DSS has been recently established. Furthermore we found evidence that the studied infections are associated with the observed levels of anemia and malnutrition, which can justify the implementation of integrated interventions for the control of these diseases and morbidities.


PubMed | Center for Tropical and Infectious Diseases
Type: Introductory Journal Article | Journal: Parasitology | Year: 2011

Without realizing it perhaps, the research activities of many parasitologists are often focused upon the study of parasites most commonly found in children. Though there is little recognition of paediatric parasitology as a separate topic within medical parasitology, with the global interest in promotion of maternal and child health, alleviation of diseases associated with poverty and requirements of child-sized medicines, a more formal consideration is now timely. Recent research, for example, has highlighted that defining precisely the first-age at which parasites interfere with a childs health, or normal developmental processes, is being revised. Attention is now drawn towards ever younger subjects, for parasites have the capacity to also influence the health of the foetus within the in utero environment, altering immune-development. These subtle, yet evolutionary profound interactions perhaps manifest themselves as to why some children are more prone to infection(s), develop overt disease and sadly die while others do not. Here, we address the growing importance of paediatric parasitology and its applications within disease control strategies as highlighted in the 2010 Autumn Symposium of the British Society of Parasitology.

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