551
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Wei J, Damania A, Gao X, Liu Z, Mejia R, Mitreva M, Strych U, Bottazzi ME, Hotez PJ, Zhan B. The hookworm Ancylostoma ceylanicum intestinal transcriptome provides a platform for selecting drug and vaccine candidates. Parasit Vectors 2016; 9:518. [PMID: 27677574 PMCID: PMC5039805 DOI: 10.1186/s13071-016-1795-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 09/12/2016] [Indexed: 12/02/2022] Open
Abstract
Background The intestine of hookworms contains enzymes and proteins involved in the blood-feeding process of the parasite and is therefore a promising source of possible vaccine antigens. One such antigen, the hemoglobin-digesting intestinal aspartic protease known as Na-APR-1 from the human hookworm Necator americanus, is currently a lead candidate antigen in clinical trials, as is Na-GST-1 a heme-detoxifying glutathione S-transferase. Methods In order to discover additional hookworm vaccine antigens, messenger RNA was obtained from the intestine of male hookworms, Ancylostoma ceylanicum, maintained in hamsters. RNA-seq was performed using Illumina high-throughput sequencing technology. The genes expressed in the hookworm intestine were compared with those expressed in the whole worm and those genes overexpressed in the parasite intestine transcriptome were further analyzed. Results Among the lead transcripts identified were genes encoding for proteolytic enzymes including an A. ceylanicum APR-1, but the most common proteases were cysteine-, serine-, and metallo-proteases. Also in abundance were specific transporters of key breakdown metabolites, including amino acids, glucose, lipids, ions and water; detoxifying and heme-binding glutathione S-transferases; a family of cysteine-rich/antigen 5/pathogenesis-related 1 proteins (CAP) previously found in high abundance in parasitic nematodes; C-type lectins; and heat shock proteins. These candidates will be ranked for downstream antigen target selection based on key criteria including abundance, uniqueness in the parasite versus the vertebrate host, as well as solubility and yield of expression. Conclusion The intestinal transcriptome of A. ceylanicum provides useful information for the identification of proteins involved in the blood-feeding process, representing a first step towards a reverse vaccinology approach to a human hookworm vaccine. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1795-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Junfei Wei
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Ashish Damania
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Xin Gao
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, 63108, USA
| | - Zhuyun Liu
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Rojelio Mejia
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Makedonka Mitreva
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, 63108, USA.,Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63108, USA
| | - Ulrich Strych
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Maria Elena Bottazzi
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Biology, Baylor University, Waco, TX, 76706, USA
| | - Peter J Hotez
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Biology, Baylor University, Waco, TX, 76706, USA
| | - Bin Zhan
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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552
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Briggs N, Weatherhead J, Sastry KJ, Hotez PJ. The Hygiene Hypothesis and Its Inconvenient Truths about Helminth Infections. PLoS Negl Trop Dis 2016; 10:e0004944. [PMID: 27632204 PMCID: PMC5025185 DOI: 10.1371/journal.pntd.0004944] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Current iterations of the hygiene hypothesis suggest an adaptive role for helminth parasites in shaping the proper maturation of the immune system. However, aspects of this hypothesis are based on assumptions that may not fully account for realities about human helminth infections. Such realities include evidence of causal associations between helminth infections and asthma or inflammatory bowel disease as well as the fact that helminth infections remain widespread in the United States, especially among populations at greatest risk for inflammatory and autoimmune diseases.
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Affiliation(s)
- Neima Briggs
- Department of Immunology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas, United States of America
- Sabin Vaccine Institute and Texas Children’s Hospital Center for Vaccine Development, Departments of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Jill Weatherhead
- Sabin Vaccine Institute and Texas Children’s Hospital Center for Vaccine Development, Departments of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - K. Jagannadha Sastry
- Department of Immunology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas, United States of America
| | - Peter J. Hotez
- Sabin Vaccine Institute and Texas Children’s Hospital Center for Vaccine Development, Departments of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
- James A Baker III Institute for Public Policy, Rice University, Houston, Texas, United States of America
- Department of Biology, Baylor University, Waco, Texas, United States of America
- Scowcroft Institute of International Affairs, Bush School of Government and Public Service, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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553
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Pinsent A, Blake IM, Basáñez MG, Gambhir M. Mathematical Modelling of Trachoma Transmission, Control and Elimination. ADVANCES IN PARASITOLOGY 2016; 94:1-48. [PMID: 27756453 DOI: 10.1016/bs.apar.2016.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The World Health Organization has targeted the elimination of blinding trachoma by the year 2020. To this end, the Global Elimination of Blinding Trachoma (GET, 2020) alliance relies on a four-pronged approach, known as the SAFE strategy (S for trichiasis surgery; A for antibiotic treatment; F for facial cleanliness and E for environmental improvement). Well-constructed and parameterized mathematical models provide useful tools that can be used in policy making and forecasting in order to help to control trachoma and understand the feasibility of this large-scale elimination effort. As we approach this goal, the need to understand the transmission dynamics of infection within areas of different endemicities, to optimize available resources and to identify which strategies are the most cost-effective becomes more pressing. In this study, we conducted a review of the modelling literature for trachoma and identified 23 articles that included a mechanistic or statistical model of the transmission, dynamics and/or control of (ocular) Chlamydia trachomatis. Insights into the dynamics of trachoma transmission have been generated through both deterministic and stochastic models. A large body of the modelling work conducted to date has shown that, to varying degrees of effectiveness, antibiotic administration can reduce or interrupt trachoma transmission. However, very little analysis has been conducted to consider the effect of nonpharmaceutical interventions (and particularly the F and E components of the SAFE strategy) in helping to reduce transmission. Furthermore, very few of the models identified in the literature review included a structure that permitted tracking of the prevalence of active disease (in the absence of active infection) and the subsequent progression to disease sequelae (the morbidity associated with trachoma and ultimately the target of GET 2020 goals). This represents a critical gap in the current trachoma modelling literature, which makes it difficult to reliably link infection and disease. In addition, it hinders the application of modelling to assist the public health community in understanding whether trachoma programmes are on track to reach the GET goals by 2020. Another gap identified in this review was that of the 23 articles examined, only one considered the cost-effectiveness of the interventions implemented. We conclude that although good progress has been made towards the development of modelling frameworks for trachoma transmission, key components of disease sequelae representation and economic evaluation of interventions are currently missing from the available literature. We recommend that rapid advances in these areas should be urgently made to ensure that mathematical models for trachoma transmission can robustly guide elimination efforts and quantify progress towards GET 2020.
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Affiliation(s)
- A Pinsent
- Monash University, Melbourne, VIC, Australia
| | - I M Blake
- Imperial College London, London, United Kingdom
| | - M G Basáñez
- Imperial College London, London, United Kingdom
| | - M Gambhir
- Monash University, Melbourne, VIC, Australia
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554
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Opportunities for Integrated Control of Neglected Tropical Diseases That Affect the Skin. Trends Parasitol 2016; 32:843-854. [PMID: 27638231 DOI: 10.1016/j.pt.2016.08.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 11/23/2022]
Abstract
Many neglected tropical diseases (NTDs) affect the skin, causing considerable disability, stigma, and exacerbation of poverty. However, there has been relatively little investment into laboratory research, epidemiology, diagnostic tools or management strategies to control tropical skin disease. Integration may advance the control of skin disease across a range of domains, including mapping, diagnosis, clinical management, and community control measures such as mass drug administration. Examples of successful integration strategies include programs targeting scabies, impetigo, yaws, and diseases causing lymphoedema. Future strategies should build on these experiences and the experience of integration of other NTDs, strengthen existing health systems, and contribute toward the attainment of Universal Health Coverage. Strong partnerships and political support and will be necessary to achieve these goals.
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555
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Müller I, Yap P, Steinmann P, Damons BP, Schindler C, Seelig H, Htun NSN, Probst-Hensch N, Gerber M, du Randt R, Pühse U, Walter C, Utzinger J. Intestinal parasites, growth and physical fitness of schoolchildren in poor neighbourhoods of Port Elizabeth, South Africa: a cross-sectional survey. Parasit Vectors 2016; 9:488. [PMID: 27595566 PMCID: PMC5011914 DOI: 10.1186/s13071-016-1761-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 08/16/2016] [Indexed: 12/11/2022] Open
Abstract
Background As traditional lifestyle and diets change with social and economic development, disadvantaged communities in low- and middle-income countries increasingly face a double burden of communicable and non-communicable diseases. We studied the relationship between physical fitness and infections with soil-transmitted helminths (STHs), intestinal protozoa and Helicobacter pylori among schoolchildren in Port Elizabeth, South Africa. Methods We conducted a cross-sectional survey among 1009 children, aged 9 to 12 years, from eight primary schools in socioeconomically disadvantaged neighbourhoods of Port Elizabeth. Physical fitness was determined using field-deployable tests of the Eurofit fitness test battery. Stool samples were analysed with the Kato-Katz thick smear technique to diagnose STHs and with rapid diagnostic tests (RDTs) to detect intestinal protozoa and H. pylori infections. Haemoglobin (Hb) levels were assessed and anthropometric indicators determined. Results Complete data were available for 934 children (92 %). In two schools, high STH prevalences were found (Ascaris lumbricoides 60 and 72 %; Trichuris trichiura 65 % each). For boys and girls co-infected with A. lumbricoides and T. trichiura (n = 155) the maximal oxygen uptake (VO2 max) was estimated to be 50.1 and 47.2 ml kg-1 min-1, compared to 51.5 and 47.4 ml kg-1 min-1 for their non-infected peers (n = 278), respectively. On average, children without helminth infections had greater body mass (P = 0.011), height (P = 0.009) and a higher body mass index (P = 0.024) and were less often stunted (P = 0.006), but not significantly less wasted compared to their peers with a single or dual species infection. Among 9-year-old boys, a negative correlation between helminth infections and VO2 max, grip strength and standing broad jump distance was observed (P = 0.038). The overall mean Hb level was 122.2 g l-1. In the two schools with the highest prevalence of STHs the Hb means were 119.7 and 120.5 g l-1, respectively. Conclusions Intestinal parasite infections appear to have a small but significant negative effect on the physical fitness of infected children, as expressed by their maximal oxygen uptake. We observed a clear impact on anthropometric indicators. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1761-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ivan Müller
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Department of Sport, Exercise and Health, University of Basel, St. Jakobsturm, Birsstrasse 320B, CH-4056, Basel, Switzerland
| | - Peiling Yap
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Institute of Infectious Disease and Epidemiology, Tan Tock Seng Hospital, 308433, Singapore, Singapore
| | - Peter Steinmann
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland
| | - Bruce P Damons
- Faculty of Education, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth, 6031, South Africa.,Department of Human Movement Science, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth, 6031, South Africa
| | - Christian Schindler
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland
| | - Harald Seelig
- University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Department of Sport, Exercise and Health, University of Basel, St. Jakobsturm, Birsstrasse 320B, CH-4056, Basel, Switzerland
| | - Nan S N Htun
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland
| | - Nicole Probst-Hensch
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland
| | - Markus Gerber
- University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Department of Sport, Exercise and Health, University of Basel, St. Jakobsturm, Birsstrasse 320B, CH-4056, Basel, Switzerland
| | - Rosa du Randt
- Department of Human Movement Science, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth, 6031, South Africa
| | - Uwe Pühse
- University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Department of Sport, Exercise and Health, University of Basel, St. Jakobsturm, Birsstrasse 320B, CH-4056, Basel, Switzerland
| | - Cheryl Walter
- Department of Human Movement Science, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth, 6031, South Africa
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland. .,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.
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556
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Chalaem P, Chusri S, Fernandez S, Chotigeat W, Anguita J, Pal U, Promnares K. Characterization of a Chikungunya virus strain isolated from banked patients' sera. Virol J 2016; 13:150. [PMID: 27590311 PMCID: PMC5009685 DOI: 10.1186/s12985-016-0606-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/24/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Chikungunya virus (CHIKV) is a prevalent mosquito-borne pathogen that is emerging in many parts of the globe causing significant human morbidity. Here, we report the isolation and characterization of an infectious CHIKV from banked serum specimens of suspected patients from the 2009 epidemic in Thailand. METHODS Standard plaque assay was used for CHIKV isolation from the banked serum specimens. Isolated CHIKV was identified base on E1 structural gene sequence. Growth kinetic, infectivity, cell viability and cytokine gene expression throughout CHIKV infection in a permissive cell line, 293T cells, was performed using several approaches, including standard plaque assay, immunofluorescence assay, classical MTT assay, and quantitative real-time PCR. Two tailed Student's t test was used for evaluation statistically significance between the mean values of the groups. RESULTS Based on the E1 structural gene sequence and phylogenetic analysis, we identified the virus as the CHIK/SBY8/10 isolate from Indonesia. Assessment of the growth kinetics, cytopathic effects as well as its ability to induce cellular immune responses suggested that the currently isolated CHIK/SBY8/10 virus is relatively more virulent than a known CHIKV vaccine strain, which also induces more dramatic proinflammatory responses. CONCLUSIONS Our studies further add to the infectivity of a less-studied yet infectious CHIKV isolate as well as underscored the importance and utility of 293T cells as an excellent cell culture model for studying viral growth, CHIKV-induced inflammatory cellular responses and cell death. Together, these studies provide novel information on the CHIKV biology, infectivity and virus-cell interaction, which would help develop novel interventions against the infection.
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Affiliation(s)
- Pattra Chalaem
- Department of Molecular Biotechnology and Bioinformatics, Faculty of Science, Prince of Songkla University, Hatyai, Songkhla 90112 Thailand
| | - Sarunyou Chusri
- Division of Infectious Disease, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hatyai, Songkhla 90112 Thailand
| | - Stefan Fernandez
- Department of Virology, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Wilaiwan Chotigeat
- Department of Molecular Biotechnology and Bioinformatics, Faculty of Science, Prince of Songkla University, Hatyai, Songkhla 90112 Thailand
| | - Juan Anguita
- CIC bioGUNE, 48160 Derio, Bizkaia Spain
- Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Bizkaia Spain
| | - Utpal Pal
- Department of Veterinary Medicine and Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742 USA
| | - Kamoltip Promnares
- Department of Molecular Biotechnology and Bioinformatics, Faculty of Science, Prince of Songkla University, Hatyai, Songkhla 90112 Thailand
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557
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Zamanian M, Andersen EC. Prospects and challenges of CRISPR/Cas genome editing for the study and control of neglected vector-borne nematode diseases. FEBS J 2016; 283:3204-21. [PMID: 27300487 PMCID: PMC5053252 DOI: 10.1111/febs.13781] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/05/2016] [Accepted: 06/13/2016] [Indexed: 01/19/2023]
Abstract
Neglected tropical diseases caused by parasitic nematodes inflict an immense health and socioeconomic burden throughout much of the developing world. Current estimates indicate that more than two billion people are infected with nematodes, resulting in the loss of 14 million disability-adjusted life years per annum. Although these parasites cause significant mortality, they primarily cause chronic morbidity through a wide range of severe clinical ailments. Treatment options for nematode infections are restricted to a small number of anthelmintic drugs, and the rapid expansion of anthelmintic mass drug administration raises concerns of drug resistance. Preservation of existing drugs is necessary, as well as the development of new treatment options and methods of control. We focus this review on how the democratization of CRISPR/Cas9 genome editing technology can be enlisted to improve our understanding of the biology of nematode parasites and our ability to treat the infections they cause. We will first explore how this robust method of genome manipulation can be used to newly exploit the powerful model nematode Caenorhabditis elegans for parasitology research. We will then discuss potential avenues to develop CRISPR/Cas9 editing protocols in filarial nematodes. Lastly, we will propose potential ways in which CRISPR/Cas9 can be used to engineer gene drives that target the transmission of mosquito-borne filarial nematodes.
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Affiliation(s)
- Mostafa Zamanian
- Department of Molecular BiosciencesNorthwestern UniversityEvanstonILUSA
| | - Erik C. Andersen
- Department of Molecular BiosciencesNorthwestern UniversityEvanstonILUSA
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558
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Abstract
The field of parasitism is broad, encompassing relationships between organisms where one benefits at the expense of another. Traditionally the discipline focuses on eukaryotes, with the study of bacteria and viruses complementary but distinct. Nonetheless, parasites vary in size and complexity from single celled protozoa, to enormous plants like those in the genus Rafflesia. Lifecycles range from obligate intracellular to extensive exoparasitism. Examples of parasites include high-profile medical and zoonotic pathogens such as Plasmodium, veterinary pathogens of wild and captive animals and many of the agents which cause neglected tropical diseases, stretching to parasites which infect plants and other parasites (e.g. Kikuchi et al. 2011; Hotez et al. 2014; Blake et al. 2015; Hemingway, 2015; Meekums et al. 2015; Sandlund et al. 2015). The breadth of parasitology has been matched by the variety of ways in which parasites are studied, drawing upon biological, chemical, molecular, epidemiological and other expertise. Despite such breadth bridging between disciplines has commonly been problematic, regardless of extensive encouragement from government agencies, peer audiences and funding bodies promoting multidisciplinary research. Now, progress in understanding and collaboration can benefit from establishment of the One Health concept (Zinsstag et al. 2012; Stark et al. 2015). One Health draws upon biological, environmental, medical, veterinary and social science disciplines in order to improve human, animal and environmental health, although it remains tantalizingly difficult to engage many relevant parties. For infectious diseases traditional divides have been exacerbated as the importance of wildlife reservoirs, climate change, food production systems and socio-economic diversity have been recognized but often not addressed in a multidisciplinary manner. In response the 2015 Autumn Symposium organized by the British Society for Parasitology (BSP; https://www.bsp.uk.net/home/) was focused on One Health, running under the title 'One Health: parasites and beyond…'. The meeting, held at the Royal Veterinary College (RVC) in Camden, London from September 14th to 15th, drew upon a blend of specialist parasitology reinforced with additional complementary expertise. Scientists, advocates, policy makers and industry representatives were invited to present at the meeting, promoting and developing One Health understanding with relevance to parasitology. The decision to widen the scope of the meeting to non-parasitological, but informative topics, is reflected in the diversity of the articles included in this special issue. A key feature of the meeting was encouragement of early career scientists, with more than 35% of the delegates registered as students and 25 posters.
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559
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Zaiss MM, Harris NL. Interactions between the intestinal microbiome and helminth parasites. Parasite Immunol 2016; 38:5-11. [PMID: 26345715 PMCID: PMC5019230 DOI: 10.1111/pim.12274] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/01/2015] [Indexed: 12/14/2022]
Abstract
Throughout evolution, both helminths and bacteria have inhabited our intestines. As intestinal helminths and bacteria inhabit the same environmental niche, it is likely that these organisms interact with, and impact on, each other. In addition, intestinal helminths are well known to alter intestinal physiology, permeability, mucous secretion and the production of antimicrobial peptides – all of which may impact on bacterial survival and spatial organization. Yet despite rapid advances in our understanding of host–intestinal bacteria interactions, the impact of helminths on this relationship has remained largely unexplored. Moreover, although intestinal helminths are generally accepted to possess potent immuno‐modulatory activity, it is unknown whether this capacity requires interactions with intestinal bacteria. We propose that this ‘ménage à trois’ situation is likely to have exerted a strong selective pressure on the development of our metabolic and immune systems. Whilst such pressures remain in developing countries, the eradication of helminths in industrialized countries has shifted this evolutionary balance, possibly underlying the increased development of chronic inflammatory diseases. Thus, helminth–bacteria interactions may represent a key determinant of healthy homoeostasis.
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Affiliation(s)
- M M Zaiss
- Global Health Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - N L Harris
- Global Health Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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560
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Helminth-Tuberculosis Co-infection: An Immunologic Perspective. Trends Immunol 2016; 37:597-607. [PMID: 27501916 DOI: 10.1016/j.it.2016.07.005] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 07/13/2016] [Accepted: 07/14/2016] [Indexed: 01/15/2023]
Abstract
Over 2 billion people worldwide are infected with helminths (worms). Similarly, infection with Mycobacterium tuberculosis (Mtb) occurs in over a third of the world's population, often with a great degree of geographical overlap with helminth infection. Interestingly, the responses induced by the extracellular helminths and those induced by the intracellular Mtb are often mutually antagonistic and, as a consequence, can result in impaired (or cross-regulated) host responses to either of the infecting pathogens. In this review, we outline the nature of the immune responses induced by infections with helminths and tuberculosis (TB) and then provide data from both experimental models and human studies that illustrate how the immune response engendered by helminth parasites modulates Mtb-specific responses in helminth-TB coinfection.
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561
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Gurarie D, King CH, Yoon N, Li E. Refined stratified-worm-burden models that incorporate specific biological features of human and snail hosts provide better estimates of Schistosoma diagnosis, transmission, and control. Parasit Vectors 2016; 9:428. [PMID: 27492409 PMCID: PMC4973538 DOI: 10.1186/s13071-016-1681-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 07/05/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schistosoma parasites sustain a complex transmission process that cycles between a definitive human host, two free-swimming larval stages, and an intermediate snail host. Multiple factors modify their transmission and affect their control, including heterogeneity in host populations and environment, the aggregated distribution of human worm burdens, and features of parasite reproduction and host snail biology. Because these factors serve to enhance local transmission, their inclusion is important in attempting accurate quantitative prediction of the outcomes of schistosomiasis control programs. However, their inclusion raises many mathematical and computational challenges. To address these, we have recently developed a tractable stratified worm burden (SWB) model that occupies an intermediate place between simpler deterministic mean worm burden models and the very computationally-intensive, autonomous agent models. METHODS To refine the accuracy of model predictions, we modified an earlier version of the SWB by incorporating factors representing essential in-host biology (parasite mating, aggregation, density-dependent fecundity, and random egg-release) into demographically structured host communities. We also revised the snail component of the transmission model to reflect a saturable form of human-to-snail transmission. The new model allowed us to realistically simulate overdispersed egg-test results observed in individual-level field data. We further developed a Bayesian-type calibration methodology that accounted for model and data uncertainties. RESULTS The new model methodology was applied to multi-year, individual-level field data on S. haematobium infections in coastal Kenya. We successfully derived age-specific estimates of worm burden distributions and worm fecundity and crowding functions for children and adults. Estimates from the new SWB model were compared with those from the older, simpler SWB with some substantial differences noted. We validated our new SWB estimates in prediction of drug treatment-based control outcomes for a typical Kenyan community. CONCLUSIONS The new version of the SWB model provides a better tool to predict the outcomes of ongoing schistosomiasis control programs. It reflects parasite features that augment and perpetuate transmission, while it also readily incorporates differences in diagnostic testing and human sub-population differences in treatment coverage. Once extended to other Schistosoma species and transmission environments, it will provide a useful and efficient tool for planning control and elimination strategies.
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Affiliation(s)
- David Gurarie
- Department of Mathematics, Applied Mathematics and Statistics, Case Western Reserve University, Cleveland, USA.,Center for Global Health and Diseases, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio, USA
| | - Charles H King
- Center for Global Health and Diseases, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio, USA. .,Schistosomiasis Consortium for Operational Research and Evaluation, University of Georgia, Athens, Georgia, USA.
| | - Nara Yoon
- Department of Mathematics, Applied Mathematics and Statistics, Case Western Reserve University, Cleveland, USA
| | - Emily Li
- Center for Global Health and Diseases, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio, USA
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de la Torre-Escudero E, Pérez-Sánchez R, Manzano-Román R, Oleaga A. Schistosoma bovis-host interplay: Proteomics for knowing and acting. Mol Biochem Parasitol 2016; 215:30-39. [PMID: 27485556 DOI: 10.1016/j.molbiopara.2016.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 07/25/2016] [Accepted: 07/26/2016] [Indexed: 01/25/2023]
Abstract
Schistosoma bovis is a parasite of ruminants that causes significant economic losses to farmers throughout Africa, Southwestern Asia and the Mediterranean. Additionally, recent studies have reported its zoonotic potential through the formation of S. bovis×Schistosoma haematobium hybrids. As observed in the Schistosoma species infecting humans, it is assumed that S. bovis has also evolved host regulatory molecules that ensure its long-term survival in the bloodstream of its host. Since these molecules could be potential targets for the development of new drugs and anti-schistosome vaccines, their identification and functional characterization were undertaken. With this aim in mind, the molecular interface between S. bovis and its vertebrate host was subjected to a series of proteomic studies, which started with the analysis of the proteomes of the S. bovis moieties exposed to the host, namely, the excretory/secretory products and the tegument surface. Thus, a wealth of novel molecular information of S. bovis was obtained, which in turn allowed the identification of several parasite proteins with fibrinolytic and anticoagulant activities that could be used by S. bovis to regulate the host defensive systems. Following on, the host interface was investigated by studying the proteome of the host vascular endothelium surface at two points along the infection: in the lung vessels during the schistosomula migration and in the portal vein after the parasites have reached adulthood and sexual maturity. These studies have provided original data regarding the proteomes of the endothelial cell surface of pulmonary vasculature and portal vein in S. bovis-infected animals, and have shown significant changes in these proteomes associated with infection. This review compiles current information and the analyses of all the proteomic data from S. bovis and the S. bovis-host interface, including the molecular and functional characterization of S. bovis proteins that were found to participate in the regulation of the host coagulation and fibrinolysis systems.
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Affiliation(s)
- Eduardo de la Torre-Escudero
- Parasitology Laboratory, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain
| | - Ricardo Pérez-Sánchez
- Parasitology Laboratory, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain
| | - Raúl Manzano-Román
- Parasitology Laboratory, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain
| | - Ana Oleaga
- Parasitology Laboratory, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain.
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563
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Sokolow SH, Wood CL, Jones IJ, Swartz SJ, Lopez M, Hsieh MH, Lafferty KD, Kuris AM, Rickards C, De Leo GA. Global Assessment of Schistosomiasis Control Over the Past Century Shows Targeting the Snail Intermediate Host Works Best. PLoS Negl Trop Dis 2016; 10:e0004794. [PMID: 27441556 PMCID: PMC4956325 DOI: 10.1371/journal.pntd.0004794] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 05/31/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Despite control efforts, human schistosomiasis remains prevalent throughout Africa, Asia, and South America. The global schistosomiasis burden has changed little since the new anthelmintic drug, praziquantel, promised widespread control. METHODOLOGY We evaluated large-scale schistosomiasis control attempts over the past century and across the globe by identifying factors that predict control program success: snail control (e.g., molluscicides or biological control), mass drug administrations (MDA) with praziquantel, or a combined strategy using both. For data, we compiled historical information on control tactics and their quantitative outcomes for all 83 countries and territories in which: (i) schistosomiasis was allegedly endemic during the 20th century, and (ii) schistosomiasis remains endemic, or (iii) schistosomiasis has been "eliminated," or is "no longer endemic," or transmission has been interrupted. PRINCIPAL FINDINGS Widespread snail control reduced prevalence by 92 ± 5% (N = 19) vs. 37 ± 7% (N = 29) for programs using little or no snail control. In addition, ecological, economic, and political factors contributed to schistosomiasis elimination. For instance, snail control was most common and widespread in wealthier countries and when control began earlier in the 20th century. CONCLUSIONS/SIGNIFICANCE Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis.
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Affiliation(s)
- Susanne H. Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Chelsea L. Wood
- Michigan Society of Fellows, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Isabel J. Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Scott J. Swartz
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Melina Lopez
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Michael H. Hsieh
- Children's National Health System, Washington, D.C., United States of America
- The George Washington University, Washington, D.C., United States of America
- Biomedical Research Institute, Rockville, Maryland, United States of America
| | - Kevin D. Lafferty
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Western Ecological Research Center, U.S. Geological Survey, Santa Barbara, California, United States of America
| | - Armand M. Kuris
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Chloe Rickards
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
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Elyana FN, Al-Mekhlafi HM, Ithoi I, Abdulsalam AM, Dawaki S, Nasr NA, Atroosh WM, Abd-Basher MH, Al-Areeqi MA, Sady H, Subramaniam LR, Anuar TS, Lau YL, Moktar N, Surin J. A tale of two communities: intestinal polyparasitism among Orang Asli and Malay communities in rural Terengganu, Malaysia. Parasit Vectors 2016; 9:398. [PMID: 27422533 PMCID: PMC4947346 DOI: 10.1186/s13071-016-1678-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/01/2016] [Indexed: 12/19/2022] Open
Abstract
Background Intestinal parasitic infections (IPIs) are still major health problems in many developing countries including Malaysia, particularly in the poor and socioeconomically deprived rural and remote communities in Peninsular Malaysia. This study was conducted to determine the prevalence of IPIs and to identify the key factors associated with intestinal polyparasitism as well as to evaluate the knowledge, attitude and practices (KAP) on IPIs among rural Orang Asli and Malay communities in Terengganu, Malaysia. Methods A cross-sectional study was conducted among 340 participants (165 Orang Asli and 175 Malay) aged ≤ 15 years from the Hulu Terengganu and Kemaman districts of Terengganu. Faecal samples were examined for the presence of intestinal parasites by using direct smear, formalin-ether sedimentation, trichrome stain, modified Ziehl Neelsen stain, in vitro cultivation in Jones’ medium, Kato Katz and Harada Mori techniques. Demographic, socioeconomic, environmental and behavioural information of the participants and their KAP for IPIs were collected by using a pre-tested questionnaire. Results Overall, 149 (90.3 %) Orang Asli and 43 (24.6 %) Malay children were infected by at least one parasite species. The overall prevalences of intestinal polyparasitism among the Orang Asli and Malay were 68.5 % (113/165) and 14.3 % (25/175), respectively. Multiple logistic regression analysis showed that using unsafe water supply as a source for drinking water, the presence of domestic animals, not wearing shoes when outside, not washing vegetables before consumption, not washing hands after playing with soil, indiscriminate defecation and the low level of mother’s education were the key risk factors for intestinal polyparasitism among the Orang Asli, while working mothers and the presence of domestic animals were the risk factors among the Malay children. Almost all the Malays were well aware about the IPIs while Orang Asli respondents had a poor level of related awareness. Conclusions This study demonstrates that IPIs are highly prevalent in rural Terengganu, Malaysia. Community awareness about IPIs was found to be imperative in protecting Malay children from these infections. An integrated control programme for the prevention and control of IPIs is highly recommended for these communities, with a special emphasis on the Orang Asli population.
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Affiliation(s)
- Fatin Nur Elyana
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Hesham M Al-Mekhlafi
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia. .,Endemic and Tropical Diseases Unit, Medical Research Center, Jazan University, Jazan, Kingdom of Saudi Arabia. .,Department of Parasitology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen.
| | - Init Ithoi
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Awatif M Abdulsalam
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Salwa Dawaki
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Nabil A Nasr
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Wahib M Atroosh
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Mohamad Hafiz Abd-Basher
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Mona A Al-Areeqi
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Hany Sady
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Lahvanya R Subramaniam
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Tengku Shahrul Anuar
- Integrative Pharmacogenomics Institute, Universiti Teknologi MARA, Puncak Alam Campus, 42300, Selangor, Malaysia.,Department of Medical Laboratory Technology, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, 42300, Selangor, Malaysia
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Norhayati Moktar
- Department of Parasitology and Medical Entomology, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, 56000, Kuala Lumpur, Malaysia
| | - Johari Surin
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.,Centre for Research and Innovation, Taylor's University, Subang Jaya, 47500, Selangor, Malaysia
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El-Moslemany RM, Eissa MM, Ramadan AA, El-Khordagui LK, El-Azzouni MZ. Miltefosine lipid nanocapsules: Intersection of drug repurposing and nanotechnology for single dose oral treatment of pre-patent schistosomiasis mansoni. Acta Trop 2016; 159:142-8. [PMID: 27039667 DOI: 10.1016/j.actatropica.2016.03.038] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/30/2016] [Accepted: 03/31/2016] [Indexed: 10/22/2022]
Abstract
A dual drug repurposing/nanotechnological approach was used to develop an alternative oral treatment for schistosomiasis mansoni using miltefosine (MFS), an anticancer alkylphosphocholine, and lipid nanocapsules (LNCs) as oral nanovectors. We demonstrated earlier that MFS possesses significant activity against different developmental stages of Schistosoma mansoni in the mouse model using 5 successive 20mg/kg/day oral doses. Moreover, an effective single dose (20mg/kg) oral treatment against the adult stage of S. mansoni in mice was developed using LNCs, particularly modified with CTAB, a positive charge imparting agent (MFS-LNC-CTAB(+)), or oleic acid as membrane permeabilizer (MFS-LNC-OA). Efficacy enhancement involved, at least in part, targeting of the worm tegument with MFS-LNCs as a new therapeutic entity. As the tegument surface charge and composition may differ in pre-patent stages of the parasite, it was of importance in the present study to assess the efficacy of a single oral dose of the two MFS-LNC formulations against invasive and immature stages for potential advantage relative to praziquantel. Results indicated potent schistosomicidal effects against both invasive and immature stages of S. mansoni in infected mice, efficacy being both formulation and developmental stage dependent. This was indicated by the significant reduction in the total worm burden of the invasive stage by 91.6% and 76.8% and the immature stage by 82.7% and 96.7% for MFS-LNC-CTAB+ and MFS-LNC-OA, respectively. Histopathological findings indicated amelioration of hepatic pathology with regression of the granulomatous inflammatory reaction and reduction in granulomas number and size, verifying marked improvement in architecture of hepatic lobules. From a clinical perspective, MFS-LNCs offer potential as an alternative single oral dose nanomedicine with a wide therapeutic profile for the mass chemotherapy of schistosomiasis mansoni.
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Assessing stool quantities generated by three specific Kato-Katz thick smear templates employed in different settings. Infect Dis Poverty 2016; 5:58. [PMID: 27364623 PMCID: PMC4929780 DOI: 10.1186/s40249-016-0150-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/19/2016] [Indexed: 02/07/2023] Open
Abstract
Background The Kato-Katz technique is recommended for the diagnosis of helminth infections in epidemiological surveys, drug efficacy studies and monitoring of control interventions. We assessed the comparability of the average amount of faeces generated by three Kato-Katz templates included in test kits from two different providers. Methods Nine hundred Kato-Katz thick smear preparations were done; 300 per kit. Empty slides, slides plus Kato-Katz template filled with stool and slides plus stool after careful removal of the template were weighed to the nearest 0.1 mg. The average amount of stool that was generated on the slide was calculated for each template, stratified by standard categories of stool consistency (i.e. mushy, soft, sausage-shaped, hard and clumpy). Results The average amount of stool generated on slides was 40.7 mg (95 % confidence interval (CI): 40.0–41.4 mg), 40.3 mg (95 % CI: 39.7–40.9 mg) and 42.8 mg (95 % CI: 42.2–43.3 mg) for the standard Vestergaard Frandsen template, and two different templates from the Chinese Center for Disease Control and Prevention (China CDC), respectively. Mushy stool resulted in considerably lower average weights when the Vestergaard Frandsen (37.0 mg; 95 % CI: 34.9–39.0 mg) or new China CDC templates (37.4 mg; 95 % CI: 35.9–38.9 mg) were used, compared to the old China CDC template (42.2 mg; 95 % CI: 40.7–43.7 mg) and compared to other stool consistency categories. Conclusion The average amount of stool generated by three specific Kato-Katz templates was similar (40.3–42.8 mg). Since the multiplication factor is somewhat arbitrary and small changes only have little effect on infection intensity categories, it is suggested that the standard multiplication factor of 24 should be kept for the calculation of eggs per gram of faeces for all investigated templates. Electronic supplementary material The online version of this article (doi:10.1186/s40249-016-0150-9) contains supplementary material, which is available to authorized users.
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567
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Accuracy of Mobile Phone and Handheld Light Microscopy for the Diagnosis of Schistosomiasis and Intestinal Protozoa Infections in Côte d'Ivoire. PLoS Negl Trop Dis 2016; 10:e0004768. [PMID: 27348755 PMCID: PMC4922625 DOI: 10.1371/journal.pntd.0004768] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 05/18/2016] [Indexed: 01/03/2023] Open
Abstract
Background Handheld light microscopy using compact optics and mobile phones may improve the quality of health care in resource-constrained settings by enabling access to prompt and accurate diagnosis. Methodology Laboratory technicians were trained to operate two handheld diagnostic devices (Newton Nm1 microscope and a clip-on version of the mobile phone-based CellScope). The accuracy of these devices was compared to conventional light microscopy for the diagnosis of Schistosoma haematobium, S. mansoni, and intestinal protozoa infection in a community-based survey in rural Côte d’Ivoire. One slide of 10 ml filtered urine and a single Kato-Katz thick smear from 226 individuals were subjected to the Newton Nm1 microscope and CellScope for detection of Schistosoma eggs and compared to conventional microscopy. Additionally, 121 sodium acetate-acetic acid-formalin (SAF)-fixed stool samples were examined by the Newton Nm1 microscope and compared to conventional microscopy for the diagnosis of intestinal protozoa. Principal Findings The prevalence of S. haematobium, S. mansoni, Giardia intestinalis, and Entamoeba histolytica/E. dispar, as determined by conventional microscopy, was 39.8%, 5.3%, 20.7%, and 4.9%, respectively. The Newton Nm1 microscope had diagnostic sensitivities for S. mansoni and S. haematobium infection of 91.7% (95% confidence interval (CI) 59.8–99.6%) and 81.1% (95% CI 71.2–88.3%), respectively, and specificities of 99.5% (95% CI 97.0–100%) and 97.1% (95% CI 92.2–99.1%), respectively. The CellScope demonstrated sensitivities for S. mansoni and S. haematobium of 50.0% (95% CI 25.4–74.6%) and 35.6% (95% CI 25.9–46.4%), respectively, and specificities of 99.5% (95% CI 97.0–100%) and 100% (95% CI 86.7–100%), respectively. For G. intestinalis and E. histolytica/E. dispar, the Newton Nm1 microscope had sensitivity of 84.0% (95% CI 63.1–94.7%) and 83.3% (95% CI 36.5–99.1%), respectively, and 100% specificity. Conclusions/Significance Handheld diagnostic devices can be employed in community-based surveys in resource-constrained settings after minimal training of laboratory technicians to diagnose intestinal parasites. Handheld light microscopes are new technologies that may be helpful in enabling better access to diagnostic testing for people living in resource-constrained settings in tropical and subtropical countries. Recent studies evaluating the accuracy of such devices have focused on their use by expert microscopists and were mainly conducted in laboratories. We evaluated the operating performance of two handheld microscopes (Newton Nm1 microscope and clip-on version of the reversed-lens CellScope) in comparison to conventional microscopy for the diagnosis of urogenital and intestinal schistosomiasis, when integrated into routine use in a community-based survey carried out in Côte d’Ivoire. Additionally, we evaluated the same microscopist’s diagnostic performance with the Newton Nm1 microscope for intestinal protozoa in a laboratory set-up. The Newton Nm1 microscope demonstrated excellent diagnostic sensitivity and specificity for schistosomiasis and intestinal protozoa. The CellScope had high specificity but only modest sensitivity for schistosomiasis diagnosis. Taken together, handheld diagnostic tools show promise to improve the quality of clinical and public health care delivered in resource-constrained settings.
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568
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Golden A, Faulx D, Kalnoky M, Stevens E, Yokobe L, Peck R, Karabou P, Banla M, Rao R, Adade K, Gantin RG, Komlan K, Soboslay PT, de Los Santos T, Domingo GJ. Analysis of age-dependent trends in Ov16 IgG4 seroprevalence to onchocerciasis. Parasit Vectors 2016; 9:338. [PMID: 27296630 PMCID: PMC4907250 DOI: 10.1186/s13071-016-1623-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/02/2016] [Indexed: 11/30/2022] Open
Abstract
Background Diagnostics provide a means to measure progress toward disease elimination. Many countries in Africa are approaching elimination of onchocerciasis after successful implementation of mass drug administration programs as well as vector control. An understanding of how markers for infection such as skin snip microfilaria and Onchocerca volvulus-specific seroconversion perform in near-elimination settings informs how to best use these markers. Methods All-age participants from 35 villages in Togo were surveyed in 2013 and 2014 for skin snip Onchocerca volvulus microfilaria and IgG4 antibody response by enzyme-linked immunosorbent assay (ELISA) to the Onchocerca volvulus-specific antigen Ov16. A Gaussian mixture model applying the expectation-maximization (EM) algorithm was used to determine seropositivity from Ov16 ELISA data. For a subset of participants (n = 434), polymerase chain reaction (PCR) was performed on the skin snips taken during surveillance. Results Within the 2,005 participants for which there was Ov16 ELISA data, O. volvulus microfilaremia prevalence and Ov16 seroprevalence were, 2.5 and 19.7 %, respectively, in the total population, and 1.6 and 3.6 % in children under 11. In the subset of 434 specimens for which ELISA, PCR, and microscopy data were generated, it was found that in children under 11 years of age, the anti-Ov16 IgG4 antibody response demonstrate a sensitivity and specificity of 80 and 97 %, respectively, against active infections as determined by combined PCR and microscopy on skin snips. Further analysis was performed in 34 of the 35 villages surveyed. These villages were stratified by all-age seroprevalence into three clusters: < 15 %; 15–20 %; and > 20 %. Age-dependence of seroprevalence for each cluster was best reflected by a two-phase force-of-infection (FOI) catalytic model. In all clusters, the lower of the two phases of FOI was associated with a younger age group, as reflected by the seroconversion rates for each phase. The age at which transition from lower to higher seroconversion, between the two phases of FOI, was found to be highest (older) for the cluster of villages with < 15 % seroprevalence and lowest (younger) for the cluster with the highest all-age seroprevalence. Conclusions The anti-Ov16 IgG4 antibody response is an accurate marker for active infection in children under 11 years of age in this population. Applying Ov16 surveillance to a broader age range provides additional valuable information for understanding progression toward elimination and can inform where targeted augmented interventions may be needed. Clustering of villages by all-age sero-surveillance allowed application of a biphasic FOI model to differentiate seroconversion rates for different age groups within the village cluster categories. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1623-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Dunia Faulx
- Diagnostics Global Program, PATH, Seattle, WA, USA
| | | | - Eric Stevens
- Diagnostics Global Program, PATH, Seattle, WA, USA
| | | | - Roger Peck
- Diagnostics Global Program, PATH, Seattle, WA, USA
| | | | - Méba Banla
- Onchocerciasis Reference Laboratory, National Institute of Hygiene, Sokodé, Togo
| | | | - Kangi Adade
- National Onchocerciasis Control Programme, Kara, Togo
| | - Richard G Gantin
- Onchocerciasis Reference Laboratory, National Institute of Hygiene, Sokodé, Togo
| | - Kossi Komlan
- Onchocerciasis Reference Laboratory, National Institute of Hygiene, Sokodé, Togo
| | - Peter T Soboslay
- Onchocerciasis Reference Laboratory, National Institute of Hygiene, Sokodé, Togo.,Institute of Tropical Medicine, University Clinics of Tübingen, Tübingen, Germany
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De Pablos LM, Díaz Lozano IM, Jercic MI, Quinzada M, Giménez MJ, Calabuig E, Espino AM, Schijman AG, Zulantay I, Apt W, Osuna A. The C-terminal region of Trypanosoma cruzi MASPs is antigenic and secreted via exovesicles. Sci Rep 2016; 6:27293. [PMID: 27270330 PMCID: PMC4897614 DOI: 10.1038/srep27293] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 05/17/2016] [Indexed: 01/08/2023] Open
Abstract
Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected and emerging tropical disease, endemic to South America and present in non-endemic regions due to human migration. The MASP multigene family is specific to T. cruzi, accounting for 6% of the parasite’s genome and plays a key role in immune evasion. A common feature of MASPs is the presence of two conserved regions: an N-terminal region codifying for signal peptide and a C-terminal (C-term) region, which potentially acts as GPI-addition signal peptide. Our aim was the analysis of the presence of an immune response against the MASP C-term region. We found that this region is highly conserved, released via exovesicles (EVs) and has an associated immune response as revealed by epitope affinity mapping, IFA and inhibition of the complement lysis assays. We also demonstrate the presence of a fast IgM response in Balb/c mice infected with T. cruzi. Our results reveal the presence of non-canonical secreted peptides in EVs, which can subsequently be exposed to the immune system with a potential role in evading immune system targets in the parasite.
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Affiliation(s)
- Luis Miguel De Pablos
- Departamento de Parasitología, Grupo de Bioquímica y Parasitología Molecular, Campus de Fuentenueva, Universidad de Granada, 18071 Granada, Spain.,Center for Immunology and Infection (CII), Biology Department, University of York, York, UK
| | - Isabel María Díaz Lozano
- Departamento de Parasitología, Grupo de Bioquímica y Parasitología Molecular, Campus de Fuentenueva, Universidad de Granada, 18071 Granada, Spain
| | - Maria Isabel Jercic
- Parasitology Reference Laboratory, Instituto de Salud Pública de Chile, Avenida Marathon 1000, 7780050 Santiago, Chile
| | - Markela Quinzada
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Panamá, República de Panamá
| | - Maria José Giménez
- Servicio de Microbiología Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Eva Calabuig
- Servicio de Microbiología Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Ana Margarita Espino
- Laboratory of Immunology and Molecular Parasitology, Department of Microbiology, University of Puerto Rico, School of Medicine. PO BOX 365067, San Juan, 00936-5067, Puerto Rico
| | | | - Inés Zulantay
- Laboratorio de Parasitología Básico-Clínico, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Werner Apt
- Laboratorio de Parasitología Básico-Clínico, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Antonio Osuna
- Departamento de Parasitología, Grupo de Bioquímica y Parasitología Molecular, Campus de Fuentenueva, Universidad de Granada, 18071 Granada, Spain
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570
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Hotez PJ, Beaumier CM, Gillespie PM, Strych U, Hayward T, Bottazzi ME. Advancing a vaccine to prevent hookworm disease and anemia. Vaccine 2016; 34:3001-3005. [DOI: 10.1016/j.vaccine.2016.03.078] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 03/11/2016] [Indexed: 01/30/2023]
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571
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Gyawali P, Sidhu J, Ahmed W, Jagals P, Toze S. An approach to reduce false viability assessment of hookworm eggs with vital stains. Food Waterborne Parasitol 2016. [DOI: 10.1016/j.fawpar.2016.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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572
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Hotez PJ, Strych U, Lustigman S, Bottazzi ME. Human anthelminthic vaccines: Rationale and challenges. Vaccine 2016; 34:3549-55. [DOI: 10.1016/j.vaccine.2016.03.112] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/23/2016] [Accepted: 03/31/2016] [Indexed: 12/29/2022]
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573
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Status of vaccine research and development of vaccines for Chagas disease. Vaccine 2016; 34:2996-3000. [DOI: 10.1016/j.vaccine.2016.03.074] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 03/09/2016] [Indexed: 12/12/2022]
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574
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A systematic review of pentacyclic triterpenes and their derivatives as chemotherapeutic agents against tropical parasitic diseases. Parasitology 2016; 143:1219-31. [PMID: 27240847 DOI: 10.1017/s0031182016000718] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Parasitic infections are among the leading global public health problems with very high economic and mortality burdens. Unfortunately, the available treatment drugs are beset with side effects and continuous parasite drug resistance is being reported. However, new findings reveal more promising compounds especially of plant origin. Among the promising leads are the pentacyclic triterpenes (PTs) made up of the oleanane, ursane, taraxastane, lupane and hopane types. This paper reviews the literature published from 1985 to date on the in vitro and in vivo anti-parasitic potency of this class of phytochemicals. Of the 191 natural and synthetic PT reported, 85 have shown high anti-parasitic activity against various species belonging to the genera of Plasmodium, Leishmania, Trypanosoma, as well as various genera of Nematoda. Moreover, structural modification especially at carbon 3 (C3) and C27 of the parent backbone of PT has led to improved anti-parasitic activity in some cases and loss of activity in others. The potential of this group of compounds as future alternatives in the treatment of parasitic diseases is discussed. It is hoped that the information presented herein will contribute to the full exploration of this promising group of compounds as possible drugs for parasitic diseases.
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575
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Gyawali P, Beale DJ, Ahmed W, Karpe AV, Magalhaes RJS, Morrison PD, Palombo EA. Determination of Ancylostoma caninum ova viability using metabolic profiling. Parasitol Res 2016; 115:3485-92. [PMID: 27236650 DOI: 10.1007/s00436-016-5112-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 05/04/2016] [Indexed: 01/05/2023]
Abstract
Differentiation between viable and non-viable hookworm ova in environmental samples is necessary in order to implement strategies to mitigate re-infections in endemic regions. In this study, an untargeted metabolic profiling method was developed that utilised gas chromatography-mass spectrometry (GC-MS) in order to investigate hookworm ova viability. Ancylostoma caninum was used to investigate the metabolites within viable and non-viable ova. Univariate and multivariate statistical analyses of the data resulted in the identification of 53 significant metabolites across all hookworm ova samples. The major compounds observed in viable and non-viable hookworm ova were tetradecanoic acid, commonly known as myristic acid [fold change (FC) = 0.4], and dodecanoic acid, commonly known as lauric acid (FC = 0.388). Additionally, the viable ova had self-protecting metabolites such as prostaglandins, a typical feature absent in non-viable ova. The results of this study demonstrate that metabolic profiling using GC-MS methods can be used to determine the viability of canine hookworm ova. Further studies are needed to assess the applicability of metabolic profiling using GC-MS to detect viable hookworm ova in the mixed (viable and non-viable) populations from environmental samples and identify the metabolites specific to human hookworm species.
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Affiliation(s)
- P Gyawali
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane, Queensland, 4102, Australia. .,School of Public Health, University of Queensland, Herston Road, Brisbane, Queensland, 4006, Australia.
| | - D J Beale
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane, Queensland, 4102, Australia
| | - W Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane, Queensland, 4102, Australia
| | - A V Karpe
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane, Queensland, 4102, Australia.,Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, 3122, Australia
| | - R J Soares Magalhaes
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, 4343, Australia.,Children's Health Research Centre, The University of Queensland, South Brisbane, Queensland, 4101, Australia
| | - P D Morrison
- Australian Centre for Research on Separation Science (ACROSS), School of Applied Sciences, RMIT University, Melbourne, Victoria, 3001, Australia
| | - E A Palombo
- Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, 3122, Australia
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576
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Kunwar R, Acharya L, Karki S. Trends in prevalence of soil-transmitted helminth and major intestinal protozoan infections among school-aged children in Nepal. Trop Med Int Health 2016; 21:703-19. [PMID: 27097973 DOI: 10.1111/tmi.12700] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVES To assess the trends in prevalence of soil-transmitted helminths (STHs), Entamoeba histolytica and Giardia lamblia among school-aged children in Nepal between 1990 and 2015. METHODS Systematic literature search in PubMed, MEDLINE, EMBASE, Google Scholar and local peer-reviewed journals for papers published between 1990 and December 2015. We conducted metaregression and meta-analyses to pool studies where applicable. RESULTS Thirty-nine studies that examined a total of 14 729 stool specimens were included in the meta-analyses. The metaregression of prevalence of hookworms, roundworm, and whipworm showed a significantly decreasing trend over time. In or after 2004, the pooled prevalence of hookworm infections was 1.53% (95% CI, 0.73-2.59), of roundworm 4.31% (95% CI, 2.52-6.53) and of whipworm 2.89% (95% CI, 1.33-4.97) vs. 16.54% (95% CI, 7.64-27.97) for hookworm, 25.20% (95% CI, 13.59-38.97) for roundworm and 11.54% (95% CI 4.25-21.76) for whipworm in 1993-2003. E. histolytica and G. lamblia had stable prevalence since early 1990s, with a pooled prevalences of 4.12% (95% CI, 2.73-5.77) and 9.40% (95% CI, 7.15-11.92), respectively. The prevalence of G. lamblia was significantly higher in urban areas. CONCLUSIONS We observed a sharp decrease in prevalence of STHs among school-aged children in Nepal in the past decade with prevalences dropping below 5% for STHs with no variation in prevalence in rural and urban areas. However, the prevalence of E. histolytica and G. lamblia remained stable over time. These results suggest that school-based deworming programmes rolled out during the study period had an observable impact on prevalence of STHs.
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Affiliation(s)
- Ritu Kunwar
- School of Public Health and Community Medicine, University of New South Wales, New South Wales, Australia
| | - Lokendra Acharya
- Kathmandu Medical College, Kathmandu University, Kathmandu, Nepal
| | - Surendra Karki
- School of Public Health and Community Medicine, University of New South Wales, New South Wales, Australia
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577
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Drabo F, Ouedraogo H, Bougma R, Bougouma C, Bamba I, Zongo D, Bagayan M, Barrett L, Yago-Wienne F, Palmer S, Chu B, Toubali E, Zhang Y. Successful Control of Soil-Transmitted Helminthiasis in School Age Children in Burkina Faso and an Example of Community-Based Assessment via Lymphatic Filariasis Transmission Assessment Survey. PLoS Negl Trop Dis 2016; 10:e0004707. [PMID: 27163294 PMCID: PMC4862685 DOI: 10.1371/journal.pntd.0004707] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 04/22/2016] [Indexed: 01/10/2023] Open
Abstract
Background Burkina Faso is endemic with soil-transmitted helminth infections. Over a decade of preventive chemotherapy has been implemented through annual lymphatic filariasis (LF) mass drug administration (MDA) for population aged five years and over, biennial treatment of school age children with albendazole together with schistosomiasis MDA and biannual treatment of pre-school age children through Child Health Days. Assessments were conducted to evaluate the current situation and to determine the treatment strategy for the future. Methodology/Principal Findings A cross-sectional assessment was conducted in 22 sentinel sites across the country in 2013. In total, 3,514 school age children (1,748 boys and 1,766 girls) were examined by the Kato-Katz method. Overall, soil-transmitted helminth prevalence was 1.3% (95% CI: 1.0–1.8%) in children examined. Hookworm was the main species detected, with prevalence of 1.2% (95% CI: 0.9–1.6%) and mean egg counts of 2.1 epg (95% CI: 0–4.2 epg). Among regions, the Centre Ouest region had the highest hookworm prevalence of 3.4% (95% CI: 1.9–6.1%) and mean egg counts of 14.9 epg (95% CI: 3.3–26.6 epg). A separate assessment was conducted in the Centre Nord region in 2014 using community-based cluster survey design during an LF transmission assessment survey (TAS). In this assessment, 351 children aged 6–7 years and 345 children aged 10–14 years were examined, with two cases (0.6% (95% CI: 0.2–2.1%)) and seven cases (2.0% (95% CI: 1.0–4.1%)) of hookworm infection was identified respectively. The results using both age groups categorized the region to be 2% to <10% in STH prevalence according to the pre-defined cut-off values. Conclusions/Significance Through large-scale preventive chemotherapy, Burkina Faso has effectively controlled STH in school age children in the country. Research should be conducted on future strategies to consolidate the gain and to interrupt STH transmission in Burkina Faso. It is also demonstrated that LF TAS provides one feasible and efficient platform to assess the STH situation for post LF MDA decision making. Burkina Faso is a West African country endemic with soil-transmitted helminth infections (STH). Mass treatment with albendazole has been implemented for over a decade in the country through annual mass drug administration (MDA) for lymphatic filariasis for population aged five years and over, biennial treatment of school age children with albendazole together with schistosomiasis MDA, and biannual treatment of pre-school age children through Child Health Days. A sentinel site survey in 2013 showed that STH infection in Burkina Faso was very low at 1.3%. Hookworm was the main species detected, but infection was low and light. An assessment was also conducted with two age groups in Centre Nord region through lymphatic filariasis transmission assessment survey in 2014. The results confirmed the low level of infection with soil-transmitted helminths in the region. Through large-scale preventive chemotherapy, Burkina Faso has effectively controlled STH in school age children in the country. The future STH deworming strategy may focus on consolidating the gain and interrupting the STH transmission in the country.
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Affiliation(s)
- François Drabo
- Programme National de Lutte contre les Maladies Tropicales Négligées, Direction de la Lutte contre la Maladies, Ministère de la Santé, Ouagadougou, Burkina Faso
| | - Hamado Ouedraogo
- Programme National de Lutte contre les Maladies Tropicales Négligées, Direction de la Lutte contre la Maladies, Ministère de la Santé, Ouagadougou, Burkina Faso
| | - Roland Bougma
- Programme National de Lutte contre les Maladies Tropicales Négligées, Direction de la Lutte contre la Maladies, Ministère de la Santé, Ouagadougou, Burkina Faso
| | - Clarisse Bougouma
- Programme National de Lutte contre les Maladies Tropicales Négligées, Direction de la Lutte contre la Maladies, Ministère de la Santé, Ouagadougou, Burkina Faso
| | - Issouf Bamba
- Helen Keller International, Ouagadougou, Burkina Faso
| | - Dramane Zongo
- Health Sciences Research Institute (IRSS), Ouagadougou, Burkina Faso
| | - Mohamed Bagayan
- Health Sciences Research Institute (IRSS), Ouagadougou, Burkina Faso
- University of Ouagadougou, Ouagadougou, Burkina Faso
| | - Laura Barrett
- Helen Keller International, Ouagadougou, Burkina Faso
| | | | - Stephanie Palmer
- Helen Keller International, New York, New York, United States of America
| | - Brian Chu
- Neglected Tropical Diseases Support Center, Task Force for Global Health, Decatur, Georgia, United States of America
| | - Emily Toubali
- Helen Keller International, New York, New York, United States of America
| | - Yaobi Zhang
- Helen Keller International, Regional Office for Africa, Dakar, Senegal
- * E-mail:
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578
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Molehin AJ, Rojo JU, Siddiqui SZ, Gray SA, Carter D, Siddiqui AA. Development of a schistosomiasis vaccine. Expert Rev Vaccines 2016; 15:619-27. [PMID: 26651503 PMCID: PMC5070536 DOI: 10.1586/14760584.2016.1131127] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Schistosomiasis is a neglected tropical disease (NTD) of public health importance. Despite decades of implementation of mass praziquantel therapy programs and other control measures, schistosomiasis has not been contained and continues to spread to new geographic areas. A schistosomiasis vaccine could play an important role as part of a multifaceted control approach. With regards to vaccine development, many biological bottlenecks still exist: the lack of reliable surrogates of protection in humans; immune interactions in co-infections with other diseases in endemic areas; the potential risk of IgE responses to antigens in endemic populations; and paucity of appropriate vaccine efficacy studies in nonhuman primate models. Research is also needed on the role of modern adjuvants targeting specific parts of the innate immune system to tailor a potent and protective immune response for lead schistosome vaccine candidates with the long-term aim to achieve curative worm reduction. This review summarizes the current status of schistosomiasis vaccine development.
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Affiliation(s)
- Adebayo J. Molehin
- Department of Internal Medicine, Texas Tech University School of Medicine, Lubbock, Texas, USA
- Center of Tropical Medicine and Infectious Diseases, Texas Tech University School of Medicine, Lubbock, Texas, USA
| | - Juan U. Rojo
- Department of Internal Medicine, Texas Tech University School of Medicine, Lubbock, Texas, USA
- Center of Tropical Medicine and Infectious Diseases, Texas Tech University School of Medicine, Lubbock, Texas, USA
| | - Sabrina Z. Siddiqui
- Department of Internal Medicine, Texas Tech University School of Medicine, Lubbock, Texas, USA
- Center of Tropical Medicine and Infectious Diseases, Texas Tech University School of Medicine, Lubbock, Texas, USA
| | | | - Darrick Carter
- PAI Life Sciences, Washington, USA
- Infectious Disease Research Institute, Seattle, Washington, USA
| | - Afzal A. Siddiqui
- Department of Internal Medicine, Texas Tech University School of Medicine, Lubbock, Texas, USA
- Center of Tropical Medicine and Infectious Diseases, Texas Tech University School of Medicine, Lubbock, Texas, USA
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579
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Stolk WA, Kulik MC, le Rutte EA, Jacobson J, Richardus JH, de Vlas SJ, Houweling TAJ. Between-Country Inequalities in the Neglected Tropical Disease Burden in 1990 and 2010, with Projections for 2020. PLoS Negl Trop Dis 2016; 10:e0004560. [PMID: 27171193 PMCID: PMC4865216 DOI: 10.1371/journal.pntd.0004560] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 02/28/2016] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The World Health Organization (WHO) has set ambitious time-bound targets for the control and elimination of neglected tropical diseases (NTDs). Investing in NTDs is not only seen as good value for money, but is also advocated as a pro-poor policy since it would improve population health in the poorest populations. We studied the extent to which the disease burden from nine NTDs (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminths, trachoma, Chagas disease, human African trypanosomiasis, leprosy, visceral leishmaniasis) was concentrated in the poorest countries in 1990 and 2010, and how this would change by 2020 in case the WHO targets are met. PRINCIPAL FINDINGS Our analysis was based on 1990 and 2010 data from the Global Burden of Disease (GBD) 2010 study and on projections of the 2020 burden. Low and lower-middle income countries together accounted for 69% and 81% of the global burden in 1990 and 2010 respectively. Only the soil-transmitted helminths and Chagas disease caused a considerable burden in upper-middle income countries. The global burden from these NTDs declined by 27% between 1990 and 2010, but reduction largely came to the benefit of upper-middle income countries. Achieving the WHO targets would lead to a further 55% reduction in the global burden between 2010 and 2020 in each country income group, and 81% of the global reduction would occur in low and lower-middle income countries. CONCLUSIONS The GBD 2010 data show the burden of the nine selected NTDs in DALYs is strongly concentrated in low and lower-middle income countries, which implies that the beneficial impact of NTD control eventually also largely comes to the benefit of these same countries. While the nine NTDs became increasingly concentrated in developing countries in the 1990-2010 period, this trend would be rectified if the WHO targets were met, supporting the pro-poor designation.
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Affiliation(s)
- Wilma A. Stolk
- Department of Public Health, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Margarete C. Kulik
- Department of Public Health, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Center for Tobacco Control Research and Education, University of California, San Francisco, San Francisco, California, United States of America
| | - Epke A. le Rutte
- Department of Public Health, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Julie Jacobson
- Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Jan Hendrik Richardus
- Department of Public Health, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Sake J. de Vlas
- Department of Public Health, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Tanja A. J. Houweling
- Department of Public Health, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
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580
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Kosinski KC, Kulinkina AV, Abrah AFA, Adjei MN, Breen KM, Chaudhry HM, Nevin PE, Warner SH, Tendulkar SA. A mixed-methods approach to understanding water use and water infrastructure in a schistosomiasis-endemic community: case study of Asamama, Ghana. BMC Public Health 2016; 16:322. [PMID: 27076042 PMCID: PMC4831178 DOI: 10.1186/s12889-016-2976-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 03/23/2016] [Indexed: 12/20/2022] Open
Abstract
Background Surface water contaminated with human waste may transmit urogenital schistosomiasis (UGS). Water-related activities that allow skin exposure place people at risk, but public health practitioners know little about why some communities with access to improved water infrastructure have substantial surface water contact with infectious water bodies. Community-based mixed-methods research can provide critical information about water use and water infrastructure improvements. Methods Our mixed-methods study assessed the context of water use in a rural community endemic for schistosomiasis. Results Eighty-seven (35.2 %) households reported using river water but not borehole water; 26 (10.5 %) reported using borehole water but not river water; and 133 (53.8 %) households reported using both water sources. All households are within 1 km of borehole wells, but tested water quality was poor in most wells. Schistosomiasis is perceived by study households (89.3 %) to be a widespread problem in the community, but perceived schistosomiasis risk fails to deter households from river water usage. Hematuria prevalence among schoolchildren does not differ by household water use preference. Focus group data provides context for water preferences. Demand for improvements to water infrastructure was a persistent theme; however, roles and responsibilities with respect to addressing community water and health concerns are ill-defined. Conclusions Collectively, our study illustrates how complex attitudes towards water resources can affect which methods will be appropriate to address schistosomiasis.
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Affiliation(s)
- Karen Claire Kosinski
- Department of Community Health, Tufts University, 574 Boston Avenue, Medford, Massachusetts, 02155, USA.
| | - Alexandra V Kulinkina
- Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, 02155, USA
| | | | | | | | | | - Paul E Nevin
- Department of Global Health, University of Washington, Seattle, Washington, 98112, USA
| | | | - Shalini Ahuja Tendulkar
- Department of Community Health, Tufts University, 574 Boston Avenue, Medford, Massachusetts, 02155, USA
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581
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Kroidl I, Saathof E, Maganga L, Clowes P, Maboko L, Hoerauf A, Makunde WH, Haule A, Mviombo P, Pitter B, Mgeni N, Mabuye J, Kowuor D, Mwingira U, Malecela MN, Löscher T, Hoelscher M. Prevalence of Lymphatic Filariasis and Treatment Effectiveness of Albendazole/ Ivermectin in Individuals with HIV Co-infection in Southwest-Tanzania. PLoS Negl Trop Dis 2016; 10:e0004618. [PMID: 27070786 PMCID: PMC4829227 DOI: 10.1371/journal.pntd.0004618] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 03/18/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Annual mass treatment with ivermectin and albendazole is used to treat lymphatic filariasis in many African countries, including Tanzania. In areas where both diseases occur, it is unclear whether HIV co-infection reduces treatment success. METHODOLOGY In a general population study in Southwest Tanzania, individuals were tested for HIV and circulating filarial antigen, an indicator of Wuchereria bancrofti adult worm burden, before the first and after 2 consecutive rounds of anti-filarial mass drug administration. PRINCIPLE FINDINGS Testing of 2104 individuals aged 0-94 years before anti-filarial treatment revealed a prevalence of 24.8% for lymphatic filariasis and an HIV-prevalence of 8.9%. Lymphatic filariasis was rare in children, but prevalence increased in individuals above 10 years, whereas a strong increase in HIV was only seen above 18 years of age. The prevalence of lymphatic filariasis in adults above 18 years was 42.6% and 41.7% (p = 0.834) in HIV-negatives and-positives, respectively. Similarly, the HIV prevalence in the lymphatic filariasis infected (16.6%) and uninfected adult population (17.1%) was nearly the same. Of the above 2104 individuals 798 were re-tested after 2 rounds of antifilarial treatment. A significant reduction in the prevalence of circulating filarial antigen from 21.6% to 19.7% was found after treatment (relative drop of 8.8%, McNemar's exact p = 0.036). Furthermore, the post-treatment reduction of CFA positivity was (non-significantly) larger in HIV-positives than in HIV-negatives (univariable linear regression p = 0.154). CONCLUSION/SIGNIFICANCE In an area with a high prevalence for both diseases, no difference was found between HIV-infected and uninfected individuals regarding the initial prevalence of lymphatic filariasis. A moderate but significant reduction in lymphatic filariasis prevalence and worm burden was demonstrated after two rounds of treatment with albendazole and ivermectin. Treatment effects were more pronounced in the HIV co-infected subgroup, indicating that the effectiveness of antifilarial treatment was not reduced by concomitant HIV-infection. Studies with longer follow-up time could validate the observed differences in treatment effectiveness.
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Affiliation(s)
- Inge Kroidl
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
- * E-mail:
| | - Elmar Saathof
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- German Center for Infection Research (DZIF), Munich, Germany
| | - Lucas Maganga
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Petra Clowes
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Leonard Maboko
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Achim Hoerauf
- German Center for Infection Research (DZIF), Bonn-Cologne, Germany
- Institute of Medical Microbiology, Immunology and Parasitology, Bonn, Germany
| | | | - Antelmo Haule
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Prisca Mviombo
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Bettina Pitter
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Neema Mgeni
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Joseph Mabuye
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Dickens Kowuor
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
| | - Upendo Mwingira
- National Institute of Medical Research (NIMR), Dar es Salaam, Tanzania
| | | | - Thomas Löscher
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
| | - Michael Hoelscher
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- National Institute of Medical Research (NIMR)-Mbeya Medical Research Centre (MMRC), Mbeya, Tanzania
- German Center for Infection Research (DZIF), Munich, Germany
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Xu J, Bergquist R, Qian YJ, Wang Q, Yu Q, Peeling R, Croft S, Guo JG, Zhou XN. China-Africa and China-Asia Collaboration on Schistosomiasis Control: A SWOT Analysis. ADVANCES IN PARASITOLOGY 2016; 92:435-66. [PMID: 27137455 DOI: 10.1016/bs.apar.2016.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Schistosomiasis, a disease caused by a trematode, parasitic worm, is a worldwide public health problem. In spite of great progress with regard to morbidity control, even elimination of this infection in recent decades, there are still challenges to overcome in sub-Saharan Africa and endemic areas in Southeast Asia. Regarded as one of the most successful countries with respect to schistosomiasis control, The People's Republic of China has accumulated considerable experience and learnt important lessons in various local settings that could benefit schistosomiasis control in other endemic countries. Based on an analysis of conceived strengths, weaknesses, opportunities and threats (SWOT) of potential collaborative activities with regard to schistosomiasis in Africa and Asia, this article addresses the importance of collaborative efforts and explores the priorities that would be expected to facilitate the transfer of Chinese experience to low- and middle-income countries in Africa and Asia.
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Affiliation(s)
- J Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| | - R Bergquist
- Geospatial Health, University of Naples Federico II, Naples, Italy
| | - Y-J Qian
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| | - Q Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| | - Q Yu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| | - R Peeling
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - S Croft
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - J-G Guo
- World Health Organization, Geneva, Switzerland
| | - X-N Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
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583
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Cai P, Liu S, Piao X, Hou N, Gobert GN, McManus DP, Chen Q. Comprehensive Transcriptome Analysis of Sex-Biased Expressed Genes Reveals Discrete Biological and Physiological Features of Male and Female Schistosoma japonicum. PLoS Negl Trop Dis 2016; 10:e0004684. [PMID: 27128440 PMCID: PMC4851400 DOI: 10.1371/journal.pntd.0004684] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 04/12/2016] [Indexed: 12/23/2022] Open
Abstract
Schistosomiasis is a chronic and debilitating disease caused by blood flukes (digenetic trematodes) of the genus Schistosoma. Schistosomes are sexually dimorphic and exhibit dramatic morphological changes during a complex lifecycle which requires subtle gene regulatory mechanisms to fulfil these complex biological processes. In the current study, a 41,982 features custom DNA microarray, which represents the most comprehensive probe coverage for any schistosome transcriptome study, was designed based on public domain and local databases to explore differential gene expression in S. japonicum. We found that approximately 1/10 of the total annotated genes in the S. japonicum genome are differentially expressed between adult males and females. In general, genes associated with the cytoskeleton, and motor and neuronal activities were readily expressed in male adult worms, whereas genes involved in amino acid metabolism, nucleotide biosynthesis, gluconeogenesis, glycosylation, cell cycle processes, DNA synthesis and genome fidelity and stability were enriched in females. Further, miRNAs target sites within these gene sets were predicted, which provides a scenario whereby the miRNAs potentially regulate these sex-biased expressed genes. The study significantly expands the expressional and regulatory characteristics of gender-biased expressed genes in schistosomes with high accuracy. The data provide a better appreciation of the biological and physiological features of male and female schistosome parasites, which may lead to novel vaccine targets and the development of new therapeutic interventions.
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Affiliation(s)
- Pengfei Cai
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P.R. China
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Queensland, Australia
| | - Shuai Liu
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P.R. China
| | - Xianyu Piao
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P.R. China
| | - Nan Hou
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P.R. China
| | - Geoffrey N. Gobert
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Queensland, Australia
| | - Donald P. McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Queensland, Australia
| | - Qijun Chen
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P.R. China
- Key Laboratory of Zoonosis, Shenyang Agriculture University, Shenyang, P.R. China
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584
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Merrifield M, Hotez PJ, Beaumier CM, Gillespie P, Strych U, Hayward T, Bottazzi ME. Advancing a vaccine to prevent human schistosomiasis. Vaccine 2016; 34:2988-2991. [PMID: 27036511 DOI: 10.1016/j.vaccine.2016.03.079] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 03/11/2016] [Indexed: 12/15/2022]
Abstract
Several candidate human schistosomiasis vaccines are in different stages of preclinical and clinical development. The major targets are Schistosoma haematobium (urogenitial schistosomiasis) and Schistosoma mansoni (intestinal schistosomiasis) that account for 99% of the world's 252 million cases, with 90% of these cases in Africa. Two recombinant S. mansoni vaccines - Sm-TSP-2 and Sm-14 are in Phase 1 trials, while Smp80 (calpain) is undergoing testing in non-human primates. Sh28GST, also known as Bilhvax is in advanced clinical development for S. haematobium infection. The possibility remains that some of these vaccines may cross-react to target both schistosome species. These vaccines were selected on the basis of their protective immunity in preclinical challenge models, through human immune-epidemiological studies or both. They are being advanced through a combination of academic research institutions, non-profit vaccine product development partnerships, biotechnology companies, and developing country vaccine manufacturers. In addition, new schistosome candidate vaccines are being identified through bioinformatics, OMICs approaches, and moderate throughput screening, although the full potential of reverse vaccinology for schistosomiasis has not yet been realized. The target product profiles of these vaccines vary but many focus on vaccinating children, in some cases following mass treatment with praziquantel, also known as vaccine-linked chemotherapy. Several regulatory pathways have been proposed, some of which rely on World Health Organization prequalification.
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Affiliation(s)
- Maureen Merrifield
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development Houston, TX, USA; Sabin Vaccine Institute, Washington, DC, USA
| | - Peter J Hotez
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development Houston, TX, USA; Sabin Vaccine Institute, Washington, DC, USA; National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA; Department of Biology, Baylor University, Waco, TX, USA.
| | - Coreen M Beaumier
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development Houston, TX, USA; National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Portia Gillespie
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development Houston, TX, USA; National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Ulrich Strych
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development Houston, TX, USA; National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | | | - Maria Elena Bottazzi
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development Houston, TX, USA; Sabin Vaccine Institute, Washington, DC, USA; National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA; Department of Biology, Baylor University, Waco, TX, USA
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585
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Weerakoon KG, Gordon CA, Gobert GN, Cai P, McManus DP. Optimisation of a droplet digital PCR assay for the diagnosis of Schistosoma japonicum infection: A duplex approach with DNA binding dye chemistry. J Microbiol Methods 2016; 125:19-27. [PMID: 27021661 DOI: 10.1016/j.mimet.2016.03.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/03/2016] [Accepted: 03/21/2016] [Indexed: 11/19/2022]
Abstract
Schistosomiasis is a chronically debilitating helminth infection with a significant socio-economic and public health impact. Accurate diagnostics play a pivotal role in achieving current schistosomiasis control and elimination goals. However, many of the current diagnostic procedures, which rely on detection of schistosome eggs, have major limitations including lack of accuracy and the inability to detect pre-patent infections. DNA-based detection methods provide a viable alternative to the current tests commonly used for schistosomiasis diagnosis. Here we describe the optimisation of a novel droplet digital PCR (ddPCR) duplex assay for the diagnosis of Schistosoma japonicum infection which provides improved detection sensitivity and specificity. The assay involves the amplification of two specific and abundant target gene sequences in S. japonicum; a retrotransposon (SjR2) and a portion of a mitochondrial gene (nad1). The assay detected target sequences in different sources of schistosome DNA isolated from adult worms, schistosomules and eggs, and exhibits a high level of specificity, thereby representing an ideal tool for the detection of low levels of parasite DNA in different clinical samples including parasite cell free DNA in the host circulation and other bodily fluids. Moreover, being quantitative, the assay can be used to determine parasite infection intensity and, could provide an important tool for the detection of low intensity infections in low prevalence schistosomiasis-endemic areas.
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Affiliation(s)
- Kosala G Weerakoon
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia; School of Public Health, University of Queensland, Brisbane, Australia; Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka.
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Geoffrey N Gobert
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Pengfei Cai
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Donald P McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
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586
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587
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Mounsey KE, Bernigaud C, Chosidow O, McCarthy JS. Prospects for Moxidectin as a New Oral Treatment for Human Scabies. PLoS Negl Trop Dis 2016; 10:e0004389. [PMID: 26985995 PMCID: PMC4795782 DOI: 10.1371/journal.pntd.0004389] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Kate E. Mounsey
- Inflammation & Healing Research Cluster, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
- Infectious Diseases & Immunology Division, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- * E-mail:
| | | | - Olivier Chosidow
- Dermatology Department, Henri Mondor Hospital, AP-HP, UPEC, Créteil, France
- Université Paris-est Créteil Val de Marne, Créteil, France
| | - James S. McCarthy
- Infectious Diseases & Immunology Division, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
- School of Medicine, University of Queensland, Herston, Queensland, Australia
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588
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Bhaumik S, Karimkhani C, Czaja CA, Williams HC, Rani M, Nasser M, Boyers LN, Dmitruk S, Dellavalle RP. Identifying gaps in research prioritization: The global burden of neglected tropical diseases as reflected in the Cochrane database of systematic reviews. J Family Med Prim Care 2016; 4:507-13. [PMID: 26985407 PMCID: PMC4776600 DOI: 10.4103/2249-4863.174266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background: Neglected tropical diseases (NTDs) impact disadvantaged populations in resource-scarce settings. Availability of synthesized evidence is paramount to end this disparity. The aim of the study was to determine whether NTD systematic reviews or protocols in the Cochrane Database of Systematic Reviews (CDSR) reflect disease burden. Methods: Two authors independently searched the CDSR for reviews/protocols regarding the NTDs diseases. Each review or protocol was classified to a single NTD category. Any discrepancy was solved by consensus with third author. NTD systematic review or protocol from CDSR were matched with disability-adjusted life year (DALY) metrics from the Global Burden of Disease 2010 Study. Spearman's rank correlation coefficient and associated P values were used to assess for correlation between the number of systematic reviews and protocols and the %2010 DALY associated with each NTD. Results: Overall, there was poor correlation between CDSR representation and DALYs. Yellow fever, echinococcus, onchocerciasis, and schistosomiasis representation was well-aligned with DALY. Leprosy, trachoma, dengue, leishmaniasis, and Chagas disease representation was greater, while cysticercosis, human African trypanosomiasis, ascariasis, lymphatic filariasis, and hookworm representation was lower than DALY. Three of the 18 NTDs had reviews/protocols of diagnostic test accuracy. Conclusions: Our results indicate the need for increased prioritization of systematic reviews on NTDs, particularly diagnostic test accuracy reviews.
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Affiliation(s)
- Soumyadeep Bhaumik
- Journal of Family Medicine and Primary Care, India; Cochrane Priority Setting Methods Group, United Kingdom
| | - Chante Karimkhani
- College of Physicians and Surgeons, Columbia University New York, USA
| | - Christopher A Czaja
- Department of Family Medicine, University of Colorado School of Medicine, Aurora; Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Colorado, USA
| | - Hywel C Williams
- Centre of Evidence Based Dermatology, University of Nottingham, Nottingham, UK
| | - Monica Rani
- Department of Dermatology and Internal Medicine, Northwestern University, Chicago, IL, USA
| | - Mona Nasser
- Cochrane Priority Setting Methods Group, United Kingdom; Evidence Based Dentistry, Peninsula Dental School, Plymouth University, Plymouth, UK
| | | | - Sergei Dmitruk
- Department of Family Medicine, University of Colorado School of Medicine, Aurora
| | - Robert P Dellavalle
- Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Colorado, USA; Department of Dermatology, University of Colorado Anschutz Medical Campus, Aurora; Department of Dermatology, Denver Veterans Administration Hospital, Denver, Colorado, USA
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589
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Gillespie PM, Beaumier CM, Strych U, Hayward T, Hotez PJ, Bottazzi ME. Status of vaccine research and development of vaccines for leishmaniasis. Vaccine 2016; 34:2992-2995. [PMID: 26973063 DOI: 10.1016/j.vaccine.2015.12.071] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 12/31/2015] [Indexed: 01/15/2023]
Abstract
A number of leishmaniasis vaccine candidates are at various stages of pre-clinical and clinical development. Leishmaniasis is a vector-borne neglected tropical disease (NTD) caused by a protozoan parasite of the genus Leishmania and transmitted to humans by the bite of a sand fly. Visceral leishmaniasis (VL, kala-azar) is a high mortality NTD found mostly in South Asia and East Africa, while cutaneous leishmaniasis (CL) is a disfiguring NTD highly endemic in the Middle East, Central Asia, North Africa, and the Americas. Estimates attribute 50,000 annual deaths and 3.3 million disability-adjusted life years to leishmaniasis. There are only a few approved drug treatments, no prophylactic drug and no vaccine. Ideally, an effective vaccine against leishmaniasis will elicit long-lasting immunity and protect broadly against VL and CL. Vaccines such as Leish-F1, F2 and F3, developed at IDRI and designed based on selected Leishmania antigen epitopes, have been in clinical trials. Other groups, including the Sabin Vaccine Institute in collaboration with the National Institutes of Health are investigating recombinant Leishmania antigens in combination with selected sand fly salivary gland antigens in order to augment host immunity. To date, both VL and CL vaccines have been shown to be cost-effective in economic modeling studies.
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Affiliation(s)
- Portia M Gillespie
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA
| | - Coreen M Beaumier
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA
| | - Ulrich Strych
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA
| | | | - Peter J Hotez
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA; Sabin Vaccine Institute, Washington, DC, USA; Department of Biology, Baylor University, Waco, TX, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Maria Elena Bottazzi
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Houston, TX, USA; Sabin Vaccine Institute, Washington, DC, USA; Department of Biology, Baylor University, Waco, TX, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
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590
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Shi L, Fu S, Wang L, Li X, Gu D, Liu C, Zhao C, He J, Liang G. Surveillance of mosquito-borne infectious diseases in febrile travelers entering China via Shenzhen ports, China, 2013. Travel Med Infect Dis 2016; 14:123-30. [PMID: 26960752 DOI: 10.1016/j.tmaid.2016.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 02/09/2016] [Accepted: 02/25/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND About 100 million passengers enter China via Shenzhen ports every year and such huge populations increase the risk of various infectious diseases, particularly mosquito-borne diseases, entering China. This paper reports the testing and monitoring of mosquito-borne diseases in febrile travelers through Shenzhen ports in 2013. METHODS The blood samples of 619 febrile cases were collected and the serum of each sample was used for the specific gene amplification and IgM antibody detection of five typical mosquito-borne pathogens: Dengue virus (DENV), Japanese encephalitis virus (JEV), Chikungunya virus (CHIKV), yellow fever virus (YFV), and West Nile Virus (WNV). Additionally, malaria was diagnosed by rapid diagnostic tests (RDTs). RESULTS In total, 34 cases were detected of DENV infection (serotype I to IV), 17 cases of JEV infection, 2 cases of CHIKV infection, and 3 cases of malaria infection. No virus genes or IgM antibodies of YFV or WNV were detected in the samples. DENV, JEV and CHIKV cases were mainly from Southeast Asia, while malaria cases from Africa. CONCLUSIONS DENV, JEV and CHIKV were the primary pathogens imported via Shenzhen ports. International travelers with mosquito-borne infections would accelerate the spread of these diseases, thus reinforcing the need for surveillance of mosquito-borne infections at ports should become a high priority.
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Affiliation(s)
- Lei Shi
- Shen Zhen International Travel Healthcare Center, 8 South of Fuqiang Road, Futian District, Shenzhen, 518033, PR China
| | - Shihong Fu
- State Key Laboratory of Infectious Disease Prevention and Control, Key Laboratory for Medical Virology, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, 310003, PR China
| | - Lihua Wang
- State Key Laboratory of Infectious Disease Prevention and Control, Key Laboratory for Medical Virology, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, 310003, PR China
| | - Xiaolong Li
- State Key Laboratory of Infectious Disease Prevention and Control, Key Laboratory for Medical Virology, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, 310003, PR China
| | - Dayong Gu
- Shen Zhen International Travel Healthcare Center, 8 South of Fuqiang Road, Futian District, Shenzhen, 518033, PR China
| | - Chunxiao Liu
- Shen Zhen International Travel Healthcare Center, 8 South of Fuqiang Road, Futian District, Shenzhen, 518033, PR China
| | - Chunzhong Zhao
- Shen Zhen International Travel Healthcare Center, 8 South of Fuqiang Road, Futian District, Shenzhen, 518033, PR China
| | - Jian'an He
- Shen Zhen International Travel Healthcare Center, 8 South of Fuqiang Road, Futian District, Shenzhen, 518033, PR China
| | - Guodong Liang
- State Key Laboratory of Infectious Disease Prevention and Control, Key Laboratory for Medical Virology, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, 310003, PR China.
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591
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Carpio A, Romo ML, Parkhouse RME, Short B, Dua T. Parasitic diseases of the central nervous system: lessons for clinicians and policy makers. Expert Rev Neurother 2016; 16:401-14. [PMID: 26894629 PMCID: PMC4926779 DOI: 10.1586/14737175.2016.1155454] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Parasitic diseases of the central nervous system are associated with high mortality and morbidity, especially in resource-limited settings. The burden of these diseases is amplified as survivors are often left with neurologic sequelae affecting mobility, sensory organs, and cognitive functions, as well as seizures/epilepsy. These diseases inflict suffering by causing lifelong disabilities, reducing economic productivity, and causing social stigma. The complexity of parasitic life cycles and geographic specificities, as well as overlapping clinical manifestations in the host reflecting the diverse pathogenesis of parasites, can present diagnostic challenges. We herein provide an overview of these parasitic diseases and summarize clinical aspects, diagnosis, therapeutic strategies and recent milestones, and aspects related to prevention and control.
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Affiliation(s)
- Arturo Carpio
- a Escuela de Medicina , Universidad de Cuenca , Cuenca , Ecuador.,b GH Sergievsky Center, College of Physicians and Surgeons , Columbia University , New York , NY , USA.,c Consultorios Sta Inés, F. Proaño y D. Cordova (esquina) , Cuenca , Ecuador
| | - Matthew L Romo
- d Epidemiology and Biostatistics Program, CUNY School of Public Health, Hunter College , New York , NY , USA.,e Dirección de Investigación , Universidad de Cuenca , Cuenca , Ecuador
| | | | - Brooke Short
- g World Health Organization (WHO Geneva) , Geneva , Switzerland
| | - Tarun Dua
- g World Health Organization (WHO Geneva) , Geneva , Switzerland
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592
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Hotez PJ, Pecoul B, Rijal S, Boehme C, Aksoy S, Malecela M, Tapia-Conyer R, Reeder JC. Eliminating the Neglected Tropical Diseases: Translational Science and New Technologies. PLoS Negl Trop Dis 2016; 10:e0003895. [PMID: 26934395 PMCID: PMC4774924 DOI: 10.1371/journal.pntd.0003895] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Today, the World Health Organization recognizes 17 major parasitic and related infections as the neglected tropical diseases (NTDs). Despite recent gains in the understanding of the nature and prevalence of NTDs, as well as successes in recent scaled-up preventive chemotherapy strategies and other health interventions, the NTDs continue to rank among the world’s greatest global health problems. For virtually all of the NTDs (including those slated for elimination under the auspices of a 2012 London Declaration for NTDs and a 2013 World Health Assembly resolution [WHA 66.12]), additional control mechanisms and tools are needed, including new NTD drugs, vaccines, diagnostics, and vector control agents and strategies. Elimination will not be possible without these new tools. Here we summarize some of the key challenges in translational science to develop and introduce these new technologies in order to ensure success in global NTD elimination efforts.
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Affiliation(s)
- Peter J Hotez
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Bernard Pecoul
- Drugs for Neglected Diseases Initiative (DNDi), Geneva, Switzerland
| | - Suman Rijal
- Drugs for Neglected Diseases Initiative (DNDi), Delhi, India
| | - Catharina Boehme
- Foundation for Innovative new Diagnostics (FIND), Geneva, Switzerland
| | - Serap Aksoy
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | | | | | - John C Reeder
- UNICEF/UNDP/ World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), Geneva, Switzerland
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593
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Machicado C, Marcos LA. Carcinogenesis associated with parasites other than Schistosoma, Opisthorchis and Clonorchis: A systematic review. Int J Cancer 2016; 138:2915-21. [DOI: 10.1002/ijc.30028] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/08/2015] [Accepted: 01/25/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Claudia Machicado
- Research Scientist, Bioinformatics Laboratory, Department of Cellular and Molecular Sciences, School of Sciences and Philosophy; Universidad Peruana Cayetano Heredia; Av Honorio Delgado 430, Urb. Ingeniería Lima 31 Peru
- Institute for Biocomputation and Physics of Complex Systems; University of Zaragoza, Spain; Mariano Esquillor, Edificio I + D Zaragoza 50018 Spain
| | - Luis A. Marcos
- Department of Medicine; Stony Brook University; Stony Brook NY
- Instituto De Medicina Tropical Alexander Von Humboldt; Universidad Peruana Cayetano Heredia; Lima Peru
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594
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de Vlas SJ, Stolk WA, le Rutte EA, Hontelez JAC, Bakker R, Blok DJ, Cai R, Houweling TAJ, Kulik MC, Lenk EJ, Luyendijk M, Matthijsse SM, Redekop WK, Wagenaar I, Jacobson J, Nagelkerke NJD, Richardus JH. Concerted Efforts to Control or Eliminate Neglected Tropical Diseases: How Much Health Will Be Gained? PLoS Negl Trop Dis 2016; 10:e0004386. [PMID: 26890362 PMCID: PMC4758649 DOI: 10.1371/journal.pntd.0004386] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 12/21/2015] [Indexed: 11/23/2022] Open
Abstract
Background The London Declaration (2012) was formulated to support and focus the control and elimination of ten neglected tropical diseases (NTDs), with targets for 2020 as formulated by the WHO Roadmap. Five NTDs (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminths and trachoma) are to be controlled by preventive chemotherapy (PCT), and four (Chagas’ disease, human African trypanosomiasis, leprosy and visceral leishmaniasis) by innovative and intensified disease management (IDM). Guinea worm, virtually eradicated, is not considered here. We aim to estimate the global health impact of meeting these targets in terms of averted morbidity, mortality, and disability adjusted life years (DALYs). Methods The Global Burden of Disease (GBD) 2010 study provides prevalence and burden estimates for all nine NTDs in 1990 and 2010, by country, age and sex, which were taken as the basis for our calculations. Estimates for other years were obtained by interpolating between 1990 (or the start-year of large-scale control efforts) and 2010, and further extrapolating until 2030, such that the 2020 targets were met. The NTD disease manifestations considered in the GBD study were analyzed as either reversible or irreversible. Health impacts were assessed by comparing the results of achieving the targets with the counterfactual, construed as the health burden had the 1990 (or 2010 if higher) situation continued unabated. Principle Findings/Conclusions Our calculations show that meeting the targets will lead to about 600 million averted DALYs in the period 2011–2030, nearly equally distributed between PCT and IDM-NTDs, with the health gain amongst PCT-NTDs mostly (96%) due to averted disability and amongst IDM-NTDs largely (95%) from averted mortality. These health gains include about 150 million averted irreversible disease manifestations (e.g. blindness) and 5 million averted deaths. Control of soil-transmitted helminths accounts for one third of all averted DALYs. We conclude that the projected health impact of the London Declaration justifies the required efforts. Neglected tropical diseases (NTDs) are a group of infectious diseases that occur mostly in poor, warm countries. NTDs are caused by various bacteria and parasites, such as worms. They can either be cured or prevented through drugs and other interventions, such as control of insects that spread the infection. The London Declaration is a statement by various organizations, including the World Health Organization (WHO) and pharmaceutical companies that donate the necessary drugs. The declaration endorses targets for disease reductions by 2020, as recently formulated in the WHO Roadmap, to be achieved by rigorous application of available interventions. We explore how much health can be gained if these targets are indeed achieved. We estimate that in such case 5 million deaths can be averted before 2030 and also that huge reductions in ill-health and disability can be realized. Over the period 2011–2030, a total health gain would be accomplished of about 600 million disability adjusted life years (DALYs) averted. DALYs are a measure of disease burden, consisting of life years lost and years lived with disability. This enormous health gain seems to justify similar investments as for e.g. HIV or malaria control.
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Affiliation(s)
- Sake J. de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- * E-mail:
| | - Wilma A. Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Epke A. le Rutte
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jan A. C. Hontelez
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Roel Bakker
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - David J. Blok
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Rui Cai
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Tanja A. J. Houweling
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Margarete C. Kulik
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Center for Tobacco Control Research and Education, University of California at San Francisco, San Francisco, California, United States of America
| | - Edeltraud J. Lenk
- Institute of Health Policy and Management, Erasmus University Rotterdam, Rotterdam, The Netherlands
| | - Marianne Luyendijk
- Institute of Health Policy and Management, Erasmus University Rotterdam, Rotterdam, The Netherlands
| | - Suzette M. Matthijsse
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - William K. Redekop
- Institute of Health Policy and Management, Erasmus University Rotterdam, Rotterdam, The Netherlands
| | - Inge Wagenaar
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Julie Jacobson
- Bill and Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Nico J. D. Nagelkerke
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jan H. Richardus
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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595
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Whole genome resequencing of the human parasite Schistosoma mansoni reveals population history and effects of selection. Sci Rep 2016; 6:20954. [PMID: 26879532 PMCID: PMC4754680 DOI: 10.1038/srep20954] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 01/13/2016] [Indexed: 12/30/2022] Open
Abstract
Schistosoma mansoni is a parasitic fluke that infects millions of people in the developing world. This study presents the first application of population genomics to S. mansoni based on high-coverage resequencing data from 10 global isolates and an isolate of the closely-related Schistosoma rodhaini, which infects rodents. Using population genetic tests, we document genes under directional and balancing selection in S. mansoni that may facilitate adaptation to the human host. Coalescence modeling reveals the speciation of S. mansoni and S. rodhaini as 107.5-147.6KYA, a period which overlaps with the earliest archaeological evidence for fishing in Africa. Our results indicate that S. mansoni originated in East Africa and experienced a decline in effective population size 20-90KYA, before dispersing across the continent during the Holocene. In addition, we find strong evidence that S. mansoni migrated to the New World with the 16-19th Century Atlantic Slave Trade.
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596
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Cai P, Gobert GN, You H, McManus DP. The Tao survivorship of schistosomes: implications for schistosomiasis control. Int J Parasitol 2016; 46:453-63. [PMID: 26873753 DOI: 10.1016/j.ijpara.2016.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 01/06/2016] [Accepted: 01/06/2016] [Indexed: 01/06/2023]
Abstract
Schistosomiasis, caused by blood flukes of the genus Schistosoma, is a major public health problem which contributes substantially to the economic and financial burdens of many nations in the developing world. An array of survival strategies, such as the unique structure of the tegument which acts as a major host-parasite interface, immune modulation mechanisms, gene regulation, and apoptosis and self-renewal have been adopted by schistosome parasites over the course of long-term evolution with their mammalian definitive hosts. Recent generation of complete schistosome genomes together with numerous biological, immunological, high-throughput "-omics" and gene function studies have revealed the Tao or strategies that schistosomes employ not only to promote long-term survival, but also to ensure effective life cycle transmission. New scenarios for the future control of this important neglected tropical disease will present themselves as our understanding of these Tao increases.
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Affiliation(s)
- Pengfei Cai
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Queensland, Australia.
| | - Geoffrey N Gobert
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Queensland, Australia
| | - Hong You
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Queensland, Australia
| | - Donald P McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Queensland, Australia.
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597
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Xu J, Yu Q, Tchuenté LAT, Bergquist R, Sacko M, Utzinger J, Lin DD, Yang K, Zhang LJ, Wang Q, Li SZ, Guo JG, Zhou XN. Enhancing collaboration between China and African countries for schistosomiasis control. THE LANCET. INFECTIOUS DISEASES 2016; 16:376-83. [PMID: 26851829 DOI: 10.1016/s1473-3099(15)00360-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 09/19/2015] [Accepted: 09/30/2015] [Indexed: 11/25/2022]
Abstract
Schistosomiasis remains an important public health issue, with a large number of cases reported across sub-Saharan Africa, and parts of Asia and Latin America. China was once highly endemic, but has made substantial progress and is moving towards elimination of schistosomiasis. Meanwhile, despite long-term, repeated, school-based chemotherapy in many African countries, more than 90% of all schistosomiasis cases are concentrated in Africa, and hence, this continent constitutes the key challenge for schistosomiasis control. Opportunities and issues for international collaboration in the fight against schistosomiasis are outlined with a focus on China's experiences, including the role of public health authorities and intersectoral collaboration, use of new and effective snail control approaches and diagnostic tools adapted to the specific stage of control, as well as the strengthening of risk mapping and surveillance-response mechanisms. Training courses targeting African governmental officials and professionals, coupled with field visits of African scientists and control programme managers to China, and vice versa, are considered important for improved schistosomiasis control and elimination. The crucial question remains whether the Chinese experience can be translated and applied in African countries to improve the effectiveness of health interventions and scale-up.
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Affiliation(s)
- Jing Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Qing Yu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | | | | | - Moussa Sacko
- National Institute for Research in Public Health, Ministry of Health, Bamako, Mali
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Dan-Dan Lin
- Jiangxi Provincial Institute of Parasitic Disease, Nanchang, China
| | - Kun Yang
- Jiangsu Provincial Institute of Schistosomiasis Control, Wuxi, China
| | - Li-Juan Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Qiang Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Shi-Zhu Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Jia-Gang Guo
- Department of Control of Neglected Tropical Diseases, WHO, Geneva, Switzerland
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Shanghai, China.
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598
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Péneau J, Nguyen A, Flores-Ferrer A, Blanchet D, Gourbière S. Amazonian Triatomine Biodiversity and the Transmission of Chagas Disease in French Guiana: In Medio Stat Sanitas. PLoS Negl Trop Dis 2016; 10:e0004427. [PMID: 26867025 PMCID: PMC4750908 DOI: 10.1371/journal.pntd.0004427] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/12/2016] [Indexed: 12/22/2022] Open
Abstract
The effects of biodiversity on the transmission of infectious diseases now stand as a cornerstone of many public health policies. The upper Amazonia and Guyana shield are hot-spots of biodiversity that offer genuine opportunities to explore the relationship between the risk of transmission of Chagas disease and the diversity of its triatomine vectors. Over 730 triatomines were light-trapped in four geomorphological landscapes shaping French-Guiana, and we determined their taxonomic status and infection by Trypanosoma cruzi. We used a model selection approach to unravel the spatial and temporal variations in species abundance, diversity and infection. The vector community in French-Guiana is typically made of one key species (Panstrongylus geniculatus) that is more abundant than three secondary species combined (Rhodnius pictipes, Panstrongylus lignarius and Eratyrus mucronatus), and four other species that complete the assemblage. Although the overall abundance of adult triatomines does not vary across French-Guiana, their diversity increases along a coastal-inland gradient. These variations unravelled a non-monotonic relationship between vector biodiversity and the risk of transmission of Chagas disease, so that intermediate biodiversity levels are associated with the lowest risks. We also observed biannual variations in triatomine abundance, representing the first report of a biannual pattern in the risk of Chagas disease transmission. Those variations were highly and negatively correlated with the average monthly rainfall. We discuss the implications of these patterns for the transmission of T. cruzi by assemblages of triatomine species, and for the dual challenge of controlling Amazonian vector communities that are made of both highly diverse and mostly intrusive species.
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Affiliation(s)
- Julie Péneau
- UMR 228 ESPACE-DEV-IMAGES, ‘Institut de Modélisation et d'Analyses en Géo-Environnement et Santé’, Université de Perpignan Via Domitia, Perpignan, France
- Laboratoire de Parasitologie-Mycologie, Centre Hospitalier de Cayenne and Faculté de Médecine, Equipe « Ecosystèmes Amazoniens et Pathologie Tropicale » (EA3593), Université de Antilles et de la Guyane, Cayenne, French Guiana
| | - Anne Nguyen
- UMR 228 ESPACE-DEV-IMAGES, ‘Institut de Modélisation et d'Analyses en Géo-Environnement et Santé’, Université de Perpignan Via Domitia, Perpignan, France
| | - Alheli Flores-Ferrer
- UMR 228 ESPACE-DEV-IMAGES, ‘Institut de Modélisation et d'Analyses en Géo-Environnement et Santé’, Université de Perpignan Via Domitia, Perpignan, France
| | - Denis Blanchet
- Laboratoire de Parasitologie-Mycologie, Centre Hospitalier de Cayenne and Faculté de Médecine, Equipe « Ecosystèmes Amazoniens et Pathologie Tropicale » (EA3593), Université de Antilles et de la Guyane, Cayenne, French Guiana
| | - Sébastien Gourbière
- UMR 228 ESPACE-DEV-IMAGES, ‘Institut de Modélisation et d'Analyses en Géo-Environnement et Santé’, Université de Perpignan Via Domitia, Perpignan, France
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599
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Walker M, Mabud TS, Olliaro PL, Coulibaly JT, King CH, Raso G, Scherrer AU, Stothard JR, Sousa-Figueiredo JC, Stete K, Utzinger J, Basáñez MG. New approaches to measuring anthelminthic drug efficacy: parasitological responses of childhood schistosome infections to treatment with praziquantel. Parasit Vectors 2016; 9:41. [PMID: 26813154 PMCID: PMC4728951 DOI: 10.1186/s13071-016-1312-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 11/20/2015] [Indexed: 11/30/2022] Open
Abstract
Background By 2020, the global health community aims to control and eliminate human helminthiases, including schistosomiasis in selected African countries, principally by preventive chemotherapy (PCT) through mass drug administration (MDA) of anthelminthics. Quantitative monitoring of anthelminthic responses is crucial for promptly detecting changes in efficacy, potentially indicative of emerging drug resistance. Statistical models offer a powerful means to delineate and compare efficacy among individuals, among groups of individuals and among populations. Methods We illustrate a variety of statistical frameworks that offer different levels of inference by analysing data from nine previous studies on egg counts collected from African children before and after administration of praziquantel. Results We quantify responses to praziquantel as egg reduction rates (ERRs), using different frameworks to estimate ERRs among population strata, as average responses, and within strata, as individual responses. We compare our model-based average ERRs to corresponding model-free estimates, using as reference the World Health Organization (WHO) 90 % threshold of optimal efficacy. We estimate distributions of individual responses and summarize the variation among these responses as the fraction of ERRs falling below the WHO threshold. Conclusions Generic models for evaluating responses to anthelminthics deepen our understanding of variation among populations, sub-populations and individuals. We discuss the future application of statistical modelling approaches for monitoring and evaluation of PCT programmes targeting human helminthiases in the context of the WHO 2020 control and elimination goals. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1312-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martin Walker
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, London, W2 1PG, UK. .,London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK.
| | - Tarub S Mabud
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, London, W2 1PG, UK. .,Present address: Stanford School of Medicine, 291 Campus Drive, Stanford, CA, 94305, USA.
| | - Piero L Olliaro
- UNICEF/UNDP/World Bank/WHO Special Programme on Research and Training in Tropical Diseases (TDR), World Health Organization, Av. Appia 20, CH-1211, Geneva 27, Switzerland. .,Centre for Tropical Medicine and Global Health Nuffield Department of Medicine Research Building, University of Oxford Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK.
| | - Jean T Coulibaly
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland. .,University of Basel, P.O. Box, CH-4003, Basel, Switzerland. .,Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, 22 BP 770, Abidjan 22, Côte d'Ivoire. .,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, 01 BP 1303, Abidjan 01, Côte d'Ivoire.
| | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University, 2109 Adelbert Road, Cleveland, OH, 44106, USA. .,Schistosomiasis Consortium for Operational Research and Evaluation, University of Georgia, 500 D W Brooks Drive, Athens, GA, 30602, USA.
| | - Giovanna Raso
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland. .,University of Basel, P.O. Box, CH-4003, Basel, Switzerland.
| | - Alexandra U Scherrer
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, CH-8091, Zurich, Switzerland.
| | - J Russell Stothard
- Department of Parasitology, London School of Tropical Medicine, Liverpool, L3 5QA, UK.
| | - José Carlos Sousa-Figueiredo
- Centro de Investigação em Saúde de Angola (Health Research Center in Angola), Rua direita do Caxito, Hospital Provincial, Bengo, Angola. .,Department of Life Sciences, Natural History Museum, Wolfson Wellcome Biomedical Laboratories, Cromwell Road, London, SW7 5BD, UK.
| | - Katarina Stete
- Center for Infectious Diseases and Travel Medicine, Department of Medicine, University Hospital Freiburg, Hugstetter Strasse 55, D-79106, Freiburg, Germany.
| | - Jürg Utzinger
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland. .,University of Basel, P.O. Box, CH-4003, Basel, Switzerland.
| | - Maria-Gloria Basáñez
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, London, W2 1PG, UK. .,London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK.
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600
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Cucunubá ZM, Okuwoga O, Basáñez MG, Nouvellet P. Increased mortality attributed to Chagas disease: a systematic review and meta-analysis. Parasit Vectors 2016; 9:42. [PMID: 26813568 PMCID: PMC4728795 DOI: 10.1186/s13071-016-1315-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 01/11/2016] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND The clinical outcomes associated with Chagas disease remain poorly understood. In addition to the burden of morbidity, the burden of mortality due to Trypanosoma cruzi infection can be substantial, yet its quantification has eluded rigorous scrutiny. This is partly due to considerable heterogeneity between studies, which can influence the resulting estimates. There is a pressing need for accurate estimates of mortality due to Chagas disease that can be used to improve mathematical modelling, burden of disease evaluations, and cost-effectiveness studies. METHODS A systematic literature review was conducted to select observational studies comparing mortality in populations with and without a diagnosis of Chagas disease using the PubMed, MEDLINE, EMBASE, Web of Science and LILACS databases, without restrictions on language or date of publication. The primary outcome of interest was mortality (as all-cause mortality, sudden cardiac death, heart transplant or cardiovascular deaths). Data were analysed using a random-effects model to obtain the relative risk (RR) of mortality, the attributable risk percent (ARP), and the annual mortality rates (AMR). The statistic I(2) (proportion of variance in the meta-analysis due to study heterogeneity) was calculated. Sensitivity analyses and publication bias test were also conducted. RESULTS Twenty five studies were selected for quantitative analysis, providing data on 10,638 patients, 53,346 patient-years of follow-up, and 2739 events. Pooled estimates revealed that Chagas disease patients have significantly higher AMR compared with non-Chagas disease patients (0.18 versus 0.10; RR = 1.74, 95% CI 1.49-2.03). Substantial heterogeneity was found among studies (I(2) = 67.3%). The ARP above background mortality was 42.5%. Through a sub-analysis patients were classified by clinical group (severe, moderate, asymptomatic). While RR did not differ significantly between clinical groups, important differences in AMR were found: AMR = 0.43 in Chagas vs. 0.29 in non-Chagas patients (RR = 1.40, 95% CI 1.21-1.62) in the severe group; AMR = 0.16 (Chagas) vs. 0.08 (non-Chagas) (RR = 2.10, 95% CI 1.52-2.91) in the moderate group, and AMR = 0.02 vs. 0.01 (RR = 1.42, 95% CI 1.14-1.77) in the asymptomatic group. Meta-regression showed no evidence of study-level covariates on the effect size. Publication bias was not statistically significant (Egger's test p=0.08). CONCLUSIONS The results indicate a statistically significant excess of mortality due to Chagas disease that is shared among both symptomatic and asymptomatic populations.
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Affiliation(s)
- Zulma M Cucunubá
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's campus), Imperial College London, Norfolk Place, London, W2 1PG, United Kingdom. .,Grupo de Parasitología - RED CHAGAS, Instituto Nacional de Salud, Bogotá, Colombia.
| | - Omolade Okuwoga
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's campus), Imperial College London, Norfolk Place, London, W2 1PG, United Kingdom.
| | - María-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's campus), Imperial College London, Norfolk Place, London, W2 1PG, United Kingdom.
| | - Pierre Nouvellet
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's campus), Imperial College London, Norfolk Place, London, W2 1PG, United Kingdom. .,Medical Research Council Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's campus), Imperial College London, London, UK.
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