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Angelo T, Kinung’hi SM, Buza J, Mwanga JR, Kariuki HC, Wilson S. Community knowledge, perceptions and water contact practices associated with transmission of urinary schistosomiasis in an endemic region: a qualitative cross-sectional study. BMC Public Health 2019; 19:703. [PMID: 31174505 PMCID: PMC6554870 DOI: 10.1186/s12889-019-7041-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 05/23/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND In an effort to complement the current chemotherapy based schistosomiasis control interventions in Shinyanga district, community knowledge, perceptions and water contact practices were qualitatively assessed using focus group discussions and semi structured interviews involving 271 participants in one S. haematobium prevalent community of Ikingwamanoti village, Shinyanga district, Northwestern, Tanzania. METHODS In October, 2016 we conducted 29 parent semi structured interviews and 16 focus group discussions with a total of 168 parent informants. Adult participants were conveniently selected from three sub-villages of Butini, Miyu, and Bomani of Ikingwamanoti village, Shinyanga district. In March, 2017, a total of 103 children informants participated in 10 focus group discussions and 20 semi structured interviews, administered to children from standard four, five, six and seven attending Ikingwamanoti Primary School. Note taking and digital recorders were used to collect narrative data for thematic analysis of emergent themes. RESULTS Among participants, 75% parents and 50% children considered urinary schistosomiasis as a low priority health problem. Of the informants, 70% children and 48.3% parents had misconceptions about the cause, modes of transmission and control of schistosomiasis demonstrating gaps in their biomedical knowledge of the disease. Assessment of treatment seeking behavior for urinary schistosomiasis revealed a combination of traditional and modern health care sectors. However, modern medicines were considered effective in the treatment of urinary schistosomiasis. Lack of alternative sources of water for domestic and recreational activities and unhygienic water use habits exposed community members to high risk of acquiring urinary schistosomiasis. CONCLUSION Use of Schistosoma haematobium contaminated water sources for daily domestic and recreational use facilitated contraction of urinary schistosomiasis among community members in Shinyanga district. People's perceptions of urinary schistosomiasis as a less priority health problem promoted persistence of the disease. Future efforts to control urinary schistosomiasis should take into account integrated approaches combining water, sanitation and hygiene, health education, alternative sources of clean and safe water to facilitate behavior change.
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Affiliation(s)
- Teckla Angelo
- Department of Global Health and Bio-Medical Sciences, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), P. O. Box 447, Arusha, Tanzania
- National Institute for Medical Research (NIMR), Mwanza Centre, P. O. Box 1462, Mwanza, Tanzania
| | - Safari M. Kinung’hi
- National Institute for Medical Research (NIMR), Mwanza Centre, P. O. Box 1462, Mwanza, Tanzania
| | - Jorum Buza
- Department of Global Health and Bio-Medical Sciences, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), P. O. Box 447, Arusha, Tanzania
| | - Joseph R. Mwanga
- National Institute for Medical Research (NIMR), Mwanza Centre, P. O. Box 1462, Mwanza, Tanzania
| | - Henry Curtis Kariuki
- Kenya Methodist University, School of Medicine and Health Sciences, P. O. Box 267, Meru, Kenya
| | - Shona Wilson
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP UK
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102
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Gichuki PM, Kepha S, Mulewa D, Masaku J, Kwoba C, Mbugua G, Mazigo HD, Mwandawiro C. Association between Schistosoma mansoni infection and access to improved water and sanitation facilities in Mwea, Kirinyaga County, Kenya. BMC Infect Dis 2019; 19:503. [PMID: 31174478 PMCID: PMC6556037 DOI: 10.1186/s12879-019-4105-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 05/17/2019] [Indexed: 11/24/2022] Open
Abstract
Background Schistosomiasis remains a public health problem in Central Kenya despite concerted control efforts. Access to improved water and sanitation has been emphasized as important control measures. Few studies have assessed the association between access to improved water sources and sanitation facilities with Schistosoma mansoni infection in different environmental settings. This study assessed the association between S. mansoni infection and household access to improved water sources and sanitation facilities in Mwea, Kirinyaga County, Kenya. Methods A cross sectional study was conducted between the months of August and October 2017. A total of 905 household heads from seven villages were interviewed and their stool samples screened for S. mansoni using the Kato Katz technique. Comparisons of demographic factors by S. mansoni infection were tested for significance using the chi-square test (χ2) or the Fisher exact test for categorical variables. Variables associated with S. mansoni infection were analyzed using univariable analysis and the strength of the association measured as odds ratio (OR) using mixed effects logistic regression at 95% CI, with values considered significant at p < 0.05. Results The overall prevalence of S. mansoni was, 23.1% (95% CI: 20.5–26.0%), with majority of the infections being of light intensity. Rurumi village had the highest prevalence at 33.3%, with Kirogo village having the least prevalence at 7.0%. Majority (84.1%) of the households lacked access to improved water sources but had access to improved sanitation facilities (75%). Households with access to piped water had the lowest S. mansoni infections. However, there was no significant association between S. mansoni infections with either the main source of water in the household (Odds Ratio (OR) =0.782 (95% CI: 0.497–1.229) p = 0.285 or sanitation facilities (OR = 1.018 (95% CI: 0.705–1.469) p = 0.926. Conclusion Our study suggests that S. mansoni is still a public health problem among all age groups in Mwea irrigation scheme, Kirinyaga County, Central Kenya. Majority of the households lacks access to improved water sources but have access to improved sanitation facilities. This study recommends initiatives to ensure adequate provision of improved water sources, and the inclusion of the adult community in preventive chemotherapy programs. Electronic supplementary material The online version of this article (10.1186/s12879-019-4105-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paul M Gichuki
- Eastern and Southern Africa Center for International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), P.O BOX 54840-00200, Nairobi, Kenya. .,School of Health Sciences, Meru University of Science and Technology, P.O BOX 972-60200, Meru, Kenya.
| | - Stella Kepha
- London School of Tropical Medicine and Hygiene, Keppel St, Bloomsbury, London, WCIE 7HT, UK.,School of Public Health, Pwani University, P.O BOX 195-80108, Mombasa, Kenya
| | - Damaris Mulewa
- Eastern and Southern Africa Center for International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), P.O BOX 54840-00200, Nairobi, Kenya
| | - Janet Masaku
- Eastern and Southern Africa Center for International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), P.O BOX 54840-00200, Nairobi, Kenya
| | - Celestine Kwoba
- Vectorborne diseases Control Unit, Ministry of Health, P.o box 86-10303, Wanguru, Kenya
| | - Gabriel Mbugua
- School of Health Sciences, Meru University of Science and Technology, P.O BOX 972-60200, Meru, Kenya
| | - Humphrey D Mazigo
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences, P.O. Box 1464, Mwanza, Tanzania
| | - Charles Mwandawiro
- Eastern and Southern Africa Center for International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), P.O BOX 54840-00200, Nairobi, Kenya
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Kulinkina AV, Kosinski KC, Adjei MN, Osabutey D, Gyamfi BO, Biritwum NK, Bosompem KM, Naumova EN. Contextualizing Schistosoma haematobium transmission in Ghana: Assessment of diagnostic techniques and individual and community water-related risk factors. Acta Trop 2019; 194:195-203. [PMID: 30871989 DOI: 10.1016/j.actatropica.2019.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 02/23/2019] [Accepted: 03/10/2019] [Indexed: 12/16/2022]
Abstract
OBJECTIVES The study assessed associations between Schistosoma haematobium infection (presence of parasite eggs in urine or hematuria) and self-reported metrics (macrohematuria, fetching surface water, or swimming) to evaluate their performance as proxies of infection in presence of regular preventive chemotherapy. It also examined community water characteristics (safe water access, surface water access, and groundwater quality) to provide context for schistosomiasis transmission in different types of communities and propose interventions. METHODS Logistic regression was used to assess the associations between the various measured and self-reported metrics in a sample of 897 primary school children in 30 rural Ghanaian communities. Logistic regression was also used to assess associations between community water characteristics, self-reported water-related behaviors and S. haematobium infection. Communities were subsequently categorized as candidates for three types of interventions: provision of additional safe water sources, provision of groundwater treatment, and health education about water-related disease risk, depending on their water profile. RESULTS Microhematuria presence measured with a reagent strip was a good proxy of eggs in urine at individual (Kendall's τb = 0.88, p < 0.001) and at school-aggregated (Spearman's rs = 0.96, p < 0.001) levels. Self-reported macrohematuria and swimming were significantly associated (p < 0.05) with egg presence, but self-reported fetching was not. Of the community water characteristics, greater surface water access and presence of groundwater quality problems were significantly associated with increased likelihood of fetching, swimming, and S. haematobium infection. Access to improved water sources did not exhibit an association with any of these outcomes. CONCLUSIONS The study illustrates that in presence of regular school-based treatment with praziquantel, microhematuria assessed via reagent strips remains an adequate proxy for S. haematobium infection in primary schoolchildren. Community water profiles, in combination with self-reported water-related behaviors, can help elucidate reasons for some endemic communities continuing to experience ongoing transmission and tailor interventions to these local contexts to achieve sustainable control.
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Affiliation(s)
| | | | | | - Dickson Osabutey
- University of Ghana, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Bernard O Gyamfi
- University College of Agriculture and Environmental Studies, Bunso, Ghana
| | | | - Kwabena M Bosompem
- Community Directed Development Foundation, Accra, Ghana; University of Ghana, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - Elena N Naumova
- Tufts University School of Engineering, Medford, MA, USA; Tufts University, Friedman School of Nutrition Science and Policy, Boston, MA, USA
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Butrous G. Schistosome infection and its effect on pulmonary circulation. Glob Cardiol Sci Pract 2019; 2019:5. [PMID: 31024947 PMCID: PMC6472693 DOI: 10.21542/gcsp.2019.5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 12/17/2018] [Indexed: 02/06/2023] Open
Abstract
Schistosomiasis is the most common parasitic disease associated with pulmonary hypertension. It induces remodelling via complex inflammatory processes, which eventually produce the clinical manifestation of pulmonary hypertension. The pulmonary hypertension shows clinical signs and symptoms that are not distinguishable from other forms of pulmonary arterial hypertension.
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Affiliation(s)
- Ghazwan Butrous
- Professor of Cardiopulmonary Sciences, Medway School of Pharmacy, University of Kent, UK and University of Greenwich, Central Ave, Gillingham, Chatham ME4 4BF, Kent, UK
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105
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Schistosoma mansoni infection and risk factors among the fishermen of Lake Hawassa, southern Ethiopia. J Biosoc Sci 2019; 51:817-826. [PMID: 30838967 DOI: 10.1017/s0021932019000075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Schistosomiasis is a neglected tropical parasitic disease caused by different species of genus Schistosoma. Schistosoma mansoni causes a severe intestinal parasitic infection of high public and medical importance in Ethiopia. This study aimed to determine the prevalence of, and risk factors for, S. mansoni infection among the fishermen of Lake Hawassa, southern Ethiopia, using a cross-sectional study design. A total of 243 fishermen were selected from the Hawassa Town Fishermen Association's list in 2013. Data on socio-demographic characteristics and risk factors were collected from the fishermen using semi-structured questionnaires. Stool samples were collected and processed using the Kato-Katz thick smear technique. The overall prevalence of S. mansoni among the fishermen was 29.21% and the mean intensity of infection was 158.88 eggs per gram (EPG). The overall prevalence of intestinal helminths, including S. mansoni, was 69.54%. Similar prevalences of S. mansoni were recorded in age groups 15-19, 20-24 and 25-29 years: 31.82%, 31.75% and 31.94%, respectively. Fishermen who swam a minimum of once a week in Lake Hawassa were 2.92 times (95% CI: 1.554, 5.502) more likely to have acquired S. mansoni infection than those who swam in the lake less than once a week. The results indicate moderate endemicity of S. mansoni infection among the fishermen of Lake Hawassa. These fishermen could be a potentially high-risk group for S. mansoni infection and might be responsible for the transmission of infection to other segments of the community visiting the lake for recreation. Moreover, a high prevalence of soil-transmitted helminths (STHs) was recorded among the fishermen. Integrated prevention and control strategies for schistosomiasis and STHs by different sectors are needed to tackle this problem.
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Asian Schistosomiasis: Current Status and Prospects for Control Leading to Elimination. Trop Med Infect Dis 2019; 4:tropicalmed4010040. [PMID: 30813615 PMCID: PMC6473711 DOI: 10.3390/tropicalmed4010040] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/12/2019] [Accepted: 02/12/2019] [Indexed: 12/22/2022] Open
Abstract
Schistosomiasis is an infectious disease caused by helminth parasites of the genus Schistosoma. Worldwide, an estimated 250 million people are infected with these parasites with the majority of cases occurring in sub-Saharan Africa. Within Asia, three species of Schistosoma cause disease. Schistosoma japonicum is the most prevalent, followed by S. mekongi and S. malayensis. All three species are zoonotic, which causes concern for their control, as successful elimination not only requires management of the human definitive host, but also the animal reservoir hosts. With regard to Asian schistosomiasis, most of the published research has focused on S. japonicum with comparatively little attention paid to S. mekongi and even less focus on S. malayensis. In this review, we examine the three Asian schistosomes and their current status in their endemic countries: Cambodia, Lao People's Democratic Republic, Myanmar, and Thailand (S. mekongi); Malaysia (S. malayensis); and Indonesia, People's Republic of China, and the Philippines (S. japonicum). Prospects for control that could potentially lead to elimination are highlighted as these can inform researchers and disease control managers in other schistosomiasis-endemic areas, particularly in Africa and the Americas.
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de Oliveira Melo A, Santos DBD, Silva LD, Rocha TL, Bezerra JCB. Molluscicidal activity of polyhexamethylene biguanide hydrochloride on the early-life stages and adults of the Biomphalaria glabrata (Say, 1818). CHEMOSPHERE 2019; 216:365-371. [PMID: 30384305 DOI: 10.1016/j.chemosphere.2018.10.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/13/2018] [Accepted: 10/06/2018] [Indexed: 06/08/2023]
Abstract
Schistosomiasis is a disease that affects tropical and subtropical areas and is considered the second most prevalent parasitic disease in the world. One of the ways of combating this disease is the use of molluscicidal agents to eliminate or reduce the population of intermediate host snails. Polyhexamethylene biguanide hydrochloride (PHMB) is a chemical biocide commonly used as a disinfectant and antiseptic in the food industry and very successfully for the disinfection of swimming pools. The US Environmental Protection Agency (USEPA) indicated the PHMB as low environmental risk. The present study aimed to evaluate the molluscicidal activity of the PHMB in freshwater snail (Biomphalaria glabrata), intermediate host of Schistosoma mansoni. The PHMB showed high toxicity against all stages of the snail B. glabrata: embryos, new-borns and adults. The LC50 estimated was 0.98 mg L-1; 1.43 mg L-1 and 1.49 mg L-1, respectively, after exposure of 144 h for embryos and 96 h for new-borns and adults. PHMB did not prevent the development of embryos within the egg mass, since at all concentrations evaluated 80% of the embryos managed to develop until the hypo-stage, which is the last stage of development before hatching. However, PHMB inhibited the hatching of embryos by 100% at all concentrations above 1.6 mg L-1. PHMB proved to be a promising substance in the fight against schistosomiasis by eliminating the intermediate host (B. glabrata). This was the first study that makes an experimental observation of the molluscicidal activity of PHMB.
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Affiliation(s)
- Amanda de Oliveira Melo
- Laboratory of Studies of the Host-parasite Relationship, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Daniela Braz Dos Santos
- Laboratory of Studies of the Host-parasite Relationship, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Luciana Damacena Silva
- Laboratory of Host-Parasite Interactions, State University of Goiás, Anápolis, Goiás, Brazil
| | - Thiago Lopes Rocha
- Laboratory of Environmental Biotechnology and Ecotoxicology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil.
| | - José Clecildo Barreto Bezerra
- Laboratory of Studies of the Host-parasite Relationship, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil
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Frahm S, Anisuzzaman A, Prodjinotho UF, Vejzagić N, Verschoor A, Prazeres da Costa C. A novel cell-free method to culture Schistosoma mansoni from cercariae to juvenile worm stages for in vitro drug testing. PLoS Negl Trop Dis 2019; 13:e0006590. [PMID: 30689639 PMCID: PMC6375649 DOI: 10.1371/journal.pntd.0006590] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 02/14/2019] [Accepted: 11/16/2018] [Indexed: 01/01/2023] Open
Abstract
Background The arsenal in anthelminthic treatment against schistosomiasis is limited and relies almost exclusively on a single drug, praziquantel (PZQ). Thus, resistance to PZQ could constitute a major threat. Even though PZQ is potent in killing adult worms, its activity against earlier stages is limited. Current in vitro drug screening strategies depend on newly transformed schistosomula (NTS) for initial hit identification, thereby limiting sensitivity to new compounds predominantly active in later developmental stages. Therefore, the aim of this study was to establish a highly standardized, straightforward and reliable culture method to generate and maintain advanced larval stages in vitro. We present here how this method can be a valuable tool to test drug efficacy at each intermediate larval stage, reducing the reliance on animal use (3Rs). Methodology/Principal findings Cercariae were mechanically transformed into skin-stage (SkS) schistosomula and successfully cultured for up to four weeks with no loss in viability in a commercially available medium. Under these serum- and cell-free conditions, development halted at the lung-stage (LuS). However, the addition of human serum (HSe) propelled further development into liver stage (LiS) worms within eight weeks. Skin and lung stages, as well as LiS, were submitted to 96-well drug screening assays using known anti-schistosomal compounds such as PZQ, oxamniquine (OXM), mefloquine (MFQ) and artemether (ART). Our findings showed stage-dependent differences in larval susceptibility to these compounds. Conclusion With this robust and highly standardized in vitro assay, important developmental stages of S. mansoni up to LiS worms can be generated and maintained over prolonged periods of time. The phenotype of LiS worms, when exposed to reference drugs, was comparable to most previously published works for ex vivo harvested adult worms. Therefore, this in vitro assay can help reduce reliance on animal experiments in search for new anti-schistosomal drugs. Schistosomiasis remains a major health threat, predominantly in developing countries. Even though there has been some progress in search of new drugs, praziquantel remains the only available drug. Probably the most important advance in the search for new drugs was in vitro transformation of cercariae and their subsequent culture. However, hit identification in compound screenings is exclusively tested in skin stage parasites and is only confirmed for more mature worms in a subsequent step. This is in part due to the lack of an easy culture system for advance-stage parasites. We present here a reliable and highly standardized way to generate LiS worms in vitro in a cell-free culture system. The inclusion of in vitro drug tests on advanced-stage parasites in initial hit identification will help to identify compounds that might otherwise be overlooked. Furthermore, the ability to continuously observe the parasite’s development in vitro will provide an important platform for a better understanding of its maturation in the human host. Taken together, this opens up new avenues to investigate the influence of specific cell types or host proteins on the development of Schistosoma mansoni and provides an additional tool to reduce animal use in future drug discovery efforts (3Rs).
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Affiliation(s)
- Sören Frahm
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany
| | - Anisuzzaman Anisuzzaman
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany
- Department of Parasitology, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Ulrich Fabien Prodjinotho
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany
| | - Nermina Vejzagić
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany
| | - Admar Verschoor
- Institute for Systemic Inflammation Research, Universität zu Lübeck, Lübeck, Germany
| | - Clarissa Prazeres da Costa
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany
- * E-mail:
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Arostegui MC, Wood CL, Jones IJ, Chamberlin AJ, Jouanard N, Faye DS, Kuris AM, Riveau G, De Leo GA, Sokolow SH. Potential Biological Control of Schistosomiasis by Fishes in the Lower Senegal River Basin. Am J Trop Med Hyg 2019; 100:117-126. [PMID: 30479247 PMCID: PMC6335894 DOI: 10.4269/ajtmh.18-0469] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 09/26/2018] [Indexed: 12/19/2022] Open
Abstract
More than 200 million people in sub-Saharan Africa are infected with schistosome parasites. Transmission of schistosomiasis occurs when people come into contact with larval schistosomes emitted from freshwater snails in the aquatic environment. Thus, controlling snails through augmenting or restoring their natural enemies, such as native predators and competitors, could offer sustainable control for this human disease. Fishes may reduce schistosomiasis transmission directly, by preying on snails or parasites, or indirectly, by competing with snails for food or by reducing availability of macrophyte habitat (i.e., aquatic plants) where snails feed and reproduce. To identify fishes that might serve as native biological control agents for schistosomiasis in the lower Senegal River basin-one of the highest transmission areas for human schistosomiasis globally-we surveyed the freshwater fish that inhabit shallow, nearshore habitats and conducted multivariate analyses with quantitative diet data for each of the fish species encountered. Ten of the 16 fish species we encountered exhibited diets that may result in direct (predation) and/or indirect (food competition and habitat removal) control of snails. Fish abundance was low, suggesting limited effects on schistosomiasis transmission by the contemporary fish community in the lower Senegal River basin in the wild. Here, we highlight some native species-such as tilapia, West African lungfish, and freshwater prawns-that could be aquacultured for local-scale biological control of schistosomiasis transmission.
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Affiliation(s)
- Martin C. Arostegui
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington
| | - Chelsea L. Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington
| | - Isabel J. Jones
- Hopkins Marine Station of Stanford University, Pacific Grove, California
| | | | - Nicolas Jouanard
- Biomedical Research Center Espoir Pour La Santé, Saint-Louis, Sénégal
| | | | - Armand M. Kuris
- Department of Ecology, Evolution and Marine Biology, and Marine Science Institute, University of California, Santa Barbara, California
| | - Gilles Riveau
- Biomedical Research Center Espoir Pour La Santé, Saint-Louis, Sénégal
| | - Giulio A. De Leo
- Hopkins Marine Station of Stanford University, Pacific Grove, California
| | - Susanne H. Sokolow
- Hopkins Marine Station of Stanford University, Pacific Grove, California
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Dong Y, Du CH, Zhang Y, Wang LF, Song J, Wu MS, Yang WC, Lv S, Zhou XN. Role of ecological approaches to eliminating schistosomiasis in Eryuan County evaluated by system modelling. Infect Dis Poverty 2018; 7:129. [PMID: 30593286 PMCID: PMC6309097 DOI: 10.1186/s40249-018-0511-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 12/06/2018] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Schistosomiasis was severely prevalent in Yunnan Province, and it is difficult to achieve its elimination by convention approaches due to complexity of the nature. We explored the comprehensive model to eliminate schistosomiasis in Eryuan County, Yunnan Province, the People's Republic of China, through integration with the ecological protection programme in Erhai Lake, in order to promote an efficient elimination strategy. We expected that this model is able to be tailored to other local settings, which help achieve the goal of precisely eliminating the disease in Yunnan Province. METHODS Eryuan County of Yunnan Province was chosen as the study area, where the data on environmental protection activities in Erhai Lake and on the schistosomiasis control programme were collected through different departments of Erhai County government since 2015. System modelling was performed using system dynamics software to establish a simulation model in order to evaluate the effectiveness of intervention activities. RESULTS Ecological approaches to control schistosomiasis in Eryuan County consist of three major components: (i) implementing precise interventions to stop schistosomiasis transmission by means of controlling the source of infection, blocking the biological transmission chains and cutting off the route of disease transmission; (ii) employing ecological approaches to improve the co-effectiveness of environmental protection and schistosomiasis prevention in the study area; and (iii) strengthening the professional skills of personnel involving in the schistosomiasis control programme. Simulation results showed that this strategy could speed up the progress of schistosomiasis control programme moving from the control stage to the elimination stage. CONCLUSIONS Ecological approaches implemented in schistosomiasis endemic areas of the Eryuan region are able to improve the co-effectiveness of environmental protection and schistosomiasis control, providing a new avenue for eliminating schistosomiasis thanks to the application of precise interventions.
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Affiliation(s)
- Yi Dong
- Yunnan Institute of Endemic Diseases Control and Prevention, Dali, 671000, Yunnan, China
| | - Chun-Hong Du
- Yunnan Institute of Endemic Diseases Control and Prevention, Dali, 671000, Yunnan, China
| | - Yun Zhang
- Yunnan Institute of Endemic Diseases Control and Prevention, Dali, 671000, Yunnan, China
| | - Li-Fang Wang
- Yunnan Institute of Endemic Diseases Control and Prevention, Dali, 671000, Yunnan, China
| | - Jing Song
- Yunnan Institute of Endemic Diseases Control and Prevention, Dali, 671000, Yunnan, China
| | - Ming-Shou Wu
- Yunnan Institute of Endemic Diseases Control and Prevention, Dali, 671000, Yunnan, China
| | - Wen-Can Yang
- Eryuan Station of Schistosomiasis Control and Prevention, Eryuan, 671200, Yunnan, China
| | - Shan Lv
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, China.,Chinese Center for Tropical Diseases Research, Shanghai, 200025, China.,WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025, China.,National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, 200025, China.,Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025, China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, China. .,Chinese Center for Tropical Diseases Research, Shanghai, 200025, China. .,WHO Collaborating Centre for Tropical Diseases, Shanghai, 200025, China. .,National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, 200025, China. .,Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025, China.
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Angelo T, Buza J, Kinung’hi SM, Kariuki HC, Mwanga JR, Munisi DZ, Wilson S. Geographical and behavioral risks associated with Schistosoma haematobium infection in an area of complex transmission. Parasit Vectors 2018; 11:481. [PMID: 30144807 PMCID: PMC6109322 DOI: 10.1186/s13071-018-3064-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/15/2018] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Schistosoma haematobium infection in endemic areas varies depending on the nature and complexity of the transmission networks present. Studies of micro-geographical transmission of S. haematobium infection indicate that discrepancy in prevalence between households is associated with diverse water contact behaviors and transmission that is restricted to particular sites harboring snail intermediate hosts. Detection of variations in the transmission sources with complex transmission networks of water bodies is required for optimization of malacological control. Longitudinal parasitological and malacological surveys were conducted to investigate geographical variations in transmission of urogenital schistosomiasis in Ikingwamanoti village, Shinyanga District, Tanzania. METHODS Urine samples were collected at baseline and follow-up time points from 282 school-aged children and examined microscopically for the presence of S. haematobium eggs. Malacological surveys involved collection of Bulinus nasutus every month from 30 sites. Snails were examined for patent infections. Global positioning system was used to map household distances from S. haematobium transmission sites, while water contact behavior was assessed using a questionnaire. RESULTS Schistosoma haematobium infection was observed to be prevalent among older children (12-14 years) compared to younger groups prior to treatment, but no significant difference in infection prevalence was observed at one-year. Boys were highly infected than girls at both time points. No spatial influence was observed between children's infection and the distance from child's residence to the nearby snail habitats nor was any significant association observed between children's reported water contact behavior with S. haematobium infection. However, malacological surveys with cercarial shedding combined with GPS data detected significant variation among different water sources in the transmission of S. haematobium with children living in households near to ponds with high B. nasutus populations having the highest prevalence of infection. CONCLUSIONS Interaction between malacological surveys with cercarial shedding combined with GPS mapping in endemic settings can help detection of transmission sources even in areas with complex transmission networks. Subsequent studies are needed to determine whether the combination of GPS mapping and parasitology screens can aid the detection of transmission hotspots across varied transmission settings to enhance schistosomiasis control programmes.
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Affiliation(s)
- Teckla Angelo
- Department of Global Health, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania
- National Institute for Medical Research, Mwanza Centre, P. O. Box 1462, Mwanza, Tanzania
| | - Joram Buza
- Department of Global Health, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania
| | | | - Henry Curtis Kariuki
- Kenya Methodist University, School of Medicine and Health Sciences, P.O. Box 267, Meru, Kenya
| | - Joseph Rogathe Mwanga
- National Institute for Medical Research, Mwanza Centre, P. O. Box 1462, Mwanza, Tanzania
| | - David Zadock Munisi
- Department of Global Health, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, P. O. Box 447, Arusha, Tanzania
| | - Shona Wilson
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP UK
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Abstract
Schistosomiasis (bilharzia) is a neglected tropical disease caused by parasitic flatworms (blood flukes) of the genus Schistosoma, with considerable morbidity in parts of the Middle East, South America, Southeast Asia and, particularly, in sub-Saharan Africa. Infective larvae grow in an intermediate host (fresh-water snails) before penetrating the skin of the definitive human host. Mature adult worms reside in the mesenteric (Schistosoma mansoni and Schistosoma japonicum) or pelvic (Schistosoma haematobium) veins, where female worms lay eggs, which are secreted in stool or urine. Eggs trapped in the surrounding tissues and organs, such as the liver and bladder, cause inflammatory immune responses (including granulomas) that result in intestinal, hepato-splenic or urogenital disease. Diagnosis requires the detection of eggs in excreta or worm antigens in the serum, and sensitive, rapid, point-of-care tests for populations living in endemic areas are needed. The anti-schistosomal drug praziquantel is safe and efficacious against adult worms of all the six Schistosoma spp. infecting humans; however, it does not prevent reinfection and the emergence of drug resistance is a concern. Schistosomiasis elimination will require a multifaceted approach, including: treatment; snail control; information, education and communication; improved water, sanitation and hygiene; accurate diagnostics; and surveillance-response systems that are readily tailored to social-ecological settings.
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Affiliation(s)
- Donald P McManus
- Immunology Department, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia.
| | - David W Dunne
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Moussa Sacko
- Department of Diagnostic and Biomedical Research, Institut National de Recherche en Santé Publique, Bamako, Mali
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Birgitte J Vennervald
- Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Shanghai, People's Republic of China
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Kulinkina AV, Walz Y, Koch M, Biritwum NK, Utzinger J, Naumova EN. Improving spatial prediction of Schistosoma haematobium prevalence in southern Ghana through new remote sensors and local water access profiles. PLoS Negl Trop Dis 2018; 12:e0006517. [PMID: 29864165 PMCID: PMC6014678 DOI: 10.1371/journal.pntd.0006517] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 06/22/2018] [Accepted: 05/10/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Schistosomiasis is a water-related neglected tropical disease. In many endemic low- and middle-income countries, insufficient surveillance and reporting lead to poor characterization of the demographic and geographic distribution of schistosomiasis cases. Hence, modeling is relied upon to predict areas of high transmission and to inform control strategies. We hypothesized that utilizing remotely sensed (RS) environmental data in combination with water, sanitation, and hygiene (WASH) variables could improve on the current predictive modeling approaches. METHODOLOGY Schistosoma haematobium prevalence data, collected from 73 rural Ghanaian schools, were used in a random forest model to investigate the predictive capacity of 15 environmental variables derived from RS data (Landsat 8, Sentinel-2, and Global Digital Elevation Model) with fine spatial resolution (10-30 m). Five methods of variable extraction were tested to determine the spatial linkage between school-based prevalence and the environmental conditions of potential transmission sites, including applying the models to known human water contact locations. Lastly, measures of local water access and groundwater quality were incorporated into RS-based models to assess the relative importance of environmental and WASH variables. PRINCIPAL FINDINGS Predictive models based on environmental characterization of specific locations where people contact surface water bodies offered some improvement as compared to the traditional approach based on environmental characterization of locations where prevalence is measured. A water index (MNDWI) and topographic variables (elevation and slope) were important environmental risk factors, while overall, groundwater iron concentration predominated in the combined model that included WASH variables. CONCLUSIONS/SIGNIFICANCE The study helps to understand localized drivers of schistosomiasis transmission. Specifically, unsatisfactory water quality in boreholes perpetuates reliance on surface water bodies, indirectly increasing schistosomiasis risk and resulting in rapid reinfection (up to 40% prevalence six months following preventive chemotherapy). Considering WASH-related risk factors in schistosomiasis prediction can help shift the focus of control strategies from treating symptoms to reducing exposure.
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Affiliation(s)
- Alexandra V Kulinkina
- Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America
| | - Yvonne Walz
- Institute for Environment and Human Security, United Nations University, Bonn, Germany
| | - Magaly Koch
- Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America
- Center for Remote Sensing, Boston University, Boston, Massachusetts, United States of America
| | | | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Elena N Naumova
- Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America
- Friedman School of Nutrition Science and Policy, Tufts University, Boston, Massachusetts, United States of America
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Knowledge, Attitudes, and Practices Related to Schistosomiasis Among Children in Northern Senegal. Ann Glob Health 2018; 82:840-847. [PMID: 28283138 DOI: 10.1016/j.aogh.2016.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Schistosomiasis is a highly prevalent parasitic disease in Senegal. The early symptoms are hematuria and dysuria. Children's comprehension of the disease is fundamental to preventing the infection. OBJECTIVES The aim of this study was to investigate the knowledge attitudes, and practices related to schistosomiasis among schoolchildren in 2 rural villages in Northern Senegal and to evaluate their impact on the disease. METHODS A cross-sectional study was conducted. Data about children's knowledge of schistosomiasis, behavior, and preventive measures were collected through a questionnaire. FINDINGS Questionnaire responses from 575 schoolchildren were analyzed. Correct answers about risky behavior for schistosomiasis were associated with early symptoms (P = 0.010). Wearing shoes and washing hands with soap were associated with not having hematuria and dysuria (P = 0.007 and 0.049, respectively). Playing in rivers was associated with the aforementioned symptoms (P < 0.001). Children who had good knowledge of schistosomiasis reportedly did not have symptoms (P = 0.002). A logistic regression model showed that female sex (odds ratio = 0.35; P = 0.01) and attending a primary school (odds ratio = 0.13; P < 0.001) were significant predictors of a lower risk of the early symptoms of urinary schistosomiasis. CONCLUSIONS This study revealed that the level of knowledge among children in North Senegal about the causes, transmission, prevention, and treatment of schistosomiasis warrants implementing educational intervention.
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Towards elimination of schistosomiasis after 5000 years of endemicity in Egypt. Acta Trop 2018; 181:112-121. [PMID: 29453950 DOI: 10.1016/j.actatropica.2018.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/29/2018] [Accepted: 02/11/2018] [Indexed: 11/21/2022]
Abstract
Schistosomiasis is a snail-transmitted infectious disease caused by a long lasting infection with a blood fluke of the genus Schistosoma. S. haematobium and S. mansoni are the species endemic in Egypt. The country has been plagued and seriously suffered from schistosomiasis over the past 5000 years. Great strides had been done in controlling the disease since 1922. The history, epidemiology and the different control approaches were reviewed. Currently, Egypt is preparing towards schistosomiasis elimination by 2020. The new strategy depends on four main axes; large scale treatment in all areas of residual transmission by targeting entire populations with PZQ, intensified snail control, heath education and behavioral changes and expansion of the complementary public health interventions. While on the road towards elimination, we addressed here the important challenges, lessons and the key issues from the different control strategies to help the achievement of our goal. Notably, frangibility of the drug based control, emergence of resistance against PZQ, persistence of some hot spots areas, the need of further control efforts to the high risk individuals and community involvement in the control programs, reconsideration of diagnostic tests used in surveillance, and continous monitoring of the field to detect changes in the snail intermediate host. Importantly, the adaptation between the parasite and its intermediate snail host throughout water bodies in Egypt merits attention as Schistosoma infection can be introduced to the new reclaimed areas. This review may help supplying information for the policy makers to tailor control measures suitable to the local context that could help in the transfer from control to elimination.
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Rinaldo A, Gatto M, Rodriguez-Iturbe I. River networks as ecological corridors: A coherent ecohydrological perspective. ADVANCES IN WATER RESOURCES 2018; 112:27-58. [PMID: 29651194 PMCID: PMC5890385 DOI: 10.1016/j.advwatres.2017.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 05/14/2023]
Abstract
This paper draws together several lines of argument to suggest that an ecohydrological framework, i.e. laboratory, field and theoretical approaches focused on hydrologic controls on biota, has contributed substantially to our understanding of the function of river networks as ecological corridors. Such function proves relevant to: the spatial ecology of species; population dynamics and biological invasions; the spread of waterborne disease. As examples, we describe metacommunity predictions of fish diversity patterns in the Mississippi-Missouri basin, geomorphic controls imposed by the fluvial landscape on elevational gradients of species' richness, the zebra mussel invasion of the same Mississippi-Missouri river system, and the spread of proliferative kidney disease in salmonid fish. We conclude that spatial descriptions of ecological processes in the fluvial landscape, constrained by their specific hydrologic and ecological dynamics and by the ecosystem matrix for interactions, i.e. the directional dispersal embedded in fluvial and host/pathogen mobility networks, have already produced a remarkably broad range of significant results. Notable scientific and practical perspectives are thus open, in the authors' view, to future developments in ecohydrologic research.
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Affiliation(s)
- Andrea Rinaldo
- Laboratory of Ecohydrology ECHO/IIE/ENAC, École Polytechinque Fédérale de Lausanne, Lausanne, CH, Switzerland
- Dipartimento ICEA, Università di Padova, Padova, IT, Italy
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano IT, Italy
| | - Ignacio Rodriguez-Iturbe
- Department of Ocean Engineering, Department of Civil Engineering and Department of Biological and Agricultural Engineering, Texas A & M University, College Station (TX), USA
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The COUNTDOWN Study Protocol for Expansion of Mass Drug Administration Strategies against Schistosomiasis and Soil-Transmitted Helminthiasis in Ghana. Trop Med Infect Dis 2018; 3:tropicalmed3010010. [PMID: 30720777 PMCID: PMC6136637 DOI: 10.3390/tropicalmed3010010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/03/2018] [Accepted: 01/04/2018] [Indexed: 11/17/2022] Open
Abstract
(1) Background: Current international policy for schistosomiasis and soil-transmitted helminthiasis (STH) control emphasises mass administration of deworming drugs in school-based programmes. However, this approach is insufficient to control the transmission of these diseases, and their burden in non-school cohorts is recognised, albeit under-researched. This research will investigate the feasibility and acceptability of expanding access to praziquantel (PZQ) against schistosomiasis, and albendazole (ALB) against STH, to communities in selected transmission settings in Ghana. (2) Methods: A three-site longitudinal study will be implemented to investigate the effectiveness of expanding treatment strategies for PZQ and ALB to community members. In the context of community mass drug administration (to preschool children, school non-attending children, and adults, including pregnant women), the intervention will be assessed in a random sample of community members, at baseline with follow-up at 6, 12, and 18 months. In each community, 658 participants will be enrolled, and 314 followed up at each time point. The primary outcome measure is the prevalence of infection of Schistosoma haematobium and/or S. mansoni at study endpoint, as assessed by longitudinal surveys. Secondary outcomes are to quantify the infection of schistosomiasis and STH infections in non-treated cohorts, reductions in prevalence of STH, and intensity of schistosomiasis and STH, and treatment coverage. Nested within this study will be qualitative, cost-benefit, and cost-effectiveness evaluations that will explore accessibility, feasibility, and economic impact of expanded treatment from different complementary perspectives. (3) Discussion: Using a multidisciplinary approach, this study will generate evidence for improved availability, acceptability, affordability, and accessibility to deworming drugs against schistosomiasis and STH to individuals and communities in Ghana. This is likely to have considerable research, programmatic, and political value to contribute evidence for national programme policy development within Ghana, and, more broadly, World Health Organization policy development.
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Means AR, van Lieshout L, Brienen E, Yuhas K, Hughes JP, Ndungu P, Singa B, Walson JL. Combined effectiveness of anthelmintic chemotherapy and WASH among HIV-infected adults. PLoS Negl Trop Dis 2018; 12:e0005955. [PMID: 29346385 PMCID: PMC5773082 DOI: 10.1371/journal.pntd.0005955] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/12/2017] [Indexed: 11/18/2022] Open
Abstract
Introduction Current global helminth control guidelines focus on regular deworming of targeted populations for morbidity control. However, water, sanitation, and hygiene (WASH) interventions may also be important for reducing helminth transmission. We evaluated the impact of different potential helminth protective packages on infection prevalence, including repeated treatment with albendazole and praziquantel with and without WASH access. Methodology/Principal findings We conducted a cohort study nested within a randomized trial of empiric deworming of HIV-infected adults in Kenya. Helminth infections and infection intensity were diagnosed using semi-quantitative real-time PCR. We conducted a manual forward stepwise model building approach to identify if there are packages of interventions that may be protective against an STH infection of any species (combined outcome) and each helminth species individually. We conducted secondary analyses using the same approach only amongst individuals with no anthelmintis exposure. We used interaction terms to test for potential intervention synergy. Approximately 22% of the 701 stool samples provided were helminth-infected, most of which were of low to moderate intensity. The odds of infection with any STH species were lower for individuals who were treated with albendazole (aOR:0.11, 95%CI: 0.05, 0.20, p<0.001), adjusting for age and sex. Although most WASH conditions demonstrated minimal additional benefit in reducing the probability of infection with any STH species, access to safe flooring did appear to offer some additional protection (aOR:0.34, 95%CI: 0.20, 0.56, p<0.001). For schistosomiasis, only treatment with praziquantel was protective (aOR:0.30 95%CI: 0.14, 0.60, p = 0.001). Amongst individuals who were not treated with albendazole or praziquantel, the most protective intervention package to reduce probability of STH infections included safe flooring (aOR:0.34, 95%CI: 0.20, 0.59, p<0.001) and latrine access (aOR:0.59, 95%CI: 0.35, 0.99, p = 0.05). Across all species, there was no evidence of synergy or antagonism between anthelmintic chemotherapy with albendazole or praziquantel and WASH resources. Conclusions/Significance Deworming is effective in reducing the probability of helminth infections amongst HIV-infected adults. With the exception of safe flooring, WASH offers minimal additional benefit. However, WASH does appear to significantly reduce infection prevalence in adults who are not treated with chemotherapy. Trial registration ClinicalTrials.gov, NCT00507221. More than 2 billion people are infected with soil transmitted helminthiasis (STH) and schistosomiasis globally. In addition to deworming with albendazole and praziquantel, water, sanitation, and hygiene (WASH) may be needed to reduce the risk of helminth reinfection and ultimately to break transmission. However evidence on the effectiveness of integrated deworming and WASH programs are mixed. Using data from a randomized controlled trial of deworming among HIV-infected adults in Kenya, we evaluated the associations between different potential packages of deworming and WASH interventions with helminth prevalence. We also aimed to understand if there was a benefit to accessing both WASH and deworming (i.e. synergy). Our findings indicate that deworming treatments were effective in reducing the probability of infection with most helminth species. Of the WASH conditions assessed, safe flooring and latrine access significantly reduced the probability of helminth infections among adults with access to treatment. However WASH may play a more prominent protective role among individuals without access to deworming treatments. These findings also suggest minimal synergistic benefit of coordinated anthelmintic chemotherapy and WASH in this population. These findings have important implications for adult populations who are currently not targeted by deworming campaigns.
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Affiliation(s)
- Arianna R. Means
- Department of Global Health, University of Washington, Seattle, WA, United States
- DeWorm3, Natural History Museum, London, United Kingdom
- * E-mail:
| | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Eric Brienen
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Krista Yuhas
- Department of Global Health, University of Washington, Seattle, WA, United States
| | - James P. Hughes
- Department of Biostatistics, University of Washington, Seattle, WA, United States
| | - Paul Ndungu
- Centre for Clinical Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Benson Singa
- Centre for Clinical Research, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Judd L. Walson
- Department of Global Health, University of Washington, Seattle, WA, United States
- DeWorm3, Natural History Museum, London, United Kingdom
- Departments of Medicine, Pediatrics, and Epidemiology, University of Washington, Seattle, WA, United States of America
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Phillips AE, Gazzinelli-Guimarães PH, Aurelio HO, Dhanani N, Ferro J, Nala R, Deol A, Fenwick A. Urogenital schistosomiasis in Cabo Delgado, northern Mozambique: baseline findings from the SCORE study. Parasit Vectors 2018; 11:30. [PMID: 29316983 PMCID: PMC5761122 DOI: 10.1186/s13071-017-2592-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 12/13/2017] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND The results presented here are part of a five-year cluster-randomised intervention trial that was implemented to understand how best to gain and sustain control of schistosomiasis through different preventive chemotherapy strategies. This paper presents baseline data that were collected in ten districts of Cabo Delgado province, northern Mozambique, before treatment. METHODS A cross-sectional study of 19,039 individuals was sampled from 144 villages from May to September 2011. In each village prevalence and intensity of S. haematobium were investigated in 100 children first-year students (aged 5-8 years), 100 school children aged 9-12 years (from classes 2 to 7) and 50 adults (20-55 years). Prevalence and intensity of S. haematobium infection were evaluated microscopically by two filtrations, each of 10 ml, from a single urine specimen. Given that individual and community perceptions of schistosomiasis influence control efforts, community knowledge and environmental risk factors were collected using a face-to-face interview. Data were entered onto mobile phones using EpiCollect. Data summary was made using descriptive statistics. Chi-square and logistic regression were used to determine the association between dependent and independent variables. RESULTS The overall prevalence of urogenital schistosomiasis was 60.4% with an arithmetic mean intensity of infection of 55.8 eggs/10 ml of urine. Heavy infections were detected in 17.7%, of which 235 individuals (6.97%) had an egg count of 1000 eggs/10 ml or more. There was a significantly higher likelihood of males being infected than females across all ages (62% vs 58%; P < 0.0005). Adolescents aged 9-12 years had a higher prevalence (66.6%) and mean infection intensity (71.9 eggs/10 ml) than first-year students (63.1%; 58.2 eggs/10 ml). This is the first study in Mozambique looking at infection rates among adults. Although children had higher levels of infection, it was found here that adults had a high average prevalence and intensity of infection (44.5%; 23.9 eggs/10 ml). Awareness of schistosomiasis was relatively high (68.6%); however, correct knowledge of how schistosomiasis is acquired was low (23.2%) among those who had heard of the disease. Schistosomiasis risk behaviour such as washing (91.3%) and bathing (86.7%) in open water sources likely to be infested with host snails was high. CONCLUSIONS Urogenital schistosomiasis is widespread in Cabo Delgado. In addition, poor community knowledge about the causes of schistosomiasis and how to prevent it increases the significant public health challenge for the national control program. This was the first study in Mozambique that examined infection levels among adults, where results showed that S. haematobium infection was also extremely high. Given that this controlled trial aims to understand the impact of different combinations of schistosomiasis control through treatment of communities, schools, and treatment holidays over a five-year period, these findings highlight the importance of examining the impact of different treatment approaches also in adults. TRIAL REGISTRATION The trials have been registered with the International Standard Randomised Controlled Trial registry under ISRCT 14117624 Mozambique (14 December 2015).
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Affiliation(s)
- Anna E. Phillips
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, W2 1PG, London, UK
| | - Pedro H. Gazzinelli-Guimarães
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, W2 1PG, London, UK
| | - Herminio O. Aurelio
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, W2 1PG, London, UK
- Faculdade of Health Sciences, Universidade Católica de Moçambique (UCM), Beira, Mozambique
| | - Neerav Dhanani
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, W2 1PG, London, UK
| | - Josefo Ferro
- Faculdade of Health Sciences, Universidade Católica de Moçambique (UCM), Beira, Mozambique
| | | | - Arminder Deol
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, W2 1PG, London, UK
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, W2 1PG, London, UK
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Water Quality: Mindanao Island of the Philippines. TRANSLATING NATIONAL POLICY TO IMPROVE ENVIRONMENTAL CONDITIONS IMPACTING PUBLIC HEALTH THROUGH COMMUNITY PLANNING 2018. [PMCID: PMC7153040 DOI: 10.1007/978-3-319-75361-4_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Philippines is an archipelagic country dominated by water and inland water sources. Water quality has been the subject of attention for the country and specifically, Mindanao Island, because of the role this natural resource plays in agriculture. Water supply and usage for the island and the nation are identified and discussed in relation to the scarcity of potable water. Potential threats and pollution hotspots bring forth the various health and environmental impact attributed to the water system accessibility, distribution, and quality. Strategies addressing water resources problems are taken into consideration side-by-side the numerous national laws, policies, standards, and guidelines in addressing water quality control and management. Therefore, the legal framework for various agencies to carry out these policies on quality control, usage, and water management are pivotal to recommendations on revision of certain provisions that rely on embedding local community involvement to lessen the environmental impact that is causal to poor population health. The World Bank has been instrumental in prompting local activity with initiatives first established in relation to the United Nations Millennium Development Goals that are being carried forward today in the Sustainable Development Initiatives. This chapter extends the recent UN and World Bank initiatives to demonstrate how further community involvement can continue to improve quality of life for Philippine citizens through education and participation.
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Donohue RE, Mashoto KO, Mubyazi GM, Madon S, Malecela MN, Michael E. Biosocial Determinants of Persistent Schistosomiasis among Schoolchildren in Tanzania despite Repeated Treatment. Trop Med Infect Dis 2017; 2:E61. [PMID: 30270918 PMCID: PMC6082061 DOI: 10.3390/tropicalmed2040061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 01/19/2023] Open
Abstract
Schistosomiasis is a parasitic disease endemic to Tanzania and other countries of the global south, which is currently being addressed through preventive chemotherapy campaigns. However, there is growing recognition that chemotherapy strategies will need to be supplemented to sustainably control and eventually eliminate the disease. There remains a need to understand the factors contributing to continued transmission in order to ensure the effective configuration and implementation of supplemented programs. We conducted a cross-sectional questionnaire, to evaluate the biosocial determinants facilitating the persistence of schistosomiasis, among 1704 Tanzanian schoolchildren residing in two districts undergoing a preventive chemotherapeutic program: Rufiji and Mkuranga. A meta-analysis was carried out to select the diagnostic questions that provided a likelihood for predicting infection status. We found that self-reported schistosomiasis continues to persist among the schoolchildren, despite multiple rounds of drug administration.Using mixed effects logistic regression modeling, we found biosocial factors, including gender, socio-economic status, and water, sanitation, and hygiene (WASH)-related variables, were associated with this continued schistosomiasis presence. These findings highlight the significant role that social factors may play in the persistence of disease transmission despite multiple treatments, and support the need not only for including integrated technical measures, such as WASH, but also addressing issues of poverty and gender when designing effective and sustainable schistosomiasis control programs.
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Affiliation(s)
- Rose E Donohue
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Kijakazi O Mashoto
- National Institute for Medical Research, P.O. Box 9653, 3 Barack Obama Drive, 11101 Dar es Salaam, Tanzania.
| | - Godfrey M Mubyazi
- National Institute for Medical Research, P.O. Box 9653, 3 Barack Obama Drive, 11101 Dar es Salaam, Tanzania.
| | - Shirin Madon
- Department of International Development, London School of Economics & Political Science, Houghton Street, London WC2A 2AE, UK.
- Department of Management, London School of Economics & Political Science, Houghton Street, London WC2A 2AE, UK.
| | - Mwele N Malecela
- Tanzania Commission for Science and Technology (COSTECH), P.O. Box 4302, Ali Hassan Mwinyi Road, Kijitonyama, 14113 Dar es Salaam, Tanzania.
| | - Edwin Michael
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
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Corstjens PLAM, Hoekstra PT, de Dood CJ, van Dam GJ. Utilizing the ultrasensitive Schistosoma up-converting phosphor lateral flow circulating anodic antigen (UCP-LF CAA) assay for sample pooling-strategies. Infect Dis Poverty 2017; 6:155. [PMID: 29089064 PMCID: PMC5664425 DOI: 10.1186/s40249-017-0368-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 10/09/2017] [Indexed: 01/08/2023] Open
Abstract
Background Methodological applications of the high sensitivity genus-specific Schistosoma CAA strip test, allowing detection of single worm active infections (ultimate sensitivity), are discussed for efficient utilization in sample pooling strategies. Besides relevant cost reduction, pooling of samples rather than individual testing can provide valuable data for large scale mapping, surveillance, and monitoring. Method The laboratory-based CAA strip test utilizes luminescent quantitative up-converting phosphor (UCP) reporter particles and a rapid user-friendly lateral flow (LF) assay format. The test includes a sample preparation step that permits virtually unlimited sample concentration with urine, reaching ultimate sensitivity (single worm detection) at 100% specificity. This facilitates testing large urine pools from many individuals with minimal loss of sensitivity and specificity. The test determines the average CAA level of the individuals in the pool thus indicating overall worm burden and prevalence. When requiring test results at the individual level, smaller pools need to be analysed with the pool-size based on expected prevalence or when unknown, on the average CAA level of a larger group; CAA negative pools do not require individual test results and thus reduce the number of tests. Results Straightforward pooling strategies indicate that at sub-population level the CAA strip test is an efficient assay for general mapping, identification of hotspots, determination of stratified infection levels, and accurate monitoring of mass drug administrations (MDA). At the individual level, the number of tests can be reduced i.e. in low endemic settings as the pool size can be increased as opposed to prevalence decrease. Conclusions At the sub-population level, average CAA concentrations determined in urine pools can be an appropriate measure indicating worm burden. Pooling strategies allowing this type of large scale testing are feasible with the various CAA strip test formats and do not affect sensitivity and specificity. It allows cost efficient stratified testing and monitoring of worm burden at the sub-population level, ideally for large-scale surveillance generating hard data for performance of MDA programs and strategic planning when moving towards transmission-stop and elimination.
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Affiliation(s)
- Paul L A M Corstjens
- Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9600, 2300, RC, Leiden, The Netherlands.
| | - Pytsje T Hoekstra
- Department of Parasitology, Leiden University Medical Center, P.O. Box 9600, 2300, RC, Leiden, The Netherlands
| | - Claudia J de Dood
- Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9600, 2300, RC, Leiden, The Netherlands
| | - Govert J van Dam
- Department of Parasitology, Leiden University Medical Center, P.O. Box 9600, 2300, RC, Leiden, The Netherlands
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Mari L, Ciddio M, Casagrandi R, Perez-Saez J, Bertuzzo E, Rinaldo A, Sokolow SH, De Leo GA, Gatto M. Heterogeneity in schistosomiasis transmission dynamics. J Theor Biol 2017; 432:87-99. [PMID: 28823529 PMCID: PMC5595357 DOI: 10.1016/j.jtbi.2017.08.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 06/30/2017] [Accepted: 08/15/2017] [Indexed: 01/30/2023]
Abstract
Transmission dynamics of schistosomiasis presents multiple heterogeneity sources. A comprehensive framework for heterogeneous disease transmission is proposed. Heterogeneous multigroup communities can be more prone to parasite transmission. Presence of multiple water sources can hinder parasite transmission. Spatial and temporal heterogeneities can have nontrivial implications for endemicity.
Simple models of disease propagation often disregard the effects of transmission heterogeneity on the ecological and epidemiological dynamics associated with host-parasite interactions. However, for some diseases like schistosomiasis, a widespread parasitic infection caused by Schistosoma worms, accounting for heterogeneity is crucial to both characterize long-term dynamics and evaluate opportunities for disease control. Elaborating on the classic Macdonald model for macroparasite transmission, we analyze families of models including explicit descriptions of heterogeneity related to differential transmission risk within a community, water contact patterns, the distribution of the snail host population, human mobility, and the seasonal fluctuations of the environment. Through simple numerical examples, we show that heterogeneous multigroup communities may be more prone to schistosomiasis than homogeneous ones, that the availability of multiple water sources can hinder parasite transmission, and that both spatial and temporal heterogeneities may have nontrivial implications for disease endemicity. Finally, we discuss the implications of heterogeneity for disease control. Although focused on schistosomiasis, results from this study may apply as well to other parasitic infections with complex transmission cycles, such as cysticercosis, dracunculiasis and fasciolosis.
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Affiliation(s)
- Lorenzo Mari
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy.
| | - Manuela Ciddio
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Renato Casagrandi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Javier Perez-Saez
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Enrico Bertuzzo
- Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari Venezia, 30170 Venezia Mestre, Italy
| | - Andrea Rinaldo
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland; Dipartimento ICEA, Università di Padova, 35131 Padova, Italy
| | - Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA; Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
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LOW PREVALENCE OF INTESTINAL SCHISTOSOMIASIS AMONG FISHERFOLK LIVING ALONG THE RIVER NILE IN NORTH-WESTERN UGANDA: A BIOSOCIAL INVESTIGATION. J Biosoc Sci 2017; 48 Suppl 1:S74-91. [PMID: 27428067 DOI: 10.1017/s0021932016000237] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mass drug administration has been less successful as a technique for controlling intestinal schistosomiasis (S. mansoni) than anticipated. In Uganda, the mass distribution of praziquantel has been provided to populations at risk of infection since the early 2000s, but prevalence mostly remains high. This is the case, for example, at locations in north-western and south-eastern Uganda. However, there is a remarkable exception. Among Madi fishing populations and their immediate neighbours, living close to the border with South Sudan, the rate of infection has dropped dramatically. A parasitological survey carried out at twelve fishing sites in 2013 identified only three cases of S. mansoni among 383 adults tested. This article asks: why is the prevalence of S. mansoni so low among fisherfolk in northern Uganda? Taking a biosocial approach, it suggests that the mass distribution of drugs, free of charge, has had an impact. However, the low prevalence of infection cannot be attributed to this alone. Other important factors may also have contributed to the decline in infection. These include changing fishing livelihoods, local attitudes to public health interventions, access to water and sanitation facilities, hygiene practices and the use of anti-malarial treatments. Above all, the article highlights the importance of investigating both social and biological dimensions of infection simultaneously, and of recognizing the local complexities of sustainably treating this debilitating parasitic disease.
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Lamberton PHL, Faust CL, Webster JP. Praziquantel decreases fecundity in Schistosoma mansoni adult worms that survive treatment: evidence from a laboratory life-history trade-offs selection study. Infect Dis Poverty 2017. [PMID: 28622767 PMCID: PMC5472905 DOI: 10.1186/s40249-017-0324-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background Mass drug administration of praziquantel is the World Health Organization’s endorsed control strategy for schistosomiasis. A decade of annual treatments across sub-Saharan Africa has resulted in significant reductions of infection prevalence and intensity levels, although ‘hotspots’ remain. Repeated drug treatments place strong selective pressures on parasites, which may affect life-history traits that impact transmission dynamics. Understanding drug treatment responses and the evolution of such traits can help inform on how to minimise the risk of drug resistance developing, maximise sustainable control programme success, and improve diagnostic protocols. Methods We performed a four-generation Schistosoma mansoni praziquantel selection experiment in mice and snails. We used three S. mansoni lines: a praziquantel-resistant isolate (R), a praziquantel-susceptible isolate (S), and a co-infected line (RS), under three treatment regimens: untreated, 25 mg/kg praziquantel, or 50 mg/kg praziquantel. Life-history traits, including parasite adult-worm establishment, survival, reproduction (fecundity), and associated morbidity, were recorded in mice across all four generations. Predictor variables were tested in a series of generalized linear mixed effects models to determine which factors had a significant influence on parasite life-history traits in definitive hosts under different selection regimes. Results Praziquantel pressure significantly reduced adult-worm burdens across all generations and isolates, including within R-lines. However, previous drug treatment resulted in an increase in adult-worm establishment with increasing generation from P1 to F3. The highest worm numbers were in the co-infected RS line. Praziquantel treatment decreased adult-worm burden, but had a larger negative impact on the mean daily number of miracidia, a proxy for fecundity, across all three parasite isolates. Conclusions Our predicted cost of resistance was not supported by the traits we measured within the murine host. We did not find evidence for negative adult worm density-dependent effects on fecundity. In contrast, of the adult worms that survived treatment, even low doses of praziquantel significantly reduced adult-worm fecundity. Such reductions in worm fecundity post treatment suggest that egg - based measures of drug efficacy, such as Kato-Katz, may overestimate the short-term effect of praziquantel on adult - worm burdens. These findings have important implications for S. mansoni transmission control, diagnostic protocols, and the potential for undetected selection toward drug resistance. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0324-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Poppy H L Lamberton
- Institute for Biodiversity, Animal Health, and Comparative Medicine & Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary & Life Sciences, University of Glasgow, G12 8QQ, Glasgow, UK. .,London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, St Mary's Campus, W2 1PG, London, UK.
| | - Christina L Faust
- Institute for Biodiversity, Animal Health, and Comparative Medicine & Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary & Life Sciences, University of Glasgow, G12 8QQ, Glasgow, UK
| | - Joanne P Webster
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, St Mary's Campus, W2 1PG, London, UK.,Centre for Endemic, Emerging and Exotic Diseases, The Royal Veterinary College, University of London, London, AL9 7TA, UK
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Freeman MC, Garn JV, Sclar GD, Boisson S, Medlicott K, Alexander KT, Penakalapati G, Anderson D, Mahtani AG, Grimes JET, Rehfuess EA, Clasen TF. The impact of sanitation on infectious disease and nutritional status: A systematic review and meta-analysis. Int J Hyg Environ Health 2017; 220:928-949. [PMID: 28602619 DOI: 10.1016/j.ijheh.2017.05.007] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/16/2017] [Accepted: 05/18/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Sanitation aims to sequester human feces and prevent exposure to fecal pathogens. More than 2.4 billion people worldwide lack access to improved sanitation facilities and almost one billion practice open defecation. We undertook systematic reviews and meta-analyses to compile the most recent evidence on the impact of sanitation on diarrhea, soil-transmitted helminth (STH) infections, trachoma, schistosomiasis, and nutritional status assessed using anthropometry. METHODS AND FINDINGS We updated previously published reviews by following their search strategy and eligibility criteria. We searched from the previous review's end date to December 31, 2015. We conducted meta-analyses to estimate pooled measures of effect using random-effects models and conducted subgroup analyses to assess impact of different levels of sanitation services and to explore sources of heterogeneity. We assessed risk of bias and quality of the evidence from intervention studies using the Liverpool Quality Appraisal Tool (LQAT) and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, respectively. A total of 171 studies met the review's inclusion criteria, including 64 studies not included in the previous reviews. Overall, the evidence suggests that sanitation is protective against diarrhea, active trachoma, some STH infections, schistosomiasis, and height-for-age, with no protective effect for other anthropometric outcomes. The evidence was generally of poor quality, heterogeneity was high, and GRADE scores ranged from very low to high. CONCLUSIONS This review confirms positive impacts of sanitation on aspects of health. Evidence gaps remain and point to the need for research that rigorously describes sanitation implementation and type of sanitation interventions.
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Affiliation(s)
- Matthew C Freeman
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
| | - Joshua V Garn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Gloria D Sclar
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Sophie Boisson
- Department of Public Health, Environmental and Social Determinants of Health (PHE), World Health Organization, Geneva, Switzerland
| | - Kate Medlicott
- Department of Public Health, Environmental and Social Determinants of Health (PHE), World Health Organization, Geneva, Switzerland
| | - Kelly T Alexander
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Gauthami Penakalapati
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Darcy Anderson
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Amrita G Mahtani
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Jack E T Grimes
- Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London, UK
| | - Eva A Rehfuess
- Institute for Medical Informatics, Biometry and Epidemiology, Pettenkofer School of Public Health, LMU Munich, Germany
| | - Thomas F Clasen
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA; Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
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Rinaldo A, Bertuzzo E, Blokesch M, Mari L, Gatto M. Modeling Key Drivers of Cholera Transmission Dynamics Provides New Perspectives for Parasitology. Trends Parasitol 2017; 33:587-599. [PMID: 28483382 DOI: 10.1016/j.pt.2017.04.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 04/01/2017] [Accepted: 04/10/2017] [Indexed: 11/15/2022]
Abstract
Hydroclimatological and anthropogenic factors are key drivers of waterborne disease transmission. Information on human settlements and host mobility on waterways along which pathogens and hosts disperse, and relevant hydroclimatological processes, can be acquired remotely and included in spatially explicit mathematical models of disease transmission. In the case of epidemic cholera, such models allowed the description of complex disease patterns and provided insight into the course of ongoing epidemics. The inclusion of spatial information in models of disease transmission can aid in emergency management and the assessment of alternative interventions. Here, we review the study of drivers of transmission via spatially explicit approaches and argue that, because many parasitic waterborne diseases share the same drivers as cholera, similar principles may apply.
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Affiliation(s)
- Andrea Rinaldo
- Laboratory of Ecohydrology, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Dipartimento ICEA, Università di Padova, Padova, Italy.
| | - Enrico Bertuzzo
- Laboratory of Ecohydrology, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Department of Environmental Sciences, Informatics and Statistics, University Cà Foscari Venice, Venezia Mestre, Italy
| | - Melanie Blokesch
- Laboratory of Molecular Microbiology, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Lorenzo Mari
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy
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128
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Ortu G, Ndayishimiye O, Clements M, Kayugi D, Campbell CH, Lamine MS, Zivieri A, Magalhaes RS, Binder S, King CH, Fenwick A, Colley DG, Jourdan PM. Countrywide Reassessment of Schistosoma mansoni Infection in Burundi Using a Urine-Circulating Cathodic Antigen Rapid Test: Informing the National Control Program. Am J Trop Med Hyg 2017; 96:664-673. [PMID: 28115675 PMCID: PMC5361543 DOI: 10.4269/ajtmh.16-0671] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Following implementation of the national control program, a reassessment of Schistosoma mansoni prevalence was conducted in Burundi to determine the feasibility of moving toward elimination. A countrywide cluster-randomized cross-sectional study was performed in May 2014. At least 25 schools were sampled from each of five eco-epidemiological risk zones for schistosomiasis. Fifty randomly selected children 13–14 years of age per school were included for a single urine-circulating cathodic antigen (CCA) rapid test and, in a subset of schools, for duplicate Kato-Katz slide preparation from a single stool sample. A total of 17,331 children from 347 schools were tested using CCA. The overall prevalence of S. mansoni infection, when CCA trace results were considered negative, was 13.5% (zone range [zr] = 4.6–17.8%), and when CCA trace results were considered positive, it was 42.8% (zr = 34.3–49.9%). In 170 schools, prevalence of this infection determined using Kato-Katz method was 1.5% (zr ==0–2.7%). The overall mean intensity of S. mansoni infection determined using Kato-Katz was 0.85 eggs per gram (standard deviation = 10.86). A majority of schools (84%) were classified as non-endemic (prevalence = 0) using Kato-Katz; however, a similar proportion of schools were classified as endemic when CCA trace results were considered negative (85%) and nearly all (98%) were endemic when CCA trace results were considered positive. The findings of this nationwide reassessment using a CCA rapid test indicate that Schistosoma infection is still widespread in Burundi, although its average intensity is probably low. Further evidence is now needed to determine the association between CCA rapid test positivity and low-intensity disease transmission.
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Affiliation(s)
- Giuseppina Ortu
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Onésime Ndayishimiye
- Programme National Intégré de lutte contre les Maladies Tropicales Négligées et la Cécité (PNIMTNC), Ministère de la Santé Publique et de la Lutte contre le SIDA, Bujumbura, Burundi
| | - Michelle Clements
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Donatien Kayugi
- Programme National Intégré de lutte contre les Maladies Tropicales Négligées et la Cécité (PNIMTNC), Ministère de la Santé Publique et de la Lutte contre le SIDA, Bujumbura, Burundi
| | - Carl H Campbell
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Department of Microbiology, Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | | | - Antonio Zivieri
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Ricardo Soares Magalhaes
- Children's Health Research Centre, The University of Queensland, South Brisbane, Australia.,School of Veterinary Science, The University of Queensland, Gatton Campus, Gatton, Australia
| | - Sue Binder
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Department of Microbiology, Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, Ohio.,Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Department of Microbiology, Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | - Alan Fenwick
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Daniel G Colley
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Department of Microbiology, Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | - Peter Mark Jourdan
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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Big-data-driven modeling unveils country-wide drivers of endemic schistosomiasis. Sci Rep 2017; 7:489. [PMID: 28352101 PMCID: PMC5428445 DOI: 10.1038/s41598-017-00493-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 02/27/2017] [Indexed: 11/09/2022] Open
Abstract
Schistosomiasis is a parasitic infection that is widespread in sub-Saharan Africa, where it represents a major health problem. We study the drivers of its geographical distribution in Senegal via a spatially explicit network model accounting for epidemiological dynamics driven by local socioeconomic and environmental conditions, and human mobility. The model is parameterized by tapping several available geodatabases and a large dataset of mobile phone traces. It reliably reproduces the observed spatial patterns of regional schistosomiasis prevalence throughout the country, provided that spatial heterogeneity and human mobility are suitably accounted for. Specifically, a fine-grained description of the socioeconomic and environmental heterogeneities involved in local disease transmission is crucial to capturing the spatial variability of disease prevalence, while the inclusion of human mobility significantly improves the explanatory power of the model. Concerning human movement, we find that moderate mobility may reduce disease prevalence, whereas either high or low mobility may result in increased prevalence of infection. The effects of control strategies based on exposure and contamination reduction via improved access to safe water or educational campaigns are also analyzed. To our knowledge, this represents the first application of an integrative schistosomiasis transmission model at a whole-country scale.
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130
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Xu J, Duan ZL, Guan ZX, Wang YY, Lin C, Zhang TT, Zhang HQ, Qian X, Xia CM. Early detection of circulating DNA of Schistosoma japonicum in sentinel mice models. Exp Parasitol 2017; 176:82-88. [PMID: 28268185 DOI: 10.1016/j.exppara.2016.12.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/07/2016] [Accepted: 12/16/2016] [Indexed: 12/22/2022]
Abstract
Currently in China, the schistosomiasis control program has shifted its focus from transmission control to the elimination of the disease. Effective forecast and surveillance systems of schistiosomiasis are of great importance for issuing timely and early warnings on risk of infection, and therefore implementing preventive measures to avoid infection. There is great demand in more sensitive and specific methods to improve the surveillance system for early detection of S. japonicum infection in sentinel mice. In this study, we reported a sensitive nested-PCR assay targeting a 303-bp fragment from highly repetitive retrotransposon SjCHGCS19 to detect the S. japonicum DNA in sera of experimental mice. Meanwhile, detection efficacy of the nested-PCR was compared with two conventional methods for field monitoring schistosomiasis such as ELISA and IHA. The nested-PCR assay could detect the specific DNA at 3-day post-infection in sera of mice with 5 cercariae infection, while for ELISA and IHA, both show negative results even after 2 weeks post-infection in mice with 20 cercariae infection. Our results demonstrated the DNA-based assay was more sensitive to make early diagnosis of S. japonicum infection in sentinel mice models, which will improve the early-warning ability of schistosomiasis surveillance system.
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Affiliation(s)
- Jing Xu
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
| | - Zhong Liang Duan
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
| | - Zhi Xun Guan
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
| | - Yan Yan Wang
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
| | - Cai Lin
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
| | - Ting Ting Zhang
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
| | - Hui Qin Zhang
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
| | - Ximei Qian
- Department of Biomedical Engineering, Emory University, 1760 Haygood Dr., Atlanta 30322, Georgia.
| | - Chao Ming Xia
- Department of Parasitology, Medical College of Soochow University, Suzhou, 215123, Jiangsu Province, China.
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Dawaki S, Al-Mekhlafi HM, Ithoi I, Ibrahim J, Abdulsalam AM, Ahmed A, Sady H, Atroosh WM, Al-Areeqi MA, Elyana FN, Nasr NA, Surin J. PREVALENCE AND RISK FACTORS OF SCHISTOSOMIASIS AMONG HAUSA COMMUNITIES IN KANO STATE, NIGERIA. Rev Inst Med Trop Sao Paulo 2017; 58:54. [PMID: 27410914 PMCID: PMC4964323 DOI: 10.1590/s1678-9946201658054] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/07/2016] [Indexed: 12/17/2022] Open
Abstract
Schistosomiasis remains one of the most prevalent neglected tropical diseases especially in Nigeria which has the greatest number of infected people worldwide. A cross-sectional study was conducted among 551 participants from Kano State, North Central Nigeria. Fecal samples were examined for the presence of Schistosoma mansoni eggs using the formalin-ether sedimentation method while the urine samples were examined using the filtration technique for the presence of S. haematobium eggs. Demographic, socioeconomic and environmental information was collected using a pre-validated questionnaire. The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium, respectively and 0.5% presenting co-infection with both species. The multiple logistic regression analysis revealed that age < 18 years (OR = 2.13; 95% CI; 1.34- 3.41), presence of infected family members (OR = 3.98; 95% CI; 2.13-7.46), and history of infection (OR = 2.87; 95% CI; 1.87- 4.56) were the significant risk factors associated with schistosomiasis in these communities. In conclusion, this study revealed that schistosomiasis is still prevalent among Hausa communities in Nigeria. Mass drug administration, health education and community mobilization are imperative strategies to significantly reduce the prevalence and morbidity of schistosomiasis in these communities.
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Affiliation(s)
- Salwa Dawaki
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Hesham Mahyoub Al-Mekhlafi
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ; .,Endemic and Tropical Diseases Unit, Medical Research Center, Jazan University, Jazan, Saudi Arabia. E-mail:
| | - Init Ithoi
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Jamaiah Ibrahim
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Awatif Mohammed Abdulsalam
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Abdulhamid Ahmed
- Department of Biology, Faculty of Natural and Applied Sciences, Umaru Musa Yar'adua University. Katsina, Katsina State, Nigeria. E-mail:
| | - Hany Sady
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Wahib Mohammed Atroosh
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Mona Abdullah Al-Areeqi
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Fatin Nur Elyana
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Nabil Ahmed Nasr
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
| | - Johari Surin
- Department of Parasitology, Faculty of Medicine, University of Malaya. 50603 Kuala Lumpur, Malaysia. E-mails: ; ; ; ; ; ; ; ; ; ;
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Kulinkina AV, Kosinski KC, Plummer JD, Durant JL, Bosompem KM, Adjei MN, Griffiths JK, Gute DM, Naumova EN. Indicators of improved water access in the context of schistosomiasis transmission in rural Eastern Region, Ghana. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 579:1745-1755. [PMID: 27939198 PMCID: PMC5226254 DOI: 10.1016/j.scitotenv.2016.11.140] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/17/2016] [Accepted: 11/20/2016] [Indexed: 06/06/2023]
Abstract
Populations with poor access to water, sanitation and hygiene (WASH) infrastructure are disproportionately affected by the neglected tropical diseases (NTDs). As a result, WASH has gained increasing prominence in integrated control and elimination of NTDs, including schistosomiasis. In order to identify underserved populations, relevant measures of access to WASH infrastructure at sub-national or local levels are needed. We conducted a field survey of all public water sources in 74 rural communities in the Eastern Region of Ghana and computed indicators of water access using two methods: one based on the design capacity and another on the spatial distribution of water sources. The spatial method was applied to improved and surface water sources. According to the spatial method, improved water sources in the study area were well-distributed within communities with 95% (CI95%: 91, 98) of the population having access within 500m when all, and 87% (CI95%: 81, 93) when only functional water sources were considered. According to the design capacity-based method, indicator values were lower: 63% (CI95%: 57, 69) for all and 49% (CI95%: 43, 55) for only functional sources. Surface water access was substantial with 62% (CI95%: 54, 71) of the population located within 500m of a perennial surface water source. A negative relationship was observed between functional improved water access and surface water access within 300m. In this context, perceived water quality of the improved sources was also important, with a 17% increase in surface water access in towns with one reported water quality problem as compared to towns with no problems. Our study offers a potential methodology to use water point mapping data to identify communities in need of improved water access to achieve schistosomiasis risk reduction.
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Affiliation(s)
- Alexandra V Kulinkina
- Department of Civil and Environmental Engineering, Tufts University, 200 College Avenue, Medford, USA.
| | - Karen C Kosinski
- Department of Community Health, Tufts University, 574 Boston Avenue, Medford, USA
| | - Jeanine D Plummer
- Water Quality & Treatment Solutions, Inc., 175A Rice Corner Road, Brookfield, USA
| | - John L Durant
- Department of Civil and Environmental Engineering, Tufts University, 200 College Avenue, Medford, USA
| | - Kwabena M Bosompem
- Noguchi Memorial Institute for Medical Research, University of Ghana, P.O. Box 25, Legon, Accra, Ghana; Community Directed Development Foundation, P.O. Box AT2374, Achimota, Accra, Ghana
| | | | | | - David M Gute
- Department of Civil and Environmental Engineering, Tufts University, 200 College Avenue, Medford, USA
| | - Elena N Naumova
- Department of Civil and Environmental Engineering, Tufts University, 200 College Avenue, Medford, USA; Tufts University School of Medicine, 136 Harrison Avenue, Boston, USA; Friedman School of Nutrition Science and Policy, Tufts University, 150 Harrison Avenue, Boston, USA
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Stothard JR, Campbell SJ, Osei-Atweneboana MY, Durant T, Stanton MC, Biritwum NK, Rollinson D, Ombede DRE, Tchuem-Tchuenté LA. Towards interruption of schistosomiasis transmission in sub-Saharan Africa: developing an appropriate environmental surveillance framework to guide and to support 'end game' interventions. Infect Dis Poverty 2017; 6:10. [PMID: 28088239 PMCID: PMC5237522 DOI: 10.1186/s40249-016-0215-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/12/2016] [Indexed: 01/03/2023] Open
Abstract
Schistosomiasis is a waterborne parasitic disease in sub-Saharan Africa, particularly common in rural populations living in impoverished conditions. With the scale-up of preventive chemotherapy, national campaigns will transition from morbidity- to transmission-focused interventions thus formal investigation of actual or expected declines in environmental transmission is needed as 'end game' scenarios arise. Surprisingly, there are no international or national guidelines to do so in sub-Saharan Africa. Our article therefore provides an introduction to key practicalities and pitfalls in the development of an appropriate environmental surveillance framework. In this context, we discuss how strategies need to be adapted and tailored to the local level to better guide and support future interventions through this transition. As detection of egg-patent infection in people becomes rare, careful sampling of schistosome larvae in freshwater and in aquatic snails with robust species-specific DNA assays will be required. Appropriate metrics, derived from observed prevalence(s) as compared with predetermined thresholds, could each provide a clearer insight into contamination- and exposure-related dynamics. Application could be twofold, first to certify areas currently free from schistosomiasis transmission or second to red-flag recalcitrant locations where extra effort or alternative interventions are needed.
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Affiliation(s)
- J. Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Suzy J. Campbell
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Mike Y. Osei-Atweneboana
- Department of Environmental Biology and Health, Council for Scientific and Industrial Research-Water Research Insitute, P.O. Box M 32, Accra, Ghana
| | - Timothy Durant
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Michelle C. Stanton
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | | | - David Rollinson
- Department of Life Sciences; Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Dieudonné R. Eloundou Ombede
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon
- Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Louis-Albert Tchuem-Tchuenté
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon
- Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
- National Programme for the Control of Schistosomiasis and Intestinal Helminthiasis, Ministry of Public Health, Yaoundé, Cameroon
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Pennance T, Person B, Muhsin MA, Khamis AN, Muhsin J, Khamis IS, Mohammed KA, Kabole F, Rollinson D, Knopp S. Urogenital schistosomiasis transmission on Unguja Island, Zanzibar: characterisation of persistent hot-spots. Parasit Vectors 2016; 9:646. [PMID: 27986092 PMCID: PMC5162088 DOI: 10.1186/s13071-016-1847-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/12/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Elimination of urogenital schistosomiasis transmission is a priority for the Zanzibar Ministry of Health. Preventative chemotherapy together with additional control interventions have successfully alleviated much of the disease burden. However, a persistently high Schistosoma haematobium prevalence is found in certain areas. Our aim was to characterise and evaluate these persistent "hot-spots" of transmission and reinfection in comparison with low-prevalence areas, to support the intervention planning for schistosomiasis elimination in Zanzibar. METHODS Prevalences of S. haematobium were annually determined by a single urine filtration in schoolchildren from 45 administrative areas (shehias) in Unguja in 2012, 2013 and 2014. Coverage data for biannual treatment with praziquantel were available from ministerial databases and internal surveys. Among the 45 shehias, five hot-spot (≥ 15 % prevalence) and two low-prevalence (≤ 5 %) shehias were identified and surveyed in mid-2014. Human-water contact sites (HWCSs) and the presence of S. haematobium-infected and uninfected Bulinus globosus, as well as safe water sources (SWSs) and their reliability in terms of water availability were determined and mapped. RESULTS We found no major difference in the treatment coverage between persistent hot-spot and low-prevalence shehias. On average, there were considerably more HWCSs containing B. globosus in hot-spot than in low-prevalence shehias (n = 8 vs n = 2) and also more HWCSs containing infected B. globosus (n = 2 vs n = 0). There was no striking difference in the average abundance of SWSs in hot-spot and low-prevalence shehias (n = 45 vs n = 38) and also no difference when considering SWSs with a constant water supply (average: 62 % vs 62 %). The average number of taps with a constant water supply, however, was lower in hot-spot shehias (n = 7 vs n = 14). Average distances from schools to the nearest HWCS were considerably shorter in hot-spot shehias (n = 229 m vs n = 722 m). CONCLUSION The number of HWCSs, their infestation with B. globosus and their distance to schools seem to play a major role for a persistently high S. haematobium prevalence in children. In addition to treatment, increasing access to reliably working taps, targeted snail control at HWCSs near schools and enhanced behaviour change measures are needed to reduce prevalences in hot-spot areas and to finally reach elimination. TRIAL REGISTRATION ISRCTN48837681 .
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Affiliation(s)
- Tom Pennance
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK.,Department of Pathology and Pathogen Biology, Centre for Emerging, Endemic and Exotic Diseases, Royal Veterinary College, University of London, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, UK
| | - Bobbie Person
- Independent Consultant, Schistosomiasis Consortium for Operational Research and Evaluation, University of Georgia, Athens, GA, USA
| | - Mtumweni Ali Muhsin
- Zanzibar Neglected Tropical Diseases Programme, Ministry of Health, P.O. Box 236, Zanzibar Town, Unguja, United Republic of Tanzania
| | - Alipo Naim Khamis
- Zanzibar Neglected Tropical Diseases Programme, Ministry of Health, P.O. Box 236, Zanzibar Town, Unguja, United Republic of Tanzania
| | - Juma Muhsin
- Zanzibar Neglected Tropical Diseases Programme, Ministry of Health, P.O. Box 236, Zanzibar Town, Unguja, United Republic of Tanzania
| | - Iddi Simba Khamis
- Zanzibar Neglected Tropical Diseases Programme, Ministry of Health, P.O. Box 236, Zanzibar Town, Unguja, United Republic of Tanzania
| | - Khalfan Abdallah Mohammed
- Zanzibar Neglected Tropical Diseases Programme, Ministry of Health, P.O. Box 236, Zanzibar Town, Unguja, United Republic of Tanzania
| | - Fatma Kabole
- Zanzibar Neglected Tropical Diseases Programme, Ministry of Health, P.O. Box 236, Zanzibar Town, Unguja, United Republic of Tanzania
| | - David Rollinson
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK
| | - Stefanie Knopp
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD, UK. .,Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, CH-4002, Basel, Switzerland. .,University of Basel, Petersplatz 1, CH-4003, Basel, Switzerland.
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135
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Amaral KB, Silva TP, Malta KK, Carmo LAS, Dias FF, Almeida MR, Andrade GFS, Martins JS, Pinho RR, Costa-Neto SF, Gentile R, Melo RCN. Natural Schistosoma mansoni Infection in the Wild Reservoir Nectomys squamipes Leads to Excessive Lipid Droplet Accumulation in Hepatocytes in the Absence of Liver Functional Impairment. PLoS One 2016; 11:e0166979. [PMID: 27880808 PMCID: PMC5120838 DOI: 10.1371/journal.pone.0166979] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/07/2016] [Indexed: 01/06/2023] Open
Abstract
Schistosomiasis is a neglected tropical disease of a significant public health impact. The water rat Nectomys squamipes is one of the most important non-human hosts in the schistosomiasis mansoni transmission in Brazil, being considered a wild reservoir. Cellular mechanisms that contribute to the physiological adaptation of this rodent to the Schistosoma mansoni parasite are poorly understood. Here we identified, for the first time, that a hepatic steatosis, a condition characterized by excessive lipid accumulation with formation of lipid droplets (LDs) within hepatocytes, occurs in response to the natural S. mansoni infection of N. squamipes, captured in an endemic region. Significant increases of LD area in the hepatic tissue and LD numbers/hepatocyte, detected by quantitative histopathological and ultrastructural analyses, were paralleled by increased serum profile (total cholesterol and triglycerides) in infected compared to uninfected animals. Raman spectroscopy showed high content of polyunsaturated fatty acids (PUFAs) in the liver of both groups. MALDI-TOFF mass spectroscopy revealed an amplified pool of omega-6 PUFA arachidonic acid in the liver of infected animals. Assessment of liver functional activity by the levels of hepatic transaminases (ALT and AST) did not detect any alteration during the natural infection. In summary, this work demonstrates that the natural infection of the wild reservoir N. squamipes with S. mansoni elicits hepatic steatosis in the absence of liver functional harm and that accumulation of lipids, markedly PUFAs, coexists with low occurrence of inflammatory granulomatous processes, suggesting that lipid stores may be acting as a protective mechanism for dealing with the infection.
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Affiliation(s)
- Kátia B. Amaral
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Thiago P. Silva
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Kássia K. Malta
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Lívia A. S. Carmo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Felipe F. Dias
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Mariana R. Almeida
- Laboratory of Plasmonic Nanostructures, Molecular Spectroscopy and Structure Group, Department of Chemistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Gustavo F. S. Andrade
- Laboratory of Plasmonic Nanostructures, Molecular Spectroscopy and Structure Group, Department of Chemistry, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Jefferson S. Martins
- Department of Physics, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Roberto R. Pinho
- Department of Physics, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
| | - Sócrates F. Costa-Neto
- Laboratory of Biology and Parasitology of Wild Reservoir Mammals, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Rosana Gentile
- Laboratory of Biology and Parasitology of Wild Reservoir Mammals, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Rossana C. N. Melo
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil, 36036–900
- * E-mail:
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136
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Al-Shehri H, Stanton MC, LaCourse JE, Atuhaire A, Arinaitwe M, Wamboko A, Adriko M, Kabatereine NB, Stothard JR. An extensive burden of giardiasis associated with intestinal schistosomiasis and anaemia in school children on the shoreline of Lake Albert, Uganda. Trans R Soc Trop Med Hyg 2016; 110:597-603. [PMID: 27864517 DOI: 10.1093/trstmh/trw072] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 10/24/2016] [Accepted: 11/14/2016] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Water-borne parasitic diseases associated with poverty still blight the lives of African school children. In Uganda, intestinal schistosomiasis is still common along the shoreline of Lake Albert, despite ongoing control, and co-infection with giardiasis and malaria is poorly described. To shed light on putative interactions between diseases, a prospective cross-sectional parasitological survey was undertaken in five primary schools. METHODS Stool samples from 254 school children, aged 5-10 years, were examined by microscopy and rapid diagnostic tests (RDTs), with additional real-time PCR assays for detection of Giardia DNA. A finger-prick blood sample was also taken from each child and tested for malaria, and haemoblobin levels measured. Assocations between diseases and anaemia were assessed. RESULTS Intestinal schistosomiasis (46.5%), giardiasis (41.6%) and malaria (56.2%) were common, and a quarter of children were anaemic (<115 g/L). Up to 87.0% of children were excreting Giardia DNA and the prevalence of heavy infection by real-time PCR (Ct≤19) was 19.5%, being positively associated with light, moderate and heavy egg-patent schistosomiasis, as well as with anaemia. CONCLUSIONS In this setting, an extensive burden of giardiasis was revealed with heavy intensity infections associated with egg-patent intestinal schistosomiasis and anaemia. To improve child health, greater attention on giardiasis is needed along with exploring joined-up actions across diseases that promote better water hygiene and sanitation measures.
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Affiliation(s)
- Hajri Al-Shehri
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK.,Ministry of Health, Asir District, Kingdom of Saudi Arabia
| | | | | | - Aaron Atuhaire
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Arinaitwe
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Aida Wamboko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Narcis B Kabatereine
- Vector Control Division, Ministry of Health, Kampala, Uganda.,Schistosomiasis Control Initiative, School of Public Health, Imperial College London, London W2 1PG, UK
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137
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Grimes JET, Templeton MR. School Water, Sanitation, and Hygiene to Reduce the Transmission of Schistosomes and Soil-Transmitted Helminths. Trends Parasitol 2016; 32:661-664. [PMID: 27426250 DOI: 10.1016/j.pt.2016.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/17/2016] [Accepted: 06/22/2016] [Indexed: 12/19/2022]
Abstract
The life cycles of schistosomes and soil-transmitted helminths (STHs) suggest that water, sanitation, and hygiene (WASH) might reduce their transmission. However, the level of impact of WASH is likely to vary with the location (in school, at home, or elsewhere), the type of WASH, and the parasite in question.
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Affiliation(s)
- Jack E T Grimes
- Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London SW7 2AZ, UK.
| | - Michael R Templeton
- Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London SW7 2AZ, UK
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138
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N'Diaye M, Dioukhane EM, Ndao B, Diedhiou K, Diawara L, Talla I, Vernet C, Bessin F, Barbier D, Dewavrin P, Klotz F, Georges P. Schistosomiasis Sustained Control Program in Ethnic Groups Around Ninefescha (Eastern Senegal). Am J Trop Med Hyg 2016; 95:614-22. [PMID: 27430549 DOI: 10.4269/ajtmh.15-0125] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/25/2016] [Indexed: 11/07/2022] Open
Abstract
Schistosomiasis is the second most significant parasitic disease in children in several African countries. For this purpose, the "Programme National de Lutte contre les Bilharzioses" (PNLB) was developed in partnership with the World Health Organization (WHO) to control this disease in Senegal. However, geographic isolation of Bedik ethnic groups challenged implementation of the key elements of the schistosomiasis program in eastern Senegal, and therefore, a hospital was established in Ninefescha to improve access to health care as well as laboratory support for this population. The program we have implemented from 2008 in partnership with the PNLB/WHO involved campaigns to 1) evaluate schistosomiasis prevalence in children of 53 villages around Ninefescha hospital, 2) perform a mass drug administration following the protocol established by the PNLB in school-aged children, 3) monitor annual prevalence, 4) implement health education campaigns, and 5) oversee the building of latrines. This campaign led to a drop in schistosomiasis prevalence but highlighted that sustainable schistosomiasis control by praziquantel treatment, awareness of the use of latrines, and inhabitants' voluntary commitment to the program are crucial to improve Schistosoma elimination. Moreover, this study revealed that preschool-aged children, for whom praziquantel was not recommended until 2014 in Senegal, constituted a significant reservoir for the parasite.
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Affiliation(s)
- Monique N'Diaye
- Université de Caen Normandie, UNICAEN, UFR des Sciences Pharmaceutiques, Laboratoire de Parasitologie et Mycologie Médicale, Caen, France.
| | | | | | - Kemo Diedhiou
- Programme National de Lutte contre les Bilharzioses/World Health Organization Neglected Tropical Diseases, Dakar, Senegal
| | - Lamine Diawara
- Inter-country Support Team for West Africa, World Health Organization Neglected Tropical Diseases, Ouagadougou, Burkina Faso
| | - Idrissa Talla
- Programme National de Lutte contre les Bilharzioses/World Health Organization Neglected Tropical Diseases, Dakar, Senegal
| | - Charlotte Vernet
- Université de Caen Normandie, UNICAEN, UFR des Sciences Pharmaceutiques, Laboratoire de Parasitologie et Mycologie Médicale, Caen, France
| | - François Bessin
- Université de Caen Normandie, UNICAEN, UFR des Sciences Pharmaceutiques, Laboratoire de Parasitologie et Mycologie Médicale, Caen, France
| | - Dominique Barbier
- Université de Caen Normandie, UNICAEN, UFR des Sciences Pharmaceutiques, Laboratoire de Parasitologie et Mycologie Médicale, Caen, France
| | | | | | - Pierre Georges
- Université de Caen Normandie, UNICAEN, UFR des Sciences Pharmaceutiques, Laboratoire de Parasitologie et Mycologie Médicale, Caen, France
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139
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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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Ezeamama AE, He CL, Shen Y, Yin XP, Binder SC, Campbell CH, Rathbun S, Whalen CC, N'Goran EK, Utzinger J, Olsen A, Magnussen P, Kinung'hi S, Fenwick A, Phillips A, Ferro J, Karanja DMS, Mwinzi PNM, Montgomery S, Secor WE, Hamidou A, Garba A, King CH, Colley DG. Gaining and sustaining schistosomiasis control: study protocol and baseline data prior to different treatment strategies in five African countries. BMC Infect Dis 2016; 16:229. [PMID: 27230666 PMCID: PMC4880878 DOI: 10.1186/s12879-016-1575-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/17/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was established in 2008 to answer strategic questions about schistosomiasis control. For programme managers, a high-priority question is: what are the most cost-effective strategies for delivering preventive chemotherapy (PCT) with praziquantel (PZQ)? This paper describes the process SCORE used to transform this question into a harmonized research protocol, the study design for answering this question, the village eligibility assessments and data resulting from the first year of the study. METHODS Beginning in 2009, SCORE held a series of meetings to specify empirical questions and design studies related to different schedules of PCT for schistosomiasis control in communities with high (gaining control studies) and moderate (sustaining control studies) prevalence of Schistosoma infection among school-aged children. Seven studies are currently being implemented in five African countries. During the first year, villages were screened for eligibility, and data were collected on prevalence and intensity of infection prior to randomisation and the implementation of different schemes of PZQ intervention strategies. RESULTS These studies of different treatment schedules with PZQ will provide the most comprehensive data thus far on the optimal frequency and continuity of PCT for schistosomiasis infection and morbidity control. CONCLUSIONS We expect that the study outcomes will provide data for decision-making for country programme managers and a rich resource of information to the schistosomiasis research community. TRIAL REGISTRATION The trials are registered at International Standard Randomised Controlled Trial registry (identifiers: ISRCTN99401114 , ISRCTN14849830 , ISRCTN16755535 , ISRCTN14117624 , ISRCTN95819193 and ISRCTN32045736 ).
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Affiliation(s)
- Amara E Ezeamama
- Department of Epidemiology & Biostatistics, University of Georgia, Athens, GA, USA.
| | - Chun-La He
- Department of Epidemiology & Biostatistics, University of Georgia, Athens, GA, USA
| | - Ye Shen
- Department of Epidemiology & Biostatistics, University of Georgia, Athens, GA, USA
| | - Xiao-Ping Yin
- Department of Epidemiology & Biostatistics, University of Georgia, Athens, GA, USA
| | - Sue C Binder
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Carl H Campbell
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Stephen Rathbun
- Department of Epidemiology & Biostatistics, University of Georgia, Athens, GA, USA
| | - Christopher C Whalen
- Department of Epidemiology & Biostatistics, University of Georgia, Athens, GA, USA
| | - Eliézer K N'Goran
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire.,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | | | | | - Alan Fenwick
- Schistosomiasis Control Initiative, Imperial College, London, UK
| | - Anna Phillips
- Schistosomiasis Control Initiative, Imperial College, London, UK
| | - Josefo Ferro
- Catholic University of Mozambique, Beira, Mozambique
| | - Diana M S Karanja
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Pauline N M Mwinzi
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - W Evan Secor
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Amina Hamidou
- Réseau International Schistosomoses, Environnement, Aménagement et Lutte (RISEAL-Niger), Niamey, Niger
| | - Amadou Garba
- Réseau International Schistosomoses, Environnement, Aménagement et Lutte (RISEAL-Niger), Niamey, Niger
| | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Daniel G Colley
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA.,Department of Microbiology, University of Georgia, Athens, GA, USA
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Vicente B, López-Abán J, Rojas-Caraballo J, del Olmo E, Fernández-Soto P, Muro A. Protection against Schistosoma mansoni infection using a Fasciola hepatica-derived fatty acid binding protein from different delivery systems. Parasit Vectors 2016; 9:216. [PMID: 27090442 PMCID: PMC4836169 DOI: 10.1186/s13071-016-1500-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/07/2016] [Indexed: 12/20/2022] Open
Abstract
Background Schistosomiasis is a water-borne disease afflicting over 261 million people in many areas of the developing countries with high morbidity and mortality. The control relies mainly on treatment with praziquantel. Fatty acid binding proteins (FABP) have demonstrated high levels of immune-protection against trematode infections. This study reports the immunoprotection induced by cross-reacting Fasciola hepatica FABP, native (nFh12) and recombinantly expressed using two different expression systems Escherichia coli (rFh15) and baculovirus (rFh15b) against Schistosoma mansoni infection. Methods BALB/c mice were vaccinated with native nFh12 or recombinant rFh15 and rFh15 FABP from F. hepatica formulated in adjuvant adaptation (ADAD) system with natural or chemical synthesised immunomodulators (PAL and AA0029) and then challenged with 150 cercariae of S. mansoni. Parasite burden, hepatic lesions and antibody response were studied in vaccination trials. Furthermore differences between rFh15 and rFh15b immunological responses (cytokine production, splenocyte population and antibody levels) were studied. Results Vaccination with nFh12 induced significant reductions in worm burden (83 %), eggs in tissues (82–92 %) and hepatic lesions (85 %) compared to infected controls using PAL. Vaccination with rFh15 showed lower total worm burden (56–64 %), eggs in the liver (21–61 %), eggs in the gut (30–77 %) and hepatic damage (67–69 %) using PAL and AA0029 as immunomodulators. In contrast, mice vaccinated with rFh15b showed only reductions in eggs trapped in the liver and intestine (53 and 60 %, respectively), and hepatic lesions (45 %). We observed a significant rise in TNFα, IL-6, IL-2, IL-4 and high antibody response (IgG, IgG1, IgG2a, IgM and IgE) in mice immunised with either rFh15 or rFh15b. Moreover, mice immunised with rFh15b showed an increase in IFNγ and a decrease in B220 cells compared to untreated mice, and less production of IgG1 and IgM than in mice immunised by rFh15. Conclusions Higher level of protection is obtained by using Fasciola hepatica-derived FABP protein against Schistosoma mansoni infection. Native FABP is more effective than both recombinant systems. It could be due to post-translational modifications or FABP isoform or changes in the recombinant proteins. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1500-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Belén Vicente
- Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, Universidad de Salamanca (IBSAL-CIETUS), Avda. Licenciado Méndez Nieto s/n, 37007, Salamanca, Spain
| | - Julio López-Abán
- Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, Universidad de Salamanca (IBSAL-CIETUS), Avda. Licenciado Méndez Nieto s/n, 37007, Salamanca, Spain.
| | - Jose Rojas-Caraballo
- Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, Universidad de Salamanca (IBSAL-CIETUS), Avda. Licenciado Méndez Nieto s/n, 37007, Salamanca, Spain.,Present address: Centro de Investigación en Salud para el Trópico (CIST), Carretera Troncal del Caribe, Sector Mamatoco, Santa Marta, Magdalena, Colombia.,Present address: Facultad de Medicina, Universidad Cooperativa de Colombia, Carretera Troncal del Caribe, Sector Mamatoco, Santa Marta, Magdalena, Colombia
| | - Esther del Olmo
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Salamanca, IBSAL-CIETUS, Salamanca, Spain
| | - Pedro Fernández-Soto
- Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, Universidad de Salamanca (IBSAL-CIETUS), Avda. Licenciado Méndez Nieto s/n, 37007, Salamanca, Spain
| | - Antonio Muro
- Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, Universidad de Salamanca (IBSAL-CIETUS), Avda. Licenciado Méndez Nieto s/n, 37007, Salamanca, Spain
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Loke I, Kolarich D, Packer NH, Thaysen-Andersen M. Emerging roles of protein mannosylation in inflammation and infection. Mol Aspects Med 2016; 51:31-55. [PMID: 27086127 DOI: 10.1016/j.mam.2016.04.004] [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: 01/21/2016] [Revised: 04/05/2016] [Accepted: 04/10/2016] [Indexed: 02/07/2023]
Abstract
Proteins are frequently modified by complex carbohydrates (glycans) that play central roles in maintaining the structural and functional integrity of cells and tissues in humans and lower organisms. Mannose forms an essential building block of protein glycosylation, and its functional involvement as components of larger and diverse α-mannosidic glycoepitopes in important intra- and intercellular glycoimmunological processes is gaining recognition. With a focus on the mannose-rich asparagine (N-linked) glycosylation type, this review summarises the increasing volume of literature covering human and non-human protein mannosylation, including their structures, biosynthesis and spatiotemporal expression. The review also covers their known interactions with specialised host and microbial mannose-recognising C-type lectin receptors (mrCLRs) and antibodies (mrAbs) during inflammation and pathogen infection. Advances in molecular mapping technologies have recently revealed novel immuno-centric mannose-terminating truncated N-glycans, termed paucimannosylation, on human proteins. The cellular presentation of α-mannosidic glycoepitopes on N-glycoproteins appears tightly regulated; α-mannose determinants are relative rare glycoepitopes in physiological extracellular environments, but may be actively secreted or leaked from cells to transmit potent signals when required. Simultaneously, our understanding of the molecular basis on the recognition of mannosidic epitopes by mrCLRs including DC-SIGN, mannose receptor, mannose binding lectin and mrAb is rapidly advancing, together with the functional implications of these interactions in facilitating an effective immune response during physiological and pathophysiological conditions. Ultimately, deciphering these complex mannose-based receptor-ligand interactions at the detailed molecular level will significantly advance our understanding of immunological disorders and infectious diseases, promoting the development of future therapeutics to improve patient clinical outcomes.
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Affiliation(s)
- Ian Loke
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Daniel Kolarich
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Nicolle H Packer
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Morten Thaysen-Andersen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia.
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143
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Grimes JET, Tadesse G, Mekete K, Wuletaw Y, Gebretsadik A, French MD, Harrison WE, Drake LJ, Gardiner IA, Yard E, Templeton MR. School Water, Sanitation, and Hygiene, Soil-Transmitted Helminths, and Schistosomes: National Mapping in Ethiopia. PLoS Negl Trop Dis 2016; 10:e0004515. [PMID: 26954688 PMCID: PMC4783033 DOI: 10.1371/journal.pntd.0004515] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 02/14/2016] [Indexed: 12/21/2022] Open
Abstract
Background It is thought that improving water, sanitation, and hygiene (WASH) might reduce the transmission of schistosomes and soil-transmitted helminths, owing to their life cycles. However, few large-scale studies have yet assessed the real extent of associations between WASH and these parasites. Methodology/Principal Findings In the 2013–2014 Ethiopian national mapping of infections with these parasites, school WASH was assessed alongside infection intensity in children, mostly between 10 and 15 years of age. Scores were constructed reflecting exposure to schistosomes arising from water collection for schools, from freshwater sources, and the adequacy of school sanitation and hygiene facilities. Kendall’s τb was used to test the WASH scores against the school-level arithmetic mean intensity of infection with each parasite, in schools with at least one child positive for the parasite in question. WASH and parasitology data were available for 1,645 schools. More frequent collection of water for schools, from open freshwater sources was associated with statistically significantly higher Schistosoma mansoni infection intensity (Kendall’s τb = 0.097, 95% confidence interval, CI: 0.011 to 0.18), better sanitation was associated with significantly lower Ascaris lumbricoides intensity (Kendall’s τb = -0.067, 95% CI: -0.11 to -0.023) and borderline significant lower hookworm intensity (Kendall’s τb = -0.039, 95% CI: -0.090 to 0.012, P = 0.067), and better hygiene was associated with significantly lower hookworm intensity (Kendall’s τb = -0.076, 95% CI: -0.13 to -0.020). However, no significant differences were observed when comparing sanitation and infection with S. mansoni or Trichuris trichiura, or hygiene and infection with A. lumbricoides or T. trichiura. Conclusions/Significance Improving school WASH may reduce transmission of these parasites. However, different forms of WASH appear to have different effects on infection with the various parasites, with our analysis finding the strongest associations between water and S. mansoni, sanitation and A. lumbricoides, and hygiene and hookworm. Water, sanitation, and hygiene (WASH) are potentially important control measures for parasitic worms, but few large-scale and well-designed research studies have aimed to quantify the relationships between WASH and infections with these parasites, or demonstrated the practicality of integrating WASH assessments into large-scale worm mapping. Here we use data from 80,475 children in 1,645 schools visited during the 2013–2014 Ethiopian national mapping of schistosomiasis and soil-transmitted helminthiases, to compare school WASH conditions with the mean intensity of infection with these parasites, using Kendall’s τb, a statistic that assesses for correlation between two variables by comparing their rankings. More frequent collection of water for schools was associated with statistically significantly (P < 0.05) higher-intensity intestinal schistosomiasis infections, better sanitation significantly with lower roundworm burdens, and better hygiene with significantly lower hookworm burdens. No statistically significant associations (P > 0.05) were found for sanitation and intestinal schistosomiasis or whipworm infections, or hygiene and roundworm or whipworm infections, but better sanitation was associated with a borderline statistically significantly less hookworm infections (P = 0.067). The results suggest that WASH improvements might have different impacts on infection with the various parasites. These differences should be borne in mind when designing WASH interventions to reduce transmission of, and prevent infection with, these parasites.
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Affiliation(s)
- Jack E. T. Grimes
- Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London, United Kingdom
- * E-mail:
| | | | | | - Yonas Wuletaw
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Michael D. French
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, St Mary’s Campus, Imperial College London, London, United Kingdom
| | - Wendy E. Harrison
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, St Mary’s Campus, Imperial College London, London, United Kingdom
| | - Lesley J. Drake
- Partnership for Child Development, Department of Infectious Disease Epidemiology, St Mary’s Campus, Imperial College London, London, United Kingdom
| | - Iain A. Gardiner
- Partnership for Child Development, Department of Infectious Disease Epidemiology, St Mary’s Campus, Imperial College London, London, United Kingdom
| | - Elodie Yard
- Partnership for Child Development, Department of Infectious Disease Epidemiology, St Mary’s Campus, Imperial College London, London, United Kingdom
| | - Michael R. Templeton
- Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London, United Kingdom
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Assaré RK, Hürlimann E, Ouattara M, N'Guessan NA, Tian-Bi YNT, Yapi A, Yao PK, Coulibaly JT, Knopp S, N'Goran EK, Utzinger J. Sustaining the Control of Schistosoma mansoni in Western Côte d'Ivoire: Baseline Findings Before the Implementation of a Randomized Trial. Am J Trop Med Hyg 2015; 94:352-60. [PMID: 26598571 DOI: 10.4269/ajtmh.15-0530] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 10/19/2015] [Indexed: 12/22/2022] Open
Abstract
We report baseline findings before the implementation of a 4-year intervention trial designed to assess the impact of three different school-based treatment schedules with praziquantel to sustain the control of intestinal schistosomiasis. The baseline survey was conducted in 75 schools of western Côte d'Ivoire previously identified with moderate Schistosoma mansoni endemicity (prevalence: 10-24% in children aged 13-14 years). Three stool samples collected over consecutive days were subjected to duplicate Kato-Katz thick smears each. A questionnaire was administered to collect village-specific information that is relevant for schistosomiasis transmission. Overall, 4,953 first graders (aged 5-8 years) and 7,011 school children (aged 9-12 years) had complete parasitologic data. The overall prevalence of S. mansoni was 5.4% among first graders and 22.1% in 9- to 12-year-old children. Open defecation was practiced in all villages. The current baseline findings will be important to better understand the dynamics of S. mansoni prevalence and intensity over the course of this trial that might be governed by village characteristics and specific treatment interventions.
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Affiliation(s)
- Rufin K Assaré
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Eveline Hürlimann
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Mamadou Ouattara
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Nicaise A N'Guessan
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Yves-Nathan T Tian-Bi
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Ahoua Yapi
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Patrick K Yao
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Jean T Coulibaly
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Stefanie Knopp
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Eliézer K N'Goran
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
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Abstract
Mass drug administration using praziquantel is the backbone of the current strategy for the control of schistosomiasis. As the theoretical plans have moved into practical application, certain challenges with this approach have surfaced, and it is likely that annual mass drug administration alone may not be sufficient to achieve program goals. However, mass drug administration is still the only available intervention that can be readily used in the wide variety of settings where schistosomiasis is endemic. The task then becomes how to improve this approach and identify what adjuncts to mass drug administration are effective, as programs move from morbidity control to elimination goals. Other aspects worthy of consideration include how best to employ new diagnostic tools to more easily identify where treatment is needed, and new formulations of praziquantel to extend the availability of treatment to all age groups. The aim of this review is to highlight both areas of challenge and of opportunity to improve the public health impact of schistosomiasis control programs.
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Affiliation(s)
- W Evan Secor
- Parasitic Diseases Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
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146
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Gambhir M, Pinsent A. Possible changes in the transmissibility of trachoma following MDA and transmission reduction: implications for the GET2020 goals. Parasit Vectors 2015; 8:530. [PMID: 26490436 PMCID: PMC4618927 DOI: 10.1186/s13071-015-1133-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 10/02/2015] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND The role of mass drug administration (MDA) and the implementation of transmission reduction measures are essential to successfully control and eliminate a wide range of NTDs, including the ocular disease trachoma. Immunity to trachoma infection acts by reducing the duration of an individual's infectious period and by reducing their infectivity with each successive infection. METHODS In this study, we use a model of trachoma infection, which includes population immunity, to explore the impact of treatment and transmission reduction measures on trachoma prevalence. Specifically, we investigate the possibility of increasing transmissibility of trachoma arising as MDA and transmission reduction measures are scaled up in endemic settings. RESULTS We demonstrate this increase in transmissibility by calculating the effective reproduction number during several simulated control programmes and show that it is related to a decrease in the level of immunity in the population. CONCLUSIONS This effect should be studied in the field by measuring the rate of return of infection and disease in at least two separate age groups. If the decline of population immunity is operating, it should be accounted for when planning for the GET2020 goal of eliminating blinding trachoma by 2020.
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Affiliation(s)
- Manoj Gambhir
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
| | - Amy Pinsent
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
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147
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Zhang Y, Zhao J, Wang X, Xu X, Pan W. Evaluation of six novel antigens as potential biomarkers for the early immunodiagnosis of schistosomiasis. Parasit Vectors 2015; 8:447. [PMID: 26338369 PMCID: PMC4558877 DOI: 10.1186/s13071-015-1048-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 08/17/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Early diagnosis of schistosomiasis, prior to egg laying, would enable earlier treatment and help interrupt the transmission cycle of the parasite and the progress of the disease. Previously we identified six novel antigens with potential as diagnostic markers for human Schistosoma japonicum infections. In this study, we evaluated these antigens as candidate biomarkers for the early diagnosis of schistosomiasis in mice and rabbits. METHODS The transcriptional profiles of the six antigens (SjSP-13, SjSP-23, SjSP-160, SjSP-164, SjSP-189 and SjSP-216) at different developmental stages were analyzed by quantitative PCR. The recombinant proteins were expressed in E. coli and purified with nickel chelate affinity chromatography. We then developed recombinant protein-based ELISA kits to analyze the kinetics of antigen-specific antibodies during the course of infection in mice and rabbits. The early diagnostic validity of the candidate SjSP-216 was further evaluated in mice and rabbits infected with S. japonicum. RESULTS Of the six antigens, SjSP-13, SjSP-160 and SjSP-216 were highly expressed in 21-day old young worms, while SjSP-23, SjSP-164 and SjSP-189 were highly expressed in eggs. In the mouse model, we detected a significant increase in antibodies against SjSP-13 and SjSP-216 at 3 weeks post-infection. However, in the rabbit model, only anti-SjSP-216 antibody showed a significant increase at this time point. We recorded 100 % diagnostic sensitivity and specificity of SjSP-216-based ELISA in both infected mice and rabbits, 3 weeks after infection. CONCLUSIONS This study strongly suggests that SjSP-216, a highly expressed gene in the young worms, could serve as a potential biomarker for the early immunodiagnosis of S. japonicum infections in vertebrate hosts.
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Affiliation(s)
- Yuanbin Zhang
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, 200092, China.
| | - Jing Zhao
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, 200092, China.
| | - Xinye Wang
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, 200092, China.
| | - Xindong Xu
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, 200092, China.
| | - Weiqing Pan
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, 200092, China. .,Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai, 200433, China.
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148
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Grimes JET, Templeton MR. Geostatistical modelling of schistosomiasis prevalence. THE LANCET. INFECTIOUS DISEASES 2015; 15:869-70. [PMID: 26004858 DOI: 10.1016/s1473-3099(15)00067-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 03/12/2015] [Indexed: 11/17/2022]
Affiliation(s)
- Jack E T Grimes
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK.
| | - Michael R Templeton
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK
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149
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Corstjens PLAM, Nyakundi RK, de Dood CJ, Kariuki TM, Ochola EA, Karanja DMS, Mwinzi PNM, van Dam GJ. Improved sensitivity of the urine CAA lateral-flow assay for diagnosing active Schistosoma infections by using larger sample volumes. Parasit Vectors 2015; 8:241. [PMID: 25896512 PMCID: PMC4418045 DOI: 10.1186/s13071-015-0857-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 04/13/2015] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Accurate determination of Schistosoma infection rates in low endemic regions to examine progress towards interruption of transmission and elimination requires highly sensitive diagnostic tools. An existing lateral flow (LF) based test demonstrating ongoing infections through detection of worm circulating anodic antigen (CAA), was improved for sensitivity through implementation of a protocol allowing increased sample input. Urine is the preferred sample as collection is non-invasive and sample volume is generally not a restriction. METHODS Centrifugal filtration devices provided a method to concentrate supernatant of urine samples extracted with trichloroacetic acid (TCA). For field trials a practical sample volume of 2 mL urine allowed detection of CAA down to 0.3 pg/mL. The method was evaluated on a set of urine samples (n = 113) from an S. mansoni endemic region (Kisumu, Kenya) and compared to stool microscopy (Kato Katz, KK). In this analysis true positivity was defined as a sample with either a positive KK or UCAA test. RESULTS Implementation of the concentration method increased clinical sensitivity (Sn) from 44 to 98% when moving from the standard 10 μL (UCAA10 assay) to 2000 μL (UCAA2000 assay) urine sample input. Sn for KK varied between 23 and 35% for a duplicate KK (single stool, two slides) to 52% for a six-fold KK (three consecutive day stools, two slides). The UCAA2000 assay indicated 47 positive samples with CAA concentration above 0.3 pg/mL. The six-fold KK detected 25 egg positives; 1 sample with 2 eggs detected in the 6-fold KK was not identified with the UCAA2000 assay. CONCLUSIONS Larger sample input increased Sn of the UCAA assay to a level indicating 'true' infection. Only a single 2 mL urine sample is needed, but analysing larger sample volumes could still increase test accuracy. The UCAA2000 test is an appropriate candidate for accurate identification of all infected individuals in low-endemic regions. Assay materials do not require refrigeration and collected urine samples may be stored and transported to central test laboratories without the need to be frozen.
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Affiliation(s)
- Paul L A M Corstjens
- Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, P.O. Box 9600, 2300 RC, Leiden, the Netherlands.
| | - Ruth K Nyakundi
- Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya.
| | - Claudia J de Dood
- Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, P.O. Box 9600, 2300 RC, Leiden, the Netherlands.
| | - Thomas M Kariuki
- Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya.
| | - Elizabeth A Ochola
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
| | - Diana M S Karanja
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
| | - Pauline N M Mwinzi
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.
| | - Govert J van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands.
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