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Perera DJ, Koger-Pease C, Paulini K, Daoudi M, Ndao M. Beyond schistosomiasis: unraveling co-infections and altered immunity. Clin Microbiol Rev 2024; 37:e0009823. [PMID: 38319102 PMCID: PMC10938899 DOI: 10.1128/cmr.00098-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024] Open
Abstract
Schistosomiasis is a neglected tropical disease caused by the helminth Schistosoma spp. and has the second highest global impact of all parasites. Schistosoma are transmitted through contact with contaminated fresh water predominantly in Africa, Asia, the Middle East, and South America. Due to the widespread prevalence of Schistosoma, co-infection with other infectious agents is common but often poorly described. Herein, we review recent literature describing the impact of Schistosoma co-infection between species and Schistosoma co-infection with blood-borne protozoa, soil-transmitted helminths, various intestinal protozoa, Mycobacterium, Salmonella, various urinary tract infection-causing agents, and viral pathogens. In each case, disease severity and, of particular interest, the immune landscape, are altered as a consequence of co-infection. Understanding the impact of schistosomiasis co-infections will be important when considering treatment strategies and vaccine development moving forward.
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Affiliation(s)
- Dilhan J. Perera
- Division of Experimental Medicine, McGill University, Montreal, Canada
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Cal Koger-Pease
- Division of Experimental Medicine, McGill University, Montreal, Canada
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Kayla Paulini
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
| | - Mohamed Daoudi
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
| | - Momar Ndao
- Division of Experimental Medicine, McGill University, Montreal, Canada
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal, Canada
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2
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Diop B, Sylla K, Kane NDMB, Boh OK, Guèye B, Ba M, Talla I, Mané M, Monteil R, Kinvi B, Zoure HGM, Ortega JC, Mwinzi P, Sacko M, Faye B. Schistosomiasis control in Senegal: results from community data analysis for optimizing preventive chemotherapy intervention with praziquantel. Infect Dis Poverty 2023; 12:106. [PMID: 38008772 PMCID: PMC10680307 DOI: 10.1186/s40249-023-01155-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 11/07/2023] [Indexed: 11/28/2023] Open
Abstract
BACKGROUND Over the past two decades, preventive chemotherapy (PC) with praziquantel (PZQ) is the major strategy for controlling schistosomiasis in Senegal. The objective of this analysis was to update the endemicity of schistosomiasis at community level for better targeting mass treatment with PZQ in Senegal. METHODS Demographic and epidemiological data from 1610 community health areas were analyzed using the schistosomiasis community data analysis tool of Expanded Special Project for Elimination of Neglected Tropical Diseases which developed by World Health Organization/Africa Office (WHO/AFRO). The tool uses a WHO/AFRO decision tree for areas without epidemiological data to determine whether mass treatment should be continued at community level. Descriptive analysis was performed. RESULTS Overall, the endemicity of 1610 community health areas were updated based on the data from the district endemicity (33.5%) and the form of Join request for selected PC medicine (40.5%). Up to 282 (17.5%) and 398 (24.7%) of community health areas were classified as moderate and high endemicity. 41.1% of communities were non endemic. High endemicity was more important in Tambacounda, Saint Louis, Matam, Louga and Kedougou. A change in endemicity category was observed when data was disagregted from district level to community level. Implementation units classified non endemic were more important at community level (n = 666) compared to district level (n = 324). Among 540 areas previously classified high endemic at district level, 392 (72.6%) remained high prevalence category, while 92 (17.0%) became moderate, 43 (8.0%) low and 13 (2.4%) non-endemics at community level. Number of implementation units requiring PC was more important at district level (1286) compared to community level (944). Number of school aged children requiring treatment was also more important at district level compared to community level. CONCLUSIONS The analysis to disaggregate data from district level to community level using the WHO/AFRO schistosomiasis sub-district data optimization tool provide an update of schistosomiasis endemicity at community level. This study has allowed to better target schistosomiasis interventions, optimize use of available PZQ and exposed data gaps.
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Affiliation(s)
- Boubacar Diop
- Programme National de Lutte Contre les Bilharzioses et les Géo-Helminthiases, Direction de la Lutte Contre la Maladie (DLM), Ministère de la Santé et de l'Action Sociale (MSAS), Dakar, Senegal
| | - Khadime Sylla
- Department of Parasitology and Mycology Faculty of Medicine, Pharmacy and Odontology, Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal.
| | - NDèye MBacké Kane
- Programme National de Lutte Contre les Bilharzioses et les Géo-Helminthiases, Direction de la Lutte Contre la Maladie (DLM), Ministère de la Santé et de l'Action Sociale (MSAS), Dakar, Senegal
| | - Oumou Kaltoum Boh
- Programme National de Lutte Contre les Bilharzioses et les Géo-Helminthiases, Direction de la Lutte Contre la Maladie (DLM), Ministère de la Santé et de l'Action Sociale (MSAS), Dakar, Senegal
| | - Babacar Guèye
- Programme National de Lutte Contre les Bilharzioses et les Géo-Helminthiases, Direction de la Lutte Contre la Maladie (DLM), Ministère de la Santé et de l'Action Sociale (MSAS), Dakar, Senegal
| | - Mady Ba
- WHO Country Office, Dakar, Senegal
| | - Idrissa Talla
- Département de Santé Publique, Faculté des Sciences de la Santé, Université Amadou Hampathé Ba, Dakar, Senegal
| | - Malang Mané
- FHI 360, Chargé des Enquêtes et Evaluation des Maladies et des Campagnes de DMM, Dakar, Senegal
| | - Rose Monteil
- FHI 360, Chargé des Enquêtes et Evaluation des Maladies et des Campagnes de DMM, Dakar, Senegal
| | - Boniface Kinvi
- Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN), WHO Africa Regional Office, Brazzaville, Congo
| | - Honorat Gustave Marie Zoure
- Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN), WHO Africa Regional Office, Brazzaville, Congo
| | - Jorge Cano Ortega
- Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN), WHO Africa Regional Office, Brazzaville, Congo
| | - Pauline Mwinzi
- Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN), WHO Africa Regional Office, Brazzaville, Congo
| | - Moussa Sacko
- Service de Parasitologie, Institut National de Santé Publique (INSP), BP 1771, Bamako, Mali
| | - Babacar Faye
- Department of Parasitology and Mycology Faculty of Medicine, Pharmacy and Odontology, Université Cheikh Anta Diop de Dakar (UCAD), Dakar, Senegal
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3
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Aboagye IF, Addison YAA. Praziquantel efficacy, urinary and intestinal schistosomiasis reinfection - a systematic review. Pathog Glob Health 2023; 117:623-630. [PMID: 36394218 PMCID: PMC10498796 DOI: 10.1080/20477724.2022.2145070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Praziquantel (PZQ) has been extensively used as the drug of choice for the treatment of schistosomiasis on account of its safety and effectiveness against all major forms of schistosomiasis. However, low cure rate, reduced susceptibility of Schistosoma mansoni to PZQ and treatment failures in S. haematobium infections have been reported, raising concerns about its efficacy. Using the search terms, 'praziquantel efficacy, schistosomiasis, school children, reinfection' as well as defined inclusion criteria, and guided by the PRISMA guidelines, articles from 2001 to 2022 were selected from the PubMed and Google Scholar databases and reviewed to assess their importance to the research question. This review assessed the efficacy of PZQ against schistosomiasis and reinfection rates following treatment of Schistosoma infections in children. Majority of both intestinal and urinary schistosomiasis studies reported comparable egg reduction rates (ERRs) of 94.2% to 99.9% and 91.9% to 98%, respectively. However, ERRs suggestive of sub-optimal PZQ efficacy as well as generally high and comparable cure rates for intestinal (81.2%-99.1%) and urinary (79%-93.7%) schistosomiasis studies were reported. Schistosomiasis reinfection rates varied widely for urinary (8.1%-39.6%) and intestinal (13.9%-63.4%) studies within eight to 28 weeks following PZQ treatment. Praziquantel treatment of urinary and intestinal schistosomiasis should be accompanied by the provision of potable water, toilet, and recreational facilities to reduce reinfection and egg reduction rates and increase cure rate to expedite schistosomiasis elimination.
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Affiliation(s)
- Isaac Frimpong Aboagye
- Department of Animal Biology and Conservation Science, University of Ghana, Legon-Accra, Ghana
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Faiad SM, Williams MA, Goodman M, Sokolow S, Olden JD, Mitchell K, Andriantsoa R, Gordon Jones JP, Andriamaro L, Ravoniarimbinina P, Rasamy J, Ravelomanana T, Ravelotafita S, Ravo R, Rabinowitz P, De Leo GA, Wood CL. Temperature affects predation of schistosome-competent snails by a novel invader, the marbled crayfish Procambarus virginalis. PLoS One 2023; 18:e0290615. [PMID: 37703262 PMCID: PMC10499222 DOI: 10.1371/journal.pone.0290615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 08/12/2023] [Indexed: 09/15/2023] Open
Abstract
The human burden of environmentally transmitted infectious diseases can depend strongly on ecological factors, including the presence or absence of natural enemies. The marbled crayfish (Procambarus virginalis) is a novel invasive species that can tolerate a wide range of ecological conditions and colonize diverse habitats. Marbled crayfish first appeared in Madagascar in 2005 and quickly spread across the country, overlapping with the distribution of freshwater snails that serve as the intermediate host of schistosomiasis-a parasitic disease of poverty with human prevalence ranging up to 94% in Madagascar. It has been hypothesized that the marbled crayfish may serve as a predator of schistosome-competent snails in areas where native predators cannot and yet no systematic study to date has been conducted to estimate its predation rate on snails. Here, we experimentally assessed marbled crayfish consumption of uninfected and infected schistosome-competent snails (Biomphalaria glabrata and Bulinus truncatus) across a range of temperatures, reflective of the habitat range of the marbled crayfish in Madagascar. We found that the relationship between crayfish consumption and temperature is unimodal with a peak at ~27.5°C. Per-capita consumption increased with body size and was not affected either by snail species or their infectious status. We detected a possible satiation effect, i.e., a small but significant reduction in per-capita consumption rate over the 72-hour duration of the predation experiment. Our results suggest that ecological parameters, such as temperature and crayfish weight, influence rates of consumption and, in turn, the potential impact of the marbled crayfish invasion on snail host populations.
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Affiliation(s)
- Sara M. Faiad
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
| | - Maureen A. Williams
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
- Department of Biology, McDaniel College, Westminster, MD, United States of America
| | - Maurice Goodman
- Hopkins Marine Station, Dept. of Oceans and of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, CA, United States of America
| | - Susanne Sokolow
- Hopkins Marine Station, Dept. of Oceans and of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, CA, United States of America
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA, United States of America
| | - Julian D. Olden
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
| | - Kaitlyn Mitchell
- Hopkins Marine Station, Dept. of Oceans and of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, CA, United States of America
| | - Ranja Andriantsoa
- Réseau International Schistosomiase Environnement Aménagement et Lutte (RISEAL) Madagascar, Madagascar
| | | | - Luciano Andriamaro
- Réseau International Schistosomiase Environnement Aménagement et Lutte (RISEAL) Madagascar, Madagascar
| | | | - Jeanne Rasamy
- Réseau International Schistosomiase Environnement Aménagement et Lutte (RISEAL) Madagascar, Madagascar
- Department of Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Tsilavina Ravelomanana
- Réseau International Schistosomiase Environnement Aménagement et Lutte (RISEAL) Madagascar, Madagascar
- Department of Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Salohy Ravelotafita
- Department of Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Ranaivosolo Ravo
- Department of Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Peter Rabinowitz
- Department of Environmental/Occupational Health Sciences, Global Health, University of Washington, Seattle, WA, United States of America
- Center for One Health Research (COHR), University of Washington, Seattle, WA, United States of America
| | - Giulio A. De Leo
- Hopkins Marine Station, Dept. of Oceans and of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, CA, United States of America
- Woods Institute for the Environment, Stanford University, Stanford, CA, United States of America
| | - Chelsea L. Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
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Silva LMN, França WWM, Santos VHB, Souza RAF, Silva AM, Diniz EGM, Aguiar TWA, Rocha JVR, Souza MAA, Nascimento WRC, Lima Neto RG, Cruz Filho IJ, Ximenes ECPA, Araújo HDA, Aires AL, Albuquerque MCPA. Plumbagin: A Promising In Vivo Antiparasitic Candidate against Schistosoma mansoni and In Silico Pharmacokinetic Properties (ADMET). Biomedicines 2023; 11:2340. [PMID: 37760782 PMCID: PMC10525874 DOI: 10.3390/biomedicines11092340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/16/2023] [Accepted: 08/19/2023] [Indexed: 09/29/2023] Open
Abstract
Schistosomiasis, a potentially fatal chronic disease whose etiological agents are blood trematode worms of the genus Schistosoma spp., is one of the most prevalent and debilitating neglected diseases. The treatment of schistosomiasis depends exclusively on praziquantel (PZQ), a drug that has been used since the 1970s and that already has reports of reduced therapeutic efficacy, related with the development of Schistosoma-resistant or -tolerant strains. Therefore, the search for new therapeutic alternatives is an urgent need. Plumbagin (PLUM), a naphthoquinone isolated from the roots of plants of the genus Plumbago, has aroused interest in research due to its antiparasitic properties against protozoa and helminths. Here, we evaluated the in vivo schistosomicidal potential of PLUM against Schistosoma mansoni and the in silico pharmacokinetic parameters. ADMET parameters and oral bioavailability were evaluated using the PkCSM and SwissADME platforms, respectively. The study was carried out with five groups of infected mice and divided as follows: an untreated control group, a control group treated with PZQ, and three groups treated orally with 8, 16, or 32 mg/kg of PLUM. After treatment, the Kato-Katz technique was performed to evaluate a quantity of eggs in the feces (EPG). The animals were euthanized for worm recovery, intestine samples were collected to evaluate the oviposition pattern, the load of eggs was determined on the hepatic and intestinal tissues and for the histopathological and histomorphometric evaluation of tissue and hepatic granulomas. PLUM reduced EPG by 65.27, 70.52, and 82.49%, reduced the total worm load by 46.7, 55.25, and 72.4%, and the female worm load by 44.01, 52.76, and 71.16%, for doses of 8, 16, and 32 mg/kg, respectively. PLUM also significantly reduced the number of immature eggs and increased the number of dead eggs in the oogram. A reduction of 36.11, 46.46, and 64.14% in eggs in the hepatic tissue, and 57.22, 65.18, and 80.5% in the intestinal tissue were also observed at doses of 8, 16, and 32 mg/kg, respectively. At all doses, PLUM demonstrated an effect on the histopathological and histomorphometric parameters of the hepatic granuloma, with a reduction of 41.11, 48.47, and 70.55% in the numerical density of the granulomas and 49.56, 57.63, and 71.21% in the volume, respectively. PLUM presented itself as a promising in vivo antiparasitic candidate against S. mansoni, acting not only on parasitological parameters but also on hepatic granuloma. Furthermore, in silico, PLUM showed good predictive pharmacokinetic profiles by ADMET.
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Affiliation(s)
- Lucas M. N. Silva
- Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Ciências Farmacêuticas, Universidade Federal de Pernambuco, Recife 50740-520, PE, Brazil; (L.M.N.S.); (V.H.B.S.); (R.A.F.S.); (E.C.P.A.X.); (M.C.P.A.A.)
| | - Wilza W. M. França
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
- Programa de Pós-Graduação em Medicina Tropical, Departamento de Medicina Tropical Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil;
| | - Victor H. B. Santos
- Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Ciências Farmacêuticas, Universidade Federal de Pernambuco, Recife 50740-520, PE, Brazil; (L.M.N.S.); (V.H.B.S.); (R.A.F.S.); (E.C.P.A.X.); (M.C.P.A.A.)
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
| | - Renan A. F. Souza
- Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Ciências Farmacêuticas, Universidade Federal de Pernambuco, Recife 50740-520, PE, Brazil; (L.M.N.S.); (V.H.B.S.); (R.A.F.S.); (E.C.P.A.X.); (M.C.P.A.A.)
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
| | - Adriana M. Silva
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
| | - Emily G. M. Diniz
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
- Programa de Pós-Graduação em Medicina Tropical, Departamento de Medicina Tropical Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil;
| | - Thierry W. A. Aguiar
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
- Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil
| | - João V. R. Rocha
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
- Programa de Pós-Graduação em Medicina Tropical, Departamento de Medicina Tropical Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil;
| | - Mary A. A. Souza
- Programa de Pós-Graduação em Morfotecnologia, Departamento de Histologia e Embriologia, Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil; (M.A.A.S.); (I.J.C.F.)
| | - Wheverton R. C. Nascimento
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
- Programa de Pós-Graduação em Morfotecnologia, Departamento de Histologia e Embriologia, Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil; (M.A.A.S.); (I.J.C.F.)
- Centro de Ciências Médicas—Área Acadêmica de Medicina Tropical, Universidade Federal de Pernambuco, Recife 50670-901, PE, Brazil
| | - Reginaldo G. Lima Neto
- Programa de Pós-Graduação em Medicina Tropical, Departamento de Medicina Tropical Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil;
- Centro de Ciências Médicas—Área Acadêmica de Medicina Tropical, Universidade Federal de Pernambuco, Recife 50670-901, PE, Brazil
| | - Iranildo J. Cruz Filho
- Programa de Pós-Graduação em Morfotecnologia, Departamento de Histologia e Embriologia, Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil; (M.A.A.S.); (I.J.C.F.)
- Departamento de Antibióticos, Universidade Federal de Pernambuco, Recife 50670-901, PE, Brazil
| | - Eulália C. P. A. Ximenes
- Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Ciências Farmacêuticas, Universidade Federal de Pernambuco, Recife 50740-520, PE, Brazil; (L.M.N.S.); (V.H.B.S.); (R.A.F.S.); (E.C.P.A.X.); (M.C.P.A.A.)
- Departamento de Antibióticos, Universidade Federal de Pernambuco, Recife 50670-901, PE, Brazil
| | - Hallysson D. A. Araújo
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
- Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil
| | - André L. Aires
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
- Programa de Pós-Graduação em Medicina Tropical, Departamento de Medicina Tropical Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil;
- Programa de Pós-Graduação em Morfotecnologia, Departamento de Histologia e Embriologia, Universidade Federal de Pernambuco, Recife 50670-420, PE, Brazil; (M.A.A.S.); (I.J.C.F.)
- Centro de Ciências Médicas—Área Acadêmica de Medicina Tropical, Universidade Federal de Pernambuco, Recife 50670-901, PE, Brazil
| | - Mônica C. P. A. Albuquerque
- Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Ciências Farmacêuticas, Universidade Federal de Pernambuco, Recife 50740-520, PE, Brazil; (L.M.N.S.); (V.H.B.S.); (R.A.F.S.); (E.C.P.A.X.); (M.C.P.A.A.)
- Instituto Keizo Asami, Universidade Federal de Pernambuco, Recife 50740-465, PE, Brazil; (W.W.M.F.); (A.M.S.); (E.G.M.D.); (T.W.A.A.); (J.V.R.R.); (W.R.C.N.); (H.D.A.A.)
- Centro de Ciências Médicas—Área Acadêmica de Medicina Tropical, Universidade Federal de Pernambuco, Recife 50670-901, PE, Brazil
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6
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Roquini V, Mengarda AC, Cajas RA, Martins-da-Silva MF, Godoy-Silva J, Santos GA, Espírito-Santo MCC, Pavani TFA, Melo VA, Salvadori MC, Teixeira FS, Rando DGG, de Moraes J. The Existing Drug Nifuroxazide as an Antischistosomal Agent: In Vitro, In Vivo, and In Silico Studies of Macromolecular Targets. Microbiol Spectr 2023; 11:e0139323. [PMID: 37409934 PMCID: PMC10434008 DOI: 10.1128/spectrum.01393-23] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/15/2023] [Indexed: 07/07/2023] Open
Abstract
Schistosomiasis is a parasitic disease that afflicts approximately 250 million people worldwide. There is an urgent demand for new antiparasitic agents because praziquantel, the only drug available for the treatment of schistosomiasis, is not universally effective and may derail current progress toward the WHO goal of eliminating this disease as a public health problem by 2030. Nifuroxazide (NFZ), an oral nitrofuran antibiotic, has recently been explored to be repurposed for parasitic diseases. Here, in vitro, in vivo, and in silico studies were conducted to evaluate the activity of NFZ on Schistosoma mansoni. The in vitro study showed significant antiparasitic activity, with 50% effective concentration (EC50) and 90% effective concentration (EC90) values of 8.2 to 10.8 and 13.7 to 19.3 μM, respectively. NFZ also affected worm pairing and egg production and induced severe damage to the tegument of schistosomes. In vivo, a single oral dose of NFZ (400 mg/kg of body weight) to mice harboring either prepatent or patent S. mansoni infection significantly reduced the total worm burden (~40%). In patent infection, NFZ achieved a high reduction in the number of eggs (~80%), but the drug caused a low reduction in the egg burden of animals with prepatent infection. Finally, results from in silico target fishing methods predicted that serine/threonine kinases could be one of the potential targets for NFZ in S. mansoni. Overall, the present study revealed that NFZ possesses antischistosomal properties, mainly in terms of egg burden reduction in animals with patent S. mansoni infection. IMPORTANCE The increasing recognition of the burden imposed by helminthiasis, associated with the limited therapeutic arsenal, has led to initiatives and strategies to research and develop new drugs for the treatment of schistosomiasis. One of these strategies is drug repurposing, which considers low-risk compounds with potentially reduced costs and shorter time for development. In this study, nifuroxazide (NFZ) was evaluated for its anti-Schistosoma mansoni potential through in vitro, in vivo, and in silico studies. In vitro, NFZ affected worm pairing and egg production and induced severe damage to the tegument of schistosomes. In vivo, a single oral dose of NFZ (400 mg/kg) to mice harboring either prepatent or patent S. mansoni infection significantly reduced the total worm burden and egg production. In silico investigations have identified serine/threonine kinases as a molecular target for NFZ. Collectively, these results implied that NFZ might be a potential therapeutic candidate for the treatment of schistosomiasis.
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Affiliation(s)
- Vinícius Roquini
- Research Center on Neglected Diseases, Guarulhos University, Guarulhos, São Paulo, Brazil
| | - Ana C. Mengarda
- Research Center on Neglected Diseases, Guarulhos University, Guarulhos, São Paulo, Brazil
| | - Rayssa A. Cajas
- Research Center on Neglected Diseases, Guarulhos University, Guarulhos, São Paulo, Brazil
| | | | - Julia Godoy-Silva
- Research Center on Neglected Diseases, Guarulhos University, Guarulhos, São Paulo, Brazil
| | - Gustavo A. Santos
- Research Center on Neglected Diseases, Guarulhos University, Guarulhos, São Paulo, Brazil
| | - Maria Cristina C. Espírito-Santo
- Laboratory of Immunopathology of Schistosomiasis (LIM-06), Department of Infectious and Parasitic Diseases, Faculty of Medicine, University of São Paulo, São Paulo, São Paulo, Brazil
- Laboratory of Helminthology, Institute of Tropical Medicine, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Thais F. A. Pavani
- Biological Chemistry Post-Graduate Course, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, Diadema, São Paulo, Brazil
| | - Vanusa A. Melo
- Biological Chemistry Post-Graduate Course, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, Diadema, São Paulo, Brazil
| | - Maria C. Salvadori
- Institute of Physics, University of São Paulo, São Paulo, São Paulo, Brazil
| | | | - Daniela G. G. Rando
- Chemico-Pharmaceutical Research Group, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, Diadema, São Paulo, Brazil
| | - Josué de Moraes
- Research Center on Neglected Diseases, Guarulhos University, Guarulhos, São Paulo, Brazil
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Gaye PM, Doucouré S, Sow D, Sokhna C, Ranque S. Identification of Bulinus forskalii as a potential intermediate host of Schistosoma hæmatobium in Senegal. PLoS Negl Trop Dis 2023; 17:e0010584. [PMID: 37159452 DOI: 10.1371/journal.pntd.0010584] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 05/19/2023] [Accepted: 04/17/2023] [Indexed: 05/11/2023] Open
Abstract
Understanding the transmission of Schistosoma hæmatobium in the Senegal River Delta requires knowledge of the snails serving as intermediate hosts. Accurate identification of both the snails and the infecting Schistosoma species is therefore essential. Cercarial emission tests and multi-locus (COX1 and ITS) genetic analysis were performed on Bulinus forskalii snails to confirm their susceptibility to S. hæmatobium infection. A total of 55 Bulinus forskalii, adequately identified by MALDI-TOF mass spectrometry, were assessed. Cercarial shedding and RT-PCR assays detected 13 (23.6%) and 17 (31.0%), respectively, Bulinus forskalii snails parasitized by S. hæmatobium complex fluke. Nucleotide sequence analysis identified S. hæmatobium in 6 (11.0%) using COX1 and 3 (5.5%) using ITS2, and S. bovis in 3 (5.5%) using COX1 and 3 (5.5%) using ITS2. This result is the first report of infection of Bulinus forskalii by S. hæmatobium complex parasites in Senegal using innovative and more accurate identification methods to discriminate this snail and characterize its infection by S. hæmatobium.
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Affiliation(s)
- Papa Mouhamadou Gaye
- Aix-Marseille Université, IRD, AP-HM, SSA, VITROME, Marseille, France
- VITROME, Campus International IRD-UCAD de l'IRD, Dakar, Senegal
- Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection de Marseille, Marseille, France
- Département Biologie Animale, Faculté des Sciences et Technique, UCAD de Dakar, Dakar, Senegal
| | | | - Doudou Sow
- Department of Parasitology-Mycology, UFR Sciences de la Santé, Université Gaston Berger, Saint-Louis, Senegal
| | - Cheikh Sokhna
- VITROME, Campus International IRD-UCAD de l'IRD, Dakar, Senegal
- Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection de Marseille, Marseille, France
| | - Stéphane Ranque
- VITROME, Campus International IRD-UCAD de l'IRD, Dakar, Senegal
- Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection de Marseille, Marseille, France
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8
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Sow D, Sylla K, Dieng NM, Senghor B, Gaye PM, Fall CB, Goumballa N, Diallo A, Ndiaye JLA, Parola P, Sokhna C, Doucouré S, Faye B. Molecular diagnosis of urogenital schistosomiasis in pre-school children, school-aged children and women of reproductive age at community level in central Senegal. Parasit Vectors 2023; 16:43. [PMID: 36717835 PMCID: PMC9887789 DOI: 10.1186/s13071-023-05671-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/16/2023] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Urogenital schistosomiasis is a major public health concern in sub-Saharan Africa. In Senegal, the disease is endemic in all regions of the country. Recently, WHO strongly recommended including pre-school children and women of reproductive age during a mass drug administration campaign. It is important to describe the burden of the disease in these group at risk using innovative diagnostic tools. This study aimed to assess the use of real-time PCR in the detection of schistosomiasis cases at the community level in a seasonal transmission area. METHODS A cross-sectional survey was carried out in Niakhar located in the centre of Senegal. Pre-schoolchildren, school-aged children and female adolescents and adults were invited to participate in the study in April 2018. Urine samples were collected and examined using Hemastix reagent strips, filtration technique and real-time PCR. Schistosoma haematobium was detected, identified by targeting the Dra1 gene. The prevalence of urogenital schistosomiasis was determined for each group and the performance of the real-time PCR was compared with the conventional techniques. RESULTS A total of 428 participants were enrolled in this study including 87 (20.4%) pre-school children (1-5 years), 262 (61.3%) school-aged children between (5-14 years), 17 (3.9%) adolescents (15-17 years) and 62 (14.4%) female adults. The comparison of the diagnostic techniques has shown that the prevalence of urogenital schistosomiasis is higher using molecular technique (34.6%) compared to microscopy (20.3%). The percentage rate of haematuria using Hemastix was 23.1%. School-aged children between 5 and 14 years old were the most affected with 29.0% and 43.1% under microscopy and RT-PCR, respectively. In female participants, microscopic prevalence decreases with age, from 21.4% in school-aged children to 17.6% in adolescents and 9.7% in adults. There was good correlation between the number of eggs per 10 ml and the cycle threshold range. CONCLUSION These results show the importance of using molecular tools in the surveillance of schistosomiasis particularly in pre-school children and women of reproductive age.
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Affiliation(s)
- Doudou Sow
- grid.442784.90000 0001 2295 6052Service de Parasitologie-Mycologie, UFR Sciences de la Santé, Université Gaston Berger, Saint-Louis, Sénégal
| | - Khadime Sylla
- grid.8191.10000 0001 2186 9619Service de Parasitologie-Mycologie, FMPO, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Ndeye Marème Dieng
- grid.8191.10000 0001 2186 9619Service de Parasitologie-Mycologie, FMPO, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Bruno Senghor
- grid.418291.70000 0004 0456 337XUnité VITROME Dakar, Institut de Recherche pour le Développement, Dakar, Sénégal
| | - Papa Mouhamadou Gaye
- grid.418291.70000 0004 0456 337XUnité VITROME Dakar, Institut de Recherche pour le Développement, Dakar, Sénégal
| | - Cheikh B. Fall
- grid.8191.10000 0001 2186 9619Service de Parasitologie-Mycologie, FMPO, Université Cheikh Anta Diop, Dakar, Sénégal
| | - Ndiaw Goumballa
- grid.418291.70000 0004 0456 337XUnité VITROME Dakar, Institut de Recherche pour le Développement, Dakar, Sénégal
| | - Aldiouma Diallo
- grid.418291.70000 0004 0456 337XUnité VITROME Dakar, Institut de Recherche pour le Développement, Dakar, Sénégal
| | - Jean Louis A. Ndiaye
- Service de Parasitologie-Mycologie, UFR Sciences de la Santé, Université Iba Der Thiam, Thies, Sénégal
| | - Philippe Parola
- Unité VITROME, IHU Méditérannée Infection, Marseille, France
| | - Cheikh Sokhna
- grid.418291.70000 0004 0456 337XUnité VITROME Dakar, Institut de Recherche pour le Développement, Dakar, Sénégal
| | - Souleymane Doucouré
- grid.418291.70000 0004 0456 337XUnité VITROME Dakar, Institut de Recherche pour le Développement, Dakar, Sénégal
| | - Babacar Faye
- grid.8191.10000 0001 2186 9619Service de Parasitologie-Mycologie, FMPO, Université Cheikh Anta Diop, Dakar, Sénégal
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Senghor B, Webster B, Pennance T, Sène M, Doucouré S, Sow D, Sokhna C. Molecular characterization of schistosome cercariae and their Bulinus snail hosts from Niakhar, a seasonal transmission focus in central Senegal. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2023; 3:100114. [PMID: 36824299 PMCID: PMC9941053 DOI: 10.1016/j.crpvbd.2023.100114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/11/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023]
Abstract
Bulinus senegalensis and Bulinus umbilicatus, two sympatric freshwater snails found in temporal ponds in Senegal, were thought to be involved in the transmission of Schistosoma haematobium and/or Schistosoma curassoni. To better understand the role of these Bulinus species in the transmission of human and animal Schistosoma species, B. senegalensis and B. umbilicatus were collected in 2015, during a malacological survey, from a temporal pond in Niakhar, central Senegal. Snails were induced to shed cercariae on two consecutive days. Individual cercariae from each snail were collected and preserved for molecular identification. Infected snails were identified by analysis of a partial region of the cytochrome c oxidase subunit 1 (cox1) gene. Six individual cercariae shed from each infected snail were identified by analyses of the cox1, nuclear ITS and partial 18S rDNA regions. Of the 98 snails collected, one B. senegalensis had a mixed infection shedding S. haematobium, S. bovis and S. haematobium-S. bovis hybrid cercariae and one B. umbilicatus was found to be shedding only S. haematobium. These data provide molecular confirmation for B. senegalensis transmitting S. bovis and S. haematobium-S. bovis hybrids in Senegal. The multiple Bulinus species involved in the human urogenital schistosomiasis in Senegal provides a high force of transmission warranting detailed mapping, surveillance and regular treatment of at-risk populations.
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Affiliation(s)
- Bruno Senghor
- VITROME, Campus International IRD-UCAD de Hann, 1386, Dakar, Senegal
| | - Bonnie Webster
- Natural History Museum, Wolfson Wellcome Biomedical Laboratories, Department of Science, Cromwell Road, London, SW7 5BD, UK
- London Centre for Neglected Tropical Disease Research, Imperial College London, School of Public Health, Norfolk Pl, Paddington, London, W21PG, UK
| | - Tom Pennance
- Natural History Museum, Wolfson Wellcome Biomedical Laboratories, Department of Science, Cromwell Road, London, SW7 5BD, UK
- London Centre for Neglected Tropical Disease Research, Imperial College London, School of Public Health, Norfolk Pl, Paddington, London, W21PG, UK
- Department of Basic Medical Sciences, Western University of Health Sciences, Lebanon, OR, 97355, USA
| | - Mariama Sène
- Laboratoire des Sciences Biologiques, Agronomiques et de Modélisation des Systems Complexes, UFRS2ATA, Université Gaston Berger de Saint-Louis, Saint-Louis, Senegal
| | | | - Doudou Sow
- Department of Parasitology-Mycology, UFR Sciences de la Santé, Université Gaston Berger, 234, Saint-Louis, Senegal
| | - Cheikh Sokhna
- VITROME, Campus International IRD-UCAD de Hann, 1386, Dakar, Senegal
- VITROME, Aix-Marseille Univ, IRD, SSA, AP-HM, IHU-Mediterranean Infection, Marseille, France
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10
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Senghor B, Mathieu-Begné E, Rey O, Doucouré S, Sow D, Diop B, Sène M, Boissier J, Sokhna C. Urogenital schistosomiasis in three different water access in the Senegal river basin: prevalence and monitoring praziquantel efficacy and re-infection levels. BMC Infect Dis 2022; 22:968. [PMID: 36581796 PMCID: PMC9801593 DOI: 10.1186/s12879-022-07813-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 10/26/2022] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Urogenital schistosomiasis is a neglected tropical disease most prevalent in sub-Saharan Africa. In the Senegal river basin, the construction of the Diama dam led to an increase and endemicity of schistosomiasis. Since 2009, praziquantel has frequently been used as preventive chemotherapy in the form of mass administration to Senegalese school-aged children without monitoring of the treatment efficacy and the prevalence after re-infection. This study aims to determine the current prevalence of urogenital schistosomiasis (caused by Schistosoma haematobium), the efficacy of praziquantel, and the re-infection rates in children from five villages with different water access. METHODS The baseline prevalence of S. haematobium was determined in August 2020 in 777 children between 5 and 11 years old and a single dose of praziquantel (40 mg/kg) was administered to those positive. The efficacy of praziquantel and the re-infection rates were monitored 4 weeks and 7 months after treatment, respectively, in 226 children with a high intensity of infection at baseline. RESULTS At the baseline, prevalence was low among children from the village of Mbane who live close to the Lac de Guiers (38%), moderate among those from the villages of Dioundou and Khodit, which neighbor the Doue river (46%), and very high at Khodit (90.6%) and Guia (91.2%) which mainly use an irrigation canal. After treatment, the observed cure rates confirmed the efficacy of praziquantel. The lowest cure rate (88.5%) was obtained in the village using the irrigation canal, while high cure rates were obtained in those using the lake (96.5%) and the river (98%). However, high egg reduction rates (between 96.7 and 99.7%) were obtained in all the villages. The re-infection was significantly higher in the village using the canal (42.5%) than in the villages accessing the Lac de Guiers (18.3%) and the Doue river (14.8%). CONCLUSION Praziquantel has an impact on reducing the prevalence and intensity of urogenital schistosomiasis. However, in the Senegal river basin, S. haematobium remains a real health problem for children living in the villages near the irrigation canals, despite regular treatment, while prevalence is declining from those frequenting the river and the Lac de Guiers. Trial registration ClinicalTrials.gov, NCT04635553. Registered 19 November 2020 retrospectively registered, https://www. CLINICALTRIALS gov/ct2/show/NCT04635553?cntry=SN&draw=2&rank=4.
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Affiliation(s)
- Bruno Senghor
- grid.418291.70000 0004 0456 337XCampus International IRD-UCAD de Hann, Vectors-Tropical and Mediterranean Infections (VITROME) Laboratory, 1386 Dakar, Senegal
| | - Eglantine Mathieu-Begné
- grid.121334.60000 0001 2097 0141Host Pathogen Environments Interactions (IHPE) Laboratory, CNRS, IFREMER, University of Montpellier, University of Perpignan via Domitia, Perpignan, France
| | - Olivier Rey
- grid.121334.60000 0001 2097 0141Host Pathogen Environments Interactions (IHPE) Laboratory, CNRS, IFREMER, University of Montpellier, University of Perpignan via Domitia, Perpignan, France
| | - Souleymane Doucouré
- grid.418291.70000 0004 0456 337XCampus International IRD-UCAD de Hann, Vectors-Tropical and Mediterranean Infections (VITROME) Laboratory, 1386 Dakar, Senegal
| | - Doudou Sow
- grid.442784.90000 0001 2295 6052Department of Parasitology-Mycology, UFR of Health Sciences, University Gaston Berger, 234, Saint-Louis, Senegal
| | - Bocar Diop
- grid.442784.90000 0001 2295 6052Laboratory of Biological and Agronomic Sciences and Modelling of Complex Systems, UFRS2ATA, Gaston Berger University of Saint-Louis, Saint-Louis, Senegal
| | - Mariama Sène
- National Schistosomiasis Control Program (NSCP), Ministry of Health, Dakar, Senegal
| | - Jérôme Boissier
- grid.121334.60000 0001 2097 0141Host Pathogen Environments Interactions (IHPE) Laboratory, CNRS, IFREMER, University of Montpellier, University of Perpignan via Domitia, Perpignan, France
| | - Cheikh Sokhna
- grid.418291.70000 0004 0456 337XCampus International IRD-UCAD de Hann, Vectors-Tropical and Mediterranean Infections (VITROME) Laboratory, 1386 Dakar, Senegal ,grid.5399.60000 0001 2176 4817VITROME, IRD, SSA, AP-HM, IHU-Mediterranean Infection, Aix-Marseille Univ, Marseille, France
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Nikolakis ZL, Adams RH, Wade KJ, Lund AJ, Carlton EJ, Castoe TA, Pollock DD. Prospects for genomic surveillance for selection in schistosome parasites. FRONTIERS IN EPIDEMIOLOGY 2022; 2:932021. [PMID: 38455290 PMCID: PMC10910990 DOI: 10.3389/fepid.2022.932021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 09/12/2022] [Indexed: 03/09/2024]
Abstract
Schistosomiasis is a neglected tropical disease caused by multiple parasitic Schistosoma species, and which impacts over 200 million people globally, mainly in low- and middle-income countries. Genomic surveillance to detect evidence for natural selection in schistosome populations represents an emerging and promising approach to identify and interpret schistosome responses to ongoing control efforts or other environmental factors. Here we review how genomic variation is used to detect selection, how these approaches have been applied to schistosomes, and how future studies to detect selection may be improved. We discuss the theory of genomic analyses to detect selection, identify experimental designs for such analyses, and review studies that have applied these approaches to schistosomes. We then consider the biological characteristics of schistosomes that are expected to respond to selection, particularly those that may be impacted by control programs. Examples include drug resistance, host specificity, and life history traits, and we review our current understanding of specific genes that underlie them in schistosomes. We also discuss how inherent features of schistosome reproduction and demography pose substantial challenges for effective identification of these traits and their genomic bases. We conclude by discussing how genomic surveillance for selection should be designed to improve understanding of schistosome biology, and how the parasite changes in response to selection.
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Affiliation(s)
- Zachary L. Nikolakis
- Department of Biology, University of Texas at Arlington, Arlington, TX, United States
| | - Richard H. Adams
- Department of Biological and Environmental Sciences, Georgia College and State University, Milledgeville, GA, United States
| | - Kristen J. Wade
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Andrea J. Lund
- Department of Environmental and Occupational Health, Colorado School of Public Health, University of Colorado, Anschutz, Aurora, CO, United States
| | - Elizabeth J. Carlton
- Department of Environmental and Occupational Health, Colorado School of Public Health, University of Colorado, Anschutz, Aurora, CO, United States
| | - Todd A. Castoe
- Department of Biology, University of Texas at Arlington, Arlington, TX, United States
| | - David D. Pollock
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, United States
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Webb AJ, Allan F, Kelwick RJR, Beshah FZ, Kinung’hi SM, Templeton MR, Emery AM, Freemont PS. Specific Nucleic AcId Ligation for the detection of Schistosomes: SNAILS. PLoS Negl Trop Dis 2022; 16:e0010632. [PMID: 35881651 PMCID: PMC9355235 DOI: 10.1371/journal.pntd.0010632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 08/05/2022] [Accepted: 07/04/2022] [Indexed: 11/18/2022] Open
Abstract
Schistosomiasis, also known as bilharzia or snail fever, is a debilitating neglected tropical disease (NTD), caused by parasitic trematode flatworms of the genus Schistosoma, that has an annual mortality rate of 280,000 people in sub-Saharan Africa alone. Schistosomiasis is transmitted via contact with water bodies that are home to the intermediate host snail which shed the infective cercariae into the water. Schistosome lifecycles are complex, and while not all schistosome species cause human disease, endemic regions also typically feature animal-infecting schistosomes that can have broader economic and/or food security implications. Therefore, the development of species-specific Schistosoma detection technologies may help to inform evidence-based local environmental, food security and health systems policy making. Crucially, schistosomiasis disproportionally affects low- and middle-income (LMIC) countries and for that reason, environmental screening of water bodies for schistosomes may aid with the targeting of water, sanitation, and hygiene (WASH) interventions and preventive chemotherapy to regions at highest risk of schistosomiasis transmission, and to monitor the effectiveness of such interventions at reducing the risk over time. To this end, we developed a DNA-based biosensor termed Specific Nucleic AcId Ligation for the detection of Schistosomes or ‘SNAILS’. Here we show that ‘SNAILS’ enables species-specific detection from genomic DNA (gDNA) samples that were collected from the field in endemic areas. Schistosomiasis is a neglected tropical disease, caused by the parasitic trematodes of the genus Schistosoma. Schistosomiasis is endemic to regions within Africa, Asia and South America with at least 250 million people infected and a further 779 million at risk of infection. The lifecycle of schistosomes are complex and involve specific freshwater intermediate snail hosts which shed infective cercariae into the waterbodies they inhabit. Schistosomiasis is subsequently transmitted to humans or animals that contact cercariae contaminated water. In Africa, human disease is largely caused by Schistosoma mansoni and Schistosoma haematobium. However, endemic regions also typically feature animal-infecting schistosomes that can have broader economic and/or food security implications. Therefore, the development of species-specific Schistosoma detection technologies may help to inform local environmental, food security and health programmes. To this end, we re-purposed a nucleic acid detection technology to enable the detection of different schistosome species. Our DNA-biosensor, abbreviated as ‘SNAILS’, employs carefully designed probes that recognise species-specific DNA sequences, coupled with enzymatic amplification steps, and a fluorescent signal-dye to indicate a positive detection. ‘SNAILS’ successfully differentiates between S. mansoni and S. haematobium samples and could conceivably be employed within future global health programmes.
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Affiliation(s)
- Alexander James Webb
- Section of Structural and Synthetic biology, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Fiona Allan
- Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Richard J. R. Kelwick
- Section of Structural and Synthetic biology, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Feleke Zewge Beshah
- College of Natural and Computational Sciences, Addis Ababa University, Arat Kilo, Addis Ababa, Ethiopia
| | | | - Michael R. Templeton
- Department of Civil and Environmental Engineering, Imperial College London, London, United Kingdom
| | - Aidan Mark Emery
- Department of Life Sciences, Natural History Museum, London, United Kingdom
- * E-mail: (AME); (PSF)
| | - Paul S. Freemont
- Section of Structural and Synthetic biology, Department of Infectious Disease, Imperial College London, London, United Kingdom
- The London Biofoundry, Imperial College Translation and Innovation Hub, White City Campus, London, United Kingdom
- UK Dementia Research Institute Care Research and Technology Centre, Imperial College London, Hammersmith Campus, London, United Kingdom
- * E-mail: (AME); (PSF)
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Norbury LJ, Shirakashi S, Power C, Nowak BF, Bott NJ. Praziquantel use in aquaculture - Current status and emerging issues. Int J Parasitol Drugs Drug Resist 2022; 18:87-102. [PMID: 35220160 PMCID: PMC8881684 DOI: 10.1016/j.ijpddr.2022.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 12/02/2022]
Abstract
Parasitic diseases are major constraints in fish mariculture. The anthelmintic praziquantel (PZQ) can effectively treat a range of flatworm parasites in a variety of fish species and has potential for broader application than its current use in the global aquaculture industry. In this review we report on PZQ's current use in the aquaculture industry and discuss its efficacy against various flatworm parasites of fish. Routes of PZQ administration are evaluated, along with issues related to palatability, pharmacokinetics and toxicity in fish, while PZQ's effects on non-target species, environmental impacts, and the development of drug-resistance are discussed.
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Affiliation(s)
- Luke J Norbury
- School of Science, STEM College, RMIT University, Bundoora, 3083, Victoria, Australia
| | - Sho Shirakashi
- Aquaculture Research Institute, Kindai University, Wakayama, 649-2211, Japan
| | - Cecilia Power
- School of Science, STEM College, RMIT University, Bundoora, 3083, Victoria, Australia
| | - Barbara F Nowak
- School of Science, STEM College, RMIT University, Bundoora, 3083, Victoria, Australia; Institute for Marine and Antarctic Studies, University of Tasmania, Launceston, 7250, Tasmania, Australia
| | - Nathan J Bott
- School of Science, STEM College, RMIT University, Bundoora, 3083, Victoria, Australia.
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Brattig NW, Graf A, Konou A, Casagrande G, Utzinger J, Meier L. More than seven decades of Acta Tropica: Looking back to move into the future. Acta Trop 2022; 226:106155. [PMID: 34634266 DOI: 10.1016/j.actatropica.2021.106155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/22/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022]
Abstract
Acta Tropica is an international, peer-reviewed journal advancing scientific research in the fields of tropical medicine and parasitology. This article elucidates the rich history of the journal and speculates about its future. Acta Tropica was launched in 1944 and formed an integral part of the establishment and running of the Swiss Tropical Institute in Basel. After two distinct periods of relatively small publication activities (1944-1976 and 1977-1988), in 1989, Acta Tropica was transferred to the Dutch publisher Elsevier. Subsequently, the annual number of publications steadily increased and the scope of the journal broadened to the biology of pathogens and their vectors, to genetics, host-parasite relationships, mechanisms of pathogenicity, diagnostics, and treatment of tropical diseases. The body of published articles contributed to an improved understanding of the prevention, surveillance, control, and elimination of diseases that are intimately linked to poverty, such as malaria and neglected tropical diseases. In recent years, the scope of Acta Tropica was widening to target emerging and re-emerging infectious diseases, epidemics and pandemics, interrelations of microbes, viruses, and parasites, co-dependencies of epidemiology, ecology, environment, and climate change. Importantly, non-communicable diseases are gaining interest in low- and middle-income countries due to urbanization, globalization, and rapidly changing life styles, and hence, these issues receive growing prominence. Acta Tropica continues to embrace inter- and, indeed, transdisciplinary research to address pressing global health issues and sustainable development.
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Landeryou T, Rabone M, Allan F, Maddren R, Rollinson D, Webster BL, Tchuem-Tchuenté LA, Anderson RM, Emery AM. Genome-wide insights into adaptive hybridisation across the Schistosoma haematobium group in West and Central Africa. PLoS Negl Trop Dis 2022; 16:e0010088. [PMID: 35100291 PMCID: PMC8803156 DOI: 10.1371/journal.pntd.0010088] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/11/2021] [Indexed: 11/30/2022] Open
Abstract
Schistosomiasis remains a public health concern across sub-Saharan Africa; current control programmes rely on accurate mapping and high mass drug administration (MDA) coverage to attempt disease elimination. Inter-species hybridisation can occur between certain species, changing epidemiological dynamics within endemic regions, which has the potential to confound control interventions. The impact of hybridisation on disease dynamics is well illustrated in areas of Cameroon where urogenital schistosomiasis, primarily due to Schistosoma haematobium and hybrid infections, now predominate over intestinal schistosomiasis caused by Schistosoma guineensis. Genetic markers have shown the ability to identify hybrids, however the underlying genomic architecture of divergence and introgression between these species has yet to be established. In this study, restriction site associated DNA sequencing (RADseq) was used on archived adult worms initially identified as; Schistosoma bovis (n = 4), S. haematobium (n = 9), S. guineensis (n = 3) and S. guineensis x S. haematobium hybrids (n = 4) from Mali, Senegal, Niger, São Tomé and Cameroon. Genome-wide evidence supports the existence of S. guineensis and S. haematobium hybrid populations across Cameroon. The hybridisation of S. guineensis x S. haematobium has not been demonstrated on the island of São Tomé, where all samples showed no introgression with S. haematobium. Additionally, all S. haematobium isolates from Nigeria, Mali and Cameroon indicated signatures of genomic introgression from S. bovis. Adaptive loci across the S. haematobium group showed that voltage-gated calcium ion channels (Cav) could play a key role in the ability to increase the survivability of species, particularly in host systems. Where admixture has occurred between S. guineensis and S. haematobium, the excess introgressive influx of tegumental (outer helminth body) and antigenic genes from S. haematobium has increased the adaptive response in hybrids, leading to increased hybrid population fitness and viability.
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Affiliation(s)
- Toby Landeryou
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Muriel Rabone
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Fiona Allan
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Rosie Maddren
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - David Rollinson
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Bonnie L. Webster
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | | | - Roy M. Anderson
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Aidan M. Emery
- The Natural History Museum, Department of Life Sciences, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom
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16
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Bulinus senegalensis and Bulinus umbilicatus Snail Infestations by the Schistosoma haematobium Group in Niakhar, Senegal. Pathogens 2021; 10:pathogens10070860. [PMID: 34358010 PMCID: PMC8308860 DOI: 10.3390/pathogens10070860] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 05/28/2021] [Accepted: 06/19/2021] [Indexed: 11/21/2022] Open
Abstract
Thorough knowledge of the dynamics of Bulinus spp. infestation could help to control the spread of schistosomiasis. This study describes the spatio-temporal dynamics of B. senegalensis and B. umbilicatus infestation by the Schistosoma haematobium group of blood flukes in Niakhar, Senegal. Molecular identification of the S. haematobium group was performed by real-time PCR, targeting the Dra 1 gene in 810 samples of Bulinus spp. collected during the schistosomiasis transmission season in 2013. In addition to Dra 1 PCR, a rapid diagnostic-PCR was performed on a sub-group of 43 snails to discriminate S. haematobium, S. bovis, and S. mattheei. Out of 810 snails, 236 (29.1%) were positive for Dra 1 based on the PCR, including 96.2% and 3.8% of B. senegalensis and B. umbilicatus, respectively. Among the sub-group, 16 samples were confirmed to be S. haematobium while one was identified as a mixture of S. haematobium and S. bovis. Snails infestations were detected in all villages sampled and infestation rates ranged from 15.38% to 42.11%. The prevalence of infestation was higher in the north (33.47%) compared to the south (25.74%). Snail populations infestations appear early in the rainy season, with a peak in the middle of the season, and then a decline towards the end of the rainy season. Molecular techniques showed, for the first time, the presence of S. bovis in the Bulinus spp. population of Niakhar. The heterogeneity of snail infestations at the village level must be taken into account in mass treatment strategies. Further studies should help to improve the characterizations of the schistosome population.
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Roucher C, Brosius I, Mbow M, Faye BT, De Hondt A, Smekens B, Arango D, Burm C, Tsoumanis A, Paredis L, van Herrewege Y, Potters I, Cisse B, Mboup S, Polman K, Bottieau E. Evaluation of Artesunate-mefloquine as a Novel Alternative Treatment for Schistosomiasis in African Children (SchistoSAM): protocol of a proof-of-concept, open-label, two-arm, individually-randomised controlled trial. BMJ Open 2021; 11:e047147. [PMID: 34168029 PMCID: PMC8231067 DOI: 10.1136/bmjopen-2020-047147] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
INTRODUCTION Alternative drugs and diagnostics are needed for the treatment and control of schistosomiasis. The exclusive use of praziquantel (PZQ) in mass drug administration programmes may result in the emergence of drug resistance. PZQ has little activity against Schistosoma larvae, thus reinfection remains a problem in high-risk communities. Furthermore, the insufficient sensitivity of conventional microscopy hinders therapeutic response assessment. Evaluation of artesunate-mefloquine (AM) as a Novel Alternative Treatment for Schistosomiasis in African Children (SchistoSAM) aims to evaluate the safety and efficacy of the antimalarial combination artesunate-mefloquine, re-purposed for the treatment of schistosomiasis, and to assess the performance of highly sensitive novel antigen-based and DNA-based assays as tools for monitoring treatment response. METHODS AND ANALYSIS The SchistoSAM study is an open-label, two-arm, individually randomised controlled non-inferiority trial, with a follow-up of 48 weeks. Primary school-aged children from the Richard Toll district in northern Senegal, an area endemic for Schistosoma mansoni and Schistosoma haematobium, are allocated to the AM intervention arm (3-day courses at 6-week intervals) or the PZQ control arm (single dose of 40 mg/kg). The trial's primary endpoints are the efficacy (cure rate (CR), assessed by microscopy) and safety (frequency and pattern of drug-related adverse events) of one AM course versus PZQ at 4 weeks after treatment. Secondary endpoints include (1) cumulative CR, egg reduction rate and safety after each additional course of AM, and at weeks 24 and 48, (2) prevalence and severity of schistosomiasis-related morbidity and (3) malaria prevalence, incidence and morbidity, both after 24 and 48 weeks. CRs and intensity reduction rates are also assessed by antigen-based and DNA-based diagnostic assays, for which performance for treatment monitoring is evaluated. ETHICS AND DISSEMINATION Ethics approval was obtained both in Belgium and Senegal. Oral assent from the children and signed informed consent from their legal representatives was obtained, prior to enrolment. The results will be disseminated in peer-reviewed journals and at international conferences. TRIAL REGISTRATION NUMBER NCT03893097; pre-results.
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Affiliation(s)
- Clémentine Roucher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Isabel Brosius
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Moustapha Mbow
- Department of Immunology, Cheikh Anta Diop University, Dakar, Senegal
- Institute for Health Research, Epidemiological Surveillance and Training (IRESSEF), Dakar, Senegal
| | | | - Annelies De Hondt
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Bart Smekens
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Diana Arango
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Christophe Burm
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Achilleas Tsoumanis
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Linda Paredis
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Yven van Herrewege
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Idzi Potters
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
| | - Badara Cisse
- Institute for Health Research, Epidemiological Surveillance and Training (IRESSEF), Dakar, Senegal
| | - Souleymane Mboup
- Institute for Health Research, Epidemiological Surveillance and Training (IRESSEF), Dakar, Senegal
| | - Katja Polman
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Health Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Emmanuel Bottieau
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerpen, Belgium
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Nanes Sarfati D, Li P, Tarashansky AJ, Wang B. Single-cell deconstruction of stem-cell-driven schistosome development. Trends Parasitol 2021; 37:790-802. [PMID: 33893056 DOI: 10.1016/j.pt.2021.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 02/07/2023]
Abstract
Schistosomes cause one of the most devastating neglected tropical diseases, schistosomiasis. Their transmission is accomplished through a complex life cycle with two obligate hosts and requires multiple radically different body plans specialized for infecting and reproducing in each host. Recent single-cell transcriptomic studies on several schistosome body plans provide a comprehensive map of their cell types, which include stem cells and their differentiated progeny along an intricate developmental hierarchy. This progress not only extends our understanding of the basic biology of the schistosome life cycle but can also inform new therapeutic and preventive strategies against the disease, as blocking the development of specific cell types through genetic manipulations has shown promise in inhibiting parasite survival, growth, and reproduction.
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Affiliation(s)
| | - Pengyang Li
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | | | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA; Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
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19
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Fukushige M, Chase-Topping M, Woolhouse MEJ, Mutapi F. Efficacy of praziquantel has been maintained over four decades (from 1977 to 2018): A systematic review and meta-analysis of factors influence its efficacy. PLoS Negl Trop Dis 2021; 15:e0009189. [PMID: 33730095 PMCID: PMC7968639 DOI: 10.1371/journal.pntd.0009189] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 02/01/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The antihelminthic drug praziquantel has been used as the drug of choice for treating schistosome infection for more than 40 years. Although some epidemiological studies have reported low praziquantel efficacy in cure rate (CR) and/or egg reduction rate (ERR), there is no consistent robust evidence of the development of schistosome resistance to praziquantel (PZQ). There is need to determine factors that lead to variable treatment CR and/or ERR. Therefore, we conducted a systematic review and meta-analysis to review CR and ERR as well as identify their predictors. METHODOLOGY/PRINCIPAL FINDINGS In this systematic review and meta-analysis, a literature review was conducted using Biosis Citation Index, Data Citation Index, MEDLINE, and Web of Science Core Collection all of which were provided through Web of Science. Alongside these, EMBASE, and CAB abstracts were searched to identify relevant articles. Random effect meta-regression models were used to identify the factors that influence CR and/or ERR by considering differences in host characteristics and drug dose. In total, 12,127 potential articles were screened and 146 eligible articles (published from 1979 to 2020) were identified and included for the meta-analysis. We found that there has been no significant reduction in CR or ERR over the study period. The results showed more variability in CR, compared with ERR which was more consistent and remained high. The results showed a positive effect of "PZQ treatment dose" with the current recommended dose of 40 mg/kg body weight achieving 57% to 88% CR depending on schistosome species, age of participants, and number of parasitological samples used for diagnosis, and ERR of 95%. CONCLUSIONS/SIGNIFICANCE Based on a review of over 40 years of research there is no evidence to support concerns about schistosomes developing resistance to PZQ. These results indicate that PZQ remains effective in treating schistosomiasis.
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Affiliation(s)
- Mizuho Fukushige
- Institute of Immunology and Infection Research, Centre for Immunity, Infection & Evolution, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Margo Chase-Topping
- Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Francisca Mutapi
- Institute of Immunology and Infection Research, Centre for Immunity, Infection & Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- NIHR Global Health Research Unit Tackling Infections to Benefit Africa (TIBA), University of Edinburgh, Edinburgh, United Kingdom
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20
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Horikoshi Y, Ibrahim UM, Morris SK. School-based approach for parasitic disease control in Japan and Africa. Pediatr Int 2021; 63:264-269. [PMID: 33174267 DOI: 10.1111/ped.14535] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/13/2020] [Accepted: 11/06/2020] [Indexed: 12/17/2022]
Abstract
Japan has achieved significant improvements in the control and prevention of parasitic infections through a school-based approach since the 1930s. The use of chemical fertilizers in agriculture, safe water and food, and improved sanitation and hygiene also contributed to the near eradication of endemic parasites. However, parasite infections continued to affect children mostly in resource-limited countries. The African continent has one of the highest burdens of such infections. The application of school-based approaches has several advantages where the structure of health-care systems is not optimal. In Africa, soil-transmitted helminths and schistosomiasis are frequently targets for school-based public health intervention. Mass drug administration by teachers at school can reach targeted children effectively and safely. The limitations of this approach include missing unattended children and absentee of teachers. Initially, mass drug administration at school for parasitic infections was thought to improve health and even socioeconomic status of children in the community. However, more recently the socioeconomic impact has been questioned although the reduction of parasitic diseases is still apparent. Moreover, other basic public health measurements such as increased toilet use, assuring safe water access and avoiding the use of human excrement as an agricultural fertilizer, are equally important for control and prevention of parasitic diseases. Further global efforts should be continued to achieve equal health for every child in a sustainable way.
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Affiliation(s)
- Yuho Horikoshi
- Bauchi branch, Nigeria country office, World Health Organization, Bauchi city, Nigeria.,Division of Infectious Diseases, Department of Pediatrics, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | | | - Shaun K Morris
- Division of Infectious Diseases and the Centre for Global Child Health, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Pediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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21
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Zacharia A, Mushi V, Makene T. A systematic review and meta-analysis on the rate of human schistosomiasis reinfection. PLoS One 2020; 15:e0243224. [PMID: 33270752 PMCID: PMC7714137 DOI: 10.1371/journal.pone.0243224] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/17/2020] [Indexed: 11/19/2022] Open
Abstract
While praziquantel mass drug administration is currently the most widely used method in the control of human schistosomiasis, it does not prevent subsequent reinfection hence persistent transmission. Towards schistosomiasis elimination, understanding the reinfection rate is crucial in planning for the future interventions. However, there is scarcity of information on the global reinfection rate of schistosomiasis. This systematic review and meta-analysis aimed at summarizing studies that estimated the reinfection rate of human schistosomiasis. Three data bases (PubMed, Hinari and Google Scholar) were thoroughly searched to retrieve original research articles presenting data on reinfection rate of human schistosomiasis. Study quality and risk of bias was assessed based on Joanna Briggs Institute critical appraisal checklist. Meta-analysis was conducted using statistical R version 3.6.2 and R Studio using "meta" and "metafor" packages. Random effect model was employed to estimate pooled reinfection rates. Heterogeneity was determined using Cochran's Q (chi-square)-test and Higgins I2 statistics. A total of 29 studies met inclusion criteria to be included in this review. All studies had at least satisfactory (5-9 scores) quality. The overal mean and pooled reinfection rates of schistosomiasis were 36.1% (±23.3%) and 33.2% (95% CI, 26.5-40.5%) respectively. For intestinal schistosomiasis, the mean and pooled reinfection rates were 43.9% (±20.6%) and 43.4% (95% CI, 35.8-51.4%), and that for urogenital schistosomiasis were 17.6% (±10.8%) and 19.4% (95% CI, 12.3%- 29.2%) respectively. Cochran's Q (chi-square)-test and Higgins I2 statistic indicated significant heterogeneity across studies (p-values < 0.001, I2 values > 95%). Results of subgroup analysis showed that, the type of Schistosoma species, participants' age group, sample size and geographical area had influence on disparity variation in reinfection rate of schistosomiasis (p < 0.1). Despite the control measures in place, the re-infection rate is still high, specifically on intestinal schistosomiasis as compared to urogenital schistosomiasis. Achieving 2030 sustainable development goal 3 on good health and wellbeing intensive programmatic strategies for schistosomiasis elimination should be implemented. Among such strategies to be used at national level are repeated mass drug administration at least every six months, intensive snails control and health education.
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Affiliation(s)
- Abdallah Zacharia
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Vivian Mushi
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Twilumba Makene
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
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22
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Ephraim RKD, Brenyah RC, Adoba P, Agbodjakey H, Allotey LE, Korang P, Duah E, Bogoch I, Abaka-Yawson A, Hotorvi C, Kwadzokpui PK. Renal function in children infected with Schistosoma haematobium: a case-control study of an endemic Ghanaian community. J Parasit Dis 2020; 45:406-411. [PMID: 34295040 DOI: 10.1007/s12639-020-01313-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/03/2020] [Indexed: 11/29/2022] Open
Abstract
Schistosomiasis has been associated with kidney diseases leading to serious health problems especially in advanced cases. Most studies have used renal biopsy, and ultrasonography in the diagnosis of renal damage among urogenital schistosomiasis affected individuals. This study assessed serum urea, creatinine, and eGFR as biochemical markers of renal abnormalities in children with urogenital schistosomiasis (Schistosoma haematobium) at a resource limited setting in Sorodofo-Abaasa in the Central Region of Ghana. A case-control study was conducted among 116 basic school children aged 9 to 17 years from January 2015 to May 2015 at Sorodofo-Abaasa in the Abura Asebu Kwamankese District of the Central Region of Ghana. A pre-tested questionnaire was used to obtain information on age, sex, guardian's occupation, water contact activities, history of gross haematuria and history of medication. Participants weight and height were measured using a bathroom scale (Zhongshan Camry Electronic Co. Ltd, Guangdong-China) and a wall-mounted ruler to the nearest 0.1 kg and 0.1 cm respectively. Approximately 4 ml of venous blood sample was collected from the median cubital vein of the study participants and used for the estimation of serum urea and creatinine levels. eGFR (mL/min/1.73 m2) was calculated using the Schwartz equation. The average ages of the cases and the controls recruited in this study were 12.7 ± 1.0 and 12. ± 2.6 years respectively. The median (minimum-maximum) did not differ between cases and controls with regards to eGFR [115.92(62.40-164.98) vs 112.50(51.82-170.36; p = 0.806], serum creatinine [57.20(28.91-84.67) vs 58.19(25.17-90.21); p = 0.876], and urea [9.82(5.80-13.74) vs 10.21(7.29-13.03); p = 0.586]. Hyperfiltration though statistically similar (p = 0.787), was observed among a higher proportion of the controls (20.5%) than observed among the cases (18.4%). This study documented no significant differences between children with light (less than 50 ova per 10 ml urine) and heavy (more than 50 ova per 10 ml urine) infection. This study documented no significant variation in the biochemical markers of renal function between the cases and controls. S. haematobium Infection intensity did not significantly alter the renal physiology of the school children studied.
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Affiliation(s)
- Richard K D Ephraim
- Department of Medical Laboratory Technology, University of Cape Coast, Cape Coast, Ghana
| | - Ruth C Brenyah
- Department of Clinical Microbiology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Prince Adoba
- Department of Medical Laboratory Technology, University of Cape Coast, Cape Coast, Ghana
| | - Hope Agbodjakey
- Department of Medical Laboratory Technology, University of Cape Coast, Cape Coast, Ghana
| | - Larissa E Allotey
- Department of Medical Laboratory Technology, University of Cape Coast, Cape Coast, Ghana
| | - Patrick Korang
- Department of Medical Laboratory Technology, University of Cape Coast, Cape Coast, Ghana
| | - Evans Duah
- Department of Medical Laboratory Technology, University of Cape Coast, Cape Coast, Ghana
| | - Isaac Bogoch
- University Health Network, University of Ontario, Oshawa, Canada
| | - Albert Abaka-Yawson
- Department of Medical Laboratory Technology, University of Health and Allied Sciences, Ho, Ghana
| | - Christian Hotorvi
- Department of Medical Laboratory Technology, University of Cape Coast, Cape Coast, Ghana
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Léger E, Borlase A, Fall CB, Diouf ND, Diop SD, Yasenev L, Catalano S, Thiam CT, Ndiaye A, Emery A, Morrell A, Rabone M, Ndao M, Faye B, Rollinson D, Rudge JW, Sène M, Webster JP. Prevalence and distribution of schistosomiasis in human, livestock, and snail populations in northern Senegal: a One Health epidemiological study of a multi-host system. Lancet Planet Health 2020; 4:e330-e342. [PMID: 32800151 PMCID: PMC7443702 DOI: 10.1016/s2542-5196(20)30129-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 05/30/2023]
Abstract
BACKGROUND Schistosomiasis is a neglected tropical disease of global medical and veterinary importance. As efforts to eliminate schistosomiasis as a public health problem and interrupt transmission gather momentum, the potential zoonotic risk posed by livestock Schistosoma species via viable hybridisation in sub-Saharan Africa have been largely overlooked. We aimed to investigate the prevalence, distribution, and multi-host, multiparasite transmission cycle of Haematobium group schistosomiasis in Senegal, West Africa. METHODS In this epidemiological study, we carried out systematic surveys in definitive hosts (humans, cattle, sheep, and goats) and snail intermediate hosts, in 2016-18, in two areas of Northern Senegal: Richard Toll and Lac de Guiers, where transmission is perennial; and Barkedji and Linguère, where transmission is seasonal. The occurrence and distribution of Schistosoma species and hybrids were assessed by molecular analyses of parasitological specimens obtained from the different hosts. Children in the study villages aged 5-17 years and enrolled in school were selected from school registers. Adults (aged 18-78 years) were self-selecting volunteers. Livestock from the study villages in both areas were also randomly sampled, as were post-mortem samples from local abattoirs. Additionally, five malacological surveys of snail intermediate hosts were carried out at each site in open water sources used by the communities and their animals. FINDINGS In May to August, 2016, we surveyed 375 children and 20 adults from Richard Toll and Lac de Guiers, and 201 children and 107 adults from Barkedji and Linguère; in October, 2017, to January, 2018, we surveyed 386 children and 88 adults from Richard Toll and Lac de Guiers, and 323 children and 85 adults from Barkedji and Linguère. In Richard Toll and Lac de Guiers the prevalence of urogenital schistosomiasis in children was estimated to be 87% (95% CI 80-95) in 2016 and 88% (82-95) in 2017-18. An estimated 63% (in 2016) and 72% (in 2017-18) of infected children were shedding Schistosoma haematobium-Schistosoma bovis hybrids. In adults in Richard Toll and Lac de Guiers, the prevalence of urogenital schistosomiasis was estimated to be 79% (52-97) in 2016 and 41% (30-54) in 2017-18, with 88% of infected samples containing S haematobium-S bovis hybrids. In Barkedji and Linguère the prevalence of urogenital schistosomiasis in children was estimated to be 30% (23-38) in 2016 and 42% (35-49) in 2017-18, with the proportion of infected children found to be shedding S haematobium-S bovis hybrid miracidia much lower than in Richard Toll and Lac de Guiers (11% in 2016 and 9% in 2017-18). In adults in Barkedji and Linguère, the prevalence of urogenital schistosomiasis was estimated to be 26% (17-36) in 2016 and 47% (34-60) in 2017-18, with 10% of infected samples containing S haematobium-S bovis hybrids. The prevalence of S bovis in the sympatric cattle population of Richard Toll and the Lac de Guiers was 92% (80-99), with S bovis also found in sheep (estimated prevalence 14% [5-31]) and goats (15% [5-33]). In Barkedji and Linguère the main schistosome species in livestock was Schistosoma curassoni, with an estimated prevalence of 73% (48-93) in sheep, 84% (61-98) in goats and 8% (2-24) in cattle. S haematobium-S bovis hybrids were not found in livestock. In Richard Toll and Lac de Guiers 35% of infected Bulinus spp snail intermediate hosts were found to be shedding S haematobium-S bovis hybrids (68% shedding S haematobium; 17% shedding S bovis); however, no snails were found to be shedding S haematobium hybrids in Barkedji and Linguère (29% shedding S haematobium; 71% shedding S curassoni). INTERPRETATION Our findings suggest that hybrids originate in humans via zoonotic spillover from livestock populations, where schistosomiasis is co-endemic. Introgressive hybridisation, evolving host ranges, and wider ecosystem contexts could affect the transmission dynamics of schistosomiasis and other pathogens, demonstrating the need to consider control measures within a One Health framework. FUNDING Zoonoses and Emerging Livestock Systems programme (UK Biotechnology and Biological Sciences Research Council, UK Department for International Development, UK Economic and Social Research Council, UK Medical Research Council, UK Natural Environment Research Council, and UK Defence Science and Technology Laboratory).
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Affiliation(s)
- Elsa Léger
- Centre for Emerging, Endemic and Exotic Diseases, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hertfordshire, UK; London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London, London, UK.
| | - Anna Borlase
- Centre for Emerging, Endemic and Exotic Diseases, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hertfordshire, UK; London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London, London, UK; NTD Modelling Consortium, Big Data Institute, University of Oxford, Oxford, UK
| | - Cheikh B Fall
- Faculté de Médecine, Pharmacie et Odontologie, Université Cheikh Anta Diop, Dakar, Senegal
| | - Nicolas D Diouf
- Institut Supérieur de Formation Agricole et Rurale, Université de Thiès, Bambey, Senegal; Unité de Formation et de Recherche des Sciences Agronomiques, d'Aquaculture et de Technologies Alimentaires, Université Gaston Berger, Saint-Louis, Senegal
| | - Samba D Diop
- Institut Supérieur de Formation Agricole et Rurale, Université de Thiès, Bambey, Senegal
| | - Lucy Yasenev
- Centre for Emerging, Endemic and Exotic Diseases, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hertfordshire, UK
| | - Stefano Catalano
- Centre for Emerging, Endemic and Exotic Diseases, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hertfordshire, UK; London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London, London, UK
| | - Cheikh T Thiam
- Unité de Formation et de Recherche des Sciences Agronomiques, d'Aquaculture et de Technologies Alimentaires, Université Gaston Berger, Saint-Louis, Senegal
| | - Alassane Ndiaye
- Unité de Formation et de Recherche des Sciences Agronomiques, d'Aquaculture et de Technologies Alimentaires, Université Gaston Berger, Saint-Louis, Senegal
| | - Aidan Emery
- London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London, London, UK; Parasites and Vectors Division, Life Sciences Department, Natural History Museum, London, UK
| | - Alice Morrell
- Centre for Emerging, Endemic and Exotic Diseases, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hertfordshire, UK
| | - Muriel Rabone
- London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London, London, UK; Parasites and Vectors Division, Life Sciences Department, Natural History Museum, London, UK
| | - Momar Ndao
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Babacar Faye
- Faculté de Médecine, Pharmacie et Odontologie, Université Cheikh Anta Diop, Dakar, Senegal
| | - David Rollinson
- London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London, London, UK; Parasites and Vectors Division, Life Sciences Department, Natural History Museum, London, UK
| | - James W Rudge
- London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London, London, UK; Communicable Diseases Policy Research Group, London School of Hygiene & Tropical Medicine, London, UK; Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Mariama Sène
- Unité de Formation et de Recherche des Sciences Agronomiques, d'Aquaculture et de Technologies Alimentaires, Université Gaston Berger, Saint-Louis, Senegal
| | - Joanne P Webster
- Centre for Emerging, Endemic and Exotic Diseases, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hertfordshire, UK; London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London, London, UK
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Buck JC, De Leo GA, Sokolow SH. Concomitant Immunity and Worm Senescence May Drive Schistosomiasis Epidemiological Patterns: An Eco-Evolutionary Perspective. Front Immunol 2020; 11:160. [PMID: 32161583 PMCID: PMC7053360 DOI: 10.3389/fimmu.2020.00160] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 01/21/2020] [Indexed: 11/13/2022] Open
Abstract
In areas where human schistosomiasis is endemic, infection prevalence and egg output are known to rise rapidly through childhood, reach a peak at 8-15 years of age, and decline thereafter. A similar peak ("overshoot") followed by return to equilibrium infection levels sometimes occurs a year or less after mass drug administration. These patterns are usually assumed to be due to acquired immunity, which is induced by exposure, directed by the host's immune system, and develops slowly over the lifetime of the host. Other explanations that have been advanced previously include differential exposure of hosts, differential mortality of hosts, and progressive pathology. Here we review these explanations and offer a novel (but not mutually exclusive) explanation, namely that adult worms protect the host against larval stages for their own benefit ("concomitant immunity") and that worm fecundity declines with worm age ("reproductive senescence"). This explanation approaches schistosomiasis from an eco-evolutionary perspective, as concomitant immunity maximizes the fitness of adult worms by reducing intraspecific competition within the host. If correct, our hypothesis could have profound implications for treatment and control of human schistosomiasis. Specifically, if immunity is worm-directed, then treatment of long-standing infections comprised of old senescent worms could enable infection with new, highly fecund worms. Furthermore, our hypothesis suggests revisiting research on therapeutics that mimic the concomitant immunity-modulating activity of adult worms, while minimizing pathological consequences of their eggs. We emphasize the value of an eco-evolutionary perspective on host-parasite interactions.
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Affiliation(s)
- Julia C. Buck
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Giulio A. De Leo
- Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States
- Woods Institute for the Environment, Stanford University, Stanford, CA, United States
| | - Susanne H. Sokolow
- Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States
- Woods Institute for the Environment, Stanford University, Stanford, CA, United States
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Tetteh-Quarcoo PB, Forson PO, Amponsah SK, Ahenkorah J, Opintan JA, Ocloo JEY, Okine EN, Aryee R, Afutu E, Anang AK, Ayeh-Kumi PF. Persistent Urogenital Schistosomiasis and Its Associated Morbidity in Endemic Communities within Southern Ghana: Suspected Praziquantel Resistance or Reinfection? Med Sci (Basel) 2020; 8:E10. [PMID: 32050572 PMCID: PMC7151560 DOI: 10.3390/medsci8010010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/31/2020] [Accepted: 02/06/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND schistosomiasis is a neglected tropical disease caused by helminths of the genus Schistosoma. The disease has a worldwide distribution, with more cases occurring in Africa. Urogenital schistosomiasis caused by S. haematobium with its associated morbidity is prevalent in many areas of Ghana. Praziquantel is still the recommended drug of choice for schistosomiasis treatment, although a number of studies have reported sub-therapeutic effects and associated treatment failure. The current study, therefore, assessed whether persistent schistosomiasis, with its associated morbidity among children living in endemic areas within the Greater Accra Region of Ghana, is as a result of reinfection or suspected praziquantel resistance. METHODOLOGY this was a longitudinal study involving a baseline and follow-up sampling after praziquantel treatment. Urine samples were collected from school children (whose parents had also consented) for the detection of S. haematobium ova using a sedimentation technique. The morbidity parameters were examined with urine chemistry strips, as well as microscopy. Viability was assessed using a modified hatchability technique, vital staining (0.4% trypan blue and 1% neutral red) and fluorescent (Hoechst 33258) microscopy. Infected individuals were treated with a single dose of praziquantel (40mg/kg). Resampling to determine reinfection was done sixth months post-treatment, after evidence of total egg clearance. For possible resistance assessment, egg counts and viability testing were conducted on the positive samples at the baseline, as well as weekly post-treatment follow-ups for 12 weeks. RESULTS out of the 420 school children sampled, 77 were initially positive but, after the sixth month sampling for reinfection assessment, eight out of the initial positives were infected again, giving a reinfection percentage of 10.4%. No suspected praziquantel resistance was recorded in the 21 positives detected out of the 360 sampled for suspected resistance assessment. The egg reduction rate increased weekly in the follow-up samples with a gradual reduction in the egg count. The study also recorded a gradual decrease in the percentage of live eggs after the first week; with all viability testing methods used complimenting each other. The morbidity parameters (proteinuria, haematuria and pyuria) changed between the baseline and post-treatment samples, eventually reducing to zero. CONCLUSIONS the outcome of this study suggests that the persistent schistosomiasis, with its associated morbidity observed in these endemic communities, is not likely to be as a result of praziquantel resistance, but reinfection. Even though there was no suspected resistance observed in the study, there remains the need to continuously intensify the monitoring of praziquantel in other endemic communities.
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Affiliation(s)
- Patience B. Tetteh-Quarcoo
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra 233, Ghana; (P.O.F.); (J.A.O.); (R.A.); (E.A.); (P.F.A.-K.)
| | - Peter O. Forson
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra 233, Ghana; (P.O.F.); (J.A.O.); (R.A.); (E.A.); (P.F.A.-K.)
| | - Seth K. Amponsah
- Department of Pharmacology and Toxicology, School of Pharmacy, College of Health Sciences, University of Ghana, Accra 233, Ghana;
| | - John Ahenkorah
- Department of Anatomy, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra 233, Ghana;
| | - Japheth A. Opintan
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra 233, Ghana; (P.O.F.); (J.A.O.); (R.A.); (E.A.); (P.F.A.-K.)
| | - Janet E. Y. Ocloo
- Department of Pathology, Korle-Bu Teaching Hospital, Korle-Bu, Accra 233, Ghana;
| | - Esther N. Okine
- Central Laboratory Services, Korle-Bu Teaching Hospital, Korle-Bu, Accra 233, Ghana;
| | - Robert Aryee
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra 233, Ghana; (P.O.F.); (J.A.O.); (R.A.); (E.A.); (P.F.A.-K.)
- Department of Physiology, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra 233, Ghana
| | - Emmanuel Afutu
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra 233, Ghana; (P.O.F.); (J.A.O.); (R.A.); (E.A.); (P.F.A.-K.)
| | - Abraham K. Anang
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra 233, Ghana;
| | - Patrick F. Ayeh-Kumi
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra 233, Ghana; (P.O.F.); (J.A.O.); (R.A.); (E.A.); (P.F.A.-K.)
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Gunda DW, Kilonzo SB, Manyiri PM, Peck RN, Mazigo HD. Morbidity and Mortality Due to Schistosoma mansoni Related Periportal Fibrosis: Could Early Diagnosis of Varices Improve the Outcome Following Available Treatment Modalities in Sub Saharan Africa? A Scoping Review. Trop Med Infect Dis 2020; 5:tropicalmed5010020. [PMID: 32028581 PMCID: PMC7157192 DOI: 10.3390/tropicalmed5010020] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/19/2019] [Accepted: 01/09/2020] [Indexed: 12/11/2022] Open
Abstract
Schistosomiasis affects about 240 million people worldwide and Schistosoma mansoni alone affects over 54 million people leaving 400 million at-risk especially in Sub Saharan Africa (SSA). About 20 million people are currently suffering from complications of chronic S. mansoni infection and up to 42% of those infected have been found with periportal fibrosis (PPF). About 0.2 million deaths are attributed to chronic S. mansoni every year, which is mainly due to varices. Death occurs in up to 29% of those who present late with bleeding varices even with the best available in-hospital care. The diagnosis of varices before incident bleeding could potentially improve the outcome of this subgroup of patients is SSA. However, there is no prior review which has ever evaluated this issue detailing the magnitude and outcome of varices following available treatment modalities among patients with Schistosoma PPF in SSA. This review summarizes the available literature on this matter and exposes potential practical gaps that could be bridged to maximize the long-term outcome of patients with S. mansoni related PPF in SSA. A total of 22 studies were included in this review. The average prevalence of varices was 82.1% (SD: 29.6; range: 11.1%–100%) among patients with PPF. Late diagnosis of varices was frequent with average bleeding and mortality of 71.2% (SD: 36.5; range: 4.3%–100.0%) and 13.6% (SD: 9.9; range: 3.5%–29%), respectively. Predictors were reported in seven (31.8%) studies including platelet count to splenic diameter ratio (PSDR) for prediction large varices in one study. Active S. mansoni infection was very prevalent, (mean: 69.9%; SD: 24.4; range: 29.2–100.0%). Praziquantel could reverse PPF and use of non-selective B-blockers reduced both rebleeding and mortality. Use of sclerotherapy for secondary prevention of variceal bleeding was associated with high rebleeding and mortality rates. Conclusions: This review shows that varices due to schistosomal PPF are a big problem in SSA. However, patients are often diagnosed late with fatal bleeding varices. No study had reported a clinical tool that could be useful in early diagnosis of patients with varices and no study reported on primary and effective secondary prevention of bleeding and its outcome. Regular screening for S. mansoni and the provision of Praziquantel (PZQ) is suggested in this review. More studies are required to bridge these practical gaps in Sub Saharan Africa.
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Affiliation(s)
- Daniel W. Gunda
- Department of Medicine, Catholic University of Health and Allied Sciences, Mwanza 1464, Tanzania
- Correspondence: (D.W.G.); (H.D.M.)
| | - Semvua B. Kilonzo
- Department of Medicine, Catholic University of Health and Allied Sciences, Mwanza 1464, Tanzania
| | - Paulina M. Manyiri
- Department of Medicine, Catholic University of Health and Allied Sciences, Mwanza 1464, Tanzania
| | - Robert N. Peck
- Department of Medicine, Catholic University of Health and Allied Sciences, Mwanza 1464, Tanzania
| | - Humphrey D. Mazigo
- Department of Parasitology, Catholic University of Health and Allied Sciences, Mwanza 1464, Tanzania
- Correspondence: (D.W.G.); (H.D.M.)
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In vitro activity of usnic acid potassium salt against different developmental stages of Schistosoma mansoni: An ultrastructural study. Acta Trop 2020; 201:105159. [PMID: 31491401 DOI: 10.1016/j.actatropica.2019.105159] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/08/2019] [Accepted: 09/02/2019] [Indexed: 12/18/2022]
Abstract
Currently, the control of schistosomiasis is based on a single drug, praziquantel, which is effective against all species of Schistosoma but only in the adult stage, presenting a schistosomicidal deficit at the other developmental stages of the parasites. Recently our research group has demonstrated that the potassium salt of usnic acid (PS-UA) presented schistosomicidal property against couples of adult worms of S. mansoni. Thus, the present study seeks to report for the first time the in vitro activity of PS-UA against different developmental stages of S. mansoni (schistosomules and young worms). As schistosomicide parameters, we evaluated motility, mortality, cell viability of the worms and tegument changes by scanning electron microscopy (SEM). After 3 h exposure, PS-UA was lethal to schistosomules at concentrations of 100 and 50 μM, whereas for concentrations 25 and 12.5 μM, 38 and 18% of mortality and 62 and 24% changes in motility, respectively, were reached. Yet for schistosomules, concentration of 25 μM caused 90 and 100% of death after 6 and 12 h, respectively. In the concentration of 12.5 μM at intervals of 12 and 24 h mortality was 68 and 100%, respectively. For young worms, after 3 h of exposure at concentrations of 200 and 100 μM caused 57 and 27% mortality, respectively. After 12 and 24 h, these concentrations caused mortality of 90 and 100% and 47 and 60% respectively. After 24 h, concentrations of 50 and 25 μM caused 80 and 30% change in motility, respectively. However, at the 12.5 μM concentration no change was observed. In addition, PS-UA reduced the cellular viability of young worms by 50.98% and 85.87% at concentrations of 100 and 200 μM, respectively. In both stages of worms and at different exposure intervals, PS-UA caused alterations such as: dorsoventral contraction, peeling, swelling, blisters, erosion, exposure of subtegumental tissue and disintegration of tegument. According to the results, changes in motility and mortality caused by PS-UA against schistosomules and young worms were concentration and time-dependents, also PS-UA even at low concentration, was able to cause profound ultrastructural changes in the integument of the worms. PS-UA is a promising candidate as prophylactic agent in the control of schistosomiasis mansoni.
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Bogoch II, Utzinger J, Lo NC, Andrews JR. Antibacterial mass drug administration for child mortality reduction: Opportunities, concerns, and possible next steps. PLoS Negl Trop Dis 2019; 13:e0007315. [PMID: 31120903 PMCID: PMC6532835 DOI: 10.1371/journal.pntd.0007315] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- Isaac I. Bogoch
- Divisions of General Internal Medicine and Infectious Diseases, Toronto General Hospital, University Health Network, Toronto, Canada
- Department of Medicine, University of Toronto, Toronto, Canada
- * E-mail:
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Nathan C. Lo
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Division of Epidemiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Jason R. Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, United States of America
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Usnic acid potassium salt from Cladonia substellata (Lichen): Synthesis, cytotoxicity and in vitro anthelmintic activity and ultrastructural analysis against adult worms of Schistosoma mansoni. Acta Trop 2019; 192:1-10. [PMID: 30571934 DOI: 10.1016/j.actatropica.2018.12.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 12/13/2018] [Accepted: 12/15/2018] [Indexed: 01/25/2023]
Abstract
We report for the first time the in vitro effect of Potassium Salt, derived from Usnic Acid (PS-UA), isolated from the lichen Cladonia substellata Vanio, on couples of Schistosoma mansoni. As schistosomicide parameters, we evaluated mortality, motility, cell viability of the worms and tegument changes by scanning electron microscopy (SEM). Exposure to a concentration of 100 μM caused 75% mortality after 3 h. After 6 h, changes in motility in concentrations of 50 and 25 μM are evidenced. After 12 h and 24h, the concentrations of 50 and 100 μM caused 6.25% and 87.5% and 50% and 100% mortality, respectively. PS-UA reduced the cell viability of the worms by 27.36% and 52.82% at concentrations 50 and 100 μM, respectively. Through SEM we observed progressive dose-and time-dependent, alterations such as swelling, blisters, dorsoventral contraction, erosion until disintegration of the tubercles in the tegument of male and female. PS-UA did not alter the viability of human peripheral blood mononuclear cells and showed high selectivity indices (IC50 > 200 μM). Our results indicate that PS-UA represents a possible candidate for a new anthelmintic drug in the control of schistosomiasis.
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Chisango TJ, Ndlovu B, Vengesai A, Nhidza AF, Sibanda EP, Zhou D, Mutapi F, Mduluza T. Benefits of annual chemotherapeutic control of schistosomiasis on the development of protective immunity. BMC Infect Dis 2019; 19:219. [PMID: 30832614 PMCID: PMC6398226 DOI: 10.1186/s12879-019-3811-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 02/13/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schistosomiasis is a devastating parasitic disease. The mainstay of schistosomiasis control is by praziquantel treatment. The study aimed to determine benefits of annual chemotherapy of schistosomiasis on development of protective immunity in school children in a selected endemic rural area in Zimbabwe. METHODS Urine specimens from 212 school children (7-13 years) were collected and examined to determine prevalence, intensity and reinfection of S.haematobium at baseline, 6 weeks and 2 years following annual rounds of praziquantel treatment. Blood samples from the participants were assayed for total and S. haematobium (Sh13)-specific antibodies before and 2 years after annual rounds of treatment. RESULTS Annual treatment reduced the prevalence of S. haematobium infection (p < 0.05) from 23.1% at baseline to 0.47% after 2 years. Overall cure rate was 97.8%. Intensity of infection declined (p < 0.05) from 15.9 eggs/10 ml urine at baseline to 2 eggs/10 ml urine. After two years, overall rate of reinfection was 0.96%. At baseline, total IgG4 was higher in S. haematobium-infected children (p = 0.042) ,while all other immunoglobulins were within normal ranges. There was an increase in total IgG2 (p = 0.044) levels and a decrease in total IgG4 (p = 0.031) levels 2 years post-treatment; and no significant changes in other total immunoglobulins. Schistosoma-infected children at baseline showed an increase in anti-Sh13 IgG1 (p = 0.005) and a decrease in Sh13 IgG4 levels (p = 0.012) following treatment. CONCLUSION Annual praziquantel treatment delivered to school children over 2 years significantly reduce prevalence, intensity of infection and reinfection of S. haematobium infection. Treatment was also observed to cause a reduction in schistosome-specific blocking IgG4 and an increase in Schistosoma-specific protecting IgG1.
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Affiliation(s)
- Tawanda J Chisango
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Bongiwe Ndlovu
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Arthur Vengesai
- Biochemistry Department, University of Zimbabwe, 630 Churchill Ave, Mount Pleasant, Harare, Zimbabwe
| | - Agness Farai Nhidza
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Edson P Sibanda
- Scientific and Industrial Research and Development Centre, 1574 Alpes Road, Box, Harare, 6640, Zimbabwe
| | - Danai Zhou
- Medical Laboratory Sciences, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe
| | - Francisca Mutapi
- Institute of Immunology & Infection Research, University of Edinburgh, Ashworth Laboratories, King's Buildings, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK
| | - Takafira Mduluza
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa. .,Biochemistry Department, University of Zimbabwe, 630 Churchill Ave, Mount Pleasant, Harare, Zimbabwe.
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Efficacy of Nutrition and WASH/Malaria Educational Community-Based Interventions in Reducing Anemia in Preschool Children from Bengo, Angola: Study Protocol of a Randomized Controlled Trial. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16030466. [PMID: 30764549 PMCID: PMC6388146 DOI: 10.3390/ijerph16030466] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/26/2019] [Accepted: 02/02/2019] [Indexed: 01/26/2023]
Abstract
Angola reports one of the highest infant mortality rates in the world, and anemia represents one of its important causes. Recent studies, in under-five children from the Bengo province of Angola, described high prevalence’s, suggesting malaria, undernutrition and urogenital schistosomiasis as important contributors for the occurrence and spatial variations of anemia. Educational community-based interventions, either in Nutrition and Water, Sanitation, Hygiene and Malaria are recommended to correct anemia. Herein, we designed a cluster-randomized controlled trial to study the efficacy of two educational-plus-therapeutic interventions in the reduction of anemia: one in nutrition and the other in WASH/Malaria. Socioeconomic, nutritional, anthropometric, parasitological and biochemical data will be collected from all willing-to-participate children, aging under four and resident in the Health Research Center of Angola study area. Considering the multifactorial causes of this condition, determining the efficacy of both interventions might help documenting weaknesses and opportunities for planning integrated strategies to reduce anemia.
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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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Kabuyaya M, Chimbari MJ, Mukaratirwa S. Efficacy of praziquantel treatment regimens in pre-school and school aged children infected with schistosomiasis in sub-Saharan Africa: a systematic review. Infect Dis Poverty 2018; 7:73. [PMID: 29986763 PMCID: PMC6036702 DOI: 10.1186/s40249-018-0448-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 06/06/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Schistosomiasis is a serious public health burden in sub-Saharan Africa. Praziquantel is the only drug recommended by the World Health Organization to treat both urogenital and intestinal schistosomiasis. The reliance on a single drug to treat a disease with such a huge burden has raised concerns of possible drug resistance mainly in endemic areas. This systematic review was conducted to identify gaps and recent progress on the efficacy of different regimens of praziquantel in treating schistosomiasis among children in sub-Saharan Africa where Schistosoma mansoni and S. haematobium are endemic. MAIN TEXT A literature search of peer-reviewed journals was done on Google Scholar, MEDLINE (under EBSCOhost) and PubMed databases using pre-defined search terms and Boolean operators. The search included studies published from 2008 to 2017 (August) with emphasis on the efficacy of praziquantel on S. haematobium and S. mansoni infections among preschool and school children. Nineteen publications satisfied the inclusion criteria for the review. The studies reviewed were from 10 sub-Saharan African countries and 7/19 of the studies (37%) were conducted in Uganda. Seven studies (37%) focused on Schistosoma mansoni, 6/19 (31.5%) on S. haematobium and another 6 on mixed infection. A single standard dose of 40 mg/kg body weight was the most used regimen (9) followed by the repeated single standard dose assessed for efficacy at 3-4 weeks post-treatment. CONCLUSIONS A repeated standard dose of 40 mg/kg achieved satisfactory efficacy compared to a single dose against both parasite species. However, findings on efficacy of repeated doses in co-infection of S. mansoni and S. haematobium were not conclusive. Praziquantel administrated at 60 mg/kg was slightly more efficacious than the 40 mg/kg standard dose. Minor and transitory side-effects were reported for both regimens. The review indicates that further investigations are necessary to conclusively determine efficacy of praziquantel on coinfection of S. haematobium and S. mansoni to formulate concrete guidelines on the use of repeated doses at 40 or 60 mg/kg for treating schistosomiasis. We recommend the use of the egg reduction rate (ERR) formula recommended by the WHO for assessing praziquantel efficacy in order for the results to be comparable for different regions.
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Affiliation(s)
- Muhubiri Kabuyaya
- Discipline of Public Health Medicine, Howard College, University of KwaZulu-Natal, P.O Box 4041, Durban, South Africa
| | - Moses John Chimbari
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Samson Mukaratirwa
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
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Wright JE, Werkman M, Dunn JC, Anderson RM. Current epidemiological evidence for predisposition to high or low intensity human helminth infection: a systematic review. Parasit Vectors 2018; 11:65. [PMID: 29382360 PMCID: PMC5791198 DOI: 10.1186/s13071-018-2656-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 01/17/2018] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The human helminth infections include ascariasis, trichuriasis, hookworm infections, schistosomiasis, lymphatic filariasis (LF) and onchocerciasis. It is estimated that almost 2 billion people worldwide are infected with helminths. Whilst the WHO treatment guidelines for helminth infections are mostly aimed at controlling morbidity, there has been a recent shift with some countries moving towards goals of disease elimination through mass drug administration, especially for LF and onchocerciasis. However, as prevalence is driven lower, treating entire populations may no longer be the most efficient or cost-effective strategy. Instead, it may be beneficial to identify individuals or demographic groups who are persistently infected, often termed as being "predisposed" to infection, and target treatment at them. METHODS The authors searched Embase, MEDLINE, Global Health, and Web of Science for all English language, human-based papers investigating predisposition to helminth infections published up to October 31st, 2017. The varying definitions used to describe predisposition, and the statistical tests used to determine its presence, are summarised. Evidence for predisposition is presented, stratified by helminth species, and risk factors for predisposition to infection are identified and discussed. RESULTS In total, 43 papers were identified, summarising results from 34 different studies in 23 countries. Consistent evidence of predisposition to infection with certain species of human helminth was identified. Children were regularly found to experience greater predisposition to Ascaris lumbricoides, Schistosoma mansoni and S. haematobium than adults. Females were found to be more predisposed to A. lumbricoides infection than were males. Household clustering of infection was identified for A. lumbricoides, T. trichiura and S. japonicum. Ascaris lumbricoides and T. trichiura also showed evidence of familial predisposition. Whilst strong evidence for predisposition to hookworm infection was identified, findings with regards to which groups were affected were considerably more varied than for other helminth species. CONCLUSION This review has found consistent evidence of predisposition to heavy (and light) infection for certain human helminth species. However, further research is needed to identify reasons for the reported differences between demographic groups. Molecular epidemiological methods associated with whole genome sequencing to determine 'who infects whom' may shed more light on the factors generating predisposition.
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Affiliation(s)
- James E. Wright
- 0000 0001 2113 8111grid.7445.2Department of Infectious Disease Epidemiology, Imperial College London, St. Mary’s Campus, London, W2 1PG UK
- 0000 0001 2113 8111grid.7445.2London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, St Mary’s Campus, London, W2 1PG UK
- 0000 0001 2172 097Xgrid.35937.3bThe DeWorm3 Project, The Natural History Museum of London, London, SW7 5BD UK
| | - Marleen Werkman
- 0000 0001 2113 8111grid.7445.2Department of Infectious Disease Epidemiology, Imperial College London, St. Mary’s Campus, London, W2 1PG UK
- 0000 0001 2113 8111grid.7445.2London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, St Mary’s Campus, London, W2 1PG UK
- 0000 0001 2172 097Xgrid.35937.3bThe DeWorm3 Project, The Natural History Museum of London, London, SW7 5BD UK
| | - Julia C. Dunn
- 0000 0001 2113 8111grid.7445.2Department of Infectious Disease Epidemiology, Imperial College London, St. Mary’s Campus, London, W2 1PG UK
- 0000 0001 2113 8111grid.7445.2London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, St Mary’s Campus, London, W2 1PG UK
| | - Roy M. Anderson
- 0000 0001 2113 8111grid.7445.2Department of Infectious Disease Epidemiology, Imperial College London, St. Mary’s Campus, London, W2 1PG UK
- 0000 0001 2113 8111grid.7445.2London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, St Mary’s Campus, London, W2 1PG UK
- 0000 0001 2172 097Xgrid.35937.3bThe DeWorm3 Project, The Natural History Museum of London, London, SW7 5BD UK
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Mass drug administration and the global control of schistosomiasis: successes, limitations and clinical outcomes. Curr Opin Infect Dis 2018; 29:595-608. [PMID: 27584590 DOI: 10.1097/qco.0000000000000312] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE OF REVIEW Preventive chemotherapy is advocated for the global control and elimination of schistosomiasis. Despite the well known short-term benefits of treating patients for schistosomiasis, the impact of mass drug administration (MDA) campaigns to control the disease in the long term remains unresolved. RECENT FINDINGS Many studies have advocated the success of MDA programs in order to attract donor funds for elimination efforts but such successes are often short-lived given the drug does not alter the life cycle of the organism or prevent reinfection. Within a matter of months to years after halting treatment, the prevalence, intensity of infection and morbidity of disease return to baseline levels. Other mitigating factors contribute to the failings of MDA campaigns namely: poverty, poor drug coverage, poor drug compliance, and, in the case of Asiatic schistosomiasis, zoonotic transmission. Genetic and innate and acquired immunologic mechanisms complicate the epidemiologic picture of schistosomiasis globally, and may contribute indirectly to MDA shortcomings. The possibility of drug resistance is an ever present concern because of the sole reliance on one drug, praziquantel. SUMMARY Preventive chemotherapy is advocated for the global control and elimination of schistosomiasis. The short-term benefits of MDA campaigns are well documented but the long-term benefits are questionable.
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Ebai CB, Kimbi HK, Sumbele IUN, Yunga JE, Lehman LG. Efficacy and safety of praziquantel against Schistosoma haematobium in the Ikata-Likoko area of southwest Cameroon. Trop Med Health 2017; 45:30. [PMID: 29270076 PMCID: PMC5733948 DOI: 10.1186/s41182-017-0071-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/03/2017] [Indexed: 01/15/2023] Open
Abstract
Background Schistosomiasis remains a parasitic infection of public health importance especially in Africa south of the Sahara including Cameroon. Chemotherapy using praziquantel has been the most effective and widespread control measure used. However, there are reports of reduced efficacy of the drug. The aim of this study was to assess the efficacy and safety of praziquantel against Schistosoma haematobium among infected individuals in the Ikata-Likoko area of southwest Cameroon. Following a baseline study, S. haematobium egg load was determined using the urine filtration technique and microscopy. Participants were treated with a unique dose of praziquantel of 40 mg/Kg body weight. A control test was carried out on the 42nd day post-treatment to determine the proportion of positive participants with viable eggs (cure rate) and the egg loads. The egg loads obtained during the control and at baseline were used to calculate the egg reduction rate (ERR) used as the main indicator of praziquantel efficacy according to the WHO, 2013 protocol. Results At baseline, the prevalence of S. haematobium was 34.3% (177/516). Out of these a total of 174 participants aged between 4 and 76 years were recruited into the study. A total of 130 participants came for follow up on day 42. Among them, 22.3% (29) were positive for eggs of S. haematobium but none of the eggs were viable giving a cure rate of 100%. The overall mean egg load per 10 mL (MEL/10 mL) of urine reduced from 31 (1–400) at baseline to 6.0 (1–35) on day 42. The overall ERR was reduced (80.3%). However, the efficacy was satisfactory (ERR ≥ 90%) in females, children ˂ 5 years, and some localities and for individuals with heavy infection intensity. Fifteen (8.6%) of the participants presented minor adverse events including abdominal disorders, headache and vomiting but did not last for more than 24 h. Conclusions Treatment with praziquantel was efficacious and safe showing reduction in prevalence as well as mean egg load in some individuals with few adverse events recorded. The distribution of praziquantel in the area should be extended to other age groups and not just school-age children. A study with multiple drug doses and longer period of evaluation could reveal more information on praziquantel efficacy in the area.
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Affiliation(s)
- Calvin Bisong Ebai
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, SWR Cameroon
| | - Helen Kuokuo Kimbi
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, SWR Cameroon.,Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Bamenda, P O Box 39, Bambili, NWR Cameroon
| | - Irene Ule Ngole Sumbele
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, SWR Cameroon
| | - Jude Ebah Yunga
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, P.O. Box 63, Buea, SWR Cameroon
| | - Leopold Gustave Lehman
- Department of Animal Biology, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon
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Siqueira LDP, Fontes DAF, Aguilera CSB, Timóteo TRR, Ângelos MA, Silva LCPBB, de Melo CG, Rolim LA, da Silva RMF, Neto PJR. Schistosomiasis: Drugs used and treatment strategies. Acta Trop 2017; 176:179-187. [PMID: 28803725 DOI: 10.1016/j.actatropica.2017.08.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/29/2017] [Accepted: 08/02/2017] [Indexed: 11/18/2022]
Abstract
Neglected tropical diseases (NTDs) affect millions of people in different geographic regions, especially the poorest and most vulnerable. Currently NTDs are prevalent in 149 countries, seventeen of these neglected tropical parasitic diseases are classified as endemic. One of the most important of these diseases is schistosomiasis, also known as bilharzia, a disease caused by the genus Schistosoma. It presents several species, such as Schistosoma haematobium, Schistosoma japonicum and Schistosoma mansoni, the latter being responsible for parasitosis in Brazil. Contamination occurs through exposure to contaminated water in the endemic region. This parasitosis is characterized by being initially asymptomatic, but it is able to evolve into more severe clinical forms, potentially causing death. Globally, more than 200 million people are infected with one of three Schistosome species, including an estimated 40 million women of reproductive age. In Brazil, about 12 million children require preventive chemotherapy with anthelmintic. However, according to the World Health Organization (WHO), only about 15% of the at-risk children receive regular treatment. The lack of investment by the pharmaceutical industry for the development and/or improvement of new pharmaceutical forms, mainly aimed at the pediatric public, is a great challenge. Currently, the main forms of treatment used for schistosomiasis are praziquantel (PZQ) and oxaminiquine (OXA). PZQ is the drug of choice because it presents as a high-spectrum anthelmintic, used in the treatment of all known species of schistosomiasis and some species of cestodes and trematodes. OXA, however, is not active against the three Schistosome species. This work presents a literature review regarding schistosomiasis. It addresses points such as available treatments, the role of the pharmaceutical industry against neglected diseases, and perspectives for treatment.
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Affiliation(s)
- Lidiany da Paixão Siqueira
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil
| | - Danilo Augusto Ferreira Fontes
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil
| | - Cindy Siqueira Britto Aguilera
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil
| | - Taysa Renata Ribeiro Timóteo
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil
| | - Matheus Alves Ângelos
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil
| | - Laysa Creusa Paes Barreto Barros Silva
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil
| | - Camila Gomes de Melo
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil
| | - Larissa Araújo Rolim
- Central de Análise de Fármacos, Medicamentos e Alimentos da Universidade Federal do Vale do São Francisco, Avenida José de Sá Maniçoba, CEP 56304-917, Petrolina, Pernambuco, Brazil
| | - Rosali Maria Ferreira da Silva
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil
| | - Pedro José Rolim Neto
- Laboratório de Tecnologia dos Medicamentos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, CEP 50740-521, Recife, Pernambuco, Brazil.
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Sundaraneedi MK, Tedla BA, Eichenberger RM, Becker L, Pickering D, Smout MJ, Rajan S, Wangchuk P, Keene FR, Loukas A, Collins JG, Pearson MS. Polypyridylruthenium(II) complexes exert anti-schistosome activity and inhibit parasite acetylcholinesterases. PLoS Negl Trop Dis 2017; 11:e0006134. [PMID: 29240773 PMCID: PMC5746282 DOI: 10.1371/journal.pntd.0006134] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/28/2017] [Accepted: 11/23/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Schistosomiasis affects over 200 million people and there are concerns whether the current chemotherapeutic control strategy (periodic mass drug administration with praziquantel (PZQ)-the only licenced anti-schistosome compound) is sustainable, necessitating the development of new drugs. METHODOLOGY/PRINCIPAL FINDINGS We investigated the anti-schistosome efficacy of polypyridylruthenium(II) complexes and showed they were active against all intra-mammalian stages of S. mansoni. Two compounds, Rubb12-tri and Rubb7-tnl, which were among the most potent in their ability to kill schistosomula and adult worms and inhibit egg hatching in vitro, were assessed for their efficacy in a mouse model of schistosomiasis using 5 consecutive daily i.v. doses of 2 mg/kg (Rubb12-tri) and 10 mg/kg (Rubb7-tnl). Mice treated with Rubb12-tri showed an average 42% reduction (P = 0.009), over two independent trials, in adult worm burden. Liver egg burdens were not significantly decreased in either drug-treated group but ova from both of these groups showed significant decreases in hatching ability (Rubb12-tri-68%, Rubb7-tnl-56%) and were significantly morphologically altered (Rubb12-tri-62% abnormal, Rubb7-tnl-35% abnormal). We hypothesize that the drugs exerted their activity, at least partially, through inhibition of both neuronal and tegumental acetylcholinesterases (AChEs), as worms treated in vitro showed significant decreases in activity of these enzymes. Further, treated parasites exhibited a significantly decreased ability to uptake glucose, significantly depleted glycogen stores and withered tubercules (a site of glycogen storage), implying drug-mediated interference in this nutrient acquisition pathway. CONCLUSIONS/SIGNIFICANCE Our data provide compelling evidence that ruthenium complexes are effective against all intra-mammalian stages of schistosomes, including schistosomula (refractory to PZQ) and eggs (agents of disease transmissibility). Further, the results of this study suggest that schistosome AChE is a target of ruthenium drugs, a finding that can inform modification of current compounds to identify analogues which are even more effective and selective against schistosomes.
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Affiliation(s)
- Madhu K. Sundaraneedi
- School of Physical, Environmental and Mathematical Sciences, UNSW Canberra, Canberra, Australian Capital Territory, Australia
| | - Bemnet A. Tedla
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Ramon M. Eichenberger
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Luke Becker
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Darren Pickering
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Michael J. Smout
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Siji Rajan
- School of Physical, Environmental and Mathematical Sciences, UNSW Canberra, Canberra, Australian Capital Territory, Australia
| | - Phurpa Wangchuk
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - F. Richard Keene
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
- School of Physical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - J. Grant Collins
- School of Physical, Environmental and Mathematical Sciences, UNSW Canberra, Canberra, Australian Capital Territory, Australia
| | - Mark S. Pearson
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
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de Melo NB, dos Santos LFM, de Castro MS, Souza RLM, Marques MJ, Castro AP, de Castro AT, de Carli ML, Hanemann JAC, Silva MS, Moraes GDOI, Beijo LA, Brigagão MRPL, Sperandio FF. Photodynamic therapy for Schistosoma mansoni : Promising outcomes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 176:157-164. [DOI: 10.1016/j.jphotobiol.2017.09.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/08/2017] [Accepted: 09/18/2017] [Indexed: 11/26/2022]
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Munisi DZ, Buza J, Mpolya EA, Angelo T, Kinung'hi SM. The Efficacy of Single-Dose versus Double-Dose Praziquantel Treatments on Schistosoma mansoni Infections: Its Implication on Undernutrition and Anaemia among Primary Schoolchildren in Two On-Shore Communities, Northwestern Tanzania. BIOMED RESEARCH INTERNATIONAL 2017; 2017:7035025. [PMID: 29094048 PMCID: PMC5637830 DOI: 10.1155/2017/7035025] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/08/2017] [Accepted: 08/21/2017] [Indexed: 12/16/2022]
Abstract
Administering more than one treatment may increase Praziquantel cure and egg reduction rates, thereby hastening achievement of schistosomiasis transmission control. A total of 431 S. mansoni-infected schoolchildren were randomized to receive either a single or repeated 40 mg/kg Praziquantel dose. Heights, weights, and haemoglobin levels were determined using a stadiometer, weighing scale, and HemoCue, respectively. At 8 weeks, cure rate was higher on repeated dose (93.10%) compared to single dose (68.68%) (p < 0.001). The egg reduction rate was higher on repeated dose (97.54%) compared to single dose (87.27%) (p = 0.0062). Geometric mean egg intensity was lower among those on repeated dose (1.30 epg) compared to single dose (3.18 epg) (p = 0.036) but not at 5 (p > 0.05) and 8 (p > 0.05) months with no difference in reinfection rate. No difference in the prevalence of stunting was observed between the two treatment regimens (p > 0.05) at 8 months, but there was an increase in the prevalence of wasting among those on repeated dose (p < 0.001). There was an increase in the mean haemoglobin levels at 8 months with no difference between the two arms (p > 0.05). To achieve reduction of transmission intensity and disease control in highly endemic areas, repeated treatments alone may not be sufficient. This trial was registered with PACTR201601001416338.
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Affiliation(s)
- David Z. Munisi
- Department of Global Health and Bio-Medical Sciences, School of Life Sciences and Bio-Engineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box 447, Arusha, Tanzania
- Department of Bio-Medical Sciences, School of Medicine and Dentistry, College of Health Sciences, University of Dodoma, P.O. Box 259, Dodoma, Tanzania
| | - Joram Buza
- Department of Global Health and Bio-Medical Sciences, School of Life Sciences and Bio-Engineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box 447, Arusha, Tanzania
| | - Emmanuel A. Mpolya
- Department of Global Health and Bio-Medical Sciences, School of Life Sciences and Bio-Engineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box 447, Arusha, Tanzania
| | - Teckla Angelo
- Department of Global Health and Bio-Medical Sciences, School of Life Sciences and Bio-Engineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box 447, Arusha, Tanzania
| | - Safari M. Kinung'hi
- National Institute for Medical Research (NIMR), Mwanza Research Centre, Isamilo Road, P.O. Box 1462, Mwanza, Tanzania
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Garchitorena A, Sokolow SH, Roche B, Ngonghala CN, Jocque M, Lund A, Barry M, Mordecai EA, Daily GC, Jones JH, Andrews JR, Bendavid E, Luby SP, LaBeaud AD, Seetah K, Guégan JF, Bonds MH, De Leo GA. Disease ecology, health and the environment: a framework to account for ecological and socio-economic drivers in the control of neglected tropical diseases. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160128. [PMID: 28438917 PMCID: PMC5413876 DOI: 10.1098/rstb.2016.0128] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2017] [Indexed: 01/27/2023] Open
Abstract
Reducing the burden of neglected tropical diseases (NTDs) is one of the key strategic targets advanced by the Sustainable Development Goals. Despite the unprecedented effort deployed for NTD elimination in the past decade, their control, mainly through drug administration, remains particularly challenging: persistent poverty and repeated exposure to pathogens embedded in the environment limit the efficacy of strategies focused exclusively on human treatment or medical care. Here, we present a simple modelling framework to illustrate the relative role of ecological and socio-economic drivers of environmentally transmitted parasites and pathogens. Through the analysis of system dynamics, we show that periodic drug treatments that lead to the elimination of directly transmitted diseases may fail to do so in the case of human pathogens with an environmental reservoir. Control of environmentally transmitted diseases can be more effective when human treatment is complemented with interventions targeting the environmental reservoir of the pathogen. We present mechanisms through which the environment can influence the dynamics of poverty via disease feedbacks. For illustration, we present the case studies of Buruli ulcer and schistosomiasis, two devastating waterborne NTDs for which control is particularly challenging.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.
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Affiliation(s)
- A Garchitorena
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA 02115, USA
- PIVOT, Division of Global Health Equity, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - S H Sokolow
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - B Roche
- UMI UMMISCO 209 IRD/UPMC - Bondy, France
- UMR MIVEGEC 5290 CNRS - IRD - Université de Montpellier, Montpellier, France
| | - C N Ngonghala
- Department of Mathematics, University of Florida, Gainesville, FL 32611, USA
| | - M Jocque
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - A Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA 94305, USA
| | - M Barry
- Center for Innovation in Global Health, Stanford University, Stanford, CA 94305, USA
| | - E A Mordecai
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - G C Daily
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - J H Jones
- Department of Earth System Science, Stanford University, Stanford, CA 94305, USA
- Department of Life Sciences, Imperial College, London, UK
| | - J R Andrews
- Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - E Bendavid
- Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - S P Luby
- Center for Innovation in Global Health, Stanford University, Stanford, CA 94305, USA
| | - A D LaBeaud
- Department of Pediatrics, Division of Infectious Diseases, Stanford University, Stanford, CA 94305, USA
| | - K Seetah
- Department of Anthropology, Stanford University, Stanford, CA 94305, USA
| | - J F Guégan
- UMR MIVEGEC 5290 CNRS - IRD - Université de Montpellier, Montpellier, France
- Future Earth international programme, OneHealth core research programme, Montréal, Canada
| | - M H Bonds
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA 02115, USA
- PIVOT, Division of Global Health Equity, Brigham and Women's Hospital, Boston, MA 02115, USA
- Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - G A De Leo
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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Kabuyaya M, Chimbari MJ, Manyangadze T, Mukaratirwa S. Efficacy of praziquantel on Schistosoma haematobium and re-infection rates among school-going children in the Ndumo area of uMkhanyakude district, KwaZulu-Natal, South Africa. Infect Dis Poverty 2017; 6:83. [PMID: 28385154 PMCID: PMC5383960 DOI: 10.1186/s40249-017-0293-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 03/22/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite its low cure rates and possible resistance, praziquantel (PZQ) is the only drug available for schistosomiasis treatment. Hence, monitoring its efficacy is crucial. This study assessed the efficacy of PZQ, determined re-infection and incidence rates of Schistosoma haematobium infection among school-going children in the Ndumo area, KwaZulu-Natal. METHODS A cohort of 320 school-going children (10 - 15 years) in 10 primary schools was screened for S. haematobium infection using the filtration technique. Infected children were treated at different times and hence were divided into two sub-cohorts; A1 and A2. Non-infected children constituted the sub-cohort B. Children who continued excreting viable eggs 4 weeks post-treatment received a second dose of PZQ. Re-infection rates were determined in sub-cohort A1 and A2 at 28 and 20 weeks post-treatment, respectively. Cure rates (CR) and egg reduction rates (ERR) were calculated. Incidence rate was assessed 28 weeks post baseline survey using children that were negative for schistosome eggs at that survey. Analysis of data was done using the Chi square and the Wilcoxon rank test. A 95% confidence interval with a P-value < 0.05 determined significance. RESULTS At baseline, 120 (37.5%) of the 320 study participants were found infected with Schistosoma haematobium. Heavy infections accounted for 36.7%. The calculated cure rates were 88.07% and 82.92% for females and males, respectively. Egg Reduction Rates of 80% and 64% for females and males were observed 4 weeks after the initial treatment. After the second treatment, CR was 100% in females and 50% in males with an ERR of 100% in females and 70% in males. At 20 and 28 weeks post treatment, reinfection rates of 8.03% and 8.00% were observed, respectively, giving an overall rate of 8.1%. An incidence rate of 4.1% was observed 28 weeks after the baseline screening. CONCLUSIONS The study indicated high CR while the ERR was low suggesting a reduced PZQ efficacy. The efficacy improved among females after the second dose. Re-infection rates at 20 and 28 weeks post-treatment were low. The study also indicated a low incidence rate for the 28 weeks period.
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Affiliation(s)
- Muhubiri Kabuyaya
- Discipline of Public Health Medicine, Howard College, University of KwaZulu-Natal, Durban, P.O Box, 4041 South Africa
| | - Moses John Chimbari
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Tawanda Manyangadze
- Discipline of Public Health Medicine, Howard College, University of KwaZulu-Natal, Durban, P.O Box, 4041 South Africa
| | - Samson Mukaratirwa
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
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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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Hybridizations within the Genus Schistosoma: implications for evolution, epidemiology and control. Parasitology 2016; 144:65-80. [PMID: 27572906 DOI: 10.1017/s0031182016001190] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hybridization of parasites is an emerging public health concern in our changing world. Hybridization and introgression in parasites and pathogens can have major impacts on the host and the epidemiology and evolution of disease. Schistosomiasis is a Neglected Tropical Disease of profound medical and veterinary importance across many parts of the world, with the greatest human burden within sub-Saharan Africa. Here we review how early phenotypic identification and recent confirmation through molecular studies on naturally occurring infections, combined with experimental manipulations, have revealed evidence of viable hybridization and introgressions within and between human and animal schistosome species. Environmental and anthropogenic changes in selective pressures following, for instance, new dam constructions, altered agricultural practices, together with mass drug administration programmes, may all be predicted to further impact the availability of suitable definitive and intermediate hosts for schistosomes. It is therefore imperative to understand the distribution and role of such novel zoonotic hybrid schistosomes on host range, drug efficacy, and hence ultimately transmission potential, if we are to achieve and maintain sustainable control.
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Sokolow SH, Wood CL, Jones IJ, Swartz SJ, Lopez M, Hsieh MH, Lafferty KD, Kuris AM, Rickards C, De Leo GA. Global Assessment of Schistosomiasis Control Over the Past Century Shows Targeting the Snail Intermediate Host Works Best. PLoS Negl Trop Dis 2016; 10:e0004794. [PMID: 27441556 PMCID: PMC4956325 DOI: 10.1371/journal.pntd.0004794] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 05/31/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Despite control efforts, human schistosomiasis remains prevalent throughout Africa, Asia, and South America. The global schistosomiasis burden has changed little since the new anthelmintic drug, praziquantel, promised widespread control. METHODOLOGY We evaluated large-scale schistosomiasis control attempts over the past century and across the globe by identifying factors that predict control program success: snail control (e.g., molluscicides or biological control), mass drug administrations (MDA) with praziquantel, or a combined strategy using both. For data, we compiled historical information on control tactics and their quantitative outcomes for all 83 countries and territories in which: (i) schistosomiasis was allegedly endemic during the 20th century, and (ii) schistosomiasis remains endemic, or (iii) schistosomiasis has been "eliminated," or is "no longer endemic," or transmission has been interrupted. PRINCIPAL FINDINGS Widespread snail control reduced prevalence by 92 ± 5% (N = 19) vs. 37 ± 7% (N = 29) for programs using little or no snail control. In addition, ecological, economic, and political factors contributed to schistosomiasis elimination. For instance, snail control was most common and widespread in wealthier countries and when control began earlier in the 20th century. CONCLUSIONS/SIGNIFICANCE Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis.
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Affiliation(s)
- Susanne H. Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Chelsea L. Wood
- Michigan Society of Fellows, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Isabel J. Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Scott J. Swartz
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Melina Lopez
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Michael H. Hsieh
- Children's National Health System, Washington, D.C., United States of America
- The George Washington University, Washington, D.C., United States of America
- Biomedical Research Institute, Rockville, Maryland, United States of America
| | - Kevin D. Lafferty
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Western Ecological Research Center, U.S. Geological Survey, Santa Barbara, California, United States of America
| | - Armand M. Kuris
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Chloe Rickards
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
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Senghor B, Diaw OT, Doucoure S, Seye M, Diallo A, Talla I, Bâ CT, Sokhna C. Impact of Annual Praziquantel Treatment on Urogenital Schistosomiasis in a Seasonal Transmission Focus in Central Senegal. PLoS Negl Trop Dis 2016; 10:e0004557. [PMID: 27015646 PMCID: PMC4807842 DOI: 10.1371/journal.pntd.0004557] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 02/27/2016] [Indexed: 11/18/2022] Open
Abstract
In Sub-Saharan Africa, urogenital schistosomiasis remains a significant public health problem, causing 150.000 deaths/year with approximately 112 million cases diagnosed. The Niakhar district is a disease hotspot in central Senegal where transmission occurs seasonally with high prevalences. The aim of this study was to determine the effect of annual treatment over 3 years on the seasonal transmission dynamics of S. haematobium in 9 villages in the Niakhar district. Adults and children aged between 5 and 60 years were surveyed from 2011 to 2014. Urine samples were collected door-to-door and examined for S. haematobium eggs at baseline in June 2011, and all participants were treated in August 2011 with PZQ (40 mg/kg). After this initial examination, evaluations were conducted at 3 successive time points from September 2011 to March 2014, to measure the efficacy of the annual treatments and the rates of reinfection. Each year, during the transmission period, from July to November-December, malacological surveys were also carried out in the fresh water bodies of each village to evaluate the infestation of the snail intermediate hosts. At baseline, the overall prevalence of S. haematobium infection was 57.7%, and the proportion of heavy infection was 45.3%, but one month after the first treatment high cure rates (92.9%) were obtained. The overall infection prevalence and proportion of heavy infection intensities were drastically reduced to 4.2% and 2.3%, respectively. The level of the first reinfection in February-March 2012 was 9.5%. At follow-up time points, prevalence levels varied slightly between reinfection and treatment from 9.5% in June 2012 to 0.3% in March 2013, 11.2 in June 2013, and 10.1% April 2014. At the end of the study, overall prevalence was significantly reduced from 57.7% to 10.1%. The overall rate of infested Bulinid snails was reduced after repeated treatment from 0.8% in 2012 to 0.5% in 2013. Repeated annual treatments are suggested to have a considerable impact on the transmission dynamics of S. haematobium in Niakhar, due to the nature of the epidemiological system with seasonal transmission. Thus, to maintain this benefit and continue to reduce the morbidity of urogenital schistosomiasis, other approaches should be integrated into the strategy plans of the National program to achieve the goal of urogenital schistosomiasis elimination in seasonal foci in Senegal. Urogenital schistosomiasis represents a serious cause of morbidity and mortality in S. haematobium endemic countries. Treatment with praziquantel (PZQ) is effective at reducing or eliminating active infection, but does not prevent reinfection that remains a continuing problem in high-risk communities, especially in areas where contacts with infested water are inevitable. The efficacy of PZQ treatment is challenged by regular re-infection in high risk communities due to frequent contact with water infested with snails carrying the larvae of S. haematobium. A large number of countries have initiated schistosomiasis control and elimination programs based on repeated PZQ mass drug administration (MDA). However, little information is available on the impact of repeated treatment on S. haematobium transmission dynamics in areas where transmission occurs seasonally in temporary water bodies. This observational study assessed the effect of annual repeated cohort treatment with PZQ over 3 years on the seasonal transmission dynamics of S. haematobium in nine villages in Niakhar district, District. Repeated annual treatments have a considerable impact on the transmission dynamics of S. haematobium in Niakhar. The prevalence of S. haematobium was dramatically reduced from 57.7% in 2011 to 10.1% in 2014. The reinfection rate did not exceed 10% from 2012 to 2014. Also, the rate of infested Bulinid snails decreased from 0.8% in 2012 to 0.5% in 2013. These results suggest that it may be possible to implement urogenital schistosomiasis elimination strategies in the Niakhar district and other seasonal transmission areas in Senegal if praziquantel MDAs are carried out in combination with other measures such as health education, improvement of access to clean water and snail control.
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Affiliation(s)
- Bruno Senghor
- Institute Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, Dakar, Sénégal
- Université Cheikh Anta Diop de Dakar, Département de Biologie Animale, laboratoire d’écologie et de Biologie évolutive, Dakar, Senegal
| | - Omar Talla Diaw
- Institut Sénégalais de Recherches Agricoles, ISRA, Dakar, Senegal
| | - Souleymane Doucoure
- Institute Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, Dakar, Sénégal
| | - Mouhamadane Seye
- Institut Sénégalais de Recherches Agricoles, ISRA, Dakar, Senegal
| | - Adiouma Diallo
- Institute Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, Dakar, Sénégal
| | - Idrissa Talla
- Programme national de lutte contre les bilharzioses et les géo-helminthiases, Ministère de la Santé et de l'Action sociale (MSAS), Dakar, Sénégal
| | - Cheikh T. Bâ
- Université Cheikh Anta Diop de Dakar, Département de Biologie Animale, laboratoire d’écologie et de Biologie évolutive, Dakar, Senegal
| | - Cheikh Sokhna
- Institute Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, Dakar, Sénégal
- * E-mail:
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Webster JP, Gower CM, Knowles SCL, Molyneux DH, Fenton A. One health - an ecological and evolutionary framework for tackling Neglected Zoonotic Diseases. Evol Appl 2016; 9:313-33. [PMID: 26834828 PMCID: PMC4721077 DOI: 10.1111/eva.12341] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/20/2015] [Indexed: 12/27/2022] Open
Abstract
Understanding the complex population biology and transmission ecology of multihost parasites has been declared as one of the major challenges of biomedical sciences for the 21st century and the Neglected Zoonotic Diseases (NZDs) are perhaps the most neglected of all the Neglected Tropical Diseases (NTDs). Here we consider how multihost parasite transmission and evolutionary dynamics may affect the success of human and animal disease control programmes, particularly neglected diseases of the developing world. We review the different types of zoonotic interactions that occur, both ecological and evolutionary, their potential relevance for current human control activities, and make suggestions for the development of an empirical evidence base and theoretical framework to better understand and predict the outcome of such interactions. In particular, we consider whether preventive chemotherapy, the current mainstay of NTD control, can be successful without a One Health approach. Transmission within and between animal reservoirs and humans can have important ecological and evolutionary consequences, driving the evolution and establishment of drug resistance, as well as providing selective pressures for spill-over, host switching, hybridizations and introgressions between animal and human parasites. Our aim here is to highlight the importance of both elucidating disease ecology, including identifying key hosts and tailoring control effort accordingly, and understanding parasite evolution, such as precisely how infectious agents may respond and adapt to anthropogenic change. Both elements are essential if we are to alleviate disease risks from NZDs in humans, domestic animals and wildlife.
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Affiliation(s)
- Joanne P. Webster
- Department of Pathology and Pathogen BiologyCentre for Emerging, Endemic and Exotic Diseases (CEEED)Royal Veterinary CollegeUniversity of LondonHertfordshireUK
| | - Charlotte M. Gower
- Department of Pathology and Pathogen BiologyCentre for Emerging, Endemic and Exotic Diseases (CEEED)Royal Veterinary CollegeUniversity of LondonHertfordshireUK
| | | | - David H. Molyneux
- Department of ParasitologyLiverpool School of Tropical MedicineLiverpoolUK
| | - Andy Fenton
- Institute of Integrative BiologyUniversity of LiverpoolLiverpoolUK
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Epidemiological Interactions between Urogenital and Intestinal Human Schistosomiasis in the Context of Praziquantel Treatment across Three West African Countries. PLoS Negl Trop Dis 2015; 9:e0004019. [PMID: 26469347 PMCID: PMC4607489 DOI: 10.1371/journal.pntd.0004019] [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: 02/10/2015] [Accepted: 07/30/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In many parts of sub-Saharan Africa, urogenital and intestinal schistosomiasis co-occur, and mixed species infections containing both Schistosoma haematobium and S. mansoni can be common. During co-infection, interactions between these two species are possible, yet the extent to which such interactions influence disease dynamics or the outcome of control efforts remains poorly understood. METHODOLOGY/PRINCIPAL FINDINGS Here we analyse epidemiological data from three West African countries co-endemic for urogenital and intestinal schistosomiasis (Senegal, Niger and Mali) to test whether the impact of praziquantel (PZQ) treatment, subsequent levels of re-infection or long-term infection dynamics are altered by co-infection. In all countries, positive associations between the two species prevailed at baseline: infection by one species tended to predict infection intensity for the other, with the strength of association varying across sites. Encouragingly, we found little evidence that co-infection influenced PZQ efficacy: species-specific egg reduction rates (ERR) and cure rates (CR) did not differ significantly with co-infection, and variation in treatment success was largely geographical. In Senegal, despite positive associations at baseline, children with S. mansoni co-infection at the time of treatment were less intensely re-infected by S. haematobium than those with single infections, suggesting competition between the species may occur post-treatment. Furthermore, the proportion of schistosome infections attributable to S. mansoni increased over time in all three countries examined. CONCLUSIONS/SIGNIFICANCE These findings suggest that while co-infection between urinary and intestinal schistosomes may not directly affect PZQ treatment efficacy, competitive interspecific interactions may influence epidemiological patterns of re-infection post-treatment. While re-infection patterns differed most strongly according to geographic location, interspecific interactions also seem to play a role, and could cause the community composition in mixed species settings to shift as disease control efforts intensify, a situation with implications for future disease management in this multi-species system.
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Reduced transmission of human schistosomiasis after restoration of a native river prawn that preys on the snail intermediate host. Proc Natl Acad Sci U S A 2015. [PMID: 26195752 DOI: 10.1073/pnas.1502651112] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Eliminating human parasitic disease often requires interrupting complex transmission pathways. Even when drugs to treat people are available, disease control can be difficult if the parasite can persist in nonhuman hosts. Here, we show that restoration of a natural predator of a parasite's intermediate hosts may enhance drug-based schistosomiasis control. Our study site was the Senegal River Basin, where villagers suffered a massive outbreak and persistent epidemic after the 1986 completion of the Diama Dam. The dam blocked the annual migration of native river prawns (Macrobrachium vollenhoveni) that are voracious predators of the snail intermediate hosts for schistosomiasis. We tested schistosomiasis control by reintroduced river prawns in a before-after-control-impact field experiment that tracked parasitism in snails and people at two matched villages after prawns were stocked at one village's river access point. The abundance of infected snails was 80% lower at that village, presumably because prawn predation reduced the abundance and average life span of latently infected snails. As expected from a reduction in infected snails, human schistosomiasis prevalence was 18 ± 5% lower and egg burden was 50 ± 8% lower at the prawn-stocking village compared with the control village. In a mathematical model of the system, stocking prawns, coupled with infrequent mass drug treatment, eliminates schistosomiasis from high-transmission sites. We conclude that restoring river prawns could be a novel contribution to controlling, or eliminating, schistosomiasis.
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Senghor B, Diaw OT, Doucoure S, Sylla SN, Seye M, Talla I, Bâ CT, Diallo A, Sokhna C. Efficacy of praziquantel against urinary schistosomiasis and reinfection in Senegalese school children where there is a single well-defined transmission period. Parasit Vectors 2015; 8:362. [PMID: 26156522 PMCID: PMC4496924 DOI: 10.1186/s13071-015-0980-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 07/01/2015] [Indexed: 11/24/2022] Open
Abstract
Background Human schistosomiasis is a significant health problem in Sub-Saharan Africa. In Niakhar, West central Senegal, the transmission of S. haematobium occurs seasonally between July and November. No control measures have been implemented despite high prevalence reported in previous studies. This aim of this study was to i) determine the current prevalence of S. haematobium in children at Niakhar, ii) assess the efficacy of one dose of PZQ (40 mg/kg) against S. haematobium and iii) monitor reinfection. Methods The current study was carried out in a cohort of 329 children aged five to 15 years enrolled from six villages in Niakhar to determine the efficacy of one dose of PZQ, as well as reinfection. Parasitological screening was performed in June 2011 to determine the baseline prevalence of S. haematobium, and then a single dose of PZQ was administered to all selected subjects in the transmission season in August 2011. The efficacy of PZQ treatment and reinfection were monitored respectively five weeks after in September 2011 and from February to March 2012. Results At baseline, the overall prevalence and the heavy intensity of infection were 73.2 % and 356.1eggs/10 ml of urine. Significant differences in the prevalence and intensity of S. haematobium infection were noted between villages. A single dose of PZQ significantly reduced the prevalence of S. haematobium infection from 73.2 % to 4.6 % and the geometric mean intensity of infection from 356.1 to 43.3 eggs/10 ml of urine. The cure rates ranged from 89.4 % to 100 %. The egg reduction rates also ranged from 77.6 % to 100 %. Two to three months after the period of transmission, the overall rate of reinfection was 12.6 % and was significantly higher in male children than in female children. The overall prevalence at this period was 13.8 %, which was significantly lower than the prevalence at baseline (73.2 %). Conclusion The Niakhar study area remains a hot spot of urinary schistosomiasis in Senegal with differences in transmission between villages. This study suggests that when transmission is strictly seasonal, Praziquantel shows the expected efficacy in reducing the prevalence and intensity of infection, but also a significant effect on the occurrence of reinfection.
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Affiliation(s)
- Bruno Senghor
- Institut de Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, BP 1386, Dakar, CP 18524, Sénégal. .,Département de Biologie Animale, Université Cheikh Anta Diop de Dakar, Dakar, BP 5005, Senegal.
| | - Omar Talla Diaw
- Institut Sénégalais de Recherches Agricoles, ISRA, route des Hydrocarbures, Bel Air, Dakar, Senegal.
| | - Souleymane Doucoure
- Institut de Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, BP 1386, Dakar, CP 18524, Sénégal.
| | - Seydou Nourou Sylla
- Institut de Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, BP 1386, Dakar, CP 18524, Sénégal. .,UFR Sciences Appliquées et Technologies, Université Gaston Berger de Saint Louis, Saint Louis, BP 234, Senegal.
| | - Mouhamadane Seye
- Institut Sénégalais de Recherches Agricoles, ISRA, route des Hydrocarbures, Bel Air, Dakar, Senegal.
| | - Idrissa Talla
- Programme national de lutte contre les bilharzioses et les géo-helminthiases, ministère de la santé et de l'action sociale, Dakar, Sénégal.
| | - Cheikh Tidiane Bâ
- Département de Biologie Animale, Université Cheikh Anta Diop de Dakar, Dakar, BP 5005, Senegal.
| | - Adiouma Diallo
- Institut de Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, BP 1386, Dakar, CP 18524, Sénégal.
| | - Cheikh Sokhna
- Institut de Recherche pour le Développement, UMR 198 (URMITE), Campus International de Hann, IRD, BP 1386, Dakar, CP 18524, Sénégal.
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