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Moscovitz S, Glassner H, Wokam Njomgang RM, Aflalo ED, Ovadia O, Sagi A. Community composition of invasive, outbreak, and non-pest snail species along a source spring-to-fishpond gradient in a spatially structured aquacultural region. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119653. [PMID: 38070421 DOI: 10.1016/j.jenvman.2023.119653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 11/16/2023] [Accepted: 11/16/2023] [Indexed: 01/14/2024]
Abstract
Agricultural lands are integrated into and interact with natural areas. Such is the case of Emek HaMa'ayanot, northern Israel, comprising a springs-rich area characterized by multiple land-uses, including spring-water-based aquaculture, recreational springs, and nature reserves. Aquacultural farms suffer from pest snails that carry fish disease; in the study region, these species are invasive (Thiara scabra, Tarebia granifera, Pseudosuccinea columella) and outbreak endemic (Melanoides tuberculata). Previous snail control efforts have focused on individual fishponds without considering management on larger environmental scales in the waterways from the source springs to the fish farms. To broaden our understanding of the status of the pest snail problem in the study area prior to suggesting environmental managerial solutions, we quantified changes in the community composition of snail species along the springs-to-fishponds gradients in a spatially explicit system. We found a remarkable increase in pest snail abundances along these gradients, indicating that pest snails might be invading upstream towards the springs. There were always nearly 100% pest snails in the endpoint sites for water tracks that ended in fishponds. Moreover, pest snails dominated the site when it was used as a fishpond, even though the site was also a spring. In contrast, in a water track that does not end in a fish farm, the relative abundances of non-pest snail species was similar between the source spring and the downstream endpoint, in spite of an increase in pest snail abundance at a midpoint site. These results suggest that invasive pest snails are actively moving upstream and that the fishponds have a marked upstream effect on the ability of non-pest snails to resist pest species invasions. We suggest further investigation of possible strategies for biocontrol of the observed invasion of the snails into natural areas as a basis for environmental management efforts. Finally, the observations made during this study could have practical global implications for snail management in aquaculture and agriculture, and for the control of snails and snail vectors implicated in animal and human diseases.
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Affiliation(s)
- Sharon Moscovitz
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 84105, Israel
| | - Hanoch Glassner
- Eden Research Station, Mobile Post Beit Shean, 11710, Israel
| | | | - Eliahu D Aflalo
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 84105, Israel; Department of Life Sciences, Achva Academic College, Mobile Post Shikmim, 79800, Israel
| | - Ofer Ovadia
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 84105, Israel; Goldman Sonnenfeldt School of Sustainability and Climate Change, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 84105, Israel.
| | - Amir Sagi
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 84105, Israel; National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 84105, Israel.
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Kappus-Kron H, Chatila DA, MacLachlan AM, Pulido N, Yang N, Larsen DA. Precision public health in schools enabled by wastewater surveillance: A case study of COVID-19 in an Upstate New York middle-high school campus during the 2021-2022 academic year. PLOS GLOBAL PUBLIC HEALTH 2024; 4:e0001803. [PMID: 38198477 PMCID: PMC10781135 DOI: 10.1371/journal.pgph.0001803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 11/30/2023] [Indexed: 01/12/2024]
Abstract
Wastewater surveillance provides a cost-effective and non-invasive way to gain an understanding of infectious disease transmission including for COVID-19. We analyzed wastewater samples from one school site in Jefferson County, New York during the 2021-2022 school year. We tested for SARS-CoV-2 RNA once weekly and compared those results with the clinical COVID-19 cases in the school. The amount of SARS-CoV-2 RNA correlated with the number of incident COVID-19 cases, with the best correlation being one day lead time between the wastewater sample and the number of COVID-19 cases. The sensitivity and positive predictive value of wastewater surveillance to correctly identify any COVID-19 cases up to 7 days after a wastewater sample collection ranged from 82-100% and 59-78% respectively, depending upon the amount of SARS-CoV-2 RNA in the sample. The specificity and negative predictive value of wastewater surveillance to correctly identify when the school was without a case of COVID-19 ranged from 67-78% and 70-80%, respectively, depending upon the amount of SARS-CoV-2 RNA in the sample. The lead time observed in this study suggests that transmission might occur within a school before SARS-CoV-2 is identified in wastewater. However, wastewater surveillance should still be considered as a potential means of understanding school-level COVID-19 trends and is a way to enable precision public health approaches tailored to the epidemiologic situation in an individual school.
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Affiliation(s)
- Haley Kappus-Kron
- Center for Environmental Health, New York State Department of Health, Albany, New York, United States of America
- CDC Foundation, Atlanta, Georgia, United States of America
| | - Dana Ahmad Chatila
- Department of Public Health, Syracuse University, Syracuse, New York, United States of America
| | | | - Nicole Pulido
- Department of Public Health, Syracuse University, Syracuse, New York, United States of America
| | - Nan Yang
- Department of Public Health, Syracuse University, Syracuse, New York, United States of America
| | - David A. Larsen
- Department of Public Health, Syracuse University, Syracuse, New York, United States of America
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Nkemngo FN, W G Raissa L, Nebangwa DN, Nkeng AM, Kengne A, Mugenzi LMJ, Fotso-Toguem YG, Wondji MJ, Shey RA, Nguiffo-Nguete D, Fru-Cho J, Ndo C, Njiokou F, Webster JP, Wanji S, Wondji CS. Epidemiology of malaria, schistosomiasis, and geohelminthiasis amongst children 3-15 years of age during the dry season in Northern Cameroon. PLoS One 2023; 18:e0288560. [PMID: 37523402 PMCID: PMC10389741 DOI: 10.1371/journal.pone.0288560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 06/29/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND The double burden of malaria and helminthiasis in children poses an obvious public health challenge, particularly in terms of anemia morbidity. While both diseases frequently geographically overlap, most studies focus on mono-infection and general prevalence surveys without molecular analysis. The current study investigated the epidemiological determinants of malaria, schistosomiasis, and geohelminthiasis transmission among children in the North Region of Cameroon. METHODOLOGY School and pre-school children aged 3-15 year-of-age were enrolled from three communities in March 2021 using a community cross-sectional design. Capillary-blood samples were obtained, and each was examined for malaria parasites using rapid-diagnostic-test (RDT), microscopy, and PCR while hemoglobin level was measured using a hemoglobinometer. Stool samples were analyzed for Schistosoma mansoni, S. guineensis, and soil-transmitted-helminthiasis (STH) infections using the Kato Katz method, and urine samples were assessed for the presence of S. haematobium eggs (including hybrids) using the standard urine filtration technique. RESULT A malaria prevalence of 56% (277/495) was recorded by PCR as opposed to 31.5% (156/495) by microscopy and 37.8% (186/495) by RDT. Similarly, schistosomiasis was observed at prevalence levels of up to 13.3% (66/495) overall [S. haematobium (8.7%); S. mansoni (3.8%); mixed Sh/Sm (0.6%); mixed Sh/Sm/Sg (0.2%). Both infections were higher in males and the 3-9 year-of-age groups. A high frequency of PCR reported P. falciparum mono-infection of 81.9% (227/277) and mixed P. falciparum/P. malariae infection of 17.3% (48/277) was observed. Malaria-helminths co-infections were observed at 13.1% (65/495) with marked variation between P. falciparum/S. haematobium (50.8%, 33/65); P. falciparum/S. mansoni (16.9%, 11/65) and P. falciparum/Ascaris (9.2%, 6/65) (χ2 = 17.5, p = 0.00003). Anemia prevalence was 32.9% (163/495), categorically associated with P. falciparum (45.8%, 104/227), Pf/Sh (11.5%, 26/227), and Pf/Sm (3.9%, 9/227) polyparasitism. CONCLUSION Polyparasitism with malaria and helminth infections is common in school-aged children despite periodic long-lasting insecticide-treated nets (LLINs) distribution and regular school-based praziquantel (for schistosomiasis) and albendazole (for STH) campaigns. Co-existence of Plasmodium parasites and helminths infections notably Schistosoma species among children may concurrently lead to an increase in Plasmodium infection with an enhanced risk of anemia, highlighting the necessity of an integrated approach for disease control interventions.
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Affiliation(s)
- Francis N Nkemngo
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Lymen W G Raissa
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Derrick N Nebangwa
- Faculty of Life Science and Medicine, King's College London, New Hunt's House, London, United Kingdom
| | - Asongha M Nkeng
- Centre for Infection Biology and Translational Research (CIBiT), Forzi Institute, Buea, Cameroon
- Department of Sociology & Anthropology, Faculty of Social and Management Sciences, University of Buea, Buea, Cameroon
| | - Alvine Kengne
- Department of Animal Biology and Physiology, Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Leon M J Mugenzi
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | | | - Murielle J Wondji
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Robert A Shey
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | | | - Jerome Fru-Cho
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Cyrille Ndo
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Joanne P Webster
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Herts, United Kingdom
| | - Samuel Wanji
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Charles S Wondji
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
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Poague KIHM, Mingoti SA, Heller L. Water, sanitation and schistosomiasis mansoni: a study based on the Brazilian National Prevalence Survey (2011-2015). CIENCIA & SAUDE COLETIVA 2023; 28:363-372. [PMID: 36651392 DOI: 10.1590/1413-81232023282.09692022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 07/23/2022] [Indexed: 01/18/2023] Open
Abstract
This study aimed to explore the association between water, sanitation, and the prevalence of schistosomiasis mansoni in students aged 7 to 17 years from all 27 federative units in Brazil. It was a cross-sectional study conducted based on data on the prevalence of schistosomiasis mansoni referring to 197,567 students from 521 Brazilian municipalities, who participated in the National Survey on the Prevalence of Schistosomiasis Mansoni and Soil-transmitted Helminth Infections (2011-2015). Univariable and multivariable generalized linear models of the negative binomial type were adjusted using 25 and 5% significance levels, respectively, considering municipalities as the unit of analysis. While a protective association was found between access to filtered water in schools and schistosomiasis mansoni prevalence, sanitation in schools was indicated as a risk factor. The collection of wastewater through a network is not universal in Brazil, and even when present, it is not necessarily carried out by the treatment of collected effluents, thus often resulting in the direct discharge of raw sewage into water resources. Regarding septic tanks, only the presence of infrastructure alone does not guarantee its correct use by the population.
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Affiliation(s)
| | | | - Léo Heller
- Instituto René Rachou, Fundação Oswaldo Cruz em Minas Gerais. Belo Horizonte MG Brasil
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Prevalence of Schistosoma mansoni infection among fishermen in Busega district, Tanzania. PLoS One 2022; 17:e0276395. [PMID: 36441724 PMCID: PMC9704623 DOI: 10.1371/journal.pone.0276395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 10/05/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Schistosoma (S.) mansoni infection is endemic in all regions around Lake Victoria and affects all age groups to different degrees. In most endemic areas, less attention has been paid to determining the prevalence of infection, sanitation status, and knowledge about intestinal schistosomiasis (KIS) in fishermen. Therefore, the purpose of this study was to establish the prevalence of S. mansoni infection and associated factors among fishermen in the Busega district. MATERIALS AND METHODS A cross-sectional study was conducted among fishermen in July, 2020 in five fishing villages in the Busega district located along Lake Victoria. A total of 352 fishermen were interviewed with regard to their sanitation status and level of KIS. A single stool sample from fishermen was examined for S.mansoni eggs by using the Formalin-Ether Concentration technique. The potential factors associated with S. mansoni infection were explored using multivariable logistic regression. RESULTS The prevalence of S. mansoni infection was high (65.0%) among fishermen and varied with age, whereby fishermen aged ≤36 years had the highest prevalence. Fishermen had a low level of KIS and the majority of them reported practicing open defecation during fishing (81%). These fishermen with a low level of KIS and who reported defecating in open areas during fishing had 2.8 times (95% CI: 1.0-7.2) and 2.1 times (95% CI: 1.1-3.9) higher odds of being infected with S. mansoni than those with a high level of KIS and those who did not report defecating in open areas during fishing, respectively. CONCLUSION S. mansoni infection was high among fishermen in the Busega district. Furthermore, fishermen had a low level of KIS and were reported to have defecated in open areas during fishing. Infection with S. mansoni was associated with age, a low level of KIS and open defecation behaviour during fishing. Therefore, mass drug administration (MDA) with praziquantel, health education, and sanitation behaviour change interventions were needed.
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Environmental DNA in human and veterinary parasitology - Current applications and future prospects for monitoring and control. Food Waterborne Parasitol 2022; 29:e00183. [DOI: 10.1016/j.fawpar.2022.e00183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 11/04/2022] [Accepted: 11/09/2022] [Indexed: 11/15/2022] Open
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Maquart PO, Froehlich Y, Boyer S. Plastic pollution and infectious diseases. Lancet Planet Health 2022; 6:e842-e845. [PMID: 36208647 DOI: 10.1016/s2542-5196(22)00198-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/19/2022] [Accepted: 08/16/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Pierre-Olivier Maquart
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia.
| | | | - Sebastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
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Inceboz T. One Health Concept against Schistosomiasis: An Overview. Infect Dis (Lond) 2022. [DOI: 10.5772/intechopen.106912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Schistosomiasis (bilharziasis) is a parasitic disease caused by Schistosoma spp. that belongs to trematode worms. These worms are known as “blood parasites”. This disease is included in “neglected tropical diseases” and “water-borne diseases”. The main species are Schistosoma (S.) haematobium, S. japonicum, S. mansoni, S. intercalatum, S. mekongi, S. guineensis and S. intercalatum, though there are more than 20 different species. The parasite in the definitive host may affect many organs and systems. The disease may become chronic and lasts 3–8 years and even up to 20–30 years. The definitive host is primarily human; however, in endemic areas animals such as monkeys, cattle, horses, rodents, cats, dogs are reservoirs. According to World Health Organization (WHO), schistosomiasis affects 250 million people, and causes 1.9 million deaths yearly in endemic areas. Moreover, due to global warming, the spread of the disease may increase. The effective way to fight against schistosomiasis is following the “one-health system”. Indeed, to overcome or “eradicate” this disease, we have to strive against different forms at different evolutionary stages of the worm such as, forms in humans, domestic or wild animals, and freshwater snails. If we combine the knowledge of professionals, we may achieve this goal.
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Hassan MM, Sedighi A, Olaoye OO, Häberli C, Merz A, Ramos-Morales E, de Araujo ED, Romier C, Jung M, Keiser J, Gunning PT. Phenotypic Screening of Histone Deacetylase (HDAC) Inhibitors against Schistosoma mansoni. ChemMedChem 2022; 17:e202100622. [PMID: 35983937 DOI: 10.1002/cmdc.202100622] [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: 09/23/2021] [Revised: 07/17/2022] [Indexed: 11/09/2022]
Abstract
Schistosomiasis is a prevalent yet neglected tropical parasitic disease caused by the Schistosoma genus of blood flukes. Praziquantel is the only currently available treatment, hence drug resistance poses a major threat. Recently, histone deacetylase 8 (HDAC8) selective inhibitors have been proposed as a viable treatment for schistosomiasis. Herein, we report the phenotypic screening of a focused library of small molecules of varying HDAC isozyme-inhibition profiles, including eight HDAC8 inhibitors with >10-fold selectivity in comparable functional inhibition assays and IC50 values against HDAC8<100 nM. HDAC8-selective inhibitors showed the lowest potency against Schistosoma mansoni newly transformed schistosomula (NTS). Pan-HDAC inhibitors MMH258, MMH259, and MMH373, as assessed by functional inhibition assays, with minimal or no-observed hHDAC8 and SmHDAC8 activities, were active against both NTS (MMH258, IC50 =1.5 μM; MMH259, IC50 =2.3 μM) and adult S. mansoni (MMH258, IC50 =2.1 μM; MMH373, IC50 =3.4 μM). Our results indicate that neither hHDAC8 nor SmHDAC8 activity were directly correlated to their NTS and adult S. mansoni activities.
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Affiliation(s)
- Muhammad Murtaza Hassan
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada.,Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| | - Abootaleb Sedighi
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada.,Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| | - Olasunkanmi O Olaoye
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada.,Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| | - Cécile Häberli
- Swiss Tropical and Public Health Institute, 4123, Allschwil, Switzerland.,University of Basel, 4003, Basel, Switzerland
| | - Annika Merz
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104, Freiburg, Germany
| | - Elizabeth Ramos-Morales
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104, U 1258, 67400, Illkirch, France.,Department of Integrated Structural Biology IGBMC, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Elvin D de Araujo
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada
| | - Christophe Romier
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104, U 1258, 67400, Illkirch, France.,Department of Integrated Structural Biology IGBMC, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Manfred Jung
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104, Freiburg, Germany
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, 4123, Allschwil, Switzerland.,University of Basel, 4003, Basel, Switzerland
| | - Patrick T Gunning
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada.,Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
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Kyambikwa Bisangamo C. Epidemiology and Control of Schistosomiasis. Infect Dis (Lond) 2022. [DOI: 10.5772/intechopen.105170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Human schistosomiasis is caused by the genus Schistosoma. Its prevalence and morbidity are highest among schoolchildren, adolescents, and young adults. It is prevalent in poor communities without access to safe drinking water and adequate sanitation. The agents of etiology of these diseases are Schistosoma mansoni, Schistosoma haematobium, Schistosoma guineensis, Schistosoma intercalatum, Schistosoma japonicum, and Schistosoma mekongi. Symptoms include anemia, stunting, fever, cough, abdominal pain, diarrhea, hepatosplenomegaly, genital lesions, and eosinophilia. Freshwater mollusks are suitable intermediate hosts, and the definitive hosts are the parasitized men. The transmission gap of disease is bridged when people come into contact with unwholesome water sources infested. People are infected through their usual agricultural, domestic, professional, or recreational activities, which expose them to contaminated water. Various animals, such as cattle, dogs, cats, rodents, pigs, horses, and goats, serve as reservoirs. Treatment of at-risk people on a wide scale, access to good water, improved sanitation, hygiene education, and snail control are all used to combat schistosomiasis. The WHO’s schistosomiasis control strategy focuses on reducing disease by regularly administering praziquantel to affected populations on a large scale. It entails the regular treatment of all at-risk populations. Disease transmission should be halted in specific countries where transmission is low.
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Mulindwa J, Namulondo J, Kitibwa A, Nassuuna J, Nyangiri OA, Kimuda MP, Boobo A, Nerima B, Busingye F, Candia R, Namukuta A, Ssenyonga R, Ukumu N, Ajal P, Adriko M, Noyes H, de Dood CJ, Corstjens PLAM, van Dam GJ, Elliott AM, Matovu E. High prevalence of Schistosoma mansoni infection and stunting among school age children in communities along the Albert-Nile, Northern Uganda: A cross sectional study. PLoS Negl Trop Dis 2022; 16:e0010570. [PMID: 35895705 PMCID: PMC9359559 DOI: 10.1371/journal.pntd.0010570] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/08/2022] [Accepted: 06/08/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Knowing the prevalence of schistosomiasis is key to informing programmes to control and eliminate the disease as a public health problem. It is also important to understand the impact of infection on child growth and development in order to allocate appropriate resources and effort to the control of the disease. METHODS We conducted a survey to estimate the prevalence of schistosomiasis among school aged children in villages along the Albert-Nile shore line in the district of Pakwach, North Western Uganda. A total of 914 children aged between 10-15 years were screened for Schistosoma mansoni using the POC-CCA and Kato Katz (KK) techniques. The infection intensities were assessed by POC-CCA and KK as well as CAA tests. The KK intensities were also correlated with POC-CCA and with CAA intensity. Anthropometric measurements were also taken and multivariate analysis was carried out to investigate their association with infection status. RESULTS The prevalence of schistosomiasis using the POC-CCA diagnostic test was estimated at 85% (95% CI: 83-87), being highest amongst children living closer to the Albert-Nile shoreline. Visual scoring of the POC-CCA results was more sensitive than the Kato Katz test and was positively correlated with the quantified infection intensities by the CAA test. The majority of the children were underweight (BMI<18.5), and most notably, boys had significantly lower height for age (stunting) than girls in the same age range (p < 0.0001), but this was not directly associated with S. mansoni infection. CONCLUSION High prevalence of S. mansoni infection in the region calls for more frequent mass drug administration with praziquantel. We observed high levels of stunting which was not associated with schistosomiasis. There is a need for improved nutrition among the children in the area.
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Affiliation(s)
- Julius Mulindwa
- Department of Biochemistry and Sports Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Joyce Namulondo
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Anna Kitibwa
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Jacent Nassuuna
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Oscar Asanya Nyangiri
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Magambo Phillip Kimuda
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Alex Boobo
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Barbara Nerima
- Department of Biochemistry and Sports Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Fred Busingye
- Vector Borne & NTD Control Division, Ministry of Health, Kampala, Uganda
| | - Rowel Candia
- Vector Borne & NTD Control Division, Ministry of Health, Kampala, Uganda
| | - Annet Namukuta
- Vector Borne & NTD Control Division, Ministry of Health, Kampala, Uganda
| | - Ronald Ssenyonga
- Department of Epidemiology and Biostatistics, School of Public Health, Makerere University, Kampala, Uganda
| | - Noah Ukumu
- Pakwach District Local Government, District Health Office, Pakwach, Uganda
| | - Paul Ajal
- Pakwach District Local Government, District Health Office, Pakwach, Uganda
| | - Moses Adriko
- Vector Borne & NTD Control Division, Ministry of Health, Kampala, Uganda
| | - Harry Noyes
- Centre for Genomic Research, University of Liverpool, Liverpool, United Kingdom
| | - Claudia J. de Dood
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Paul L. A. M. Corstjens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Govert J. van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Alison M. Elliott
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Enock Matovu
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
- * E-mail:
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12
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Clark J, Moses A, Nankasi A, Faust CL, Moses A, Ajambo D, Besigye F, Atuhaire A, Wamboko A, Carruthers LV, Francoeur R, Tukahebwa EM, Prada JM, Lamberton PHL. Reconciling Egg- and Antigen-Based Estimates of Schistosoma mansoni Clearance and Reinfection: A Modeling Study. Clin Infect Dis 2022; 74:1557-1563. [PMID: 34358299 PMCID: PMC9070857 DOI: 10.1093/cid/ciab679] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Despite decades of interventions, 240 million people have schistosomiasis. Infections cannot be directly observed, and egg-based Kato-Katz thick smears lack sensitivity, affected treatment efficacy and reinfection rate estimates. The point-of-care circulating cathodic antigen (referred to from here as POC-CCA+) test is advocated as an improvement on the Kato-Katz method, but improved estimates are limited by ambiguities in the interpretation of trace results. METHOD We collected repeated Kato-Katz egg counts from 210 school-aged children and scored POC-CCA tests according to the manufacturer's guidelines (referred to from here as POC-CCA+) and the externally developed G score. We used hidden Markov models parameterized with Kato-Katz; Kato-Katz and POC-CCA+; and Kato-Katz and G-Scores, inferring latent clearance and reinfection probabilities at four timepoints over six-months through a more formal statistical reconciliation of these diagnostics than previously conducted. Our approach required minimal but robust assumptions regarding trace interpretations. RESULTS Antigen-based models estimated higher infection prevalence across all timepoints compared with the Kato-Katz model, corresponding to lower clearance and higher reinfection estimates. Specifically, pre-treatment prevalence estimates were 85% (Kato-Katz; 95% CI: 79%-92%), 99% (POC-CCA+; 97%-100%) and 98% (G-Score; 95%-100%). Post-treatment, 93% (Kato-Katz; 88%-96%), 72% (POC-CCA+; 64%-79%) and 65% (G-Score; 57%-73%) of those infected were estimated to clear infection. Of those who cleared infection, 35% (Kato-Katz; 27%-42%), 51% (POC-CCA+; 41%-62%) and 44% (G-Score; 33%-55%) were estimated to have been reinfected by 9-weeks. CONCLUSIONS Treatment impact was shorter-lived than Kato-Katz-based estimates alone suggested, with lower clearance and rapid reinfection. At 3 weeks after treatment, longer-term clearance dynamics are captured. At 9 weeks after treatment, reinfection was captured, but failed clearance could not be distinguished from rapid reinfection. Therefore, frequent sampling is required to understand these important epidemiological dynamics.
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Affiliation(s)
- Jessica Clark
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | | | | | - Christina L Faust
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Adriko Moses
- Vector Control Division, Ministry of Health, Uganda
| | - Diana Ajambo
- Vector Control Division, Ministry of Health, Uganda
| | - Fred Besigye
- Vector Control Division, Ministry of Health, Uganda
| | | | | | - Lauren V Carruthers
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Rachel Francoeur
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- Faculty of Science & Engineering, University of Chester, Chester, United Kingdom
| | | | - Joaquin M Prada
- Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Poppy H L Lamberton
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
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Hossain F, Picado A, Owen SI, Ghosh P, Chowdhury R, Maruf S, Khan MAA, Rashid MU, Nath R, Baker J, Ghosh D, Adams ER, Duthie MS, Hossain MS, Basher A, Nath P, Aktar F, Cruz I, Mondal D. Evaluation of Loopamp™ Leishmania Detection Kit and Leishmania Antigen ELISA for Post-Elimination Detection and Management of Visceral Leishmaniasis in Bangladesh. Front Cell Infect Microbiol 2021; 11:670759. [PMID: 33981632 PMCID: PMC8108992 DOI: 10.3389/fcimb.2021.670759] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/29/2021] [Indexed: 11/13/2022] Open
Abstract
With reduced prevalence of visceral leishmaniasis (VL) in the Indian subcontinent (ISC), direct and field deployable diagnostic tests are needed to implement an effective diagnostic and surveillance algorithm for post-elimination VL control. In this regard, here we investigated the diagnostic efficacies of a loop-mediated isothermal amplification (LAMP) assay (Loopamp™ Leishmania Detection Kit, Eiken Chemical CO., Ltd, Japan), a real-time quantitative PCR assay (qPCR) and the Leishmania antigen ELISA (CLIN-TECH, UK) with different sampling techniques and evaluated their prospect to incorporate into post-elimination VL control strategies. Eighty clinically and rK39 rapid diagnostic test confirmed VL cases and 80 endemic healthy controls were enrolled in the study. Peripheral blood and dried blood spots (DBS) were collected from all the participants at the time of diagnosis. DNA was extracted from whole blood (WB) and DBS via silica columns (QIAGEN) and boil & spin (B&S) methods and tested with qPCR and Loopamp. Urine was collected from all participants at the time of diagnosis and was directly subjected to the Leishmania antigen ELISA. 41 patients were followed up and urine samples were collected at day 30 and day 180 after treatment and ELISA was performed. The sensitivities of the Loopamp-WB(B&S) and Loopamp-WB(QIA) were 96.2% (95% CI 89·43-99·22) and 95% (95% CI 87·69-98·62) respectively. The sensitivity of Loopamp-DBS(QIA) was 85% (95% CI 75·26- 92·00). The sensitivities of the qPCR-WB(QIA) and qPCR-DBS(QIA) were 93.8% (95% CI 86·01-97·94) and 72.5% (95% CI 61·38-81·90) respectively. The specificity of all molecular assays was 100%. The sensitivity and specificity of the Leishmania antigen ELISA were 97.5% (95% CI 91·47-99·70) and 91.95% (95% CI 84·12-96·70) respectively. The Leishmania antigen ELISA depicted clinical cure at day 180 in all the followed-up cases. Efficacy and sustainability identify the Loopamp-WB(B&S) and the Leishmania antigen ELISA as promising and minimally invasive VL diagnostic tools to support VL diagnostic and surveillance activities respectively in the post-elimination era.
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Affiliation(s)
- Faria Hossain
- Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Albert Picado
- Neglected Tropical Diseases, Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - Sophie I. Owen
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Prakash Ghosh
- Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Rajashree Chowdhury
- Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shomik Maruf
- Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | | | - Md. Utba Rashid
- Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Rupen Nath
- Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - James Baker
- Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Debashis Ghosh
- Emerging infections and Parasitology laboratory, Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Emily R. Adams
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | | | - Ariful Basher
- Department of Medicine, Infectious Disease Hospital, Dhaka, Bangladesh
| | - Proggananda Nath
- Infectious diseases and Tropical Medicine, Mymensingh Medical College and Hospital, Mymensingh, Bangladesh
| | - Fatima Aktar
- Research, HDT Bio-Corp., Seattle, WA, United States
| | - Israel Cruz
- Neglected Tropical Diseases, Foundation for Innovative New Diagnostics, Geneva, Switzerland
- International Health Department, National School of Public Health, Instituto de Salud Carlos III, Madrid, Spain
| | - Dinesh Mondal
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
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Abstract
PURPOSE OF REVIEW Pulmonary hypertension is a deadly disease, the causes of which vary between geographical regions. Eighty four percentage of the world's population lives in majority countries (also called low-income and middle-income countries), yet data on pulmonary hypertension in these settings are proportionally scarce. This article provides a review of pulmonary hypertension in majority countries, focusing in detail on the most common causes in these regions, and highlights contextual challenges faced. RECENT FINDINGS Epidemiological data confirms a complex and overlapping array of causes, with pulmonary hypertension because of conditions such as rheumatic heart disease, HIV, schistosomiasis, chronic lung disease and sickle cell disease. Delayed pulmonary hypertension diagnosis remains a concern and is ascribed to a lack of resources and lack of pulmonary hypertension awareness by health professionals. Pulmonary hypertension diagnosis is frequently considered once signs of right heart failure emerge, while echocardiography and right heart catheterization are unavailable in many settings. Accurate data on the prevalence of pulmonary hypertension in many of these regions are needed and could be achieved by establishing and frequent review of national databases where the incident and prevalent pulmonary hypertension cases are captured. SUMMARY There is urgent need for pulmonary hypertension advocacy among clinicians in the primary, secondary and tertiary healthcare sectors of majority countries, and validated noninvasive diagnostic algorithms are needed. Increased awareness and early diagnosis are likely to improve outcomes of pulmonary hypertension patients in these regions, and potentially stimulate locally relevant research.
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15
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Kamel B, Laidemitt MR, Lu L, Babbitt C, Weinbaum OL, Mkoji GM, Loker ES. Detecting and identifying Schistosoma infections in snails and aquatic habitats: A systematic review. PLoS Negl Trop Dis 2021; 15:e0009175. [PMID: 33760814 PMCID: PMC8021170 DOI: 10.1371/journal.pntd.0009175] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/05/2021] [Accepted: 01/26/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND We were tasked by the World Health Organization (WHO) to address the following question: What techniques should be used to diagnose Schistosoma infections in snails and in the water in potential transmission sites? Our goal was to review and evaluate the available literature and provide recommendations and insights for the development of WHO's Guidelines Development Group for schistosomiasis control and elimination. METHODOLOGY We searched several databases using strings of search terms, searched bibliographies of pertinent papers, and contacted investigators who have made contributions to this field. Our search covered from 1970 to Sept 2020. All papers were considered in a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework, and retained papers were grouped by technique and subjected to our GRADE (Grading of Recommendations, Assessment, Development and Evaluations) evidence assessment profile determined in consultation with WHO. We also considered issues of sensitivity, specificity, coverage, cost, robustness, support needs, schistosome species discrimination, and relevant detection limits. PRINCIPAL FINDINGS Our PRISMA process began with the perusal of 949 articles, of which 158 were retained for data extraction and evaluation. We identified 25 different techniques and for each applied a GRADE assessment considering limitations, inconsistency, imprecision, indirectness, and publication bias. We also provide advantages and disadvantages for each category of techniques. CONCLUSIONS Our GRADE analysis returned an assessment of moderate quality of evidence for environmental DNA (eDNA), qPCR and LAMP (Loop-mediated isothermal amplification). No single ideal diagnostic approach has yet been developed, but considerable recent progress has been made. We note a growing trend to use eDNA techniques to permit more efficient and replicable sampling. qPCR-based protocols for follow-up detection offer a versatile, mature, sensitive, and specific platform for diagnosis though centralized facilities will be required to favor standardization. Droplet digital PCR (ddPCR) can play a complementary role if inhibitors are a concern, or more sensitivity or quantification is needed. Snail collection, followed by shedding, is encouraged to provide specimens for sequence verifications of snails or schistosomes. LAMP or other isothermal detection techniques offer the prospect of less expensive and more distributed network of analysis but may face standardization and verification challenges related to actual sequences amplified. Ability to detect schistosome infections in snails or in the water is needed if control and elimination programs hope to succeed. Any diagnostic techniques used need to be regularly verified by the acquisition of DNA sequences to confirm that the detected targets are of the expected species. Further improvements may be necessary to identify the ideal schistosome or snail sequences to target for amplification. More field testing and standardization will be essential for long-term success.
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Affiliation(s)
- Bishoy Kamel
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Martina R. Laidemitt
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
- Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Lijun Lu
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
- Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Caitlin Babbitt
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
- Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Ola Liota Weinbaum
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Gerald M. Mkoji
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Eric S. Loker
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
- Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
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Sumbele IUN, Otia OV, Bopda OSM, Ebai CB, Kimbi HK, Nkuo-Akenji T. Polyparasitism with Schistosoma haematobium, Plasmodium and soil-transmitted helminths in school-aged children in Muyuka-Cameroon following implementation of control measures: a cross sectional study. Infect Dis Poverty 2021; 10:14. [PMID: 33597042 PMCID: PMC7890808 DOI: 10.1186/s40249-021-00802-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 01/29/2021] [Indexed: 01/04/2023] Open
Abstract
Background Despite the ubiquity of polyparasitism, its health impacts have been inadequately studied. The aim of this study was to determine the prevalence and determinants of polyparasitism with Schistosoma haematobium, Plasmodium and soil-transmitted helminths (STH) following sustained control measures, as well as evaluate the outcomes and clinical correlates of infection in school-aged children (SAC) living in the schistosomiasis endemic focus of Muyuka-Cameroon. Methods In a cross-sectional study, urine, blood and stool samples were each collected from SAC (4–14 years) selected at random between March and June 2015. Microhaematuria in urine was detected using reagent strip and S. haematobium ova by filtration/microscopy methods. Plasmodium was detected using Giemsa-stained blood films and complete blood count was obtained using an auto-haematology analyser. STH in stool was detected by the Kato-Katz method. Categorical and continuous variables were compared as required, Kappa value estimated and the adjusted odds ratio (aOR) in the multivariate analysis was used to evaluate association of the risk factors with infection. Results Out of the 638 SAC examined, single infection was prevalent in 33.4% while polyparasitism was 19.9%. Prevalence of S. haematobium + Plasmodium was 7.8%; S. haematobium + STH was 0.8%; Plasmodium + STH was 0.8%; while S. haematobium + Plasmodium + STH was 0.9%. Higher preponderance of S. haematobium + Plasmodium infection occurred in females, those from Likoko, did not use potable water, practiced bathing in stream and carried out open defecation than their equivalents. However, being female (aOR = 2.38, P = 0.009) was the only significant risk factor identified. Anaemia was a common morbidity (74.3%) with a slight agreement with microscopy in predicting S. haematobium and Plasmodium infections. The sensitivity and specificity of haematuria (13.0%) in predicting S. haematobium infection was 46.5% and 100% with a moderate agreement with microscopy. Co-infection with S. haematobium and malaria parasite was significantly associated with threefold odds of history of fever in the last three days. Conclusions Polyparasitism is a public health problem in Muyuka with females most at risk. Anaemia prevalence is exacerbated in co- and triple-infections and together with a history of fever are of value in predicting polyparasitism.![]()
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Affiliation(s)
- Irene Ule Ngole Sumbele
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon. .,Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
| | - Ofon Vitalis Otia
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon
| | - Orelien Sylvain Mtopi Bopda
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.,Department of Medical Laboratory Sciences, University of Buea, Buea, Cameroon
| | - Calvin Bisong Ebai
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.,Department of Medical Laboratory Science, University of Bamenda, Bambili, Cameroon
| | - Helen KuoKuo Kimbi
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.,Department of Medical Laboratory Science, University of Bamenda, Bambili, Cameroon
| | - Theresa Nkuo-Akenji
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
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17
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Ndassi VD, Anchang-Kimbi JK, Sumbele IUN, Ngufor LA, Nadege K, Kimbi HK. The epidemiological status of urogenital schistosomiasis among reproductive aged individuals in the Tiko Health Area- a semi-urban setting in the Mount Cameroon area. PLoS Negl Trop Dis 2021; 15:e0008978. [PMID: 33428614 PMCID: PMC7822554 DOI: 10.1371/journal.pntd.0008978] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 01/22/2021] [Accepted: 11/11/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Urogenital schistosomiasis (UGS) caused by S. haematobium has enormous reproductive health consequences including infertility. Reproductive aged individuals are a neglected group and not included in control programs in Cameroon. This study investigated the prevalence and severity of S. haematobium infection in the context of gender and socio-economic structures that shape behaviour among reproductive aged individuals living in Tiko, a semi-urban setting, Cameroon. METHODOLOGY/PRINCIPAL FINDINGS A cross-sectional study was carried out in the Tiko Health District (THD) between May to September 2019. Consenting individuals were enrolled using a convenient sampling technique and administered a semi-structured questionnaire to document data on socio-demographic and stream contact behaviour. A urine sample was collected and screened for the presence of S. haematobium ova using reagent strips, filtration and microscopy. The overall prevalence of S. haematobium infection was 22.8% (95% CL: 19.27-26.73) with geometric mean egg load of 18.74 (range: 1-1600) per 10ml of urine. Younger age group (15 - 20years) (OR: 5.13; 95% CL: 1.35-19.42), male (OR: 2.60 3.07; 95% CL: 1.54-4.40) and awareness of UGS (OR: 1.73; 95% CL: 1.02-2.95) were associated with higher odds of exposure to infection. Significantly higher intensity of infection was seen in males, singles and in the age group 15-30 years. It is worth noting that males carried out more activities which entailed longer duration in streams. CONCLUSION/SIGNIFICANCE The prevalence obtained shows that Tiko is a moderate-risk area for UGS with underlying morbidity-inducing infection intensity. The severity of the infection is more in males. Awareness of the disease is not enough to protect these communities from infection, but provision of public infrastructures and health education will limit contact with infested water and thus curtail the infection. There is an urgent need to involve all age groups in control programs.
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Affiliation(s)
- Vicky Daonyle Ndassi
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon
| | | | - Irene Ule Ngole Sumbele
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Lennin Azaofah Ngufor
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Kouemou Nadege
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Helen Kuokuo Kimbi
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon
- Department of Medical Laboratory Science, Faculty of Health Sciences, University of Bamenda, Bamenda, Cameroon
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18
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Eyre MT, Stanton MC, Macklin G, Bartoníček Z, O'Halloran L, Eloundou Ombede DR, Chuinteu GD, Stewart M, LaCourse EJ, Tchuem Tchuenté LA, Stothard JR. Piloting an integrated approach for estimation of environmental risk of Schistosoma haematobium infections in pre-school-aged children and their mothers at Barombi Kotto, Cameroon. Acta Trop 2020; 212:105646. [PMID: 32721393 DOI: 10.1016/j.actatropica.2020.105646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/27/2022]
Abstract
Within schistosomiasis control, assessing environmental risk of currently non-treated demographic groups e.g. pre-school-aged children (PSAC) and their mothers is important. We conducted a pilot micro-epidemiological assessment at the crater lake of Barombi Kotto, Cameroon with GPS tracking and infection data from 12 PSAC-mother pairs (n = 24) overlaid against environmental sampling inclusive of snail, parasite and water-use information. Several high-risk locations or 'hotspots' with elevated water contact, increased intermediate snail host densities and detectable schistosome environmental DNA (eDNA) were identified. Exposure between PSAC and mother pairs was temporally and spatially associated, suggesting interventions which can benefit both groups simultaneously might be feasible. When attempting to interrupt parasite transmission in future, overlaid maps of snail, parasite and water contact data can guide fine-scale spatial targeting of environmental interventions.
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Affiliation(s)
- M T Eyre
- Liverpool School of Tropical Medicine, Liverpool L3 5QA United Kingdom; Centre for Health Informatics, Computing, and Statistics, Lancaster University Medical School, Lancaster LA1 4YW United Kingdom
| | - M C Stanton
- Liverpool School of Tropical Medicine, Liverpool L3 5QA United Kingdom; Centre for Health Informatics, Computing, and Statistics, Lancaster University Medical School, Lancaster LA1 4YW United Kingdom
| | - G Macklin
- Liverpool School of Tropical Medicine, Liverpool L3 5QA United Kingdom
| | - Z Bartoníček
- Liverpool School of Tropical Medicine, Liverpool L3 5QA United Kingdom
| | - L O'Halloran
- Liverpool School of Tropical Medicine, Liverpool L3 5QA United Kingdom
| | | | - G D Chuinteu
- Centre for Schistosomiasis & Parasitology, P.O. Box 7244 Yaoundé, Cameroon
| | - M Stewart
- Liverpool School of Tropical Medicine, Liverpool L3 5QA United Kingdom
| | - E J LaCourse
- Liverpool School of Tropical Medicine, Liverpool L3 5QA United Kingdom
| | | | - J R Stothard
- Liverpool School of Tropical Medicine, Liverpool L3 5QA United Kingdom.
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19
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Phillips AE, Tohon Z, Dhanani NA, Sofo B, Gnandou I, Sidikou B, Noma AG, Madougou B, Alto O, Sebangou H, Halilou KM, Andia R, Garba A, Fenwick A, Hamidou AA. Evaluating the impact of biannual school-based and community-wide treatment on urogenital schistosomiasis in Niger. Parasit Vectors 2020; 13:557. [PMID: 33203477 PMCID: PMC7672903 DOI: 10.1186/s13071-020-04411-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/21/2020] [Indexed: 11/10/2022] Open
Abstract
Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinated a five-year study implemented in several countries, including Niger, to provide an evidence-base for programmatic decisions regarding cost-effective approaches to preventive chemotherapy for schistosomiasis control. Methods This was a cluster-randomised trial investigating six possible combinations of annual or biannual community-wide treatment (CWT), school-based treatment (SBT), and holidays from mass treatment over four years. The most intense arm involved two years of annual CWT followed by 2 years of biannual CWT, while the least intensive arm involved one year of annual SBT followed by a year without treatment and two more years of annual SBT. The primary outcome of interest was prevalence and intensity of Schistosoma haematobium among 100 children aged 9–12 years sampled each year. In addition, 100 children aged 5–8 years in their first year of school and 50 adults (aged 20–55 years) were tested in the first and final fifth year of the study. Results In total, data were collected from 167,500 individuals across 225 villages in nine districts within the Niger River valley, Western Niger. Overall, the prevalence of S. haematobium decreased from baseline to Year 5 across all study arms. The relative reduction of prevalence was greater in biannual compared with annual treatment across all arms; however, the only significant difference was seen in areas with a high starting prevalence. Although adults were not targeted for treatment in SBT arms, a statistically significant decrease in prevalence among adults was seen in moderate prevalence areas receiving biannual (10.7% to 4.8%) SBT (P < 0.001). Adults tested in the annual SBT group also showed a decrease in prevalence between Year 1 and Year 5 (12.2% to 11.0%), but this difference was not significant. Conclusions These findings are an important consideration for schistosomiasis control programmes that are considering elimination and support the idea that scaling up the frequency of treatment rounds, particularly in areas of low prevalence, will not eliminate schistosomiasis. Interestingly, the finding that prevalence decreased among adults in SBT arms suggests that transmission in the community can be reduced, even where only school children are being treated, which could have logistical and cost-saving implications for the national control programmes.
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Affiliation(s)
- Anna E Phillips
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| | - Zilahatou Tohon
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | - Neerav A Dhanani
- Schistosomiasis control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Boubacar Sofo
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | | | - Boubacar Sidikou
- Hôpital National de Niamey rond-point Hôpital, BP 238, Niamey, Niger
| | - Adamou Garba Noma
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | - Bassirou Madougou
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | - Oumarou Alto
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | - Hannatou Sebangou
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | - Kader M Halilou
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | - Roumanatou Andia
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | - Amadou Garba
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
| | - Alan Fenwick
- Schistosomiasis control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Amina A Hamidou
- Aménagement et Lutte (RISEAL NIGER), Réseau International Schistosomiases Environnement, Avenue de l'indépendance, BP. 13724, Niamey, Niger
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Kayuni SA, O'Ferrall AM, Baxter H, Hesketh J, Mainga B, Lally D, Al-Harbi MH, LaCourse EJ, Juziwelo L, Musaya J, Makaula P, Stothard JR. An outbreak of intestinal schistosomiasis, alongside increasing urogenital schistosomiasis prevalence, in primary school children on the shoreline of Lake Malawi, Mangochi District, Malawi. Infect Dis Poverty 2020; 9:121. [PMID: 32867849 PMCID: PMC7456765 DOI: 10.1186/s40249-020-00736-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/07/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Intestinal schistosomiasis was not considered endemic in Lake Malawi until November 2017 when populations of Biomphalaria pfeifferi were first reported; in May 2018, emergence of intestinal schistosomiasis was confirmed. This emergence was in spite of ongoing control of urogenital schistosomiasis by preventive chemotherapy. Our current study sought to ascertain whether intestinal schistosomiasis is transitioning from emergence to outbreak, to judge if stepped-up control interventions are needed. METHODS During late-May 2019, three cross-sectional surveys of primary school children for schistosomiasis were conducted using a combination of rapid diagnostic tests, parasitological examinations and applied morbidity-markers; 1) schistosomiasis dynamics were assessed at Samama (n = 80) and Mchoka (n = 80) schools, where Schistosoma mansoni was first reported, 2) occurrence of S. mansoni was investigated at two non-sampled schools, Mangochi Orphan Education and Training (MOET) (n = 60) and Koche (n = 60) schools, where B. pfeifferi was nearby, and 3) rapid mapping of schistosomiasis, and B. pfeifferi, conducted across a further 8 shoreline schools (n = 240). After data collection, univariate analyses and Chi-square testing were performed, followed by binary logistic regression using generalized linear models, to investigate epidemiological associations. RESULTS In total, 520 children from 12 lakeshore primary schools were examined, mean prevalence of S. mansoni by 'positive' urine circulating cathodic antigen (CCA)-dipsticks was 31.5% (95% confidence interval [CI]: 27.5-35.5). Upon comparisons of infection prevalence in May 2018, significant increases at Samama (relative risk [RR] = 1.7, 95% CI: 1.4-2.2) and Mchoka (RR = 2.7, 95% CI: 1.7-4.3) schools were observed. Intestinal schistosomiasis was confirmed at MOET (18.3%) and Koche (35.0%) schools, and in all rapid mapping schools, ranging from 10.0 to 56.7%. Several populations of B. pfeifferi were confirmed, with two new eastern shoreline locations noted. Mean prevalence of urogenital schistosomiasis was 24.0% (95% CI: 20.3-27.7). CONCLUSIONS We notify that intestinal schistosomiasis, once considered non-endemic in Lake Malawi, is now transitioning from emergence to outbreak. Once control interventions can resume after coronavirus disease 2019 (COVID-19) suspensions, we recommend stepped-up preventive chemotherapy, with increased community-access to treatments, alongside renewed efforts in appropriate environmental control.
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Affiliation(s)
- Sekeleghe A Kayuni
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK.,Medi Clinic Limited, Medical Aid Society of Malawi (MASM), 22 Lower Sclatter Road, P.O. Box 1254, Blantyre, Malawi
| | - Angus M O'Ferrall
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | - Hamish Baxter
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | - Josie Hesketh
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | - Bright Mainga
- Laboratory Department, Mangochi District Hospital, P.O. Box 42, Mangochi, Malawi
| | - David Lally
- Malawi Liverpool Wellcome Trust Programme of Clinical Tropical Research, Queen Elizabeth Central Hospital, College of Medicine, P.O. Box 30096, Blantyre, Malawi
| | | | - E James LaCourse
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | - Lazarus Juziwelo
- National Schistosomiasis and STH Control Programme, Ministry of Health, Lilongwe, Malawi
| | - Janelisa Musaya
- Malawi Liverpool Wellcome Trust Programme of Clinical Tropical Research, Queen Elizabeth Central Hospital, College of Medicine, P.O. Box 30096, Blantyre, Malawi.,Department of Basic Medical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Peter Makaula
- Research for Health Environment and Development, P.O. Box 345, Mangochi, Malawi
| | - J Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK.
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Chibwana FD, Tumwebaze I, Mahulu A, Sands AF, Albrecht C. Assessing the diversity and distribution of potential intermediate hosts snails for urogenital schistosomiasis: Bulinus spp. (Gastropoda: Planorbidae) of Lake Victoria. Parasit Vectors 2020; 13:418. [PMID: 32795373 PMCID: PMC7427762 DOI: 10.1186/s13071-020-04281-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 08/03/2020] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND The Lake Victoria basin is one of the most persistent hotspots of schistosomiasis in Africa, the intestinal form of the disease being studied more often than the urogenital form. Most schistosomiasis studies have been directed to Schistosoma mansoni and their corresponding intermediate snail hosts of the genus Biomphalaria, while neglecting S. haematobium and their intermediate snail hosts of the genus Bulinus. In the present study, we used DNA sequences from part of the cytochrome c oxidase subunit 1 (cox1) gene and the internal transcribed spacer 2 (ITS2) region to investigate Bulinus populations obtained from a longitudinal survey in Lake Victoria and neighbouring systems during 2010-2019. METHODS Sequences were obtained to (i) determine specimen identities, diversity and phylogenetic positions, (ii) reconstruct phylogeographical affinities, and (iii) determine the population structure to discuss the results and their implications for the transmission and epidemiology of urogenital schistosomiasis in Lake Victoria. RESULTS Phylogenies, species delimitation methods (SDMs) and statistical parsimony networks revealed the presence of two main groups of Bulinus species occurring in Lake Victoria; B. truncatus/B. tropicus complex with three species (B. truncatus, B. tropicus and Bulinus sp. 1), dominating the lake proper, and a B. africanus group, prevalent in banks and marshes. Although a total of 47 cox1 haplotypes, were detected within and outside Lake Victoria, there was limited haplotype sharing (only Haplotype 6 was shared between populations from Lake Victoria open waters and neighbouring aquatic systems) - an indication that haplotypes are specific to habitats. CONCLUSIONS The Bulinus fauna of Lake Victoria consists of at least B. truncatus, B. tropicus, Bulinus sp. 1 (B. trigonus?) and B. ugandae. The occurrence and wide distribution of Bulinus species in Lake Victoria potentially implies the occurrence of urogenital schistosomiasis in communities living along the shores and on islands of the lake who depend solely on the lake for their livelihood. More in-depth studies are needed to obtain a better picture of the extent of the disease in the Lake Victoria basin.
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Affiliation(s)
- Fred D. Chibwana
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
- Department of Zoology and Wildlife Conservation, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Immaculate Tumwebaze
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | - Anna Mahulu
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | - Arthur F. Sands
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | - Christian Albrecht
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
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22
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Stothard JR, Kayuni SA, Al-Harbi MH, Musaya J, Webster BL. Future schistosome hybridizations: Will all Schistosoma haematobium hybrids please stand-up! PLoS Negl Trop Dis 2020; 14:e0008201. [PMID: 32614820 PMCID: PMC7332241 DOI: 10.1371/journal.pntd.0008201] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- J. Russell Stothard
- Department of Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| | - Sekeleghe A. Kayuni
- Department of Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- MASM Medi Clinics Limited, Medical Society of Malawi (MASM), Blantyre, Malawi
| | - Mohammad H. Al-Harbi
- Department of Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Ministry of Health, Qassim, Kingdom of Saudi Arabia
| | - Janelisa Musaya
- Department of Pathology, College of Medicine, University of Malawi, Blantyre, Malawi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital College of Medicine, Blantyre, Malawi
| | - Bonnie L. Webster
- Parasites and Vectors Division, Life Sciences Department, Natural History Museum, London, United Kingdom
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23
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Hoover CM, Sokolow SH, Kemp J, Sanchirico JN, Lund AJ, Jones IJ, Higginson T, Riveau G, Savaya A, Coyle S, Wood CL, Micheli F, Casagrandi R, Mari L, Gatto M, Rinaldo A, Perez-Saez J, Rohr JR, Sagi A, Remais JV, De Leo GA. Modelled effects of prawn aquaculture on poverty alleviation and schistosomiasis control. NATURE SUSTAINABILITY 2020; 2:611-620. [PMID: 33313425 PMCID: PMC7731924 DOI: 10.1038/s41893-019-0301-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 04/26/2019] [Indexed: 05/23/2023]
Abstract
Recent evidence suggests that snail predators may aid efforts to control the human parasitic disease schistosomiasis by eating aquatic snail species that serve as intermediate hosts of the parasite. Potential synergies between schistosomiasis control and aquaculture of giant prawns are evaluated using an integrated bio-economic-epidemiologic model. Combinations of stocking density and aquaculture cycle length that maximize cumulative, discounted profit are identified for two prawn species in sub-Saharan Africa: the endemic, non-domesticated Macrobrachium vollenhovenii, and the non-native, domesticated Macrobrachium rosenbergii. At profit maximizing densities, both M. rosenbergii and M. vollenhovenii may substantially reduce intermediate host snail populations and aid schistosomiasis control efforts. Control strategies drawing on both prawn aquaculture to reduce intermediate host snail populations and mass drug administration to treat infected individuals are found to be superior to either strategy alone. Integrated aquaculture-based interventions can be a win-win strategy in terms of health and sustainable development in schistosomiasis endemic regions of the world.
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Affiliation(s)
- Christopher M. Hoover
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, CA 94720 USA
| | - Susanne H. Sokolow
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950 USA
- Woods Institute for the Environment and Center for Innovation in Global Health, Stanford University, Stanford, CA 94305 USA
| | - Jonas Kemp
- Program in Human Biology, Stanford University, Stanford, CA 94305 USA
| | - James N. Sanchirico
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA 95616 USA
| | - Andrea J. Lund
- Emmett Interdisciplinary Program in Environment and Resources, School of Earth, Energy and Environmental Sciences, Stanford University, Stanford, CA 94305 USA
| | - Isabel J. Jones
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950 USA
| | - Tyler Higginson
- Middlebury Institute of International Studies at Monterey, Monterey, CA 93940 USA
| | - Gilles Riveau
- Biomedical Research Center EPLS, Saint Louis, Senegal
| | - Amit Savaya
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Shawn Coyle
- Kentucky State University, Aquaculture Division, Aquaculture Research Center, Frankfort, KY 40601 USA
| | - Chelsea L. Wood
- University of Washington, School of Aquatic and Fishery Sciences, Seattle, WA 98195 USA
| | - Fiorenza Micheli
- Hopkins Marine Station and Center for Ocean Solutions, Stanford University, Pacific Grove, CA 93950 USA
| | - Renato Casagrandi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Lorenzo Mari
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Andrea Rinaldo
- Laboratory of Ecohydrology, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Switzerland
| | - Javier Perez-Saez
- Laboratory of Ecohydrology, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Switzerland
| | - Jason R. Rohr
- Department of Biological Sciences, Eck Institute of Global Health, Environmental Change Initiative University of Notre Damea, Notre Dame, IN, 46556 USA
- Department of Integrative Biology, University of South Florida, Tampa, FL, 33620 USA
| | - Amir Sagi
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Justin V. Remais
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, CA 94720 USA
| | - Giulio A. De Leo
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950 USA
- Woods Institute for the Environment and Center for Innovation in Global Health, Stanford University, Stanford, CA 94305 USA
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Schistosoma species detection by environmental DNA assays in African freshwaters. PLoS Negl Trop Dis 2020; 14:e0008129. [PMID: 32203507 PMCID: PMC7117781 DOI: 10.1371/journal.pntd.0008129] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 04/02/2020] [Accepted: 02/10/2020] [Indexed: 12/17/2022] Open
Abstract
Background Schistosomiasis is a neglected tropical parasitic disease associated with severe pathology, mortality and economic loss worldwide. Programs for disease control may benefit from specific and sensitive diagnostic methods to detect Schistosoma trematodes in aquatic environments. Here we report the development of novel environmental DNA (eDNA) qPCR assays for the presence of the human-infecting species Schistosoma mansoni, S. haematobium and S. japonicum. Methodology/Principal findings We first tested the specificity of the assays across the three species using genomic DNA preparations which showed successful amplification of target sequences with no cross amplification between the three focal species. In addition, we evaluated the specificity of the assays using synthetic DNA of multiple Schistosoma species, and demonstrated a high overall specificity; however, S. japonicum and S. haematobium assays showed cross-species amplification with very closely-related species. We next tested the effectiveness of the S. mansoni assay using eDNA samples from aquaria containing infected host gastropods, with the target species revealed as present in all infected aquaria. Finally, we evaluated the effectiveness of the S. mansoni and S. haematobium assays using eDNA samples from eight discrete natural freshwater sites in Tanzania, and demonstrated strong correspondence between infection status established using eDNA and conventional assays of parasite prevalence in host snails. Conclusions/Significance Collectively, our results suggest that eDNA monitoring is able to detect schistosomes in freshwater bodies, but refinement of the field sampling, storage and assay methods are likely to optimise its performance. We anticipate that environmental DNA-based approaches will help to inform epidemiological studies and contribute to efforts to control and eliminate schistosomiasis in endemic areas. Schistosomiasis, otherwise known as bilharzia or snail fever, is a prevalent human disease found across tropical regions of the world and is a major cause of disability. The disease is acquired from exposure to the schistosome infectious larvae released by infected host snails in freshwaters. Programs to restrict the transmission of schistosomiasis would benefit from rapid and reliable diagnostic methods to detect schistosomes. Here we report a study that has developed new diagnostic tools to identify the DNA from three human-infecting Schistosoma species within water samples. This “environmental DNA” (eDNA) approach requires the filtering and laboratory analyses of water samples, and avoids the requirements to locate, identify and individually test the infectious status of host snails. Our results showed that eDNA methods detect the presence of the parasite in freshwater bodies. However, there is need for further refinement for sampling and laboratory techniques to improve the performance of the assays. We anticipate that eDNA approaches will provide information on the distribution and abundance the water-borne parasites, and potentially contribute to the control and elimination of schistosomiasis.
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25
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Fuss A, Mazigo HD, Mueller A. Malacological survey to identify transmission sites for intestinal schistosomiasis on Ijinga Island, Mwanza, north-western Tanzania. Acta Trop 2020; 203:105289. [PMID: 31837312 DOI: 10.1016/j.actatropica.2019.105289] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 11/28/2019] [Accepted: 12/03/2019] [Indexed: 12/18/2022]
Abstract
The role of malacological surveys to identify potential transmission sites for schistosomiasis control in this era of mass drug administration have received little attention. In that context, the present study was conducted to determine the abundance, identity and disease transmission potential of intermediate host snails for intestinal schistosomiasis on Ijinga Island, north-western Tanzania. A cross-sectional malacological study was conducted between February and March 2016 on Ijinga Island, Lake Victoria, north-western Tanzania. Snails were collected at points where humans are in frequent contact with water using a standardized scooping technique and have been identified using shell morphological features. The Schistosoma infection status of the collected snails was determined by using real-time Polymerase Chain Reaction (real-time PCR). A total number of 4,888 snails were putatively identified as Biomphalaria species. A random sample of 788 snails underwent molecular analyses for Schistosoma infection. Overall, 279 (35.4%) of Biomphalaria species were identified to be infected with parasites of the lateral spined S. mansoni group. The findings confirm that Biomphalaria species collected in areas with high human water contacts are infected with Schistosoma and that there is a likeliness of local risk for schistosomiasis transmission at most water contact points around Ijinga Island.
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26
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Alzaylaee H, Collins RA, Shechonge A, Ngatunga BP, Morgan ER, Genner MJ. Environmental DNA-based xenomonitoring for determining Schistosoma presence in tropical freshwaters. Parasit Vectors 2020; 13:63. [PMID: 32051004 PMCID: PMC7017522 DOI: 10.1186/s13071-020-3941-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 02/03/2020] [Indexed: 02/07/2023] Open
Abstract
Background Schistosomiasis is a neglected tropical disease that infects over 200 million people worldwide. Control measures can benefit from improved surveillance methods in freshwaters, with environmental DNA (eDNA) surveys having the potential to offer effective and rapid detection of schistosomes. However, sampling eDNA directly from natural water bodies can lead to inaccurate estimation of infection risk if schistosome eDNA is rare in the environment. Here we report a xenomonitoring method that allows schistosome infections of host snail species to be determined from eDNA in water used to house those snails. Methods Host snail species were collected and placed in containers of water and allowed to shed cercariae, and then water samples were filtered and tested using qPCR assays specific to the African species Schistosoma mansoni and Schistosoma haematobium. We evaluated this “eDNA-based xenomonitoring” approach by experimentally comparing the results to those obtained from direct qPCR screening of tissue sourced from the snails in the experiment. Results We found that our method accurately diagnosed the presence of S. mansoni-infected snails in all tests, and S. haematobium-infected snails in 92% of tests. Moreover, we found that the abundance of Schistosoma eDNA in experiments was directly dependent on the number and biomass of infected snails. Conclusions These results provide a strong indication that this surveillance method combining the utility of eDNA-based monitoring with the reliability of traditional xenomonitoring approaches could be used to accurately assay the presence of Schistosoma species in natural habitats. This approach may be well-suited for epidemiological studies and monitoring in endemic areas, where it can assist schistosomiasis control by indicating infection risk from freshwaters and guiding necessary interventions to eliminate the disease.![]()
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Affiliation(s)
- Hind Alzaylaee
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.,Biology Department, Faculty of Sciences, Prince Nourah Bin Abdulrahman University, Riyadh, Saudi Arabia
| | - Rupert A Collins
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Asilatu Shechonge
- Tanzania Fisheries Research Institute (TAFIRI), PO Box 9750, Dar es Salaam, Tanzania
| | - Benjamin P Ngatunga
- Tanzania Fisheries Research Institute (TAFIRI), PO Box 9750, Dar es Salaam, Tanzania
| | - Eric R Morgan
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.,School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK
| | - Martin J Genner
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.
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27
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Saelens G, Gabriël S. Currently Available Monitoring and Surveillance Systems for Taenia spp., Echinococcus spp., Schistosoma spp., and Soil-Transmitted Helminths at the Control/Elimination Stage: A Systematic Review. Pathogens 2020; 9:E47. [PMID: 31935916 PMCID: PMC7168685 DOI: 10.3390/pathogens9010047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/02/2020] [Accepted: 01/02/2020] [Indexed: 12/13/2022] Open
Abstract
An increasing global focus on neglected tropical diseases (NTDs) has resulted in the set up of numerous control and elimination activities worldwide. This is partly true for Taenia solium taeniasis/cysticercosis, the most important foodborne parasitic infection. Despite substantial progress, adequate monitoring and surveillance (M&S) are required to sustain a status of control/elimination. This is often lacking, especially for T. solium. Therefore, the objective was to conduct a systematic literature review of the currently available M&S systems at the control/elimination stage of the four top-ranked helminth NTDs. Specifically, Taenia spp., Echinococcus spp., Schistosoma spp., and soil-transmitted helminths (STHs) were considered to determine if there are any similarities between their M&S systems and whether certain approaches can be adopted from each other. The systematic review demonstrated that rigorous M&S systems have been designed for the control/elimination stage of both STHs and schistosomiasis, particularly in China. On the other hand, a concept of M&S for Taenia spp. and Echinococcus spp. has not been fully developed yet, due to a lack of epidemiological data and the fact that many endemic countries are far away from reaching control/elimination. Moreover, accurate diagnostic tools for all four diseases are still imperfect, which complicates proper M&S. Finally, there is an urgent need to develop and harmonize/standardize M&S activities in order to reliably determine and compare the epidemiological situation worldwide.
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Affiliation(s)
- Ganna Saelens
- Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke B-9820, Belgium
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28
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Deol AK, Fleming FM, Calvo-Urbano B, Walker M, Bucumi V, Gnandou I, Tukahebwa EM, Jemu S, Mwingira UJ, Alkohlani A, Traoré M, Ruberanziza E, Touré S, Basáñez MG, French MD, Webster JP. Schistosomiasis - Assessing Progress toward the 2020 and 2025 Global Goals. N Engl J Med 2019; 381:2519-2528. [PMID: 31881138 PMCID: PMC6785807 DOI: 10.1056/nejmoa1812165] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND With the vision of "a world free of schistosomiasis," the World Health Organization (WHO) set ambitious goals of control of this debilitating disease and its elimination as a public health problem by 2020 and 2025, respectively. As these milestones become imminent, and if programs are to succeed, it is important to evaluate the WHO programmatic guidelines empirically. METHODS We collated and analyzed multiyear cross-sectional data from nine national schistosomiasis control programs (in eight countries in sub-Saharan Africa and in Yemen). Data were analyzed according to schistosome species (Schistosoma mansoni or S. haematobium), number of treatment rounds, overall prevalence, and prevalence of heavy-intensity infection. Disease control was defined as a prevalence of heavy-intensity infection of less than 5% aggregated across sentinel sites, and the elimination target was defined as a prevalence of heavy-intensity infection of less than 1% in all sentinel sites. Heavy-intensity infection was defined as at least 400 eggs per gram of feces for S. mansoni infection or as more than 50 eggs per 10 ml of urine for S. haematobium infection. RESULTS All but one country program (Niger) reached the disease-control target by two treatment rounds or less, which is earlier than projected by current WHO guidelines (5 to 10 years). Programs in areas with low endemicity levels at baseline were more likely to reach both the control and elimination targets than were programs in areas with moderate and high endemicity levels at baseline, although the elimination target was reached only for S. mansoni infection (in Burkina Faso, Burundi, and Rwanda within three treatment rounds). Intracountry variation was evident in the relationships between overall prevalence and heavy-intensity infection (stratified according to treatment rounds), a finding that highlights the challenges of using one metric to define control or elimination across all epidemiologic settings. CONCLUSIONS These data suggest the need to reevaluate progress and treatment strategies in national schistosomiasis control programs more frequently, with local epidemiologic data taken into consideration, in order to determine the treatment effect and appropriate resource allocations and move closer to achieving the global goals. (Funded by the Children's Investment Fund Foundation and others.).
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Affiliation(s)
- Arminder K Deol
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Fiona M Fleming
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Beatriz Calvo-Urbano
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Martin Walker
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Victor Bucumi
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Issah Gnandou
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Edridah M Tukahebwa
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Samuel Jemu
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Upendo J Mwingira
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Abdulhakeem Alkohlani
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Mahamadou Traoré
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Eugene Ruberanziza
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Seydou Touré
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Maria-Gloria Basáñez
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Michael D French
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Joanne P Webster
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
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Perez-Saez J, Mande T, Zongo D, Rinaldo A. Comparative analysis of time-based and quadrat sampling in seasonal population dynamics of intermediate hosts of human schistosomes. PLoS Negl Trop Dis 2019; 13:e0007938. [PMID: 31860653 PMCID: PMC6957212 DOI: 10.1371/journal.pntd.0007938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 01/13/2020] [Accepted: 11/20/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Despite their importance for designing and evaluating schistosomiasis control trials, little attention in the literature has been dedicated to sampling protocols for the parasite's snail intermediate hosts since their first development. We propose a comparative analysis of time-based and quadrat sampling protocols to quantify the seasonal variations in the abundance of these aquatic snail species of medical importance. METHODOLOGY/PRINCIPAL FINDINGS Snail populations were monitored during 42 consecutive months in three types of habitats (ephemeral pond, ephemeral river and permanent stream) in two sites covering different climatic zones in Burkina Faso. We employed both a widely used time-based protocol of 30min of systematic collection at a weekly interval, and a quadrat protocol of 8 replicates per sample at a monthly interval. The correspondence between the two protocols was evaluated using an ensemble of statistical models including linear and saturating-type functional forms as well as allowing for count zero-inflation. The quadrat protocol yielded on average a relative standard error of 40%, for a mean snail density of 16.7 snails/m2 and index of dispersion of 1.51. Both protocols yielded similar seasonal patterns in snail abundance, confirming the asynchrony between permanent and ephemeral habitats with respect to the country's seasonal rainfall patterns. Formal model comparison of the link between time vs. quadrat counts showed strong support of saturation for the latter and measurement zero-inflation, providing important evidence for the presence of density feedbacks in the snail's population dynamics, as well as for spatial clustering. CONCLUSIONS/SIGNIFICANCE In addition to the agreement with the time-based method, quadrat sampling provided insight into snail population dynamics and comparable density estimates across sites. The re-evaluation of these "traditional" sampling protocols, as well as the correspondence between their outputs, is of practical importance for the design and evaluation of schistosomiasis control trials.
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Affiliation(s)
- Javier Perez-Saez
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Théophile Mande
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Dramane Zongo
- Départemente Biomédical et Santé publique, Institut de Recherche en Sciences de la Santé, Ouagadougou, Burkina Faso
| | - Andrea Rinaldo
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Dipartimento ICEA, Università di Padova, Padova, Italy
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How can schistosome circulating antigen assays be best applied for diagnosing male genital schistosomiasis (MGS): an appraisal using exemplar MGS cases from a longitudinal cohort study among fishermen on the south shoreline of Lake Malawi. Parasitology 2019; 146:1785-1795. [PMID: 31452477 PMCID: PMC6939168 DOI: 10.1017/s0031182019000969] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.
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Takeuchi R, Njenga SM, Ichinose Y, Kaneko S, Estrada CA, Kobayashi J. Is there a gap between health education content and practice toward schistosomiasis prevention among schoolchildren along the shores of Lake Victoria in Kenya? PLoS Negl Trop Dis 2019; 13:e0007572. [PMID: 31425499 PMCID: PMC6715249 DOI: 10.1371/journal.pntd.0007572] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 08/29/2019] [Accepted: 06/22/2019] [Indexed: 01/07/2023] Open
Abstract
Despite provision of preventive measures against schistosomiasis such as mass drug administration (MDA), the prevalence of Schistosoma mansoni remains high in communities living near Lake Victoria. This study aimed to analyse the status of schistosomiasis, including its prevalence, health education, knowledge, attitudes, and practices (KAP) among pupils, and water use in schools in Mbita situated along the shores of Lake Victoria. Four primary schools were selected as target schools and pupils in classes six and seven were recruited as study participants. The prevalence of S. mansoni was examined by Kato-Katz method. Simultaneously, a KAP survey toward schistosomiasis was conducted among the pupils. Health education contents were extracted from textbooks. All primary schools in the study site were surveyed regarding how each secured water used for daily school life. The prevalence of S. mansoni was 56% and 36% in 2015 and 2016, respectively. 60–70% of pupils chose a correct answer for the mode of transmission. More than 70% of pupils answered that bathing in Lake Victoria causes Schistosoma infection; however, more than 70% of pupils bathed in Lake Victoria sometimes or every day. According to the science textbook, “avoiding contact with contaminated water” is the way to prevent schistosomiasis; however, 66% of schools asked pupils to bring water from Lake Victoria. The prevalence of S. mansoni among pupils remains high. Schoolchildren are taught to avoid contact with contaminated water but are often asked to fetch water from the lake. From the school health viewpoint, health education that reflects the social and cultural context of the community in the contents and teaching methods are needed. In addition to this, provision of sanitation infrastructure is needed. A comprehensive and innovative approach which harmonises central and local governments and other stakeholders, as well as community is important to prevent schistosomiasis. According to WHO, it is estimated that at least 206 million people required preventive treatment for schistosomiasis in 2016 and of those at least 90% live in Africa. Moreover, school-age children are most affected by this worm. In Kenya, despite preventive measures against schistosomiasis such as mass drug administration (MDA) in primary schools, it remains a major public health problem, especially along the shores of Lake Victoria. Our study revealed that the prevalence of Schistosoma mansoni was high among pupils despite their knowledge about schistosomiasis transmission. This can be attributed to lack of safe water supply and latrines. A comprehensive approach which harmonises central and local governments and other stakeholders, as well as community is needed to prevent schistosomiasis. For example, the combination of health education (in which schools play as focal point) with provision of water infrastructure, encouragement to use and construct toilets in both schools and community/households, snail control, and MDA with monitoring can be employed to control and prevent schistosomiasis. From the school health viewpoint, it is necessary to develop health education contents and teaching methods that reflect the social and cultural context of the community in order to improve their behaviour and change the social norm.
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Affiliation(s)
- Rie Takeuchi
- Kenya Research Station, Institute of Tropical Medicine, Nagasaki University, Nairobi, Kenya
- * E-mail:
| | - Sammy M. Njenga
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Yoshio Ichinose
- Kenya Research Station, Institute of Tropical Medicine, Nagasaki University, Nairobi, Kenya
| | - Satoshi Kaneko
- Kenya Research Station, Institute of Tropical Medicine, Nagasaki University, Nairobi, Kenya
- Department of Eco-epidemiology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Crystal A. Estrada
- Department of Global Health, Graduate School of Health Sciences, University of the Ryukyus, Okinawa, Japan
| | - Jun Kobayashi
- Department of Global Health, Graduate School of Health Sciences, University of the Ryukyus, Okinawa, Japan
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Exum NG, Kibira SPS, Ssenyonga R, Nobili J, Shannon AK, Ssempebwa JC, Tukahebwa EM, Radloff S, Schwab KJ, Makumbi FE. The prevalence of schistosomiasis in Uganda: A nationally representative population estimate to inform control programs and water and sanitation interventions. PLoS Negl Trop Dis 2019; 13:e0007617. [PMID: 31412023 PMCID: PMC6709927 DOI: 10.1371/journal.pntd.0007617] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 08/26/2019] [Accepted: 07/09/2019] [Indexed: 12/13/2022] Open
Abstract
Background To improve schistosomiasis control programs in Uganda, where intestinal schistosomiasis is a widespread public health problem, a country-wide assessment of the disease prevalence among all age ranges is needed. Few studies have aimed to quantify the relationships between disease prevalence and water and sanitation characteristics across Uganda to understand the potential to interrupt disease transmission with an integrated package of interventions. Methodology/Principal findings A nationally representative survey was undertaken that included a household and individual questionnaire followed by disease testing based on detection of worm antigens (circulating cathodic antigen–CCA), diagnosis and treatment. A comprehensive set of questions was asked of randomly sampled individuals, two years of age and above, to understand their water and sanitation infrastructure, open defecation behaviors, exposure to surface water bodies, and knowledge of schistosomiasis. From a set of 170 randomly sampled, geographically diverse enumeration areas, a total of 9,183 study participants were included. After adjustment with sample weights, the national prevalence of schistosomiasis was 25.6% (95% confidence interval (CI): 22.3, 29.0) with children ages two to four most at risk for the disease with 36.1% infected (95% CI: 30.1, 42.2). The defecation behaviors of an individual were more strongly associated with infection status than the household water and sanitation infrastructure, indicating the importance of incorporating behavior change into community-led total sanitation coverage. Conclusions/Significance Our results highlight the importance of incorporating monitoring and evaluation data into control programs in Uganda to understand the geographic distribution of schistosomiasis prevalence outside of communities where endemicity is known to be high. The high prevalence of schistosomiasis among the youngest age group, ineligible to receive drug treatment, shows the imperative to develop a child-appropriate drug protocol that can be safely administered to preschool-aged children. Water and sanitation interventions should be considered an essential investment for elimination alongside drug treatment. Schistosomiasis is a neglected tropical disease in sub-Saharan Africa that has remained intractable despite efforts to eliminate it through mass drug administration. The transmission cycle is perpetuated when sanitation infrastructure does not adequately capture infected urine or feces and local water bodies, with snail vectors, are contaminated. Schistosomiasis has been linked with stunting and cognitive deficits and there is particular concern for the most vulnerable age group under five years old who are undergoing critical intestinal development but are ineligible to receive drug treatment. Efforts to reduce the disease have focused on children and young adolescents in endemic areas, near water bodies where transmission is known to be high. In Uganda, where fresh water bodies are abundant and intestinal schistosomiasis is endemic, very little is understood about the disease prevalence at a national level. We conducted a large, nationally representative survey and found a national prevalence of 25.6% where the 2–4 year old children had the highest prevalence for schistosomiasis with 36.1% infected. The most significant risk-factor for the disease was an individual’s open defecation behaviors in surface waters. This emphasizes the need to include water and sanitation investments alongside drug treatment and behavior change to control schistosomiasis in Uganda.
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Affiliation(s)
- Natalie G. Exum
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
- * E-mail:
| | - Simon P. S. Kibira
- Department of Community Health and Behavioral Sciences, School of Public Health, Makerere University, Kampala, Uganda
| | - Ronald Ssenyonga
- Department of Epidemiology and Biostatistics, School of Public Health, Makerere University, Kampala, Uganda
| | - Julien Nobili
- Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Alexandra K. Shannon
- Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - John C. Ssempebwa
- Department of Disease Control and Environmental Health, School of Public Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Scott Radloff
- Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Kellogg J. Schwab
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Fredrick E. Makumbi
- Department of Epidemiology and Biostatistics, School of Public Health, Makerere University, Kampala, Uganda
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Environmental DNA for improved detection and environmental surveillance of schistosomiasis. Proc Natl Acad Sci U S A 2019; 116:8931-8940. [PMID: 30975758 DOI: 10.1073/pnas.1815046116] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Schistosomiasis is a water-based, infectious disease with high morbidity and significant economic burdens affecting >250 million people globally. Disease control has, with notable success, for decades focused on drug treatment of infected human populations, but a recent paradigm shift now entails moving from control to elimination. To achieve this ambitious goal, more sensitive diagnostic tools are needed to monitor progress toward transmission interruption in the environment, especially in low-intensity infection areas. We report on the development of an environmental DNA (eDNA)-based tool to efficiently detect DNA traces of the parasite Schistosoma mansoni directly in the aquatic environment, where the nonhuman part of the parasite life cycle occurs. This is a report of the successful detection of S. mansoni in freshwater samples by using aquatic eDNA. True eDNA was detected in as few as 10 cercariae per liter of water in laboratory experiments. The field applicability of the method was tested at known transmission sites in Kenya, where comparison of schistosome detection by conventional snail surveys (snail collection and cercariae shedding) with eDNA (water samples) showed 71% agreement between the methods. The eDNA method furthermore detected schistosome presence at two additional sites where snail shedding failed, demonstrating a higher sensitivity of eDNA sampling. We conclude that eDNA provides a promising tool to substantially improve the environmental surveillance of S. mansoni Given the proper method and guideline development, eDNA could become an essential future component of the schistosomiasis control tool box needed to achieve the goal of elimination.
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Kukula VA, MacPherson EE, Tsey IH, Stothard JR, Theobald S, Gyapong M. A major hurdle in the elimination of urogenital schistosomiasis revealed: Identifying key gaps in knowledge and understanding of female genital schistosomiasis within communities and local health workers. PLoS Negl Trop Dis 2019; 13:e0007207. [PMID: 30897093 PMCID: PMC6428244 DOI: 10.1371/journal.pntd.0007207] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/31/2019] [Indexed: 12/24/2022] Open
Abstract
Background Urogenital schistosomiasis is endemic throughout Ghana with elevated infection levels in certain areas e.g. Lake Volta Region. While the primary focus of the national control program is on mass drug administration of praziquantel to school-aged children, Female Genital Schistosomiasis (FGS), a disease-specific affliction of girls and women, has been largely overlooked. To better focus future actions, our study investigated the perceptions, knowledge and understanding of FGS amongst community members and health providers. Method/Principal findings We used qualitative methods including 12 focus group discussions and 34 in-depth interviews. We purposively selected 16 communities along the Lake Volta in the Shai-Osudoku District. Participant selection was based on gender, age and occupation; providing an opportunity to explore community understanding of FGS through participants own words and perceptions. Awareness of schistosomiasis was reported and is commonly experienced among children (12–17 years) and younger adults (18–25 years) in the study communities but is typically considered a boy’s disease. Knowledge of FGS was lacking in women, girls and front-line health workers. There was a general misconception that FGS may be the result of sexual promiscuity. Adolescent girls reporting vaginal discharge and itching were often stigmatized by health workers and treated for sexually transmitted infections. Limited alternatives to the river as key source of water meant that all members of the community faced the regular risk of schistosomiasis. Conclusion/Significance There is a clear imperative for the national control program to better engage on FGS and implement interventions to meet girls and women’s needs. The key consideration is to integrate more adequately preventive services with sexual and reproductive primary health care with future training of health workers for improved management of FGS cases. More broadly, harmonizing the portfolio of all actions on FGS is needed, especially with a call for improved access to safe water and sanitation for all those at current or future risk. Female Genital Schistosomiasis (FGS) is a serious, chronic gynecological condition that affects up to 56 million African women and girls. To date, FGS has been mostly overlooked within national neglected tropical disease control programs and associated health systems in sub-Saharan Africa. Furthermore, knowledge and understanding of FGS within affected communities themselves are often incomplete and confused with other ailments. Using qualitative research methods, we explored the knowledge and understanding of girls and women on FGS, as well as, local health care providers’ knowledge and practice relating to FGS. While, our work found that FGS was rarely on the radar of suspicion for health workers, more importantly, adolescent girls were often stigmatized by health care workers when they sought care in public health facilities owing to misdiagnosis of the disease as sexually transmitted infections. Our work speaks to the urgent need for national control programs to expand their remit outside current focus of annual provision of praziquantel to in-school children and integrate such treatments within sexual and reproductive health services available in primary health care services. Ultimately, urogenital and intestinal schistosomiasis is a disease of poverty and there is an urgent need to extend access to improved water and sanitation facilities to all affected communities.
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Affiliation(s)
- Vida Ami Kukula
- Dodowa Health Research Centre, Ghana Health Service, Dodowa, Ghana
- * E-mail: ,
| | - Eleanor E. MacPherson
- Malawi-Liverpool-Wellcome Trust, Blantyre, Malawi
- Department of International Public Health, COUNTDOWN Consortium, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Irene Honam Tsey
- Dodowa Health Research Centre, Ghana Health Service, Dodowa, Ghana
| | - J. Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Sally Theobald
- Department of International Public Health, COUNTDOWN Consortium, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Margaret Gyapong
- COUNTDOWN Consortium, Institute for Health Research, University of Health and Allied Sciences, Ho, Ghana
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Human schistosomiasis in Benin: Countrywide evidence of Schistosoma haematobium predominance. Acta Trop 2019; 191:185-197. [PMID: 30633895 DOI: 10.1016/j.actatropica.2019.01.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 12/28/2018] [Accepted: 01/07/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND A national mapping of human schistosomiasis was conducted in Benin to provide the baseline epidemiological data required to implement the national strategy for schistosomiasis control and elimination to achieve the WHO's goal of reaching at least 75% of school-age children in endemic areas by 2020. METHODS Parasitological surveys were conducted from 2013 to 2015, among 19,250 children aged 8-14 years randomly sampled in 385 units (schools/villages) across all districts. Urine and stool samples were examined using parasite-egg filtration for urine samples and the Kato-Katz technique for stool specimens. RESULTS Human schistosome eggs from two major species (S. haematobium and S. mansoni) were detected in the surveyed population with variable prevalence and parasite intensity. Urinary schistosomiasis due to S. haematobium was widely distributed and detected in 76/77 districts with a national average prevalence of 17.56% (95 °CI:16.80%- 18.32%), compared to S. mansoni detected in 28/77 districts with a national prevalence of 2.45% (95 °CI:2.14%-2.76%). The combined national prevalence of schistosomiasis, defined by infections with either or both schistosome species was 19.78% (95% CI:18.90% -20.49%), and was detected in 76/77 districts. Based on our findings, 31 districts were classified as low-risk (>0% and <10%); 37 as moderate-risk (≥10% and <50%); and 8 as high-risk (≥50%) of schistosome infection. No infection was detected in Kpomassè district in this study. In several districts where the two species were endemic with prevalence ≥10%, S. haematobium was the most prevalent schistosome species. Boys were relatively more infected than girls (18.29% v 16.82%, p = 0.007). Of note, heavy infections with S. haematobium (>50 eggs/10 mL) were detected in several districts of Atacora, Donga, Borgou, Collines, Ouémé and Atlantique departments. CONCLUSIONS The schistosomiasis mapping reported here clearly present a nationwide view of the epidemiological pattern of Schistosoma infections and the baseline data for implementing an effective control strategy by preventive chemotherapy (PCT). Although PCT might not be required in 32/77 districts, a yearly and bi-annual deworming is needed in 2 and 43 districts, respectively. If no environmental change occurs, and no mass treatment is delivered, prevalence is likely to remain stable for many years owing to poor hygiene and sanitation.
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Mpairwe H, Amoah AS. Parasites and allergy: Observations from Africa. Parasite Immunol 2018; 41:e12589. [PMID: 30216486 PMCID: PMC6587767 DOI: 10.1111/pim.12589] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 08/15/2018] [Accepted: 09/10/2018] [Indexed: 12/17/2022]
Abstract
Population studies from the African continent have observed a marked increase in the prevalence of allergy‐related diseases over the past few decades, but the cause of this rise is not fully understood. The most investigated potential risk factor has been the relationship between exposure to helminths and allergy‐related outcomes. Immunologically, parallels exist between responses to helminths and to allergens as both are associated with elevated levels of immunoglobulin E, increased numbers of T helper 2 cells and other immune cells. However, epidemiological studies from the African continent have found inconsistent results. In this review, observations from population studies carried out in Africa over the last decade that focus on the relationship between helminth infections and allergy‐related outcomes are examined. How these findings advance our understanding of the complex interactions between helminths and allergies at the population level is also explored as well as some of the underlying immune mechanisms involved. This knowledge is important for better diagnosis, treatment and prevention of allergy‐related diseases and has wider global significance.
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Affiliation(s)
- Harriet Mpairwe
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Abena S Amoah
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
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Nono JK, Kamdem SD, Netongo PM, Dabee S, Schomaker M, Oumarou A, Brombacher F, Moyou-Somo R. Schistosomiasis Burden and Its Association With Lower Measles Vaccine Responses in School Children From Rural Cameroon. Front Immunol 2018; 9:2295. [PMID: 30356757 PMCID: PMC6189399 DOI: 10.3389/fimmu.2018.02295] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 09/17/2018] [Indexed: 12/19/2022] Open
Abstract
Background and Methods: Schistosomiasis is debilitating and reported to impair immune responsiveness of infected hosts. In Cameroon, mass drug administration (MDA) is used in schoolchildren to reduce transmission of S. haematobium and S. mansoni. The effects of MDA and the impact of schistosomiasis on the titers of antibodies in vaccinated children have been poorly studied. We therefore assessed the prevalence of schistosomiasis in schoolchildren, eight months after MDA, in two locations: Barombi Koto (BK), endemic for S. haematobium (N = 169) and Yoro (Y), endemic for S. mansoni (N = 356). Age, gender, residence time and frequency of contact with river water were assessed as risk factors for infection and morbidity in both localities. In 70 schoolchildren from BK and 83 from Y, ultrasound was used to assess morbidity according to the WHO guidelines. Evaluation of measles antibodies was performed in previously vaccinated schoolchildren (14 with S. haematobium and 12 egg-negative controls from BK and 47 with S. mansoni and12 egg-negative controls from Y). Principal Findings and conclusions: The prevalence of S. haematobium was 25. 4% in BK (43/169) and 34.8% for S. mansoni in Y (124/356), indicating the persistent transmission of schistosomiasis despite MDA. Older age (AOR 1.31; 95%CI 1.12–1.54) and higher frequencies of exposure to river water (AOR 1.99; 95%CI 1.03–3.86) were identified as risks for infection in BK whereas only older age (OR 1.15; 95%CI 1.04–1.27) was a risk for infection in Y. Bladder pathology (score 2 to 5) was observed in 29.2% (7/24) of egg-positive children in BK and liver pathology (pattern C) in 31.1% (19/61) of egg-positive children in Y. There was a positive correlation between S. haematobium egg burden and bladder pathology (AOR 1.01; 95% CI 0.99–1.02) and positive correlation between S. mansoni-driven liver pathology and female gender (AOR 3.01; 95% CI 0.88–10.26). Anti-measles antibodies in vaccinated children were significantly lower in S. mansoni-infected when compared to egg-negative controls (p = 0.001), which was not observed in the S. haematobium-infected group from BK. Our results demonstrate a questionable efficacy of MDA alone in halting schistosomiasis transmission and confirm a possible immunomodulatory effect of S. mansoni on response to vaccines.
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Affiliation(s)
- Justin Komguep Nono
- The Medical Research Centre, Institute of Medical Research and Medicinal Plant Studies, Ministry of Scientific Research and Innovation, Yaoundé, Cameroon.,Division of Immunology, Health Science Faculty, University of Cape Town, Cape Town, South Africa.,Cytokines and Diseases Group, International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa.,Immunology of Infectious Disease Research Unit, South African Medical Research Council, Cape Town, South Africa
| | - Severin Donald Kamdem
- Division of Immunology, Health Science Faculty, University of Cape Town, Cape Town, South Africa.,Cytokines and Diseases Group, International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa.,Immunology of Infectious Disease Research Unit, South African Medical Research Council, Cape Town, South Africa
| | | | - Smritee Dabee
- Division of Medical Virology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Michael Schomaker
- Centre for Infectious Disease Epidemiology & Research, University of Cape Town, Cape Town, South Africa
| | | | - Frank Brombacher
- Division of Immunology, Health Science Faculty, University of Cape Town, Cape Town, South Africa.,Cytokines and Diseases Group, International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa.,Immunology of Infectious Disease Research Unit, South African Medical Research Council, Cape Town, South Africa.,Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Roger Moyou-Somo
- The Medical Research Centre, Institute of Medical Research and Medicinal Plant Studies, Ministry of Scientific Research and Innovation, Yaoundé, Cameroon
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Occurrence of Schistosoma bovis on Pemba Island, Zanzibar: implications for urogenital schistosomiasis transmission monitoring. Parasitology 2018; 145:1727-1731. [PMID: 30086805 PMCID: PMC7116046 DOI: 10.1017/s0031182018001154] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The causative agent of urogenital schistosomiasis, Schistosoma haematobium, was thought to be the only schistosome species transmitted through Bulinus snails on Unguja and Pemba Island (Zanzibar, United Republic of Tanzania). For insights into the environmental risk of S. haematobium transmission on Pemba Island, malacological surveys collecting Bulinus globosus and B. nasutus, two closely related potential intermediate hosts of S. haematobium were conducted across the island in November 2016. Of 1317 B. globosus/B. nasutus collected, seven B. globosus, identified through sequencing a DNA region of the mitochondrial cytochrome oxidase subunit 1 (cox1), were observed with patent infections assumed to be S. haematobium. However, when the collected cercariae were identified through sequencing a region of the cox1 and the nuclear internal transcribed spacer (ITS1 + 2), schistosomes from five of these B. globosus collected from a single locality were in fact S. bovis. The identified presence of S. bovis raises concerns for animal health on Pemba, and complicates future transmission monitoring of S. haematobium. These results show the pertinence for not only sensitive, but also species-specific markers to be used when identifying cercariae during transmission monitoring, and also provide the first molecular confirmation for B. globosus transmitting S. bovis in East Africa.
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Tchuem Tchuenté LA, Stothard JR, Rollinson D, Reinhard-Rupp J. Precision mapping: An innovative tool and way forward to shrink the map, better target interventions, and accelerate toward the elimination of schistosomiasis. PLoS Negl Trop Dis 2018; 12:e0006563. [PMID: 30071014 PMCID: PMC6071947 DOI: 10.1371/journal.pntd.0006563] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Louis-Albert Tchuem Tchuenté
- University of Yaoundé I, Yaoundé, Cameroon
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon
- * E-mail:
| | - J. Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - David Rollinson
- Global Schistosomiasis Alliance, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Jutta Reinhard-Rupp
- Merck Global Health Institute, Ares Trading SA, Switzerland, Subsidiary of Merck KGaA, Darmstadt, Germany
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Macklin G, Stanton MC, Tchuem-Tchuenté LA, Stothard JR. A pilot study using wearable global positioning system data loggers to compare water contact levels: Schistosoma haematobium infection in pre-school-age children (PSAC) and their mothers at Barombi Kotto, Cameroon. Trans R Soc Trop Med Hyg 2018; 112:361-365. [PMID: 29992295 DOI: 10.1093/trstmh/try059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 06/27/2018] [Indexed: 12/22/2022] Open
Abstract
Background Barombi Kotto, Cameroon serves as a reference location for assessing intervention strategies against Schistosoma haematobium. Methods As part of a pilot study, the whole community was treated with praziquantel, inclusive of pre-school-age children (PSAC) and their mothers. One year later, egg-patent infections were reassessed and water contact patterns of 12 pairs of PSAC and their mothers were measured with global positioning system (GPS) data loggers. Results A substantial reduction in general infection prevalence, from 44.8% to 12.2%, was observed but certain PSAC and mothers continued to have egg-patent infections. Analysis of GPS data demonstrated similar water contact levels between the child and mother groups, although certain individuals were numerical outliers. Conclusions This study shows the potential of GPS data loggers to clarify the at-risk status of PSAC and mothers.
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Affiliation(s)
- Grace Macklin
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | | | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
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French MD, Evans D, Fleming FM, Secor WE, Biritwum NK, Brooker SJ, Bustinduy A, Gouvras A, Kabatereine N, King CH, Rebollo Polo M, Reinhard-Rupp J, Rollinson D, Tchuem Tchuenté LA, Utzinger J, Waltz J, Zhang Y. Schistosomiasis in Africa: Improving strategies for long-term and sustainable morbidity control. PLoS Negl Trop Dis 2018; 12:e0006484. [PMID: 29953454 PMCID: PMC6023105 DOI: 10.1371/journal.pntd.0006484] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
| | - Darin Evans
- United States Agency for International Development, Washington, DC, United States of America
| | - Fiona M. Fleming
- Schistosomiasis Control Initiative, Imperial College London, London, United Kingdom
| | - W. Evan Secor
- Centers of Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Nana-Kwadwo Biritwum
- Bill and Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Simon J. Brooker
- Bill and Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Amaya Bustinduy
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Anouk Gouvras
- Global Schistosomiasis Alliance, London, United Kingdom
| | | | - Charles H. King
- Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Maria Rebollo Polo
- Expanded Special Program for Elimination of NTDs (ESPEN), World Health Organization Regional Office for Africa, Brazzaville, Republic of Congo
| | | | | | | | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Ajibola O, Gulumbe BH, Eze AA, Obishakin E. Tools for Detection of Schistosomiasis in Resource Limited Settings. Med Sci (Basel) 2018; 6:medsci6020039. [PMID: 29789498 PMCID: PMC6024580 DOI: 10.3390/medsci6020039] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 12/20/2022] Open
Abstract
Schistosomiasis is a debilitating disease affecting over 200 million people, with the highest burden of morbidity and mortality in African countries. Despite its huge impact on the health and socio-economic burden of the society, it remains a neglected tropical disease, with limited attention from governments and stakeholders in healthcare. One of the critical areas that is hugely under-developed is the development of accurate diagnostics for both intestinal and urogenital schistosomiasis. Diagnosis of schistosomiasis is important for the detection and treatment of disease in endemic and non-endemic settings. A conclusive detection method is also an indispensable part of treatment, both in the clinic and during mass drug administration (MDA), for the monitoring efficacy of treatment. Here, we review the available diagnostic methods and discuss the challenges encountered in diagnosis in resource limited settings. We also present the available diagnostics and cost implications for deployment in resource limited settings. Lastly, we emphasize the need for more funding directed towards the development of affordable diagnostic tools that is affordable for endemic countries as we work towards the elimination of the disease.
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Affiliation(s)
- Olumide Ajibola
- Department of Microbiology, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo Road, Birnin Kebbi 860222, Kebbi State, Nigeria.
| | - Bashar Haruna Gulumbe
- Department of Microbiology, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo Road, Birnin Kebbi 860222, Kebbi State, Nigeria.
| | - Anthonius Anayochukwu Eze
- Department of Medical Biochemistry, University of Nigeria, Enugu Campus, Enugu 400241, Enugu State, Nigeria.
| | - Emmanuel Obishakin
- Biotechnology Division, National Veterinary Research Institute, P.M.B. 001, Vom, Jos, 930281, Plateau State, Nigeria.
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Surveillance of intestinal schistosomiasis during control: a comparison of four diagnostic tests across five Ugandan primary schools in the Lake Albert region. Parasitology 2018; 145:1715-1722. [PMID: 29560841 PMCID: PMC6533640 DOI: 10.1017/s003118201800029x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Programmatic surveillance of intestinal schistosomiasis during control can typically use four diagnostic tests, either singularly or in combination, but these have yet to be cross-compared directly. Our study assembled a complete diagnostic dataset, inclusive of infection intensities, from 258 children from five Ugandan primary schools. The schools were purposely selected as typical of the endemic landscape near Lake Albert and reflective of high- and low-transmission settings. Overall prevalence was: 44.1% (95% CI 38.0–50.2) by microscopy of duplicate Kato-Katz smears from two consecutive stools, 56.9% (95% CI 50.8–63.0) by urine-circulating cathodic antigen (CCA) dipstick, 67.4% (95% CI 61.6–73.1) by DNA-TaqMan® and 75.1% (95% CI 69.8–80.4) by soluble egg antigen enzyme-linked immunosorbent assay (SEA-ELISA). A cross-comparison of diagnostic sensitivities, specificities, positive and negative predictive values was undertaken, inclusive of a latent class analysis (LCA) with a LCA-model estimate of prevalence by each school. The latter ranged from 9.6% to 100.0%, and prevalence by school for each diagnostic test followed a static ascending order or monotonic series of Kato-Katz, urine-CCA dipstick, DNA-TaqMan® and SEA-ELISA. We confirm that Kato-Katz remains a satisfactory diagnostic standalone in high-transmission settings but in low-transmission settings should be augmented or replaced by urine-CCA dipsticks. DNA-TaqMan® appears suitable in both endemic settings though is only implementable if resources permit. In low-transmission settings, SEA-ELISA remains the method of choice to evidence an absence infection. We discuss the pros and cons of each method concluding that future surveillance of intestinal schistosomiasis would benefit from a flexible, context-specific approach both in choice and application of each diagnostic method, rather than a single one-size fits all approach.
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Bergquist R, Zhou XN, Rollinson D, Reinhard-Rupp J, Klohe K. Elimination of schistosomiasis: the tools required. Infect Dis Poverty 2017; 6:158. [PMID: 29151362 PMCID: PMC5694902 DOI: 10.1186/s40249-017-0370-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 10/19/2017] [Indexed: 11/13/2022] Open
Abstract
Background Historically, the target in the schistosomiasis control has shifted from infection to morbidity, then back to infection, but now as a public health problem, before moving on to transmission control. Currently, all endemic countries are encouraged to increase control efforts and move towards elimination as required by the World Health Organization (WHO) roadmap for the global control of the neglected tropical diseases (NTDs) and the WHA65.21 resolution issued by the World Health Assembly. However, schistosomiasis prevalence is still alarmingly high and the global number of disability-adjusted life years (DALYs) due to this infection has in fact increased due to inclusion of some ‘subtle’ clinical symptoms not previously counted. Main body There is a need to restart and improve efforts to reach the elimination goal. To that end, the first conference of the Global Schistosomiasis Alliance (GSA) Research Working Group was held in mid-June 2016 in Shanghai, People’s Republic of China. It reviewed current progress in schistosomiasis control and elimination, identified pressing operational research gaps that need to be addressed and discussed new tools and strategies required to make elimination a reality. The articles emanating from the lectures and discussions during this meeting, together with some additional invited papers, have been collected as a special issue of the ‘Infectious Diseases of Poverty’ entitled ‘Schistosomiasis Research: Providing the Tools Needed for Elimination’, consisting of 26 papers in all. This paper refers to these papers and discusses critical questions arising at the conference related to elimination of schistosomiasis. Conclusion The currently most burning questions are the following: Can schistosomiasis be eliminated? Does it require better, more highly sensitive diagnostics? What is the role of preventive chemotherapy at the elimination stage? Is praziquantel sufficient or do we need new drugs? Contemplating these questions, it is felt that the heterogeneity of the endemic areas in the world requires WHO policies to be upgraded instituting new, differentiated guidelines. Electronic supplementary material The online version of this article (doi: 10.1186/s40249-017-0370-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases Chinese Center for Disease Control and Prevention, Shanghai, 200025, China.
| | - David Rollinson
- Department of Life Sciences, The Natural History Museum, London, SW7 5BD, UK
| | | | - Katharina Klohe
- Global Schistosomiasis Alliance, Westenriederstrasse 10, 80331, Munich, Germany
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45
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Brandão E, Romero S, da Silva MAL, Santos FLN. Neglected tropical diseases in Brazilian children and adolescents: data analysis from 2009 to 2013. Infect Dis Poverty 2017; 6:154. [PMID: 29096720 PMCID: PMC5668976 DOI: 10.1186/s40249-017-0369-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 10/13/2017] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Neglected tropical diseases (NTDs) prevail in conditions of poverty and contribute to the maintenance of social inequality. Out of the NTDs prioritized by the Brazilian Ministry of Health, four parasitic infections require mandatory notification: acute Chagas disease, leishmaniasis, malaria, and schistosomiasis. Data on the behaviour of these NTDs in the young population are currently limited. This study seeks to analyse the epidemiological aspects of these parasitic infections in children and adolescents in Brazil. METHODS A retrospective exploratory ecological study was conducted. A spatial analysis of the cases reported between 2009 and 2013 in individuals aged between 0 and 19 years that were notified through the Health Notification Aggravation Information System (SINAN) was performed. RESULTS In total, 64,567 cases of cutaneous and visceral leishmaniasis, malaria, schistosomiasis, and acute Chagas disease were recorded in the SINAN database, representing a rate of 20.15 cases per 100,000 inhabitants. The average age of the cases was 12.2 years and 62.32% were male. Four hundred and three deaths related to these obligatorily reported parasites were recorded, indicating a case fatality rate of 0.62%. Visceral leishmaniasis and acute Chagas disease had the highest rates of lethality. A heterogeneous spatial distribution of the studied parasites was observed. CONCLUSIONS The number of cases and the lethality rate described in this study show that these diseases still represent a serious problem for public health in Brazil. This points to the need to encourage new research and the reformulation of social, economic, and public health policies aimed at ensuring better health and living conditions for all individuals, especially those among the populations considered vulnerable, as is the case of the young.
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Affiliation(s)
- Eduardo Brandão
- National Reference Service for Filariasis, Aggeu Magalhães Institute (Fiocruz-PE), Recife, Pernambuco Brazil
- Faculty of Medical Sciences, National University of Rosario, Rosario, Santa Fe Argentina
| | - Sebastián Romero
- Faculty of Medical Sciences, National University of Rosario, Rosario, Santa Fe Argentina
| | - Maria Almerice Lopes da Silva
- Laboratory of Communicable Diseases, Parasitology Department, Aggeu Magalhães Institute (Fiocruz-PE), Recife, Pernambuco Brazil
| | - Fred Luciano Neves Santos
- Laboratory of Pathology and Bio-Intervention, Gonçalo Moniz Institute (Fiocruz-BA), Salvador, Bahia Brazil
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Campbell SJ, Biritwum NK, Woods G, Velleman Y, Fleming F, Stothard JR. Tailoring Water, Sanitation, and Hygiene (WASH) Targets for Soil-Transmitted Helminthiasis and Schistosomiasis Control. Trends Parasitol 2017; 34:53-63. [PMID: 29055522 DOI: 10.1016/j.pt.2017.09.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 09/22/2017] [Accepted: 09/25/2017] [Indexed: 12/17/2022]
Abstract
The World Health Organization's (WHO) 2015-2020 Global Strategy on water, sanitation, and hygiene (WASH) and neglected tropical diseases (NTDs) encourages integration, whilst maintaining existing structured NTD investments, and acceleration towards Sustainable Development Goal (SDG) targets. Accordingly, SDG-associated and WASH-NTD indicators have been developed, commencing important intersectoral dialogue, alongside opportunities for future disease-specific refinements. The rationale for soil-transmitted helminthiasis (STH)- and schistosomiasis-specific WASH considerations, and a traffic-light figure, are presented here to indicate where current international definitions may, or may not, suffice. Certain unique aspects in control dynamics and parasitic lifecycles, however, necessitate additional implementation research with more appropriate measurement indicators developed to record programmatic interventions and to define strategic priorities more effectively.
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Affiliation(s)
- Suzy J Campbell
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK; Present address: Deworm the World Initiative, Evidence Action, Brisbane, 4020, Australia.
| | - Nana-Kwadwo Biritwum
- National Neglected Tropical Disease Control Programme, Ghana Health Services, Accra, Ghana
| | | | | | - Fiona Fleming
- Schistosomiasis Control Initiative, Imperial College, London, W2 1PG, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
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47
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Bustinduy AL, Stothard JR, Friedman JF. Paediatric and maternal schistosomiasis: shifting the paradigms. Br Med Bull 2017; 123:115-125. [PMID: 28910994 PMCID: PMC6279106 DOI: 10.1093/bmb/ldx028] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 07/16/2017] [Indexed: 11/13/2022]
Abstract
BACKGROUND In endemic areas, schistosomiasis causes both overt and subclinical disease in young children and their mothers, as well as in returned travellers. SOURCES OF DATA Key recently published literature. AREAS OF AGREEMENT An action plan for paediatric schistosomiasis and female genital schistosomiasis (FGS) is needed with expanded access to praziquantel (PZQ) treatment required. AREAS OF CONTROVERSY Schistosomiasis-related morbidity is underappreciated. Present and future demand for PZQ treatment is bottlenecked, imbalanced and inequitable. Current dosing, treatment algorithms and access plans are suboptimal with treatment stalled during pregnancy. GROWING POINTS Raised dosing of PZQ (>40 mg/kg) is being explored in young children. Surveillance of female genital schistosomiasis FGS is increasing. Use of PZQ in pregnancy is safe and preventive chemotherapy guidelines are being revised in morbidity- and transmission-control settings. AREAS TIMELY FOR DEVELOPING RESEARCH Shifting focus of population-level control to individual-case management. Detection and prevention of FGS within general health services and integration of PZQ treatment for women and children in antenatal clinics. Feasibility studies assessing alternative and expanded access to PZQ treatment to at-risk children and mothers and pregnant women.
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Affiliation(s)
- Amaya L Bustinduy
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Jennifer F Friedman
- Center for International Health Research, Rhode Island Hospital, 55 Claverick Street, Suite 101, Providence, RI 02903, USA
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48
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Kincaid-Smith J, Rey O, Toulza E, Berry A, Boissier J. Emerging Schistosomiasis in Europe: A Need to Quantify the Risks. Trends Parasitol 2017; 33:600-609. [PMID: 28539255 DOI: 10.1016/j.pt.2017.04.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/19/2017] [Accepted: 04/27/2017] [Indexed: 11/29/2022]
Abstract
The recent recurrent outbreaks of urogenital schistosomiasis in the south of Europe were unanticipated and caught scientists and health authorities unprepared. It is now time to learn lessons from these outbreaks and to implement concrete procedures in order to better quantify the risks and prevent future outbreaks of schistosomiasis in Europe. In this context, we propose a reflection on the factors that currently hamper our ability to quantify these risks and argue that we are incapable of predicting future outbreaks. We base our reflexion on an ecological two-step filter concept that drives host-parasite interactions, namely the encounter and the compatibility filters.
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Affiliation(s)
- Julien Kincaid-Smith
- Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan, France
| | - Olivier Rey
- Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan, France
| | - Eve Toulza
- Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan, France
| | - Antoine Berry
- Service de Parasitologie-Mycologie, CHU Toulouse and Centre de Physiopathologie de Toulouse Purpan, INSERM U1043, CNRS UMR5282, Université de Toulouse, Toulouse, France
| | - Jérôme Boissier
- Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan, France.
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49
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Sun LP, Wang W, Hong QB, Li SZ, Liang YS, Yang HT, Zhou XN. Approaches being used in the national schistosomiasis elimination programme in China: a review. Infect Dis Poverty 2017; 6:55. [PMID: 28292327 PMCID: PMC5351197 DOI: 10.1186/s40249-017-0271-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 02/27/2017] [Indexed: 01/07/2023] Open
Abstract
Schistosomiasis japonica, caused by the human blood fluke Schistosoma japonicum, remains a major public health problem in China, although great success has been achieved. The control efforts during the past half-decade, notably the wide implementation of the new integrated strategy with emphasis on control of the source of S. japonicum infection across the country since 2004, has greatly reduced S. japonicum in humans, livestock, and intermediate host Oncomelania hupensis snails, and transmission control of schistosomiasis was achieved in China in 2015. A two-stage roadmap was therefore proposed for schistosomiasis elimination in 2015, with aims to achieve transmission interruption by 2020 and achieve disease elimination by 2025 in the country. During the last two decades, a variety of approaches, which target the epidemiological factors of schistosomiasis japonica have been developed, in order to block the transmission cycle of the parasite. These approaches have been employed in the national or local schistosomiasis control activities, and facilitated, at least in part, the progress of the schistosomiasis elimination programs. Here, we present an approach to control the source of S. japonicum infection, three new tools for snail control, three approaches for detecting and monitoring S. japonicum infection, and a novel model for health education. These approaches are considered to play a great role in the stage moving towards transmission interruption and elimination of schistosomiasis in China.
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Affiliation(s)
- Le-Ping Sun
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Wuxi, 214064, China.,Jiangsu Provincial Key Laboratory on Parasites and Vector Control Technology, Wuxi, 214064, China.,Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Wei Wang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Wuxi, 214064, China. .,Jiangsu Provincial Key Laboratory on Parasites and Vector Control Technology, Wuxi, 214064, China. .,Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China. .,School of Public Health, Fujian Medical University, Fuzhou, 350004, China.
| | - Qing-Biao Hong
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Wuxi, 214064, China.,Jiangsu Provincial Key Laboratory on Parasites and Vector Control Technology, Wuxi, 214064, China.,Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Shi-Zhu Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, China.,Key Laboratory for Parasite and Vector Biology, National Health and Family Planning Commission, Shanghai, 200025, China.,WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, China
| | - You-Sheng Liang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Wuxi, 214064, China.,Jiangsu Provincial Key Laboratory on Parasites and Vector Control Technology, Wuxi, 214064, China.,Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Hai-Tao Yang
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Wuxi, 214064, China.,Jiangsu Provincial Key Laboratory on Parasites and Vector Control Technology, Wuxi, 214064, China.,Jiangsu Institute of Parasitic Diseases, Wuxi, 214064, China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, China. .,Key Laboratory for Parasite and Vector Biology, National Health and Family Planning Commission, Shanghai, 200025, China. .,WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, China.
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50
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Tchuem Tchuenté LA, Rollinson D, Stothard JR, Molyneux D. Moving from control to elimination of schistosomiasis in sub-Saharan Africa: time to change and adapt strategies. Infect Dis Poverty 2017; 6:42. [PMID: 28219412 PMCID: PMC5319063 DOI: 10.1186/s40249-017-0256-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 02/08/2017] [Indexed: 11/17/2022] Open
Abstract
Schistosomiasis is a water borne parasitic disease of global importance and with ongoing control the disease endemic landscape is changing. In sub-Saharan Africa, for example, the landscape is becoming ever more heterogeneous as there are several species of Schistosoma that respond in different ways to ongoing preventive chemotherapy and the inter-sectoral interventions currently applied. The major focus of preventive chemotherapy is delivery of praziquantel by mass drug administration to those shown to be, or presumed to be, at-risk of infection and disease. In some countries, regional progress may be uneven but in certain locations there are very real prospects to transition from control into interruption of transmission, and ultimately elimination. To manage this transition requires reconsideration of some of the currently deployed diagnostic tools used in surveillance and downward realignment of existing prevalence thresholds to trigger mass treatment. A key challenge will be maintaining and if possible, expanding the current donation of praziquantel to currently overlooked groups, then judging when appropriate to move from mass drug administration to selective treatment. In so doing, this will ensure the health system is adapted, primed and shown to be cost-effective to respond to these changing disease dynamics as we move forward to 2020 targets and beyond.
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Affiliation(s)
- Louis-Albert Tchuem Tchuenté
- National Programme for the Control of Schistosomiasis and STH, Ministry of Public Health, Yaoundé, Cameroon. .,Centre for Schistosomiasis and Parasitology, University of Yaoundé I, Yaoundé, Cameroon.
| | - David Rollinson
- Department of Life Sciences, The Natural History Museum, London, SW7 5BD, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - David Molyneux
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
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