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Tao C, Liu Z, Fan Y, Yuan Y, Wang X, Qiao Z, Li Z, Xu Q, Lou Z, Wang H, Li X, Li R, Lu C. Estimating neighborhood-based mortality risk associated with air pollution: A prospective study. JOURNAL OF HAZARDOUS MATERIALS 2024; 475:134861. [PMID: 38870855 DOI: 10.1016/j.jhazmat.2024.134861] [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: 04/08/2024] [Revised: 06/06/2024] [Accepted: 06/07/2024] [Indexed: 06/15/2024]
Abstract
Effect modification of integrated neighborhood environment on associations of air pollution with mortality remained unclear. We analyzed data from UK biobank prospective study (n = 421,650, median 12.5 years follow-up) to examine disparities of mortality risk associated with air pollution among varied neighborhood settings. Fine particulate matter (PM2.5), PM10 and nitrogen dioxide (NO2) were measured and assigned to each participants' address. Diverse ecological and societal settings of neighborhoods were integrated with principal component analysis and categorized into disadvantaged, intermediate and advantaged levels. We estimated mortality risk associated with air pollution across diverse neighborhoods using Cox regression. We calculated community-level proportions of mortality attributable to air pollutants. There was evidence of higher all-cause and respiratory disease mortality risk associated with PM2.5 and NO2 among those in disadvantaged neighborhoods. In disadvantaged communities, air pollutants explained larger proportions of deaths and such disparities persisted over past decades. Across 2010-2021, reducing PM2.5 and NO2 to 10 μg/m3 (World Health Organization limits) would save 87,000 (52,000-120,000) and 91,000 (37,000-145,000) deaths of populations aged ≥ 40 years, with 150 000 deaths occurred in disadvantaged neighborhood settings. These findings suggested that disadvantaged neighborhoods can exacerbate mortality risk associated with air pollution.
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Affiliation(s)
- Chengzhe Tao
- State Key Laboratory of Reproductive Medicine and Offspring Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Zhaoyin Liu
- Department of Epidemiology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Yun Fan
- State Key Laboratory of Reproductive Medicine and Offspring Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Yiting Yuan
- State Key Laboratory of Reproductive Medicine and Offspring Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Xinru Wang
- State Key Laboratory of Reproductive Medicine and Offspring Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Ziyan Qiao
- State Key Laboratory of Reproductive Medicine and Offspring Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Zhi Li
- State Key Laboratory of Reproductive Medicine and Offspring Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Qiaoqiao Xu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Zhe Lou
- Department of Epidemiology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Haowei Wang
- School of Public Health, Imperial College London, UK; MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics, Imperial College London, UK
| | - Xiang Li
- School of Public Health, Imperial College London, UK; MRC Centre for Global Infectious Disease Analysis and Abdul Latif Jameel Institute for Disease and Emergency Analytics, Imperial College London, UK
| | - Ruiyun Li
- Department of Epidemiology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
| | - Chuncheng Lu
- State Key Laboratory of Reproductive Medicine and Offspring Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
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Rayment Gomez S, Maddren R, Liyew EF, Chernet M, Anjulo U, Tamiru A, Tollera G, Tasew G, Mengistu B, Collyer B, Forbes K, Anderson R. Spatial heterogeneity in mass drug administration from a longitudinal epidemiological study assessing transmission interruption of soil transmitted helminths in the Wolaita zone of southern Ethiopia (Geshiyaro Project). PLoS Negl Trop Dis 2024; 18:e0011947. [PMID: 38330143 PMCID: PMC10880954 DOI: 10.1371/journal.pntd.0011947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 02/21/2024] [Accepted: 01/28/2024] [Indexed: 02/10/2024] Open
Abstract
OBJECTIVES Deworming programmes of soil-transmitted helminths are generally monitored and evaluated by aggregating drug coverage and infection levels at a district level. However, heterogeneity in drug coverage at finer spatial scales means indicators may remain above thresholds for elimination as a public health problem or of transmission in some areas. This paper aims to highlight the misleading information that aggregating data at larger spatial scales can have for programme decision making. METHODS Drug coverage data from the Geshiyaro project were compared at two spatial scales with reference to the World Health Organisation's targets. District (woreda) and village (kebele) level were compared. The association between infection levels and drug coverage was analysed by fitting a weighted least-squares function to the mean intensity of infection (eggs per gram of faeces) against drug coverage. RESULTS The data show clearly that when the evaluation of coverage is aggregated to the district level, information on heterogeneity at a finer spatial scale is lost. Infection intensity decreases significantly (p = 0.0023) with increasing drug coverage. CONCLUSION Aggregating data at large spatial scales can result in prematurely ceasing deworming, prompting rapid infection bounce-back. There is a strong need to define context-specific spatial scales for monitoring and evaluating intervention programmes.
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Affiliation(s)
- Santiago Rayment Gomez
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Rosie Maddren
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Ewnetu Firdawek Liyew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Melkie Chernet
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Ufaysa Anjulo
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Wolaita, Ethiopia
| | - Adugna Tamiru
- Disease Prevention and Health Promotion Core Process, Ministry of Health, Wolaita, Ethiopia
| | - Getachew Tollera
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Geremew Tasew
- Bacterial, Parasitic and Zoonotic Disease Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Birhan Mengistu
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Benjamin Collyer
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Kathryn Forbes
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
| | - Roy Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, Faculty of Medicine, St Marys Campus, Imperial College London, London, United Kingdom
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Kazura E, Johnson J, Morozoff C, Aruldas K, Avokpaho E, Togbevi CI, Chabi F, Gwayi-Chore MC, Nindi P, Titus A, Houngbegnon P, Kaliappan SP, Jacob Y, Simwanza J, Kalua K, Walson JL, Ibikounlé M, Ajjampur SSR, Means AR. Identifying opportunities to optimize mass drug administration for soil-transmitted helminths: A visualization and descriptive analysis using process mapping. PLoS Negl Trop Dis 2024; 18:e0011772. [PMID: 38175837 DOI: 10.1371/journal.pntd.0011772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 01/17/2024] [Accepted: 11/06/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND The control of soil-transmitted helminths (STH) is achieved through mass drug administration (MDA) with deworming medications targeting children and other high-risk groups. Recent evidence suggests that it may be possible to interrupt STH transmission by deworming individuals of all ages via community-wide MDA (cMDA). However, a change in delivery platforms will require altering implementation processes. METHODS We used process mapping, an operational research methodology, to describe the activities required for effective implementation of school-based and cMDA in 18 heterogenous areas and over three years in Benin, India, and Malawi. Planned activities were identified during workshops prior to initiation of a large cMDA trial (the DeWorm3 trial). The process maps were updated annually post-implementation, including adding or removing activities (e.g., adaptations) and determining whether activities occurred according to plan. Descriptive analyses were performed to quantify differences and similarities at baseline and over three implementation years. Comparative analyses were also conducted between study sites and areas implementing school-based vs. cMDA. Digitized process maps were developed to provide a visualization of MDA processes and inspected to identify implementation bottlenecks and inefficient activity flows. RESULTS Across three years and all clusters, implementation of cMDA required an average of 13 additional distinct activities and was adapted more often (5.2 adaptations per year) than school-based MDA. An average of 41% of activities across both MDA platforms did not occur according to planned timelines; however, deviations were often purposeful to improve implementation efficiency or effectiveness. Visualized process maps demonstrated that receipt of drugs at the local level may be an implementation bottleneck. Many activities rely on the effective setting of MDA dates and estimating quantity of drugs, suggesting that the timing of these activities is important to meet planned programmatic outcomes. CONCLUSION Implementation processes were heterogenous across settings, suggesting that MDA is highly context and resource dependent and that there are many viable ways to implement MDA. Process mapping could be deployed to support a transition from a school-based control program to community-wide STH transmission interruption program and potentially to enable integration with other community-based campaigns. TRIAL REGISTRATION NCT03014167.
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Affiliation(s)
- Eileen Kazura
- The Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Jabaselvi Johnson
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Chloe Morozoff
- The Department of Global Health, University of Washington, Seattle, Washington, United States of America
- The DeWorm3 Project, Seattle, Washington, United States of America
| | - Kumudha Aruldas
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | | | | | - Félicien Chabi
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Bénin
| | - Marie-Claire Gwayi-Chore
- The Department of Global Health, University of Washington, Seattle, Washington, United States of America
- The DeWorm3 Project, Seattle, Washington, United States of America
| | | | - Angelin Titus
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | | | | | - Yesudoss Jacob
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - James Simwanza
- Blantyre Institute for Community Outreach, Blantyre, Malawi
| | - Khumbo Kalua
- Blantyre Institute for Community Outreach, Blantyre, Malawi
| | - Judd L Walson
- The DeWorm3 Project, Seattle, Washington, United States of America
- The Departments of Global Health, Medicine, Pediatrics and Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Moudachirou Ibikounlé
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Bénin
- Centre de Recherche pour la lutte contre les Maladies Infectieuses Tropicales (CReMIT/TIDRC), Université d'Abomey-Calavi, Benin
| | - Sitara S R Ajjampur
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Arianna Rubin Means
- The Department of Global Health, University of Washington, Seattle, Washington, United States of America
- The DeWorm3 Project, Seattle, Washington, United States of America
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Cherif MS, Keita M, Dahal P, Guilavogui T, Beavogui AH, Diassy L, Conde M, Touré A, Delamou A. Neglected tropical diseases in Republic of Guinea: disease endemicity, case burden and the road towards the 2030 target. Int Health 2023; 15:490-504. [PMID: 37232124 PMCID: PMC10472893 DOI: 10.1093/inthealth/ihad036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 03/02/2023] [Accepted: 05/01/2023] [Indexed: 05/27/2023] Open
Abstract
Neglected tropical diseases (NTDs) predominantly affect vulnerable and marginalized populations in tropical and subtropical areas and globally affect more than one billion people. In Guinea, the burden of NTDs is estimated to be >7.5 disability-adjusted life years per million inhabitants. Currently the Guinea NTDs master plan (2017-2020) has identified eight diseases as public health problems: onchocerciasis, lymphatic filariasis, trachoma, schistosomiasis and soil-transmitted helminthiasis, leprosy, human African trypanosomiasis and Buruli ulcer. In this review we discuss the past and the current case burden of the priority NTDs in Guinea, highlight the major milestones and discuss current and future areas of focus for achieving the 2030 target outlined by the World Health Organization.
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Affiliation(s)
- Mahamoud Sama Cherif
- Faculty of Sciences and Health Technics, Gamal Abdel Nasser University of Conakry, Conakry, Guinea
- Direction Regionale de la Santé de Faranah, Ministère de la santé et de l'hygiène publique, Faranah, Guinea
- Service de Pediatrie, Hospital National Ignace Deen, Ministère de la santé et de l'Hygiène Publique, Conakry, Guinea
| | - Mory Keita
- World Health Organization, Regional Office for the Eastern Mediterranean, Cairo, Egypt
- Institute of Global Health, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Prabin Dahal
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Timothé Guilavogui
- Management and Programmes Coordination, Ministry of Health, Conakry, Guinea
| | - Abdoul Habib Beavogui
- Faculty of Sciences and Health Technics, Gamal Abdel Nasser University of Conakry, Conakry, Guinea
- Centre National de Formation et Recherche en Sante Rurale de Maferinyah, Maferinyah, Guinea
| | - Lamine Diassy
- World Health Organization, Guinea office, Landreah, Corniche Nord, Boîte postale 817, Conakry, Guinea
| | - Mohamed Conde
- Service de Pediatrie, Hospital National Ignace Deen, Ministère de la santé et de l'Hygiène Publique, Conakry, Guinea
| | - Abdoulaye Touré
- Faculty of Sciences and Health Technics, Gamal Abdel Nasser University of Conakry, Conakry, Guinea
- Institut National de Santé Publique, Ministère de la Santé et de l'Hygiène Publique, Conakry, Guinea
| | - Alexandre Delamou
- Faculty of Sciences and Health Technics, Gamal Abdel Nasser University of Conakry, Conakry, Guinea
- Centre National de Formation et Recherche en Sante Rurale de Maferinyah, Maferinyah, Guinea
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Xu Y, Wang Y, Wang L, Kong X, Yan G, Li Y, Bu C, Zhang B. The prevalence of soil transmitted helminths and its influential factors in Shandong Province, China: an analysis of surveillance data from 2016 to 2020. Infect Dis Poverty 2023; 12:54. [PMID: 37217956 DOI: 10.1186/s40249-023-01100-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 05/04/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND Soil-transmitted helminths (STHs) were previously endemic in Shandong Province, China. This study aimed to analyze the STHs prevalence trend and the natural, social, and human cognitive and behavioural factors influencing the discrepancies between high and low infection levels from 2016 to 2020 in Shandong Province in eastern China. METHODS STHs surveillance data of Shandong Province from 2016 to 2020 were obtained from China Information Management System for Prevention and Control of Parasitic Diseases. STHs infections were detected by modified Kato-Katz method. Comprehensive information on the natural and social factors, STHs-related knowledge and behaviours were collected through questionnaire surveys. Retrospective spatial scan analysis was performed using SaTScan v10.1 to evaluate any identified spatial clusters of STHs infection for statistical significance and Bayes discriminant analysis was used to discriminate the high or low infection groups of the villages. RESULTS In total, 72,160 participants were involved in our survey from 2016 to 2020. The overall STHs prevalence rate was 1.13%, with the eastern region of Shandong Province having the highest rate (2.02%). The predominant species was T. trichiura, with the prevalence rate of 0.99% and the ≥ 70-year age group possessed the highest rate of 2.21%. The STHs prevalence rate showed an annual linear downward trend from 2016 to 2020 ([Formula: see text] = 127.600, P < 0.001). Respondents aged ≥ 60 years had the lowest awareness level of STHs-related prevention knowledge (all P < 0.05), and were the most likely to adopt the practice of fertilizing with fresh stool (χ2 = 28.354, P < 0.001). Furthermore, the southern region demonstrated the highest temperature and rainfall level and the lowest GNP and annual net income per capita (all P < 0.05). CONCLUSIONS There is a remarkable declining in STHs prevalence in Shandong Province from 2016 to 2020. However, the prevalence rates of STHs especially T. trichiura in the southern and eastern regions were still high, and the elderly were more susceptible to be infected with STHs owning to their low awareness level of STHS-related prevention knowledge and high adoption rate of dangerous production and living behaviours. Integrated approaches of health education, environment improvement and behaviour change should be strengthened to obtain a further reduction of STHs prevalence in China.
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Affiliation(s)
- Yan Xu
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Yongbin Wang
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Longjiang Wang
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Xiangli Kong
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Ge Yan
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Yuejin Li
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Cancan Bu
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Benguang Zhang
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China.
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Aruldas K, Israel GJ, Johnson J, Titus A, Saxena M, Kaliappan SP, Ramesh RM, Walson JL, Means AR, Ajjampur SSR. Impact of adverse events during community-wide mass drug administration for soil-transmitted helminths on subsequent participation-a Theory of Planned Behaviour analysis. PLoS Negl Trop Dis 2023; 17:e0011148. [PMID: 36917597 PMCID: PMC10013912 DOI: 10.1371/journal.pntd.0011148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 02/07/2023] [Indexed: 03/15/2023] Open
Abstract
BACKGROUND Experiencing adverse events (AEs) during mass drug administration (MDA) could affect participation in future MDAs. This study aims to understand the potential influence of AEs during a community-wide MDA (cMDA) trial for soil-transmitted helminths (STH) in India on intention to participate in future cMDAs. METHODS This study was conducted using a multi-method quantitative and qualitative approach among 74 participants who experienced an AE during STH cMDA and the 12 participants who subsequently refused cMDA treatment of the ongoing DeWorm3 trial. Path analysis and thematic analysis guided by the Theory of Planned Behaviour, was used. PRINCIPAL FINDINGS Among 74 individuals who reported an AE, 12% refused treatment in the cMDA immediately subsequent to their AE and 4% refused in all subsequent cMDAs. Of these 74 individuals, 59 (80%) completed a survey and eight participated in in-depth interviews. A positive attitude towards deworming and perceived ability to participate in cMDA (perceived behavioural control) were significant predictors of intention to participate in cMDA (p<0.05). A positive attitude towards cMDA was associated with caste (χ2 = 3.83, P = 0.05), particularly among the scheduled caste/scheduled tribe (SC/ST) (62%). Perceived behavioural control in cMDA participation was associated with occupation (χ2 = 5.02, P<0.05), with higher perceived control among those engaged in skilled occupations (78%). Intention to participate in subsequent cMDAs was associated with caste and family type (χ2 = 3.83, P = 0.05 and χ2 = 7.50, P<0.05 respectively) and was higher among SC/ST (62%) and those with extended families (67%). In-depth interviews demonstrated that perceived severe AEs may lead to treatment refusal in future, particularly if children were affected. CONCLUSIONS Intention to participate in future STH cMDAs was associated with caste (SC/ST) and family type (extended families). Therefore, community mobilization messages about potential AEs and their management may need to intentionally target non-SC/ST households, nuclear families, and those engaged in unskilled occupations to increase cMDA participation given the possibility of AEs occurring. TRIAL REGISTRATION NCT03014167, ClinicalTrials.gov.
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Affiliation(s)
- Kumudha Aruldas
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Gideon John Israel
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Jabaselvi Johnson
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Angelin Titus
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Malvika Saxena
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | | | - Rohan Michael Ramesh
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Judd L. Walson
- Departments of Global Health, Medicine, Pediatrics and Epidemiology, University of Washington, Seattle, Washington, United States of America
- The DeWorm3 Project, University of Washington, Seattle, Washington, United States of America
| | - Arianna Rubin Means
- The DeWorm3 Project, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Sitara S. R. Ajjampur
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
- * E-mail:
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Intestinal Helminth Infections in Ghanaian Children from the Ashanti Region between 2007 and 2008—A Retrospective Cross-Sectional Real-Time PCR-Based Assessment. Trop Med Infect Dis 2022; 7:tropicalmed7110374. [DOI: 10.3390/tropicalmed7110374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 10/18/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022] Open
Abstract
In spite of ongoing eradication programs, helminth infections are still a medical issue in Ghana. For follow-up assessments on the decline of regional helminth infections, historic baseline prevalence values obtained with standardized diagnostic procedures can be helpful. In this retrospective cross-sectional study, real-time PCR targeting the nematodes Ancylostoma spp. (ITS2), Ascaris lumbricoides (ITS1), Enterobius vermicularis (ITS1), Necator americanus (ITS2), Strongyloides stercoralis (18S rRNA) and Trichuris trichiura (18S rRNA), the trematodes Schistosoma spp. (ITS2) as well as the cestodes Hymenolepis nana (ITS1), Taenia saginata (ITS1) and Taenia solium (ITS1) was applied with 2046 DNA eluates from stool samples of Ghanaian children from the Ashanti region collected between 2007 and 2008 in order to retrospectively define prevalence values. The overall prevalence was low with 3.8% (n = 77) and only 0.1% (n = 2) double infections with helminths were recorded. The three most frequently detected enteric helminth species comprised 2% S. stercoralis (n = 41), 0.8% H. nana (n = 16), and 0.7% N. americanus (n = 14), while only sporadic infection events were recorded for other helminth species comprising 0.1% E. vermicularis (n = 2), 0.1% Schistosoma spp. (n = 2), 0.1% T. saginata (n = 1) and 0.1% T. trichiura (n = 1). A. lumbricoides, Ancylostoma spp. and T. solium were not detected at all. In conclusion, the retrospective assessment suggests a low prevalence of enteric helminth infections in Ghanaian children from the Ashanti Region within the assessment period between 2007 and 2008.
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Optimizing Implementation of Preventive Chemotherapy against Soil-Transmitted Helminthiasis and Intestinal Schistosomiasis Using High-Resolution Data: Field-Based Experiences from Côte d’Ivoire. Diseases 2022; 10:diseases10040066. [PMID: 36278565 PMCID: PMC9590038 DOI: 10.3390/diseases10040066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/07/2022] [Accepted: 09/14/2022] [Indexed: 11/17/2022] Open
Abstract
Background: Despite efforts to control neglected tropical diseases (NTDs) using preventive chemotherapy (PC), soil-transmitted helminthiases and schistosomiasis remain widely prevalent in sub-Saharan Africa. The current PC regimen in endemic settings is defined based on health district-level prevalence. This work aims to highlight the need for high-resolution data when elimination, rather than morbidity control, is the targeted goal. Methodology: Cross-sectional parasitological surveys were conducted from July to August 2019 and from September to October 2019, respectively, across the entire Dabou and Jacqueville health districts in southern Côte d’Ivoire. From every village, 60 school-aged children (6–15 years) were randomly selected and invited to provide one fresh stool sample, whereof duplicate Kato–Katz thick smears were prepared and read by two independent technicians. Principal Findings: 4338 school-aged children from 77 villages were screened from the Dabou (n = 2174; 50.12%, 39 villages) and Jacqueville (n = 2164; 49.88%, 38 villages) health districts. The prevalence of any soil-transmitted helminth (STH) infection was 12.47% and 11.09% in the Dabou and Jacqueville health districts, respectively. Species-specific district-level prevalence remained below 10%, varying between 0.51% (hookworm in Jacqueville) and 9.06% (Trichuris trichiura in Dabou). However, when considering sub-districts or villages only, several STH infection hotspots (five sub-districts with ≥20% and four villages with more than 50% infected) were observed. Schistosoma mansoni infection was found in less than 1% of the examined children in each health district. Conclusions/Significance: We conclude that keeping health district-level prevalence as a reference for PC implementation leaves many high-risk sub-districts or villages requiring PC (≥20% prevalence) untreated. To avoid maintaining those high-risk villages as STH reservoirs by skipping control interventions and jeopardizing the successes already achieved in STH control through PC during the past two decades, precision mapping is required. Further investigation is needed to assess cost-efficient approaches to implement small-scale disease surveillance.
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Morozoff C, Avokpaho E, Puthupalayam Kaliappan S, Simwanza J, Gideon SP, Lungu W, Houngbegnon P, Galactionova K, Sahu M, Kalua K, Luty AJF, Ibikounlé M, Bailey R, Pullan R, Ajjampur SSR, Walson J, Means AR. Costs of community-wide mass drug administration and school-based deworming for soil-transmitted helminths: evidence from a randomised controlled trial in Benin, India and Malawi. BMJ Open 2022; 12:e059565. [PMID: 35803632 PMCID: PMC9272108 DOI: 10.1136/bmjopen-2021-059565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES Current guidelines for the control of soil-transmitted helminths (STH) recommend deworming children and other high-risk groups, primarily using school-based deworming (SBD) programmes. However, targeting individuals of all ages through community-wide mass drug administration (cMDA) may interrupt STH transmission in some settings. We compared the costs of cMDA to SBD to inform decision-making about future updates to STH policy. DESIGN We conducted activity-based microcosting of cMDA and SBD for 2 years in Benin, India and Malawi within an ongoing cMDA trial. SETTING Field sites and collaborating research institutions. PRIMARY AND SECONDARY OUTCOMES We calculated total financial and opportunity costs and costs per treatment administered (unit costs in 2019 USD ($)) from the service provider perspective, including costs related to community drug distributors and other volunteers. RESULTS On average, cMDA unit costs were more expensive than SBD in India ($1.17 vs $0.72) and Malawi ($2.26 vs $1.69), and comparable in Benin ($2.45 vs $2.47). cMDA was more expensive than SBD in part because most costs (~60%) were 'supportive costs' needed to deliver treatment with high coverage, such as additional supervision and electronic data capture. A smaller fraction of cMDA costs (~30%) was routine expenditures (eg, drug distributor allowances). The remaining cMDA costs (~10%) were opportunity costs of staff and volunteer time. A larger percentage of SBD costs was opportunity costs for teachers and other government staff (between ~25% and 75%). Unit costs varied over time and were sensitive to the number of treatments administered. CONCLUSIONS cMDA was generally more expensive than SBD. Accounting for local staff time (volunteers, teachers, health workers) in community programmes is important and drives higher cost estimates than commonly recognised in the literature. Costs may be lower outside of a trial setting, given a reduction in supportive costs used to drive higher treatment coverage and economies of scale. TRIAL REGISTRATION NUMBER NCT03014167.
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Affiliation(s)
- Chloe Morozoff
- Department of Global Health, University of Washington, Seattle, Washington, USA
| | | | | | - James Simwanza
- Blantyre Institute for Community Outreach, Blantyre, Malawi
| | - Samuel Paul Gideon
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Wongani Lungu
- Blantyre Institute for Community Outreach, Blantyre, Malawi
| | | | - Katya Galactionova
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Faculty of Medicine, University of Basel, Basel, Switzerland
| | - Maitreyi Sahu
- Department of Global Health, University of Washington, Seattle, Washington, USA
| | - Khumbo Kalua
- Blantyre Institute for Community Outreach, Blantyre, Malawi
| | | | - Moudachirou Ibikounlé
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Bénin
- Centre de Recherche pour la lutte contre les Maladies Infectieuses Tropicales (CReMIT/TIDRC), Université d'Abomey-Calavi, Abomey-Calavi, Bénin
| | - Robin Bailey
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, UK
| | - Rachel Pullan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Sitara Swarna Rao Ajjampur
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Judd Walson
- Department of Global Health, University of Washington, Seattle, Washington, USA
| | - Arianna Rubin Means
- Department of Global Health, University of Washington, Seattle, Washington, USA
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Gwayi-Chore MC, Aruldas K, Avokpaho E, Chirambo CM, Kaliappan SP, Houngbégnon P, Togbevi CI, Chabi F, Nindi P, Simwanza J, Johnson J, Miech EJ, Kalua K, Ibikounlé M, Ajjampur SSR, Weiner BJ, Walson JL, Means AR. Defining optimal implementation packages for delivering community-wide mass drug administration for soil-transmitted helminths with high coverage. BMC Health Serv Res 2022; 22:792. [PMID: 35717193 PMCID: PMC9206125 DOI: 10.1186/s12913-022-08080-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 05/13/2022] [Indexed: 11/21/2022] Open
Abstract
Background Recent evidence suggests that community-wide mass drug administration (MDA) may interrupt the transmission of soil-transmitted helminths (STH), a group of intestinal worms that infect 1.5 billion individuals globally. Although current operational guidelines provide best practices for effective MDA delivery, they do not describe which activities are most essential for achieving high coverage or how they work together to produce effective intervention delivery. We aimed to identify the various packages of influential intervention delivery activities that result in high coverage of community-wide MDA for STH in Benin, India, and Malawi. Methods We applied coincidence analysis (CNA), a novel cross-case analytical method, to process mapping data as part of the implementation science research of the DeWorm3 Project, a Hybrid Type 1 cluster randomized controlled trial assessing the feasibility of interrupting the transmission of STH using bi-annual community-wide MDA in Benin, India, and Malawi. Our analysis aimed to identify any necessary and/or sufficient combinations of intervention delivery activities (i.e., implementation pathways) that resulted in high MDA coverage. Activities were related to drug supply chain, implementer training, community sensitization strategy, intervention duration, and implementation context. We used pooled implementation data from three sites and six intervention rounds, with study clusters serving as analytical cases (N = 360). Secondary analyses assessed differences in pathways across sites and over intervention rounds. Results Across all three sites and six intervention rounds, efficient duration of MDA delivery (within ten days) singularly emerged as a common and fundamental component for achieving high MDA coverage when combined with other particular activities, including a conducive implementation context, early arrival of albendazole before the planned start of MDA, or a flexible community sensitization strategy. No individual activity proved sufficient by itself for producing high MDA coverage. We observed four possible overall models that could explain effective MDA delivery strategies, all which included efficient duration of MDA delivery as an integral component. Conclusion Efficient duration of MDA delivery uniquely stood out as a highly influential implementation activity for producing high coverage of community-wide MDA for STH. Effective MDA delivery can be achieved with flexible implementation strategies that include various combinations of influential intervention components. Supplementary Information The online version contains supplementary material available at 10.1186/s12913-022-08080-5.
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Affiliation(s)
- Marie-Claire Gwayi-Chore
- Department of Global Health, University of Washington, Seattle, USA. .,The DeWorm3 Project, University of Washington, Seattle, WA, USA.
| | - Kumudha Aruldas
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | | | | | | | | | | | - Félicien Chabi
- Institut de Recherche Clinique du Benin, Abomey-Calavi, Benin
| | - Providence Nindi
- Blantyre Institute for Community Outreach (BICO), Lions Sight First Eye Hospital, Blantyre, Malawi
| | - James Simwanza
- Blantyre Institute for Community Outreach (BICO), Lions Sight First Eye Hospital, Blantyre, Malawi
| | - Jabaselvi Johnson
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Edward J Miech
- Center for Health Services Research, Regenstrief Institute, Indianapolis, USA
| | - Khumbo Kalua
- Blantyre Institute for Community Outreach (BICO), Lions Sight First Eye Hospital, Blantyre, Malawi.,Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Moudachirou Ibikounlé
- Institut de Recherche Clinique du Benin, Abomey-Calavi, Benin.,Centre de Recherche pour la Lutte Contre les Maladies Infectieuses Tropicales, Université d'Abomey-Calavi, Abomey-Calavi, Bénin
| | - Sitara S R Ajjampur
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Bryan J Weiner
- Department of Global Health, University of Washington, Seattle, USA
| | - Judd L Walson
- Department of Global Health, University of Washington, Seattle, USA.,The DeWorm3 Project, University of Washington, Seattle, WA, USA.,Departments of Medicine, Pediatrics, & Epidemiology, University of Washington, Seattle, USA
| | - Arianna Rubin Means
- Department of Global Health, University of Washington, Seattle, USA.,The DeWorm3 Project, University of Washington, Seattle, WA, USA
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11
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Avokpaho E, Lawrence S, Roll A, Titus A, Jacob Y, Puthupalayam Kaliappan S, Gwayi-Chore MC, Chabi F, Togbevi CI, Elijan AB, Nindi P, Walson JL, Ajjampur SSR, Ibikounle M, Kalua K, Aruldas K, Means AR. It depends on how you tell: a qualitative diagnostic analysis of the implementation climate for community-wide mass drug administration for soil-transmitted helminth. BMJ Open 2022; 12:e061682. [PMID: 35701056 PMCID: PMC9198697 DOI: 10.1136/bmjopen-2022-061682] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Current soil-transmitted helminth (STH) morbidity control guidelines primarily target deworming of preschool and school-age children. Emerging evidence suggests that community-wide mass drug administration (cMDA) may interrupt STH transmission. However, the success of such programmes depends on achieving high treatment coverage and uptake. This formative analysis was conducted to evaluate the implementation climate for cMDA and to determine barriers and facilitators to launch. SETTINGS Prior to the launch of a cMDA trial in Benin, India and Malawi. PARTICIPANTS Community members (adult women and men, children, and local leaders), community drug distributors (CDDs) and health facility workers. DESIGN We conducted 48 focus group discussions (FGDs) with community members, 13 FGDs with CDDs and 5 FGDs with health facility workers in twelve randomly selected clusters across the three study countries. We used the Consolidated Framework for Implementation Research to guide the design of the interview guide and thematic analysis. RESULTS Across all three sites, aspects of the implementation climate that were facilitators to cMDA launch included: high community member demand for cMDA, integration of cMDA into existing vaccination campaigns and/or health services, and engagement with familiar health workers. Barriers to launching cMDA included mistrust towards medical interventions, fear of side effects and limited perceived need for interrupting STH transmission. We include specific recommendations from community members regarding cMDA distribution sites, personnel requirements, delivery timing and incentives, leaders to engage and methods for mobilising participants. CONCLUSIONS Prior to launching the cMDA programme as an alternative to school-based MDA, cMDA was found to be generally acceptable across diverse geographical and demographic settings. Community members, CDDs and health workers felt that engaging communities and tailoring programmes to the local context are critical for success. Potential barriers may be mitigated by identifying local concerns and addressing them via targeted community sensitisation prior to implementation. TRIAL REGISTRATION NUMBER NCT03014167; Pre-results.
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Affiliation(s)
| | - Sarah Lawrence
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Amy Roll
- Department of Global Health, University of Washington, Seattle, Washington, USA
- The DeWorm3 Project, Seattle, Washington, USA
| | - Angelin Titus
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College Vellore, Vellore, India
| | - Yesudoss Jacob
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College Vellore, Vellore, India
| | | | - Marie Claire Gwayi-Chore
- Department of Global Health, University of Washington, Seattle, Washington, USA
- The DeWorm3 Project, Seattle, Washington, USA
| | - Félicien Chabi
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Benin
| | | | | | | | - Judd L Walson
- Department of Global Health, University of Washington, Seattle, Washington, USA
- The DeWorm3 Project, Seattle, Washington, USA
| | - Sitara Swarna Rao Ajjampur
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College Vellore, Vellore, India
| | - Moudachirou Ibikounle
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Benin
- Centre de Recherche pour la lutte contre les Maladies Infectieuses Tropicales (CReMIT/TIDRC), Université d'Abomey-Calavi, Cotonou, Littoral, Benin
| | - Khumbo Kalua
- Blantyre Institute for Community Outreach, Blantyre, Malawi
| | - Kumudha Aruldas
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College Vellore, Vellore, India
| | - Arianna Rubin Means
- Department of Global Health, University of Washington, Seattle, Washington, USA
- The DeWorm3 Project, Seattle, Washington, USA
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Guo Y, Lu MK, Dong HY, Zhao Y, Zhang L, Shen XL, Shen SY, Meng YZ. Rural Left-Behind Children are Seriously Afflicted with Intestinal Helminth Infections in Southern Sichuah, China. J Parasitol 2022; 108:53-56. [DOI: 10.1645/20-173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Yue Guo
- School of Medicine, Huzhou University, 759 Er Huan Rd., Huzhou, Zhejiang, Peoples Republic of China
| | - Ming-Ke Lu
- School of Life Sciences, Xiamen University, 4221-120 Xiangannan Road, Xiang'an District, Xiamen, Fujian, Peoples Republic of China
| | - Hai-Yan Dong
- School of Medicine, Huzhou University, 759 Er Huan Rd., Huzhou, Zhejiang, Peoples Republic of China
| | - Yu Zhao
- School of Medicine, Huzhou University, 759 Er Huan Rd., Huzhou, Zhejiang, Peoples Republic of China
| | - Lu Zhang
- School of Medicine, Huzhou University, 759 Er Huan Rd., Huzhou, Zhejiang, Peoples Republic of China
| | - Xiao-Ling Shen
- School of Medicine, Huzhou University, 759 Er Huan Rd., Huzhou, Zhejiang, Peoples Republic of China
| | - Shu-Yi Shen
- School of Medicine, Huzhou University, 759 Er Huan Rd., Huzhou, Zhejiang, Peoples Republic of China
| | - Yuan-Zheng Meng
- School of Life Sciences, Xiamen University, 4221-120 Xiangannan Road, Xiang'an District, Xiamen, Fujian, Peoples Republic of China
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Aruldas K, Kaliappan SP, Israel GJ, Palanisamy G, Johnson J, Titus A, Walson JL, Means AR, Ajjampur SSR. Community Drug Distributor Knowledge, Attitudes, and Motivation Surrounding Mass Drug Administration for Soil-Transmitted Helminths in India. Front Public Health 2021; 9:714606. [PMID: 34888277 PMCID: PMC8650093 DOI: 10.3389/fpubh.2021.714606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 10/27/2021] [Indexed: 11/24/2022] Open
Abstract
Background: DeWorm3 is an ongoing multi-country community-based cluster-randomized trial assessing the feasibility of interrupting transmission of soil-transmitted helminths (STH) with community-wide mass drug administration (cMDA). In Tamil Nadu, India, community drug distributors (CDDs) worked with DeWorm3 field staff to counsel community members and deliver door-to-door deworming treatment. As CDDs were likely to influence successful delivery of cMDA, we describe drivers of CDDs' knowledge, attitudes, and motivation toward delivery of cMDA. Methods: In this convergent mixed-methods study, a questionnaire on STH and cMDA was administered to 104 CDDs and 17 focus group discussions (FGDs) were conducted. Key outcomes in the quantitative and qualitative analyses included CDDs' knowledge about STH and cMDA and attitudes toward cMDA for STH. Univariate and multivariable logistic regression analyses were performed to determine the strength of associations between independent and outcome variables. The FGDs were analyzed using a priori thematic coding. Results: CDDs who completed at least secondary school education [adjusted odds ratio (aOR): 2.71, 95% CI: 1.16–6.33] and had prior experience in health programs (aOR: 2.72, 95% CI: 1.15–6.44) were more knowledgeable about STH and cMDA. CDDs belonging to the scheduled castes and scheduled tribes (aOR: 2.37, 95% CI: 1.04–5.39), and to households engaged in a skilled occupation (aOR: 2.77, 95% CI: 1.21–6.34) had a more positive attitude toward cMDA for STH. The FGDs showed that while there were myths and misconceptions about STH, many CDDs believed that the adult population in their communities were infected with STH, and that a door-to-door drug delivery strategy would be optimal to reach adults. Conclusions: Educational and socioeconomic backgrounds and experience in health programs should be considered while designing CDD trainings. Along with cMDA delivery for STH, as CDD do share community myths and misconceptions around STH, they should be proactively addressed during the CDD training to strengthen competency in counseling.
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Affiliation(s)
- Kumudha Aruldas
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | | | - Gideon John Israel
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Gokila Palanisamy
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Jabaselvi Johnson
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Angelin Titus
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Judd L Walson
- Department of Global Health, University of Washington, Seattle, WA, United States.,The DeWorm3 Project, University of Washington, Seattle, WA, United States
| | - Arianna Rubin Means
- Department of Global Health, University of Washington, Seattle, WA, United States.,The DeWorm3 Project, University of Washington, Seattle, WA, United States
| | - Sitara Swarna Rao Ajjampur
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
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Aruldas K, Khera AK, Ajjampur SSR. Perspective: Opportunities and Scope for Expanded Deworming Programs for Soil-Transmitted Helminths in India. FRONTIERS IN TROPICAL DISEASES 2021. [DOI: 10.3389/fitd.2021.778364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The current deworming strategy for soil-transmitted helminthiases (STH) focuses on pre-school and school-aged children and women in the reproductive age to eliminate morbidity. However, mathematical modeling and meta-analysis show that STH could be eliminated if the entire population, including adults, were treated. The Government of India (GOI) has been deworming children through various maternal and child health programs and school health programs. One of the largest initiatives is the school-based biannual deworming program for children aged 1-19 years in the ‘National Deworming Day’ since 2015. Women of the reproductive age have the opportunity to get dewormed under the Anemia Free India program. Adult men and women have the opportunity to receive Albendazole in the lymphatic filariasis (LF) endemic districts. The gaps in deworming are women above the age of 49 and adult men above 19 years, living in non-LF endemic areas. Understanding gaps in deworming will help plan policy changes and program strategies for STH elimination in India, which has 21% of the global STH burden, as well as in other STH endemic countries.
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Walson JL. Establishing control and breaking transmission: the importance of accurately classifying cure following treatment for soil-transmitted helminths. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2021; 16:100288. [PMID: 34881372 PMCID: PMC8551819 DOI: 10.1016/j.lanwpc.2021.100288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
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16
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Chen YD, Qian MB, Zhu HH, Zhou CH, Zhu TJ, Huang JL, Li ZJ, Li SZ, Zhou XN. Soil-transmitted helminthiasis in China: A national survey in 2014-2015. PLoS Negl Trop Dis 2021; 15:e0009710. [PMID: 34665821 PMCID: PMC8555824 DOI: 10.1371/journal.pntd.0009710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 10/29/2021] [Accepted: 08/05/2021] [Indexed: 11/18/2022] Open
Abstract
Background Based on two national surveys, the prevalence of soil-transmitted helminthiasis (STH) in China had decreased from 53.58% in 1988–1992 to 19.56% in 2001–2004. To update the epidemiology and characteristics of STH in China, a third national survey was implemented in 2014–2015. Methodology/Principal findings This survey covered rural areas in 31 provinces in mainland of China. Multiple-stage stratified cluster sampling was employed, which included three levels (provinces, ecozones and economical levels). Stool samples were collected and the Kato-Katz method was applied for helminth eggs detection. Samples with hookworm eggs were selected and hatched to differentiate the species based on larval morphology. Between June 2014 and May 2015, a total of 484,210 participants from 604 counties were enrolled. The weighted prevalence of STH overall was 4.49% (95% confidential interval (CI): 2.45%-6.53%), including 2.62% (95% CI: 0.86%-4.38%) hookworm infections, 1.36% (95% CI: 0.49%-2.23%) ascariasis, and 1.02% (95% CI: 0.15%-1.89%) trichuriasis. The estimated population infected was 29.12 million (95% CI: 15.88 million-42.32 million) for all STH; 16.97 million (95% CI: 5.57 million-28.39 million) for hookworm infections; 8.83 million (95% CI: 3.18 million-14.45 million) for ascariasis; and 6.60 million (95% CI: 0.97 million-12.25 million) for trichuriasis. Overall, the prevalence of ascariasis and trichuriasis was relatively high in children, while hookworm infections were more common in the older population, especially those over 60. STH was highly prevalent in western China, and moderately in central areas, but low in eastern and northern regions. Out of 3,579 hookworm cases with species differentiation, 479 cases (13.38%) were infected with only Ancylostoma spp., 2,808 cases (78.46%) with only Necator americanus, and another 292 cases (8.16%) with both species. Conclusions/Significance This survey demonstrated the continuous decrease of STH in rural China. However, endemicity still prevails in the western areas of the country. Hookworm, especially N. americanus, is becoming the predominant species. Older farmers in western China should be prioritized for control due to the high prevalence of hookworm. Soil-transmitted helminthiasis (STH) had decreased significantly in China based on the two national surveys implemented in 1988–1992 and 2001–2004, respectively. In 2014–2015, an updated national survey on STH was implemented in rural China. This survey covered rural areas of 31 provinces in mainland of China and multiple-stage stratified cluster sampling was employed. Stool samples were collected and examined for helminth eggs. Totally, 484,210 villagers from 604 counties in 31 provinces participated in the survey. The adjusted prevalence of STH was 4.49%, and that of hookworm infections, ascariasis, trichuriasis was 2.62%, 1.36%, 1.02%, respectively. The estimated population with STH was 29.12 million, while that with hookworm infections, ascariasis, trichuriasis was 16.97 million, 8.83 million, 6.60 million, respectively. Children showed a high prevalence in ascariasis and trichuriasis, while the older population had a high prevalence of hookworm infections. STH was still highly prevalent in western parts, moderately in central areas, and low in eastern and northern regions. Further efforts are needed to control STH in China.
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Affiliation(s)
- Ying-Dan Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Shanghai, China
| | - Men-Bao Qian
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hui-Hui Zhu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Shanghai, China
| | - Chang-Hai Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Shanghai, China
| | - Ting-Jun Zhu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Shanghai, China
| | - Ji-Lei Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Shanghai, China
| | - Zhong-Jie Li
- Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Centre for Disease Control and Prevention, Beijing, China
| | - Shi-Zhu Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China
- NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- * E-mail:
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17
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Mather W, Hutchings P, Budge S, Jeffrey P. Association between water and sanitation service levels and soil-transmitted helminth infection risk factors: a cross-sectional study in rural Rwanda. Trans R Soc Trop Med Hyg 2021; 114:332-338. [PMID: 32052038 DOI: 10.1093/trstmh/trz119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/25/2019] [Accepted: 10/30/2019] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Soil-transmitted helminth (STH) infections are one of the most prevalent neglected tropical diseases in the world. Drug treatment is the preferred method for infection control yet reinfection occurs rapidly, so water and sanitation represent important complementary barriers to transmission. METHODS A cross-sectional study was conducted to observe STH risk factors in rural Rwandan households in relation to the Sustainable Development Goal for water and sanitation service levels. Survey and observation data were collected from 270 households and 67 water sources in rural Rwanda and were processed in relation to broader risk factors identified from the literature for the role of water and sanitation in STH infection pathways. RESULTS A significant association between higher water and sanitation service levels and lower STH infection risk profiles was found for both water and sanitation. However, variability existed within service level classifications. CONCLUSIONS Greater granularity within service level assessments is required to more precisely assess the efficacy of water and sanitation interventions in reducing STH infection risks.
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Affiliation(s)
- William Mather
- Cranfield Water Science Institute, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK
| | - Paul Hutchings
- Cranfield Water Science Institute, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK
| | - Sophie Budge
- Cranfield Water Science Institute, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK
| | - Paul Jeffrey
- Cranfield Water Science Institute, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK
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18
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Rosa BA, Snowden C, Martin J, Fischer K, Kupritz J, Beshah E, Supali T, Gankpala L, Fischer PU, Urban JF, Mitreva M. Whipworm-Associated Intestinal Microbiome Members Consistent Across Both Human and Mouse Hosts. Front Cell Infect Microbiol 2021; 11:637570. [PMID: 33777847 PMCID: PMC7991909 DOI: 10.3389/fcimb.2021.637570] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/09/2021] [Indexed: 12/14/2022] Open
Abstract
The human whipworm Trichuris trichiura infects 289 million people worldwide, resulting in substantial morbidity. Whipworm infections are difficult to treat due to low cure rates and high reinfection rates. Interactions between whipworm and its host's intestinal microbiome present a potential novel target for infection control or prevention but are very complicated and are identified using inconsistent methodology and sample types across the literature, limiting their potential usefulness. Here, we used a combined 16S rRNA gene OTU analysis approach (QIIME2) for samples from humans and mice infected with whipworm (T. trichiura and T. muris, respectively) to identify for the first time, bacterial taxa that were consistently associated with whipworm infection spanning host species and infection status using four independent comparisons (baseline infected vs uninfected and before vs after deworming for both humans and mice). Using these four comparisons, we identified significant positive associations for seven taxa including Escherichia, which has been identified to induce whipworm egg hatching, and Bacteroides, which has previously been identified as a major component of the whipworm internal microbiome. We additionally identified significant negative associations for five taxa including four members of the order Clostridiales, two from the family Lachnospiraceae, including Blautia which was previously identified as positively associated with whipworm in independent human and mouse studies. Using this approach, bacterial taxa of interest for future association and mechanistic studies were identified, and several were validated by RT-qPCR. We demonstrate the applicability of a mouse animal model for comparison to human whipworm infections with respect to whipworm-induced intestinal microbiome disruption and subsequent restoration following deworming. Overall, the novel cross-species analysis approach utilized here provides a valuable research tool for studies of the interaction between whipworm infection and the host intestinal microbiome.
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Affiliation(s)
- Bruce A. Rosa
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Caroline Snowden
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - John Martin
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Kerstin Fischer
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Jonah Kupritz
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Ethiopia Beshah
- U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, United States
| | - Taniawati Supali
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Lincoln Gankpala
- Public Health and Medical Research, National Public Health Institute of Liberia, Charlesville, Liberia
| | - Peter U. Fischer
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Joseph F. Urban
- U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD, United States
| | - Makedonka Mitreva
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
- McDonnell Genome Institute, Washington University in St. Louis, St. Louis, MO, United States
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19
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Kim SH, Stothard JR, Rinamalo M, Rainima-Qaniuci M, Talemaitoga N, Kama M, Rafai E, Jang S, Kim JY, Oh YM, Kim EM, Hong ST, Lowry JH, Verweij JJ, Kelly-Hope LA, Choi MH. A first nation-wide assessment of soil-transmitted helminthiasis in Fijian primary schools, and factors associated with the infection, using a lymphatic filariasis transmission assessment survey as surveillance platform. PLoS Negl Trop Dis 2020; 14:e0008511. [PMID: 32976499 PMCID: PMC7518615 DOI: 10.1371/journal.pntd.0008511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/23/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Soil-transmitted helminthiasis (STH) is endemic in Fiji but its prevalence is not known and likely to have changed after a decade of mass drug administration (MDA) for lymphatic filariasis (LF). By linking with LF transmission assessment surveys (LF-TAS), we undertook the first nation-wide assessment of STH in Fijian primary schools, as well as an analysis of factors associated with STH infections. METHODOLOGY/PRINCIPAL FINDINGS A cross-sectional assessment for STH was conducted in all four Divisions of Fiji from 2014 to 2015. In the Western, Central, and Northern Divisions, schools were sub-sampled after LF-TAS, while, in the Eastern Division, schools were selected via simple random sampling. For the diagnosis of STH, stool samples were examined by coproscopy with a single Kato-Katz thick smear (KK) and the formol-ether-acetate concentration technique, except for the samples from the Eastern Division where only KK was used. Mean prevalence of any STH among class 1-2 students at the national level was 10.5% (95% CI: 6.9-15.5). Across the three Divisions via LF-TAS, the prevalence levels for ascariasis were 8.7% (95% CI: 4.3-16.6), hookworm 3.9% (95% CI: 2.3-6.6) and trichuriasis 0%. In the Eastern Division, ascariasis prevalence was 13.3% (95% CI: 6.4-25.6), and hookworm 0.7% (95% CI: 0.2-2.5), with one case of trichuriasis. Among class 3-8 students, ascariasis prevalence was lower. Lower risk of any STH was associated with wearing shoes (adjusted OR 0.54, 95% CI: 0.32-0.90) and having piped water from the Fiji Water Authority at home (adjusted OR 0.48, 95% CI: 0.25-0.92). CONCLUSIONS After a decade of community-based LF-MDA, STH in school-age children in Fiji is now close to 10%, but localities of endemicity remain. Preventive chemotherapy should be maintained in areas with elevated STH prevalence alongside targeted delivery of integrated WASH interventions. LF-TAS has provided an opportunity to develop future public health surveillance platforms.
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Affiliation(s)
- Sung Hye Kim
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - J. Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | | | | | - Mike Kama
- Ministry of Health, Dinem House, Suva, Republic of Fiji
| | - Eric Rafai
- Ministry of Health, Dinem House, Suva, Republic of Fiji
| | - Seoyun Jang
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul, Korea
| | - Ji Young Kim
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul, Korea
| | - Yoo Min Oh
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul, Korea
| | - Eun-Min Kim
- Department of Environmental Medical Biology and Arthropods of Medical Importance Resource Research Bank, Institute of Tropical Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Sung-Tae Hong
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul, Korea
| | - John H. Lowry
- School of Geography, Earth Science, and Environment, The University of South Pacific, Suva, Republic of Fiji
| | - Jaco J. Verweij
- Laboratory of Medical Microbiology and Immunology, Elisabeth Hospital, Tilburg, The Netherlands
| | - Louise A. Kelly-Hope
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Min-Ho Choi
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul, Korea
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20
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Zhu HH, Huang JL, Zhu TJ, Zhou CH, Qian MB, Chen YD, Zhou XN. National surveillance on soil-transmitted helminthiasis in the People's Republic of China. Acta Trop 2020; 205:105351. [PMID: 31958411 DOI: 10.1016/j.actatropica.2020.105351] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/15/2020] [Accepted: 01/17/2020] [Indexed: 11/18/2022]
Abstract
Soil-transmitted helminths (STHs) are widely distributed and remain a public health problem in the People's Republic of China. Altogether, 301 counties across 30 regions were investigated during the national surveillance on STHs carried out in 2016 based on the modified Kato-Katz thick smear method to examine faecal samples. A total of 305 081 people were investigated with 7 366 (2.4%) found to be infected. The infection rates were the following: hookworm 1.4%, Ascaris lumbricoides 0.8% and Trichuris trichiura 0.5%. Having established that the STHs infection rate is relatively low, it is time to move towards elimination. The national surveillance system is essential for providing basic data and formulation of useful control strategies towards achieving this goal.
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Affiliation(s)
- Hui-Hui Zhu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China
| | - Ji-Lei Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China
| | - Ting-Jun Zhu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China
| | - Chang-Hai Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China
| | - Men-Bao Qian
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China
| | - Ying-Dan Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China.
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China.
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21
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Hasegawa M, Pilotte N, Kikuchi M, Means AR, Papaiakovou M, Gonzalez AM, Maasch JRMA, Ikuno H, Sunahara T, Ásbjörnsdóttir KH, Walson JL, Williams SA, Hamano S. What does soil-transmitted helminth elimination look like? Results from a targeted molecular detection survey in Japan. Parasit Vectors 2020; 13:6. [PMID: 31915050 PMCID: PMC6950881 DOI: 10.1186/s13071-019-3875-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 12/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Japan is one of the few countries believed to have eliminated soil-transmitted helminths (STHs). In 1949, the national prevalence of Ascaris lumbricoides was 62.9%, which decreased to 0.6% in 1973 due to improvements in infrastructure, socioeconomic status, and the implementation of national STH control measures. The Parasitosis Prevention Law ended in 1994 and population-level screening ceased in Japan; therefore, current transmission status of STH in Japan is not well characterized. Sporadic cases of STH infections continue to be reported, raising the possibility of a larger-scale recrudescence of STH infections. Given that traditional microscopic detection methods are not sensitive to low-intensity STH infections, we conducted targeted prevalence surveys using sensitive PCR-based assays to evaluate the current STH-transmission status and to describe epidemiological characteristics of areas of Japan believed to have achieved historical elimination of STHs. METHODS Stool samples were collected from 682 preschool- and school-aged children from six localities of Japan with previously high prevalence of STH. Caregivers of participants completed a questionnaire to ascertain access to water, sanitation and hygiene (WASH), and potential exposures to environmental contamination. For fecal testing, multi-parallel real-time PCR assays were used to detect infections of Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale and Trichuris trichiura. RESULTS Among the 682 children, no positive samples were identified, and participants reported high standards of WASH. CONCLUSIONS To our knowledge, this is the first STH-surveillance study in Japan to use sensitive molecular techniques for STH detection. The results suggest that recrudescence of STH infections has not occurred, and that declines in prevalence have been sustained in the sampled areas. These findings suggest that reductions in prevalence below the elimination thresholds, suggestive of transmission interruption, are possible. Additionally, this study provides circumstantial evidence that multi-parallel real-time PCR methods are applicable for evaluating elimination status in areas where STH prevalence is extremely low.
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Affiliation(s)
- Mitsuko Hasegawa
- Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.,Doctoral Leadership Program, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,The Joint Usage/Research Center on Tropical Disease, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA.,Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, USA
| | - Mihoko Kikuchi
- Doctoral Leadership Program, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,The Joint Usage/Research Center on Tropical Disease, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.,Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Arianna R Means
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Department of Life Sciences, Natural History Museum, London, UK
| | - Marina Papaiakovou
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA.,Department of Life Sciences, Natural History Museum, London, UK
| | - Andrew M Gonzalez
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA
| | | | - Hiroshi Ikuno
- Department of Bacteriology, BML, Inc, Saitama, Japan
| | - Toshihiko Sunahara
- The Joint Usage/Research Center on Tropical Disease, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.,Department of Vector Ecology and Environment, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | | | - Judd L Walson
- Department of Global Health, University of Washington, Seattle, Washington, USA.,Department of Life Sciences, Natural History Museum, London, UK.,Departments of Medicine (Infectious Disease), Pediatrics and Epidemiology, University of Washington, Seattle, Washington, USA
| | - Steven A Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA.,Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, USA
| | - Shinjiro Hamano
- Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan. .,Doctoral Leadership Program, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. .,The Joint Usage/Research Center on Tropical Disease, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.
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22
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Mekete K, Ower A, Dunn J, Sime H, Tadesse G, Abate E, Nigussu N, Seife F, McNaughton E, Anderson RM, Phillips AE. The Geshiyaro Project: a study protocol for developing a scalable model of interventions for moving towards the interruption of the transmission of soil-transmitted helminths and schistosome infections in the Wolaita zone of Ethiopia. Parasit Vectors 2019; 12:503. [PMID: 31665080 PMCID: PMC6820996 DOI: 10.1186/s13071-019-3757-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/22/2019] [Indexed: 12/21/2022] Open
Abstract
Background National deworming programmes rely almost exclusively on mass drug administration (MDA) to children to control morbidity caused by these parasitic infections. The provision of other interventions, consisting of preventive chemotherapy at high population level coverage together with water, sanitation and hygiene (WaSH) and changes in risk behaviour, should enable sustainable control of soil-transmitted helminths (STH) and schistosomiasis and ultimately interrupt transmission. Methods/Design Two interventions will be implemented by the project: (i) community-wide biannual albendazole and annual praziquantel treatment with a target of 80–90% treatment coverage (“expanded MDA”); and (ii) provision of WaSH with behaviour change communication (BCC), within the Wolaita zone, Ethiopia. The project has three study arms: (i) expanded community-wide MDA, WaSH and BCC; (ii) expanded community-wide MDA only; and (iii) annual school-based MDA (the current National STH/schistosomiasis Control Programme). The impact of these interventions will be evaluated through prevalence mapping at baseline and endline (after four rounds of MDA), combined with annual longitudinal parasitological surveillance in defined cohorts of people to monitor trends in prevalence and reinfection throughout the project. Treatment coverage and individual compliance to treatment will be monitored by employing fingerprint biometric technology and barcoded identification cards at treatment. WaSH utilisation will be evaluated through school and household level observations and annual WaSH assessment survey. Complementary qualitative surveys will explore practices, cultural and social drivers of risk behaviours, uptake of WaSH and treatment, and assessing the impact of the BCC. Discussion The study has the potential to define an ‘End Game’ for STH and schistosomiasis programmes through provision of multiple interventions. Interrupting transmission of these infections would eliminate the need for long-term repeated MDA, lead to sustained health improvements in children and adults, thereby allowing health systems to focus on other disease control priorities.
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Affiliation(s)
| | - Alison Ower
- London Centre for Neglected Tropical Disease Research, Department of Infectious Diseases Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, W2 1PG, UK
| | - Julia Dunn
- London Centre for Neglected Tropical Disease Research, Department of Infectious Diseases Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, W2 1PG, UK
| | - Heven Sime
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Ebba Abate
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | | | - Emily McNaughton
- London Centre for Neglected Tropical Disease Research, Department of Infectious Diseases Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, W2 1PG, UK
| | - Roy Malcolm Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Diseases Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, W2 1PG, UK
| | - Anna Elizabeth Phillips
- London Centre for Neglected Tropical Disease Research, Department of Infectious Diseases Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, W2 1PG, UK.
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23
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Jeske S, Bianchi TF, Leon ÍF, Villela MM. Neoplastic patients' knowledge about intestinal parasitoses in southern Brazil. BRAZ J BIOL 2019; 80:386-392. [PMID: 31411251 DOI: 10.1590/1519-6984.211560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 01/25/2019] [Indexed: 11/22/2022] Open
Abstract
Since oncologic patients have been considered an important risk group for parasitic infections, it is fundamental to find out what they know about intestinal parasites. This study aimed at evaluating knowledge that the adult oncologic patients undergoing chemotherapy in the main centers of treatment for cancer in the city of Pelotas, Brazil, has about intestinal parasites. A semi-structured questionnaire was used for collecting data from two hundred oncologic patients who were undergoing chemotherapy. Results showed that 69.5% know what intestinal parasites are and cited Ascaris lumbricoides and Taenia sp. as being the most known ones. The statistical comparison between the group that knows intestinal parasites and the one that does not know about them - associated with socioeconomic variables -, showed that factors that significantly influenced their knowledge were their place of residence, schooling and household income (p≤0.05). Only 36% stated that they know when they are infected with parasites and misdescribed some signs and symptoms. Regarding prevention, 52% mentioned that they do not know how to avoid parasitism. The population under study showed that there are some gaps in its knowledge of the theme under investigation. Therefore, it is important to implement socioeducational measures in hospitals and clinics that treat cancer patients.
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Affiliation(s)
- S Jeske
- Programa de Pós-graduação em Parasitologia, Departamento de Microbiologia e Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas - UFPel, Campus Universitário, Av. Eliseu Maciel, s/n, CEP 96160-000, Capão do Leão, RS, Brasil
| | - T F Bianchi
- Programa de Pós-graduação em Parasitologia, Departamento de Microbiologia e Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas - UFPel, Campus Universitário, Av. Eliseu Maciel, s/n, CEP 96160-000, Capão do Leão, RS, Brasil
| | - Í F Leon
- Programa de Pós-graduação em Parasitologia, Departamento de Microbiologia e Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas - UFPel, Campus Universitário, Av. Eliseu Maciel, s/n, CEP 96160-000, Capão do Leão, RS, Brasil
| | - M M Villela
- Programa de Pós-graduação em Parasitologia, Departamento de Microbiologia e Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas - UFPel, Campus Universitário, Av. Eliseu Maciel, s/n, CEP 96160-000, Capão do Leão, RS, Brasil
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24
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Monteiro KJL, Calegar DA, Santos JP, Bacelar PAA, Coronato-Nunes B, Reis ERC, Boia MN, Carvalho-Costa FA, Jaeger LH. Genetic diversity of Ascaris spp. infecting humans and pigs in distinct Brazilian regions, as revealed by mitochondrial DNA. PLoS One 2019; 14:e0218867. [PMID: 31233550 PMCID: PMC6590885 DOI: 10.1371/journal.pone.0218867] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 06/11/2019] [Indexed: 11/19/2022] Open
Abstract
In this study, we assessed the genetic diversity of Ascaris lumbricoides / Ascaris suum circulating in humans and pigs, exploring potential zoonotic cycles in endemic areas in Brazil. We carried out cross-sectional surveys in four municipalities: Santa Isabel do Rio Negro (SIRN-AM) (n = 328); Nossa Senhora de Nazaré (NSN-PI) and Teresina (TER-PI) (n = 605 and n = 297, respectively); and Cachoeiras de Macacu (CAM-RJ) (n = 543). We also studied 61 fecal samples/adult worms obtained from pigs (n = 53 in NSN-PI and n = 8 in TER-PI). A ~450 bp fragment of the Ascaris cytochrome c oxidase subunit 1 (cox1) and ~400 bp of the NADH dehydrogenase subunit 1 (nad1) were amplified and sequenced. Maximum-likelihood (ML) tree and Median-joining (MJ) haplotype network analyses were performed. We also performed scanning electron micrographs of adult specimens. Positivity rates were 93/328 (28.4%) in SIRN-AM, 6/297 (2.0%) in TER-PI, 0/605 (0%) in NSN-PI, and 6/543 (1.1%) in CAM-RJ. In NSN-PI it reached 11/53 (20.7%) in pigs. The MJ network based on cox1 locus (383 bp) revealed three main clusters, one centered around haplotypes H01/H28/H32 and the other around H07/H11. The cox1 haplotypes had a heterogeneous distribution, showing no pattern by geographic region, and high haplotype diversity. The ML trees based on cox1 and nad1 loci showed a similar topology with each other, and with the haplotype networks. Three distinct clusters were observed. Sequences of cox1 and nad1 from humans and animals were distributed throughout the tree and it was not possible to differentiate specimens of human and swine origin. Ascaris populations obtained from humans and swine in different Brazilian regions are not discriminable through the genetic markers used, which indicates the potential for zoonotic transmission and the need for better control of these infections in swine herds, mainly when created in a peridomestic environment.
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Affiliation(s)
- Kerla J. L. Monteiro
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
- Escritório Técnico Regional, Fundação Oswaldo Cruz Piauí, Teresina, Piauí, Brazil
| | - Deiviane A. Calegar
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jessica P. Santos
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
- Escritório Técnico Regional, Fundação Oswaldo Cruz Piauí, Teresina, Piauí, Brazil
| | - Polyanna A. A. Bacelar
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
- Escritório Técnico Regional, Fundação Oswaldo Cruz Piauí, Teresina, Piauí, Brazil
| | - Beatriz Coronato-Nunes
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Elis Regina C. Reis
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Márcio N. Boia
- Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro,Brazil
| | - Filipe A. Carvalho-Costa
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
- Escritório Técnico Regional, Fundação Oswaldo Cruz Piauí, Teresina, Piauí, Brazil
| | - Lauren H. Jaeger
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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Freeman MC, Akogun O, Belizario V, Brooker SJ, Gyorkos TW, Imtiaz R, Krolewiecki A, Lee S, Matendechero SH, Pullan RL, Utzinger J. Challenges and opportunities for control and elimination of soil-transmitted helminth infection beyond 2020. PLoS Negl Trop Dis 2019; 13:e0007201. [PMID: 30973872 PMCID: PMC6459486 DOI: 10.1371/journal.pntd.0007201] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Matthew C. Freeman
- Department of Environmental Health, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
| | | | - Vicente Belizario
- College of Public Health, University of the Philippines Manila, Manila, the Philippines
| | - Simon J. Brooker
- Global Health, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| | - Theresa W. Gyorkos
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
| | - Rubina Imtiaz
- Children Without Worms, The Task Force for Global Health, Decatur, Georgia, United States of America
| | - Alejandro Krolewiecki
- Instituto de Investigaciones en Enfermedades Tropicales, Universidad Nacional de Salta, Oran, Argentina
| | - Seung Lee
- Save the Children, Washington, DC, United States of America
| | | | - Rachel L. Pullan
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Steinbaum L, Mboya J, Mahoney R, Njenga SM, Null C, Pickering AJ. Effect of a sanitation intervention on soil-transmitted helminth prevalence and concentration in household soil: A cluster-randomized controlled trial and risk factor analysis. PLoS Negl Trop Dis 2019; 13:e0007180. [PMID: 30742614 PMCID: PMC6386409 DOI: 10.1371/journal.pntd.0007180] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 02/22/2019] [Accepted: 01/22/2019] [Indexed: 12/19/2022] Open
Abstract
Improved sanitation has been associated with a reduced prevalence of soil-transmitted helminth (STH) infection and has been hypothesized to prevent fecal contamination from spreading throughout the household environment. We evaluated the effect of providing households with a pit latrine with a plastic slab and drophole cover, child feces management tools, and associated behavioral messaging on reducing STH eggs in household soil. We collected soil samples from 2107 households (898 control and 1209 improved sanitation intervention households) that were enrolled in the WASH Benefits cluster randomized controlled trial in rural Kenya and performed a post-intervention analysis after two years of intervention exposure. Following a pre-specified analysis plan, we combined all households that received the sanitation intervention into one group for comparison to control households. The prevalence of STH eggs in soil was 18.9% in control households and 17.0% in intervention households. The unadjusted prevalence ratio of total STH eggs in the intervention groups compared to the control group was 0.94 (95% CI: 0.78-1.13). The geometric mean concentration was 0.05 eggs/g dry soil in control households and intervention households. Unadjusted and adjusted models gave similar results. We found use of a shared latrine, presence of a roof over the sampling area, and the number of dogs owned at baseline was associated with an increased prevalence of STH eggs in soil; the presence of a latrine that was at least 2 years old and a latrine with a covered drophole was associated with a reduction in the prevalence of STH eggs in soil. Soil moisture content was also associated with an increased prevalence of STH eggs in soil. Our results indicate that an intervention designed to increase access to improved latrines and child feces management tools may not be enough to impact environmental occurrence of STH in endemic areas where latrine coverage is already high.
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Affiliation(s)
- Lauren Steinbaum
- Civil and Environmental Engineering, Stanford University, Stanford, California, United States of America
- Epidemiology and Biostatistics, University of Georgia, Athens, Georgia, United States of America
| | - John Mboya
- Innovations for Poverty Action, Nairobi, Kenya
| | - Ryan Mahoney
- Innovations for Poverty Action, New Haven, Connecticut, United States of America
| | - Sammy M. Njenga
- Eastern and Southern Africa Center of International Parasite Control, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Clair Null
- Innovations for Poverty Action, New Haven, Connecticut, United States of America
- Mathematica, Washington, D.C., United States of America
| | - Amy J. Pickering
- Civil and Environmental Engineering, Stanford University, Stanford, California, United States of America
- Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America
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O'Shea MK, Fletcher TE, Muller J, Tanner R, Matsumiya M, Bailey JW, Jones J, Smith SG, Koh G, Horsnell WG, Beeching NJ, Dunbar J, Wilson D, Cunningham AF, McShane H. Human Hookworm Infection Enhances Mycobacterial Growth Inhibition and Associates With Reduced Risk of Tuberculosis Infection. Front Immunol 2018; 9:2893. [PMID: 30619265 PMCID: PMC6302045 DOI: 10.3389/fimmu.2018.02893] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 11/26/2018] [Indexed: 12/22/2022] Open
Abstract
Soil-transmitted helminths and Mycobacterium tuberculosis frequently coincide geographically and it is hypothesized that gastrointestinal helminth infection may exacerbate tuberculosis (TB) disease by suppression of Th1 and Th17 responses. However, few studies have focused on latent TB infection (LTBI), which predominates globally. We performed a large observational study of healthy adults migrating from Nepal to the UK (n = 645). Individuals were screened for LTBI and gastrointestinal parasite infections. A significant negative association between hookworm and LTBI-positivity was seen (OR = 0.221; p = 0.039). Hookworm infection treatment did not affect LTBI conversions. Blood from individuals with hookworm had a significantly greater ability to control virulent mycobacterial growth in vitro than from those without, which was lost following hookworm treatment. There was a significant negative relationship between mycobacterial growth and eosinophil counts. Eosinophil-associated differential gene expression characterized the whole blood transcriptome of hookworm infection and correlated with improved mycobacterial control. These data provide a potential alternative explanation for the reduced prevalence of LTBI among individuals with hookworm infection, and possibly an anti-mycobacterial role for helminth-induced eosinophils.
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Affiliation(s)
- Matthew K. O'Shea
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Oxford, United Kingdom
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
- Royal Centre for Defence Medicine, Joint Medical Command, Birmingham, United Kingdom
| | - Thomas E. Fletcher
- Royal Centre for Defence Medicine, Joint Medical Command, Birmingham, United Kingdom
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Julius Muller
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Rachel Tanner
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Magali Matsumiya
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - J. Wendi Bailey
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jayne Jones
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Steven G. Smith
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Gavin Koh
- Department of Infectious Diseases, Northwick Park Hospital, London, United Kingdom
| | - William G. Horsnell
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
- Institute of Infectious Disease and Molecular Medicine and Division of Immunology, University of Cape Town, Cape Town, South Africa
| | - Nicholas J. Beeching
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - James Dunbar
- Royal Centre for Defence Medicine, Joint Medical Command, Birmingham, United Kingdom
- Department of Infectious Diseases, The Friarage Hospital, Northallerton, United Kingdom
| | - Duncan Wilson
- Royal Centre for Defence Medicine, Joint Medical Command, Birmingham, United Kingdom
| | - Adam F. Cunningham
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Helen McShane
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Oxford, United Kingdom
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Lin WM, Addiss DG. Sustainable access to deworming drugs in a changing landscape. THE LANCET. INFECTIOUS DISEASES 2018; 18:e395-e398. [PMID: 30122439 DOI: 10.1016/s1473-3099(18)30351-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 05/10/2018] [Accepted: 05/17/2018] [Indexed: 12/23/2022]
Abstract
The global effort to control and eliminate soil-transmitted helminthiasis (STH) currently depends on donations of albendazole and mebendazole, which reached more than 530 million children in 2016. As we approach 2020, the WHO goal of eliminating STH as a public health problem will not be met in most endemic countries, and ongoing treatment will be necessary. Additionally, the volume of drugs required might increase because global strategies for STH aim to interrupt transmission. Under the 2012 London Declaration on Neglected Tropical Diseases, pharmaceutical company commitments to donate drugs to control or eliminate neglected tropical diseases extend to 2020. We are approaching a period of uncertainty regarding different strategies for control and elimination of STH, the size and target populations for future donations, and optimum drugs and drug combinations. Long-term reliance on large-scale donation of deworming drugs is not sustainable. The global STH community need to develop a strategy to secure a sustainable global supply of affordable and effective anthelmintic drugs. This strategy should include improvement of the quality of generic drugs through innovative technical partnerships.
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Affiliation(s)
- William M Lin
- EJD Global Health, Langhorne, PA, USA; Department of Health, University of Bath, Bath, UK.
| | - David G Addiss
- The Task Force for Global Health, Decatur, GA, USA; Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
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Monteiro KJL, Reis ERCD, Nunes BC, Jaeger LH, Calegar DA, Santos JPD, Maia ADO, Xavier SCDC, Bóia MN, Carvalho-Costa FA. Focal persistence of soil-transmitted helminthiases in impoverished areas in the State of Piaui, Northeastern Brazil. Rev Inst Med Trop Sao Paulo 2018; 60:e24. [PMID: 29972463 PMCID: PMC6029850 DOI: 10.1590/s1678-9946201860024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/28/2018] [Indexed: 11/21/2022] Open
Abstract
This study aims to describe the prevalence, distribution, and factors associated with soil-transmitted helminthiases (STHs) in rural localities in Piaui, Brazil. Two cross-sectional surveys (n=605 subjects; 172 families) were carried out in order to obtain socio-demographic, anthropometric, spatial and parasitological data. Parasites were evaluated using Kato-Katz and centrifugal sedimentation techniques. Eggs were measured to assess infection with zoonotic Strongylida parasites. Kernel maps were constructed with Q-GIS. The prevalence of hookworm infection was 12.4% (75/605). Other helminthes found were Trichuris trichiura (n=1; 0.2%) and Hymenolepis nana (n=1; 0.2%). The hookworm positivity rate was significantly lower among subjects who had used albendazole when compared with individuals who had not used anthelmintics or had used antiprotozoal drugs in the last 6 months (8/134 [6.0%] vs. 59/415 [14.2%]; p=0.009). A total of 39/172 (22.7%) families had at least one infected member. The association between the number of dwellers and hookworm positivity in the family was present in a logistic regression multivariate model. Assessment of worm burdens showed 92.2% light, 6.2% moderate, and 1.6% heavy infections. Hookworm eggs (n=34) measured 57.2 - 75.4 µm in length and 36.4 - 44.2 µm in width (mean ± SD = 65.86 ± 4.66 µm L and 40.05 ± 1.99 µm W), commensurate with human hookworms. Hotspots suggest that transmission has a focal pattern. STHs persist in impoverished rural areas in Northeastern Brazil where currently available control strategies (mass drug administration) apparently do not allow the elimination of the infection.
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Affiliation(s)
- Kerla Joeline Lima Monteiro
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Elis Regina Chaves Dos Reis
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Beatriz Coronato Nunes
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lauren Hubert Jaeger
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Deiviane Aparecida Calegar
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Alexander de Oliveira Maia
- Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Márcio Neves Bóia
- Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Filipe Anibal Carvalho-Costa
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
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Rosa BA, Supali T, Gankpala L, Djuardi Y, Sartono E, Zhou Y, Fischer K, Martin J, Tyagi R, Bolay FK, Fischer PU, Yazdanbakhsh M, Mitreva M. Differential human gut microbiome assemblages during soil-transmitted helminth infections in Indonesia and Liberia. MICROBIOME 2018; 6:33. [PMID: 29486796 PMCID: PMC6389212 DOI: 10.1186/s40168-018-0416-5] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 01/26/2018] [Indexed: 05/11/2023]
Abstract
BACKGROUND The human intestine and its microbiota is the most common infection site for soil-transmitted helminths (STHs), which affect the well-being of ~ 1.5 billion people worldwide. The complex cross-kingdom interactions are not well understood. RESULTS A cross-sectional analysis identified conserved microbial signatures positively or negatively associated with STH infections across Liberia and Indonesia, and longitudinal samples analysis from a double-blind randomized trial showed that the gut microbiota responds to deworming but does not transition closer to the uninfected state. The microbiomes of individuals able to self-clear the infection had more alike microbiome assemblages compared to individuals who remained infected. One bacterial taxon (Lachnospiracae) was negatively associated with infection in both countries, and 12 bacterial taxa were significantly associated with STH infection in both countries, including Olsenella (associated with reduced gut inflammation), which also significantly reduced in abundance following clearance of infection. Microbial community gene abundances were also affected by deworming. Functional categories identified as associated with STH infection included arachidonic acid metabolism; arachidonic acid is the precursor for pro-inflammatory leukotrienes that threaten helminth survival, and our findings suggest that some modulation of arachidonic acid activity in the STH-infected gut may occur through the increase of arachidonic acid metabolizing bacteria. CONCLUSIONS For the first time, we identify specific members of the gut microbiome that discriminate between moderately/heavily STH-infected and non-infected states across very diverse geographical regions using two different statistical methods. We also identify microbiome-encoded biological functions associated with the STH infections, which are associated potentially with STH survival strategies, and changes in the host environment. These results provide a novel insight of the cross-kingdom interactions in the human gut ecosystem by unlocking the microbiome assemblages at taxonomic, genetic, and functional levels so that advances towards key mechanistic studies can be made.
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Affiliation(s)
- Bruce A. Rosa
- McDonnell Genome Institute, Washington University, St. Louis, MO 63108 USA
| | - Taniawati Supali
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Lincoln Gankpala
- Public Health and Medical Research, National Public Health Institute of Liberia, Charlesville, Liberia
| | - Yenny Djuardi
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Erliyani Sartono
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Yanjiao Zhou
- Microbial Genomics, The Jackson Laboratory for Genomic Medicine, Farmington, CT USA
| | - Kerstin Fischer
- Department of Medicine, Washington University School of Medicine, St. Louis, MO USA
| | - John Martin
- McDonnell Genome Institute, Washington University, St. Louis, MO 63108 USA
| | - Rahul Tyagi
- McDonnell Genome Institute, Washington University, St. Louis, MO 63108 USA
| | - Fatorma K. Bolay
- Public Health and Medical Research, National Public Health Institute of Liberia, Charlesville, Liberia
| | - Peter U. Fischer
- Department of Medicine, Washington University School of Medicine, St. Louis, MO USA
| | - Maria Yazdanbakhsh
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Makedonka Mitreva
- McDonnell Genome Institute, Washington University, St. Louis, MO 63108 USA
- Department of Medicine, Washington University School of Medicine, St. Louis, MO USA
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Abstract
Purpose of review Soil-transmitted helminths (STH) are endemic in 120 countries and are associated with substantial morbidity and loss of economic productivity. Although current WHO guidelines focus on morbidity control through mass drug administration (MDA), there is global interest in whether a strategy targeting disease elimination might be feasible in some settings. This review summarizes the prospects for switching from control to an elimination strategy. Recent findings STH control efforts have reduced the intensity of infections in targeted populations with associated reductions in morbidity. However, adults are not frequently targeted and remain important reservoirs for reinfection of treated children. Recent modeling suggests that transmission interruption may be possible through expanded community-wide delivery of MDA, the feasibility of which has been demonstrated by other programs. However, these models suggest that high levels of coverage and compliance must be achieved. Potential challenges include the risk of prematurely dismantling STH programs and the potential increased risk of antihelminthic resistance. Summary Elimination of STH may offer an opportunity to eliminate substantial STH-related morbidity while reducing resource needs of neglected tropical disease programs. Evidence from large community trials is needed to determine the feasibility of interrupting the transmission of STH in some geographic settings.
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Ásbjörnsdóttir KH, Ajjampur SSR, Anderson RM, Bailey R, Gardiner I, Halliday KE, Ibikounle M, Kalua K, Kang G, Littlewood DTJ, Luty AJF, Means AR, Oswald W, Pullan RL, Sarkar R, Schär F, Szpiro A, Truscott JE, Werkman M, Yard E, Walson JL. Assessing the feasibility of interrupting the transmission of soil-transmitted helminths through mass drug administration: The DeWorm3 cluster randomized trial protocol. PLoS Negl Trop Dis 2018; 12:e0006166. [PMID: 29346377 PMCID: PMC5773085 DOI: 10.1371/journal.pntd.0006166] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/14/2017] [Indexed: 12/23/2022] Open
Abstract
Current control strategies for soil-transmitted helminths (STH) emphasize morbidity control through mass drug administration (MDA) targeting preschool- and school-age children, women of childbearing age and adults in certain high-risk occupations such as agricultural laborers or miners. This strategy is effective at reducing morbidity in those treated but, without massive economic development, it is unlikely it will interrupt transmission. MDA will therefore need to continue indefinitely to maintain benefit. Mathematical models suggest that transmission interruption may be achievable through MDA alone, provided that all age groups are targeted with high coverage. The DeWorm3 Project will test the feasibility of interrupting STH transmission using biannual MDA targeting all age groups. Study sites (population ≥80,000) have been identified in Benin, Malawi and India. Each site will be divided into 40 clusters, to be randomized 1:1 to three years of twice-annual community-wide MDA or standard-of-care MDA, typically annual school-based deworming. Community-wide MDA will be delivered door-to-door, while standard-of-care MDA will be delivered according to national guidelines. The primary outcome is transmission interruption of the STH species present at each site, defined as weighted cluster-level prevalence ≤2% by quantitative polymerase chain reaction (qPCR), 24 months after the final round of MDA. Secondary outcomes include the endline prevalence of STH, overall and by species, and the endline prevalence of STH among children under five as an indicator of incident infections. Secondary analyses will identify cluster-level factors associated with transmission interruption. Prevalence will be assessed using qPCR of stool samples collected from a random sample of cluster residents at baseline, six months after the final round of MDA and 24 months post-MDA. A smaller number of individuals in each cluster will be followed with annual sampling to monitor trends in prevalence and reinfection throughout the trial. TRIAL REGISTRATION ClinicalTrials.gov NCT03014167.
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Affiliation(s)
- Kristjana Hrönn Ásbjörnsdóttir
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, United States
| | | | - Roy M. Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, St. Marys Campus, Imperial College London, London, United Kingdom
| | - Robin Bailey
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Iain Gardiner
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
| | - Katherine E. Halliday
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Moudachirou Ibikounle
- Département de Zoologie, Faculté des Sciences et Techniques, Université d'Abomey-Calavi 01BP526, Cotonou, Benin
| | - Khumbo Kalua
- Blantyre Institute for Community Outreach, Lions Sight First Eye Hospital, Blantyre, Malawi
| | - Gagandeep Kang
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | | | - Adrian J. F. Luty
- MERIT UMR 216, Institut de Recherche pour le Développement, Paris, France
| | - Arianna Rubin Means
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, United States
| | - William Oswald
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Rachel L. Pullan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Rajiv Sarkar
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Fabian Schär
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
| | - Adam Szpiro
- Department of Biostatistics, University of Washington, Seattle, United States
| | - James E. Truscott
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, St. Marys Campus, Imperial College London, London, United Kingdom
| | - Marleen Werkman
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, St. Marys Campus, Imperial College London, London, United Kingdom
| | - Elodie Yard
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
| | - Judd L. Walson
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, United States
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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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34
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Jenkins TP, Rathnayaka Y, Perera PK, Peachey LE, Nolan MJ, Krause L, Rajakaruna RS, Cantacessi C. Infections by human gastrointestinal helminths are associated with changes in faecal microbiota diversity and composition. PLoS One 2017; 12:e0184719. [PMID: 28892494 PMCID: PMC5593201 DOI: 10.1371/journal.pone.0184719] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/29/2017] [Indexed: 12/20/2022] Open
Abstract
Investigations of the impact that patent infections by soil-transmitted gastrointestinal nematode parasites exert on the composition of the host gut commensal flora are attracting growing interest by the scientific community. However, information collected to date varies across experiments, and further studies are needed to identify consistent relationships between parasites and commensal microbial species. Here, we explore the qualitative and quantitative differences between the microbial community profiles of cohorts of human volunteers from Sri Lanka with patent infection by one or more parasitic nematode species (H+), as well as that of uninfected subjects (H-) and of volunteers who had been subjected to regular prophylactic anthelmintic treatment (Ht). High-throughput sequencing of the bacterial 16S rRNA gene, followed by bioinformatics and biostatistical analyses of sequence data revealed no significant differences in alpha diversity (Shannon) and richness between groups (P = 0.65, P = 0.13 respectively); however, beta diversity was significantly increased in H+ and Ht when individually compared to H-volunteers (P = 0.04). Among others, bacteria of the families Verrucomicrobiaceae and Enterobacteriaceae showed a trend towards increased abundance in H+, whereas the Leuconostocaceae and Bacteroidaceae showed a relative increase in H- and Ht respectively. Our findings add valuable knowledge to the vast, and yet little explored, research field of parasite—microbiota interactions and will provide a basis for the elucidation of the role such interactions play in pathogenic and immune-modulatory properties of parasitic nematodes in both human and animal hosts.
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Affiliation(s)
- Timothy P. Jenkins
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Yasara Rathnayaka
- Department of Zoology, University of Peradeniya, Peradeniya, Sri Lanka
| | | | - Laura E. Peachey
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Matthew J. Nolan
- Royal Veterinary College, University of London, North Mymms, United Kingdom
| | - Lutz Krause
- The University of Queensland Diamantina Institute, Translational Research Institute, Woolloongabba, Australia
| | | | - Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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Truscott JE, Werkman M, Wright JE, Farrell SH, Sarkar R, Ásbjörnsdóttir K, Anderson RM. Identifying optimal threshold statistics for elimination of hookworm using a stochastic simulation model. Parasit Vectors 2017; 10:321. [PMID: 28666452 PMCID: PMC5493114 DOI: 10.1186/s13071-017-2256-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 06/12/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND There is an increased focus on whether mass drug administration (MDA) programmes alone can interrupt the transmission of soil-transmitted helminths (STH). Mathematical models can be used to model these interventions and are increasingly being implemented to inform investigators about expected trial outcome and the choice of optimum study design. One key factor is the choice of threshold for detecting elimination. However, there are currently no thresholds defined for STH regarding breaking transmission. METHODS We develop a simulation of an elimination study, based on the DeWorm3 project, using an individual-based stochastic disease transmission model in conjunction with models of MDA, sampling, diagnostics and the construction of study clusters. The simulation is then used to analyse the relationship between the study end-point elimination threshold and whether elimination is achieved in the long term within the model. We analyse the quality of a range of statistics in terms of the positive predictive values (PPV) and how they depend on a range of covariates, including threshold values, baseline prevalence, measurement time point and how clusters are constructed. RESULTS End-point infection prevalence performs well in discriminating between villages that achieve interruption of transmission and those that do not, although the quality of the threshold is sensitive to baseline prevalence and threshold value. Optimal post-treatment prevalence threshold value for determining elimination is in the range 2% or less when the baseline prevalence range is broad. For multiple clusters of communities, both the probability of elimination and the ability of thresholds to detect it are strongly dependent on the size of the cluster and the size distribution of the constituent communities. Number of communities in a cluster is a key indicator of probability of elimination and PPV. Extending the time, post-study endpoint, at which the threshold statistic is measured improves PPV value in discriminating between eliminating clusters and those that bounce back. CONCLUSIONS The probability of elimination and PPV are very sensitive to baseline prevalence for individual communities. However, most studies and programmes are constructed on the basis of clusters. Since elimination occurs within smaller population sub-units, the construction of clusters introduces new sensitivities for elimination threshold values to cluster size and the underlying population structure. Study simulation offers an opportunity to investigate key sources of sensitivity for elimination studies and programme designs in advance and to tailor interventions to prevailing local or national conditions.
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Affiliation(s)
- James E Truscott
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary's Campus, Imperial College London, W2 1PG, London, UK. .,The DeWorm3 Project, The Natural History Museum of London, London, SW7 5BD, UK.
| | - Marleen Werkman
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary's Campus, Imperial College London, W2 1PG, London, UK.,The DeWorm3 Project, The Natural History Museum of London, London, SW7 5BD, UK
| | - James E Wright
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary's Campus, Imperial College London, W2 1PG, London, UK.,The DeWorm3 Project, The Natural History Museum of London, London, SW7 5BD, UK
| | - Sam H Farrell
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary's Campus, Imperial College London, W2 1PG, London, UK
| | - Rajiv Sarkar
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, 632004, India
| | - Kristjana Ásbjörnsdóttir
- The DeWorm3 Project, The Natural History Museum of London, London, SW7 5BD, UK.,Department of Global Health, University of Washington, Seattle, USA
| | - Roy M Anderson
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, St. Mary's Campus, Imperial College London, W2 1PG, London, UK.,The DeWorm3 Project, The Natural History Museum of London, London, SW7 5BD, UK
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Turner HC, Bettis AA, Dunn JC, Whitton JM, Hollingsworth TD, Fleming FM, Anderson RM. Economic Considerations for Moving beyond the Kato-Katz Technique for Diagnosing Intestinal Parasites As We Move Towards Elimination. Trends Parasitol 2017; 33:435-443. [PMID: 28187989 PMCID: PMC5446322 DOI: 10.1016/j.pt.2017.01.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/29/2016] [Accepted: 01/09/2017] [Indexed: 12/30/2022]
Abstract
While the need for more sensitive diagnostics for intestinal helminths is well known, the cost of developing and implementing new tests is considered relatively high compared to the Kato-Katz technique. Here, we review the reported costs of performing the Kato-Katz technique. We also outline several economic arguments we believe highlight the need for further investment in alternative diagnostics, and considerations that should be made when comparing their costs. In our opinion, we highlight that, without new diagnostic methods, it will be difficult for policy makers to make the most cost-effective decisions and that the potentially higher unit costs of new methods can be outweighed by the long-term programmatic benefits they have (such as the ability to detect the interruption of transmission).
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Affiliation(s)
- Hugo C Turner
- London Centre for Neglected Tropical Disease Research, London, UK; Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London,Norfolk Place, London W2 1PG, UK; Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Alison A Bettis
- London Centre for Neglected Tropical Disease Research, London, UK; Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London,Norfolk Place, London W2 1PG, UK
| | - Julia C Dunn
- London Centre for Neglected Tropical Disease Research, London, UK; Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London,Norfolk Place, London W2 1PG, UK
| | - Jane M Whitton
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, Norfolk Place, London W2 1PG, UK
| | - T Déirdre Hollingsworth
- Mathematics Institute, University of Warwick, Coventry CV4 7AL, UK; School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Fiona M Fleming
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's Campus), Imperial College London, Norfolk Place, London W2 1PG, UK
| | - Roy M Anderson
- London Centre for Neglected Tropical Disease Research, London, UK; Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London,Norfolk Place, London W2 1PG, UK
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37
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Campbell SJ, Nery SV, Wardell R, D’Este CA, Gray DJ, McCarthy JS, Traub RJ, Andrews RM, Llewellyn S, Vallely AJ, Williams GM, Clements ACA. Water, Sanitation and Hygiene (WASH) and environmental risk factors for soil-transmitted helminth intensity of infection in Timor-Leste, using real time PCR. PLoS Negl Trop Dis 2017; 11:e0005393. [PMID: 28346536 PMCID: PMC5383321 DOI: 10.1371/journal.pntd.0005393] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 04/06/2017] [Accepted: 02/06/2017] [Indexed: 11/18/2022] Open
Abstract
Background No investigations have been undertaken of risk factors for intensity of soil-transmitted helminth (STH) infection in Timor-Leste. This study provides the first analysis of risk factors for intensity of STH infection, as determined by quantitative PCR (qPCR), examining a broad range of water, sanitation and hygiene (WASH) and environmental factors, among communities in Manufahi District, Timor-Leste. Methods A baseline cross-sectional survey of 18 communities was undertaken as part of a cluster randomised controlled trial, with additional identically-collected data from six other communities. qPCR was used to assess STH infection from stool samples, and questionnaires administered to collect WASH, demographic, and socioeconomic data. Environmental information was obtained from open-access sources and linked to infection outcomes. Mixed-effects multinomial logistic regression was undertaken to assess risk factors for intensity of Necator americanus and Ascaris infection. Results 2152 participants provided stool and questionnaire information for this analysis. In adjusted models incorporating WASH, demographic and environmental variables, environmental variables were generally associated with infection intensity for both N. americanus and Ascaris spp. Precipitation (in centimetres) was associated with increased risk of moderate-intensity (adjusted relative risk [ARR] 6.1; 95% confidence interval [CI] 1.9–19.3) and heavy-intensity (ARR 6.6; 95% CI 3.1–14.1) N. americanus infection, as was sandy-loam soil around households (moderate-intensity ARR 2.1; 95% CI 1.0–4.3; heavy-intensity ARR 2.7; 95% CI 1.6–4.5; compared to no infection). For Ascaris, alkaline soil around the household was associated with reduced risk of moderate-intensity infection (ARR 0.21; 95% CI 0.09–0.51), and heavy-intensity infection (ARR 0.04; 95% CI 0.01–0.25). Few WASH risk factors were significant. Conclusion In this high-prevalence setting, strong risk associations with environmental factors indicate that anthelmintic treatment alone will be insufficient to interrupt STH transmission, as conditions are favourable for ongoing environmental transmission. Integrated STH control strategies should be explored as a priority. We present a detailed analysis of WASH, environmental and demographic factors associated with intensity of STH infection in Manufahi District, Timor-Leste, using qPCR. Investigation of risk factors for intensity of STH infection is rarely undertaken, and prior analyses have used microscopic-based eggs per gram of faeces (epg) measures, which are of lower diagnostic accuracy than qPCR. Additionally, few analyses have investigated combined WASH and environmental risk factors in association with STH. This is important due to the extensive potential interrelatedness of environmental, social, behavioural and host factors in any given setting influencing STH survival and transmission. This analysis uses categorical intensity of infection variables for Necator americanus and Ascaris spp., and advanced statistical modelling to adjust for multinomial intensity outcomes, dependency of observations, effects of poverty, and confounding from other measured variables. As such, this analysis provides a comprehensive assessment of risk factors for STH in Manufahi District, Timor-Leste. This is of importance for development of policy and programmatic decisions; risk factors need to be considered not only for their clinical and statistical significance, but more broadly in terms of what may represent modifiable pathways for STH transmission.
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Affiliation(s)
- Suzy J. Campbell
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Acton, Australian Capital Territory, Australia
- * E-mail:
| | - Susana V. Nery
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Rebecca Wardell
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Catherine A. D’Este
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Darren J. Gray
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Acton, Australian Capital Territory, Australia
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
- School of Public Health, University of Queensland, Brisbane, Queensland, Australia
| | - James S. McCarthy
- School of Public Health, University of Queensland, Brisbane, Queensland, Australia
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Rebecca J. Traub
- Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, Victoria, Australia
| | - Ross M. Andrews
- Menzies School of Health Research, Charles Darwin University, Casuarina, Northern Territory, Australia
| | - Stacey Llewellyn
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Andrew J. Vallely
- Kirby Institute, University of New South Wales, Wallace Wurth Building, Kensington, New South Wales, Australia
| | - Gail M. Williams
- School of Public Health, University of Queensland, Brisbane, Queensland, Australia
| | - Archie C. A. Clements
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, Acton, Australian Capital Territory, Australia
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Truscott JE, Turner HC, Farrell SH, Anderson RM. Soil-Transmitted Helminths: Mathematical Models of Transmission, the Impact of Mass Drug Administration and Transmission Elimination Criteria. ADVANCES IN PARASITOLOGY 2016; 94:133-198. [PMID: 27756454 DOI: 10.1016/bs.apar.2016.08.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Infections caused by soil-transmitted helminthias (STHs) affect over a billion people worldwide, causing anaemia and having a large social and economic impact through poor educational outcomes. They are identified in the World Health Organization (WHO) 2020 goals for neglected tropical diseases as a target for renewed effort to ameliorate their global public health burden through mass drug administration (MDA) and water and hygiene improvement. In this chapter, we review the underlying biology and epidemiology of the three causative intestinal nematode species that are mostly considered under the STH umbrella term. We review efforts to model the transmission cycle of these helminths in populations and the effects of preventative chemotherapy on their control and elimination. Recent modelling shows that the different epidemiological characteristics of the parasitic nematode species that make up the STH group can lead to quite distinct responses to any given form of MDA. When connected with models of treatment cost-effectiveness, these models are potentially a powerful tool for informing public policy. A number of shortcomings are identified; lack of critical types of data and poor understanding of diagnostic sensitivities hamper efforts to test and hence improve models.
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Affiliation(s)
- J E Truscott
- London Centre for Neglected Tropical Disease Research, London, United Kingdom; School of Public Health, Imperial College London, London, United Kingdom
| | - H C Turner
- London Centre for Neglected Tropical Disease Research, London, United Kingdom; School of Public Health, Imperial College London, London, United Kingdom
| | - S H Farrell
- London Centre for Neglected Tropical Disease Research, London, United Kingdom; School of Public Health, Imperial College London, London, United Kingdom
| | - R M Anderson
- London Centre for Neglected Tropical Disease Research, London, United Kingdom; School of Public Health, Imperial College London, London, United Kingdom
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Ortu G, Assoum M, Wittmann U, Knowles S, Clements M, Ndayishimiye O, Basáñez MG, Lau C, Clements A, Fenwick A, Magalhaes RJS. The impact of an 8-year mass drug administration programme on prevalence, intensity and co-infections of soil-transmitted helminthiases in Burundi. Parasit Vectors 2016; 9:513. [PMID: 27660114 PMCID: PMC5034474 DOI: 10.1186/s13071-016-1794-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 09/07/2016] [Indexed: 11/18/2022] Open
Abstract
Background Soil-transmitted helminth (STH) infections are amongst the most prevalent infections in the world. Mass drug administration (MDA) programmes have become the most commonly used national interventions for endemic countries to achieve elimination. This paper aims to describe the effect of an 8-year MDA programme on the prevalence, intensity of infection and co-infection of STH in Burundi from 2007 to 2014 and critically appraise the trajectory towards STH elimination in the country. Results Annual STH parasitological surveys (specifically, a “pilot study” from 2007 to 2011, an “extension study” from 2008 to 2011, and a “national reassessment” in 2014; n = 27,658 children), showed a significant drop in prevalence of infection with any STH (“pooled STH”) between baseline and 2011 in both studies, falling from 32 to 16 % in the pilot study, and from 35 to 16 % in the extension study. Most STH infections were of low intensity according to WHO classification. The national reassessment in 2014 showed that prevalence of pooled STH remained significantly below the prevalence in 2007 in both studies but there was no further decrease in STH prevalence from 2011 levels during this time. Spatial dependence analysis showed that prevalence of Trichuris trichiura and Ascaris lumbricoides had a tendency to cluster over the years, whilst only trends in spatial dependence were evident for hookworm infections. Spatial dependence fluctuated over the course of the programme for Ascaris lumbricoides and Trichuris trichiura. However, spatial trends in spatial dependence were evident in 2010 for Ascaris lumbricoides. Analysis of spatial clustering of intensity of infection and heavy infections revealed that the intensity changed over time for all parasites. Heavy intensity was only evident in Ascaris lumbricoides for 2008 and did not appear in proceeding years and other parasites. Conclusions These results demonstrate that sustained annual MDA significantly reduced the prevalence of STH infection in school-age children but was unable to achieve elimination. Additionally, significant decline in prevalence was accompanied by a drop in spatial clustering of infection indicators across all sites from 2008. The lack of consistency in the results of the spatial dependence analysis highlights that MDA programmes can interrupt the normal transmission dynamics of STH parasites. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1794-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Giuseppina Ortu
- Schistosomiasis Control Initiative, Imperial College London, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Norfolk Place, London, W2 1PG, UK.
| | - Mohamad Assoum
- School of Medicine, The University of Queensland, Brisbane, Australia.,Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, Brisbane, Australia
| | - Udo Wittmann
- Schistosomiasis Control Initiative, Imperial College London, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Norfolk Place, London, W2 1PG, UK
| | - Sarah Knowles
- Schistosomiasis Control Initiative, Imperial College London, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Norfolk Place, London, W2 1PG, UK
| | - Michelle Clements
- Schistosomiasis Control Initiative, Imperial College London, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Norfolk Place, London, W2 1PG, UK
| | - Onésime Ndayishimiye
- Programme National Intégré de lutte contre les Maladies Tropicales Négligées et la Cécité (PNIMTNC) - Ministère de la Santé Publique et de la lutte contre le SIDA, Bujumbura, Burundi
| | - Maria-Gloria Basáñez
- Schistosomiasis Control Initiative, Imperial College London, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Norfolk Place, London, W2 1PG, UK.,London Centre for Neglected Tropical Disease Research, Imperial College London, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Norfolk Place, London, W2 1PG, UK
| | - Colleen Lau
- Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, Brisbane, Australia.,Research School of Population Health, Australian National University, Canberra, Australia
| | - Archie Clements
- Research School of Population Health, Australian National University, Canberra, Australia
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Imperial College London, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Norfolk Place, London, W2 1PG, UK
| | - Ricardo J Soares Magalhaes
- Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, Brisbane, Australia.,School of Veterinary Science, The University of Queensland (Gatton Campus), Via Warrego Highway, Gatton, QLD, 4343, Australia
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Wang JL, Li TT, Huang SY, Cong W, Zhu XQ. Major parasitic diseases of poverty in mainland China: perspectives for better control. Infect Dis Poverty 2016; 5:67. [PMID: 27476746 PMCID: PMC4967992 DOI: 10.1186/s40249-016-0159-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 06/20/2016] [Indexed: 02/07/2023] Open
Abstract
Significant progress has been made in the prevention, control, and elimination of human parasitic diseases in China in the past 60 years. However, parasitic diseases of poverty remain major causes of morbidity and mortality, and inflict enormous economic costs on societies.In this article, we review the prevalence rates, geographical distributions, epidemic characteristics, risk factors, and clinical manifestations of parasitic diseases of poverty listed in the first issue of the journal Infectious Diseases of Poverty on 25 October 2012. We also address the challenges facing control of parasitic diseases of poverty and provide suggestions for better control.
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Affiliation(s)
- Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046 People’s Republic of China
| | - Ting-Ting Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046 People’s Republic of China
| | - Si-Yang Huang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046 People’s Republic of China
| | - Wei Cong
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046 People’s Republic of China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046 People’s Republic of China
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Analysis of the population-level impact of co-administering ivermectin with albendazole or mebendazole for the control and elimination of Trichuris trichiura. Parasite Epidemiol Control 2016; 1:177-187. [PMID: 27430028 PMCID: PMC4946157 DOI: 10.1016/j.parepi.2016.02.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/22/2016] [Accepted: 02/23/2016] [Indexed: 11/25/2022] Open
Abstract
Introduction Soil-transmitted helminth (STH) infections are predominately controlled by providing children with preventive chemotherapy with either albendazole or mebendazole. However, neither has a high efficacy against Trichuris trichiura. This low efficacy limits the overall effectiveness of the current STH control programmes against T. trichiura. It has been demonstrated that co-administering ivermectin with albendazole or mebendazole significantly increases the efficacy of current treatments, which may increase the overall effectiveness of control programmes. Methods Using a STH transmission mathematical model, we evaluated the potential impact of co-administering ivermectin with albendazole or mebendazole to treat T. trichiura within a preventive chemotherapy programme targeting children (2–15 year olds). We evaluated the impact in terms of reduction in prevalent infections, mean worm burden, and prevalence of heavy infections. Results Although the current treatment strategy reduced T. trichiura worm burden and prevalence of heavy infections, due to their poor efficacy the long term impact of preventive chemotherapy for children was smaller compared to the other STH. Co-administering ivermectin increased the projected impact of the preventive chemotherapy programme in terms of all three of the explored metrics, practically in high transmission settings. Furthermore, ivermectin co-administration greatly increased the feasibility of and timeframe for breaking transmission. Conclusions Co-administering ivermectin notably increased the projected impact of preventive chemotherapy in high transmission settings and increased the feasibility for breaking transmission. This has important implications for control programmes, some of which may be shifting focus from morbidity control to interruption of transmission, and some of which may be logistically unable to provide preventive chemotherapy twice a year as recommended. However, the benefit of co-administering ivermectin is limited by the fact that 2–5 year olds are often ineligible to receive treatment. The impact of chemotherapy against Trichuris is smaller compared to what can be seen for the other soil-transmitted helminths. Co-administering ivermectin increases the projected impact of preventive chemotherapy. It also has the potential to interrupt transmission in some settings.
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Key Words
- ALB, albendazole
- Control
- ERRs, egg reduction rates
- Elimination
- IVM, ivermectin
- Ivermectin co-administration
- MBZ, mebendazole
- Mass drug administration
- Pre-SAC, preschool-aged
- R0, basic reproductive number
- SAC, school-aged children
- STH, soil-transmitted helminth
- Soil-transmitted helminth
- Trichuris trichiura
- WASH, water, sanitation and hygiene
- WHO, World Health Organisation
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Hotez PJ, Pecoul B, Rijal S, Boehme C, Aksoy S, Malecela M, Tapia-Conyer R, Reeder JC. Eliminating the Neglected Tropical Diseases: Translational Science and New Technologies. PLoS Negl Trop Dis 2016; 10:e0003895. [PMID: 26934395 PMCID: PMC4774924 DOI: 10.1371/journal.pntd.0003895] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Today, the World Health Organization recognizes 17 major parasitic and related infections as the neglected tropical diseases (NTDs). Despite recent gains in the understanding of the nature and prevalence of NTDs, as well as successes in recent scaled-up preventive chemotherapy strategies and other health interventions, the NTDs continue to rank among the world’s greatest global health problems. For virtually all of the NTDs (including those slated for elimination under the auspices of a 2012 London Declaration for NTDs and a 2013 World Health Assembly resolution [WHA 66.12]), additional control mechanisms and tools are needed, including new NTD drugs, vaccines, diagnostics, and vector control agents and strategies. Elimination will not be possible without these new tools. Here we summarize some of the key challenges in translational science to develop and introduce these new technologies in order to ensure success in global NTD elimination efforts.
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Affiliation(s)
- Peter J Hotez
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Bernard Pecoul
- Drugs for Neglected Diseases Initiative (DNDi), Geneva, Switzerland
| | - Suman Rijal
- Drugs for Neglected Diseases Initiative (DNDi), Delhi, India
| | - Catharina Boehme
- Foundation for Innovative new Diagnostics (FIND), Geneva, Switzerland
| | - Serap Aksoy
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | | | | | - John C Reeder
- UNICEF/UNDP/ World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), Geneva, Switzerland
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Dunn JC, Turner HC, Tun A, Anderson RM. Epidemiological surveys of, and research on, soil-transmitted helminths in Southeast Asia: a systematic review. Parasit Vectors 2016; 9:31. [PMID: 26813007 PMCID: PMC4728827 DOI: 10.1186/s13071-016-1310-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/08/2016] [Indexed: 11/10/2022] Open
Abstract
Soil-transmitted helminth (STH) infections of humans fall within the World Health Organization's (WHO) grouping termed the neglected tropical diseases (NTDs). It is estimated that they affect approximately 1.4 billion people worldwide. A significant proportion of these infections are in the population of Southeast Asia. This review analyses published data on STH prevalence and intensity in Southeast Asia over the time period of 1900 to the present to describe age related patterns in these epidemiological measures. This is with a focus on the four major parasite species affecting humans; namely Ascaris lumbricoides, Trichuris trichiura and the hookworms; Necator americanus and Ancylostoma duodenale. Data were also collected on the diagnostic methods used in the published surveys and how the studies were designed to facilitate comparative analyses of recorded patterns and changes therein over time. PubMed, Google Scholar, EMBASE, ISI Web of Science, Cochrane Database of Systematic Reviews and the Global Atlas of Helminth Infections search engines were used to identify studies on STH in Southeast Asia with the search based on the major key words, and variants on, "soil-transmitted helminth" "Ascaris" "Trichuris" "hookworm" and the country name. A total of 280 studies satisfied the inclusion criteria from 11 Southeast Asian countries; Brunei, Cambodia, Indonesia, Lao People's Democratic Republic (Lao PDR), Malaysia, Myanmar, Philippines, Singapore, Thailand, Timor-Leste and Vietnam. It was concluded that the epidemiological patterns of STH infection by age and species mix in Southeast Asia are similar to those reported in other parts of the world. In the published studies there were a large number of different diagnostic methods used with differing sensitivities and specificities, which makes comparison of the results both within and between countries difficult. There is a clear requirement to standardise the methods of both STH diagnosis in faecal material and how the intensity of infection is recorded and reported in future STH research and in monitoring and evaluation (M&E) of the impact of continuing and expanding mass drug administration (MDA) programmes.
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Affiliation(s)
- Julia C Dunn
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK.
| | - Hugo C Turner
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK.
| | - Aung Tun
- Worm Free Myanmar Kids Program, Tun Khit Foundation, Yangon, Myanmar.
| | - Roy M Anderson
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, Imperial College London, London, UK.
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Campbell SJ, Nery SV, McCarthy JS, Gray DJ, Soares Magalhães RJ, Clements ACA. A Critical Appraisal of Control Strategies for Soil-Transmitted Helminths. Trends Parasitol 2016; 32:97-107. [PMID: 26795294 DOI: 10.1016/j.pt.2015.10.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 10/10/2015] [Accepted: 10/13/2015] [Indexed: 12/29/2022]
Abstract
Interventions that lead to reductions in soil-transmitted helminths (STHs) include chemotherapy with anthelmintic drugs and improvements in water, sanitation, and hygiene (WASH). In this opinion article we aim to determine the evidence for optimal approaches for STH control. First we explore the evidence for the above interventions. We then appraise two integration strategies: current chemotherapy-oriented integrated neglected tropical disease (NTD) control and expanded 'multicomponent integration', which includes integrated chemotherapy, WASH, and other intervention strategies. While multicomponent integrated control may be an effective approach to sustainably reduce STH transmission, there is a need for evidence to prove the feasibility of this approach.
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Affiliation(s)
- Suzy J Campbell
- Research School of Population Health, College of Medicine, Biology, and Environment, The Australian National University, Canberra, Australia.
| | - Susana V Nery
- Research School of Population Health, College of Medicine, Biology, and Environment, The Australian National University, Canberra, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia; School of Public Health, University of Queensland, Brisbane, Australia
| | - Darren J Gray
- Research School of Population Health, College of Medicine, Biology, and Environment, The Australian National University, Canberra, Australia; QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Ricardo J Soares Magalhães
- Children's Health and Environment Program, Queensland Children's Medical Research Institute, University of Queensland, Brisbane, Australia; School of Veterinary Science, University of Queensland, Gatton, Australia
| | - Archie C A Clements
- Research School of Population Health, College of Medicine, Biology, and Environment, The Australian National University, Canberra, Australia
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Medley GF, Turner HC, Baggaley RF, Holland C, Hollingsworth TD. The Role of More Sensitive Helminth Diagnostics in Mass Drug Administration Campaigns: Elimination and Health Impacts. ADVANCES IN PARASITOLOGY 2016; 94:343-392. [PMID: 27756457 DOI: 10.1016/bs.apar.2016.08.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Diagnostics play a crucial role in determining treatment protocols and evaluating success of mass drug administration (MDA) programmes used to control soil-transmitted helminths (STHs). The current diagnostic, Kato-Katz, relies on inexpensive, reusable materials and can be used in the field, but only trained microscopists can read slides. This diagnostic always underestimates the true prevalence of infection, and the accuracy worsens as the true prevalence falls. We investigate how more sensitive diagnostics would impact on the management and life cycle of MDA programmes, including number of mass treatment rounds, health impact, number of unnecessary treatments and probability of elimination. We use an individual-based model of STH transmission within the current World Health Organization (WHO) treatment guidelines which records individual disability-adjusted life years (DALY) lost. We focus on Ascaris lumbricoides due to the availability of high-quality data on existing diagnostics. We show that the effect of improving the sensitivity of diagnostics is principally determined by the precontrol prevalence in the community. Communities at low true prevalence (<30%) and high true prevalence (>70%) do not benefit greatly from improved diagnostics. Communities with intermediate prevalence benefit greatly from increased chemotherapy application, both in terms of reduced DALY loss and increased probability of elimination. Our results suggest that programmes should be extended beyond school-age children, especially in high prevalence communities. Finally, we argue against using apparent or measured prevalence as an uncorrected proxy for true prevalence.
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Affiliation(s)
- G F Medley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - H C Turner
- Imperial College London, London, United Kingdom
| | - R F Baggaley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - C Holland
- Trinity College Dublin, Dublin, Ireland
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Turner HC, Truscott JE, Bettis AA, Shuford KV, Dunn JC, Hollingsworth TD, Brooker SJ, Anderson RM. An economic evaluation of expanding hookworm control strategies to target the whole community. Parasit Vectors 2015; 8:570. [PMID: 26542226 PMCID: PMC4635541 DOI: 10.1186/s13071-015-1187-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/23/2015] [Indexed: 11/10/2022] Open
Abstract
Background The WHO treatment guidelines for the soil-transmitted helminths (STH) focus on targeting children for the control of morbidity induced by heavy infections. However, unlike the other STHs, the majority of hookworm infections are harboured by adults. This untreated burden may have important implications for controlling both hookworm’s morbidity and transmission. This is particularly significant in the context of the increased interest in investigating STH elimination strategies. Methods We used a deterministic STH transmission model and parameter estimates derived from field epidemiological studies to evaluate the impact of child-targeted (2–14 year olds) versus community-wide treatment against hookworm in terms of preventing morbidity and the timeframe for breaking transmission. Furthermore, we investigated how mass treatment may influence the long-term programmatic costs of preventive chemotherapy for hookworm. Results The model projected that a large proportion of the overall morbidity due to hookworm was unaffected by the current child-targeted strategy. Furthermore, driving worm burdens to levels low enough to potentially break transmission was only possible when using community-wide treatment. Due to these projected reductions in programme duration, it was possible for community-wide treatment to generate cost savings – even if it notably increases the annual distribution costs. Conclusions Community-wide treatment is notably more cost-effective for controlling hookworm’s morbidity and transmission than the current child-targeted strategies and could even be cost-saving in many settings in the longer term. These calculations suggest that it is not optimum to treat using the same treatment strategies as other STH. Hookworm morbidity and transmission control require community-wide treatment. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1187-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hugo C Turner
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK.
| | - James E Truscott
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK.
| | - Alison A Bettis
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK.
| | - Kathryn V Shuford
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK.
| | - Julia C Dunn
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK.
| | - T Déirdre Hollingsworth
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK. .,School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
| | - Simon J Brooker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Roy M Anderson
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK.
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Soil-transmitted helminths in China. THE LANCET. INFECTIOUS DISEASES 2015; 15:1262-3. [DOI: 10.1016/s1473-3099(15)00373-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/24/2015] [Indexed: 11/19/2022]
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Truscott JE, Turner HC, Anderson RM. What impact will the achievement of the current World Health Organisation targets for anthelmintic treatment coverage in children have on the intensity of soil transmitted helminth infections? Parasit Vectors 2015; 8:551. [PMID: 26490544 PMCID: PMC4618937 DOI: 10.1186/s13071-015-1135-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/02/2015] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND It is the aim of the World Health Organisation to eliminate soil-transmitted helminths (STH) as a health problem in children. To this end, the goal is to increase anthelmintic treatment coverage for soil transmitted helminths to reach 75 % in pre-school aged and school aged children by 2020 in endemic countries. In this paper, we use mathematical models to investigate the impact of achieving this goal on the burdens of Ascaris lumbricoides, Trichuris trichuria and hookworm. METHODS We employ a deterministic fully age-structured model of STH transmission and mass drug administration to examine the changes in worm burden in response to the known and projected coverage trends in children up to 2020 and beyond. Parameters are estimated from worm expulsion data and age intensity profiles before treatment using maximum likelihood methods. Model validation is performed using reinfection studies for Ascaris and analyses are conducted to assess the sensitivity of the predicted outcomes to variation in parameter estimates including transmission intensity (R0), children's contributions to the pool of infective stages and drug coverage levels. RESULTS The impact of the required increase in coverage trends are quite different across the three species. Ascaris burdens are reduced dramatically by 2020 with elimination predicted within studied the setting a further 10 years. For Trichuris and hookworm, however, impact is more limited, due to issues of drug efficacy (Trichuris) and distribution of worms in the population (hookworm). Sensitivity analysis indicates that results are largely robust. However, validation against Ascaris data indicates that assumptions concerning re-infection among children may have to be revised. CONCLUSIONS The 2020 coverage target is predicted to have a major impact on Ascaris levels by 2020. However, there is evidence from model validation that Ascaris in children is more resilient to treatment than currently assumed in the model. Broader coverage across all age classes is required to break transmission for hookworm and alternative dual drug treatment approaches are needed for Trichuris.
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Affiliation(s)
- J E Truscott
- London Centre for Neglected Tropical Disease Research, London, UK.
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary's Campus, Imperial College London, Norfolk Place, London, W2 1PG, , UK.
| | - H C Turner
- London Centre for Neglected Tropical Disease Research, London, UK
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary's Campus, Imperial College London, Norfolk Place, London, W2 1PG, , UK
| | - R M Anderson
- London Centre for Neglected Tropical Disease Research, London, UK
- Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary's Campus, Imperial College London, Norfolk Place, London, W2 1PG, , UK
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Understanding Heterogeneity in the Impact of National Neglected Tropical Disease Control Programmes: Evidence from School-Based Deworming in Kenya. PLoS Negl Trop Dis 2015; 9:e0004108. [PMID: 26421808 PMCID: PMC4589351 DOI: 10.1371/journal.pntd.0004108] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 09/01/2015] [Indexed: 11/29/2022] Open
Abstract
Background The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya. Materials and Methods Data on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels. Principal Findings The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores. Conclusions The study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes. Most countries with endemic soil-transmitted helminth (STH) infections have started implementing deworming programmes in recent years. However, the achievable impact on the prevalence and intensity of infections will depend on the socioeconomic and environmental context in which the programme is implemented. We use a previously developed framework that considers the epidemiology of STH transmission, capacity to deliver treatment, operational and financial feasibility, to investigate reasons for the observed within-country variation of deworming programme impact based on data from the national school based deworming programme in Kenya. The study demonstrates that programme impact varied markedly within the country and that reductions in STH infection were associated with levels of access to water, sanitation and hygiene (at schools or within communities). The described framework can help to identify areas where lower programme impact can be expected, and also to determine which additional interventions should be implemented in support of the deworming efforts.
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50
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Addiss DG. Soil-transmitted helminthiasis: back to the original point. THE LANCET. INFECTIOUS DISEASES 2015; 15:871-2. [PMID: 25886797 DOI: 10.1016/s1473-3099(15)70095-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- David G Addiss
- Children Without Worms, Task Force for Global Health, Decatur, GA, USA.
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