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Mutono N, Basáñez MG, James A, Stolk WA, Makori A, Kimani TN, Hollingsworth TD, Vasconcelos A, Dixon MA, de Vlas SJ, Thumbi SM. Elimination of transmission of onchocerciasis (river blindness) with long-term ivermectin mass drug administration with or without vector control in sub-Saharan Africa: a systematic review and meta-analysis. Lancet Glob Health 2024; 12:e771-e782. [PMID: 38484745 PMCID: PMC11009120 DOI: 10.1016/s2214-109x(24)00043-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 01/11/2024] [Accepted: 01/19/2024] [Indexed: 04/15/2024]
Abstract
BACKGROUND WHO has proposed elimination of transmission of onchocerciasis (river blindness) by 2030. More than 99% of cases of onchocerciasis are in sub-Saharan Africa. Vector control and mass drug administration of ivermectin have been the main interventions for many years, with varying success. We aimed to identify factors associated with elimination of onchocerciasis transmission in sub-Saharan Africa. METHODS For this systematic review and meta-analysis we searched for published articles reporting epidemiological or entomological assessments of onchocerciasis transmission status in sub-Saharan Africa, with or without vector control. We searched MEDLINE, PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials, African Index Medicus, and Google Scholar databases for all articles published from database inception to Aug 19, 2023, without language restrictions. The search terms used were "onchocerciasis" AND "ivermectin" AND "mass drug administration". The three inclusion criteria were (1) focus or foci located in Africa, (2) reporting of elimination of transmission or at least 10 years of ivermectin mass drug administration in the focus or foci, and (3) inclusion of at least one of the following assessments: microfilarial prevalence, nodule prevalence, Ov16 antibody seroprevalence, and blackfly infectivity prevalence. Epidemiological modelling studies and reviews were excluded. Four reviewers (NM, AJ, AM, and TNK) extracted data in duplicate from the full-text articles using a data extraction tool developed in Excel with columns recording the data of interest to be extracted, and a column where important comments for each study could be highlighted. We did not request any individual-level data from authors. Foci were classified as achieving elimination of transmission, being close to elimination of transmission, or with ongoing transmission. We used mixed-effects meta-regression models to identify factors associated with transmission status. This study is registered in PROSPERO, CRD42022338986. FINDINGS Of 1525 articles screened after the removal of duplicates, 75 provided 282 records from 238 distinct foci in 19 (70%) of the 27 onchocerciasis-endemic countries in sub-Saharan Africa. Elimination of transmission was reported in 24 (9%) records, being close to elimination of transmission in 86 (30%) records, and ongoing transmission in 172 (61%) records. I2 was 83·3% (95% CI 79·7 to 86·3). Records reporting 10 or more years of continuous mass drug administration with 80% or more therapeutic coverage of the eligible population yielded significantly higher odds of achieving elimination of transmission (log-odds 8·5 [95% CI 3·5 to 13·5]) or elimination and being close to elimination of transmission (42·4 [18·7 to 66·1]) than those with no years achieving 80% coverage or more. Reporting 15-19 years of ivermectin mass drug administration (22·7 [17·2 to 28·2]) and biannual treatment (43·3 [27·2 to 59·3]) were positively associated with elimination and being close to elimination of transmission compared with less than 15 years and no biannual mass drug administration, respectively. Having had vector control without vector elimination (-42·8 [-59·1 to -26·5]) and baseline holoendemicity (-41·97 [-60·6 to -23·2]) were associated with increased risk of ongoing transmission compared with no vector control and hypoendemicity, respectively. Blackfly disappearance due to vector control or environmental change contributed to elimination of transmission. INTERPRETATION Mass drug administration duration, frequency, and coverage; baseline endemicity; and vector elimination or disappearance are important determinants of elimination of onchocerciasis transmission in sub-Saharan Africa. Our findings underscore the importance of improving and sustaining high therapeutic coverage and increasing treatment frequency if countries are to achieve elimination of onchocerciasis transmission. FUNDING The Bill & Melinda Gates Foundation and Neglected Tropical Diseases Modelling Consortium, UK Medical Research Council, and Global Health EDCTP3 Joint Undertaking. TRANSLATIONS For the Swahili, French, Spanish and Portuguese translations of the abstract see Supplementary Materials section.
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Affiliation(s)
- Nyamai Mutono
- Centre for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya; Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA.
| | - Maria-Gloria Basáñez
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK; London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
| | - Ananthu James
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Wilma A Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Anita Makori
- Centre for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya; Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Teresia Njoki Kimani
- Centre for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya; Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA; Ministry of Health Kenya, Kiambu Town, Kenya
| | | | | | - Matthew A Dixon
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK; London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
| | - Sake J de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - S M Thumbi
- Centre for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya; Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA; Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, UK
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Kargbo-Labour I, Bah MS, Melchers NVSV, Conteh A, Redwood-Sawyerr V, Stolk WA, Paye J, Sonnie M, Veinoglou A, Koroma JB, Hodges MH, Weaver AM, Zhang Y. Impact assessment of onchocerciasis through lymphatic filariasis transmission assessment surveys using Ov-16 rapid diagnostic tests in Sierra Leone. Parasit Vectors 2024; 17:121. [PMID: 38468307 PMCID: PMC10926616 DOI: 10.1186/s13071-024-06198-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 02/15/2024] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND Onchocerciasis is endemic in 14 of Sierra Leone's 16 districts with high prevalence (47-88.5%) according to skin snips at baseline. After 11 rounds of mass treatment with ivermectin with good coverage, an impact assessment was conducted in 2017 to assess the progress towards eliminating onchocerciasis in the country. METHODS A cluster survey was conducted, either integrated with lymphatic filariasis (LF) transmission assessment survey (TAS) or standalone with the LF TAS sampling strategy in 12 (now 14) endemic districts. Finger prick blood samples of randomly selected children in Grades 1-4 were tested in the field using SD Bioline Onchocerciasis IgG4 rapid tests. RESULTS In total, 17,402 children aged 4-19 years in 177 schools were tested, and data from 17,364 children aged 4-14 years (14,230 children aged 5-9 years) were analyzed. Three hundred forty-six children were confirmed positive for Ov-16 IgG4 antibodies, a prevalence of 2.0% (95% CI 1.8-2.2%) in children aged 4-14 years with prevalence increasing with age. Prevalence in boys (2.4%; 95% CI 2.1-2.7%) was higher than in girls (1.6%; 95% CI 1.4-1.9%). There was a trend of continued reduction from baseline to 2010. Using data from children aged 5-9 years, overall prevalence was 1.7% (95% CI 1.5-1.9%). The site prevalence ranged from 0 to 33.3% (median prevalence = 0.0%): < 2% in 127 schools, 2 to < 5% in 34 schools and ≥ 5% in 16 schools. There was a significant difference in average prevalence between districts. Using spatial analysis, the Ov-16 IgG4 antibody prevalence was predicted to be < 2% in coastal areas and in large parts of Koinadugu, Bombali and Tonkolili Districts, while high prevalence (> 5%) was predicted in some focal areas, centered in Karene, Kailahun and Moyamba/Tonkolili. CONCLUSIONS Low Ov-16 IgG4 antibody prevalence was shown in most areas across Sierra Leone. In particular, low seroprevalence in children aged 5-9 years suggests that the infection was reduced to a low level after 11 rounds of treatment intervention. Sierra Leone has made major progress towards elimination of onchocerciasis. However, attention must be paid to those high prevalence focal areas.
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Affiliation(s)
- Ibrahim Kargbo-Labour
- National Neglected Tropical Disease Control Programme, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | | | - Natalie V S Vinkeles Melchers
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Social Sciences, Health and Society, Wageningen University and Research Centre, Wageningen, The Netherlands
| | - Abdulai Conteh
- National Neglected Tropical Disease Control Programme, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | | | - Wilma A Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jusufu Paye
- Helen Keller International, Freetown, Sierra Leone
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Maddren R, Phillips A, Rayment Gomez S, Forbes K, Collyer BS, Kura K, Anderson R. Individual longitudinal compliance to neglected tropical disease mass drug administration programmes, a systematic review. PLoS Negl Trop Dis 2023; 17:e0010853. [PMID: 37459369 PMCID: PMC10374057 DOI: 10.1371/journal.pntd.0010853] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 07/27/2023] [Accepted: 06/05/2023] [Indexed: 07/28/2023] Open
Abstract
Repeated distribution of preventative chemotherapy (PC) by mass drug administration forms the mainstay of transmission control for five of the 20 recognised neglected tropical diseases (NTDs); soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. The efficiency of such programmes is reliant upon participants swallowing the offered treatment consistently at each round. This is measured by compliance, defined as the proportion of eligible participants swallowing treatment. Individually linked longitudinal compliance data is important for assessing the potential impact of MDA-based control programmes, yet this accurate monitoring is rarely implemented in those for NTDs. Longitudinal compliance data reported by control programmes globally for the five (PC)-NTDs since 2016 is examined, focusing on key associations of compliance with age and gender. PubMed and Web of Science was searched in January 2022 for articles written in English and Spanish, and the subsequent extraction adhered to PRISMA guidelines. Study title screening was aided by Rayyan, a machine learning software package. Studies were considered for inclusion if primary compliance data was recorded for more than one time point, in a population larger than 100 participants. All data analysis was conducted in R. A total of 89 studies were identified containing compliance data, 57 were longitudinal studies, of which 25 reported individually linked data reported by varying methods. The association of increasing age with the degree of systematic treatment was commonly reported. The review is limited by the paucity of data published on this topic. The varying and overlapping terminologies used to describe coverage (receiving treatment) and compliance (swallowing treatment) is reviewed. Consequently, it is recommended that WHO considers clearly defining the terms for coverage, compliance, and longitudinal compliance which are currently contradictory across their NTD treatment guidelines. This review is registered with PROSPERO (number: CRD42022301991).
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Affiliation(s)
- Rosie Maddren
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Anna Phillips
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
- FHI 360, Durham, North Carolina, United States of America
| | - Santiago Rayment Gomez
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Kathryn Forbes
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Benjamin S Collyer
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Klodeta Kura
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Roy Anderson
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
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Guillot C, Bouchard C, Aenishaenslin C, Berthiaume P, Milord F, Leighton PA. Criteria for selecting sentinel unit locations in a surveillance system for vector-borne disease: A decision tool. Front Public Health 2022; 10:1003949. [PMID: 36438246 PMCID: PMC9686450 DOI: 10.3389/fpubh.2022.1003949] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/10/2022] [Indexed: 11/11/2022] Open
Abstract
Objectives With vector-borne diseases emerging across the globe, precipitated by climate change and other anthropogenic changes, it is critical for public health authorities to have well-designed surveillance strategies in place. Sentinel surveillance has been proposed as a cost-effective approach to surveillance in this context. However, spatial design of sentinel surveillance system has important impacts on surveillance outcomes, and careful selection of sentinel unit locations is therefore an essential component of planning. Methods A review of the available literature, based on the realist approach, was used to identify key decision issues for sentinel surveillance planning. Outcomes of the review were used to develop a decision tool, which was subsequently validated by experts in the field. Results The resulting decision tool provides a list of criteria which can be used to select sentinel unit locations. We illustrate its application using the case example of designing a national sentinel surveillance system for Lyme disease in Canada. Conclusions The decision tool provides researchers and public health authorities with a systematic, evidence-based approach for planning the spatial design of sentinel surveillance systems, taking into account the aims of the surveillance system and disease and/or context-specific considerations.
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Affiliation(s)
- Camille Guillot
- Groupe de recherche en épidémiologie des zoonoses et santé publique (GREZOSP), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada,Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada,Centre de recherche en santé publique de l'Université de Montréal et du CIUSSS du Centre-Sud-de-l'île-de-Montréal (CReSP), Montréal, QC, Canada,*Correspondence: Camille Guillot
| | - Catherine Bouchard
- Groupe de recherche en épidémiologie des zoonoses et santé publique (GREZOSP), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada,Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, St. Hyacinthe, QC, Canada
| | - Cécile Aenishaenslin
- Groupe de recherche en épidémiologie des zoonoses et santé publique (GREZOSP), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Philippe Berthiaume
- Groupe de recherche en épidémiologie des zoonoses et santé publique (GREZOSP), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada,Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, St. Hyacinthe, QC, Canada
| | - François Milord
- Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Patrick A. Leighton
- Groupe de recherche en épidémiologie des zoonoses et santé publique (GREZOSP), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada,Centre de recherche en santé publique de l'Université de Montréal et du CIUSSS du Centre-Sud-de-l'île-de-Montréal (CReSP), Montréal, QC, Canada
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Baiden F, Fleck S, Leigh B, Ayieko P, Tindanbil D, Otieno T, Lawal B, Tehtor M, Rogers M, Odeny L, Hodges MH, Sonnie M, Samai M, Ishola D, Lowe B, Watson-Jones D, Greenwood B. Prevalence of malaria and helminth infections in rural communities in northern Sierra Leone, a baseline study to inform Ebola vaccine study protocols. PLoS One 2022; 17:e0270968. [PMID: 35793331 PMCID: PMC9258822 DOI: 10.1371/journal.pone.0270968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/21/2022] [Indexed: 11/18/2022] Open
Abstract
Introduction
Recurrent parasitic infections may influence the immune response to vaccines. In the Partnership for Research on Ebola VACcinations extended follow-UP and clinical research capacity build-UP (PREVAC-UP) study being undertaken in Mambolo, northern Sierra Leone, participants are being followed up to assess the potential impact of exposure to malaria and/or helminth infections on long-term immune response to two Ebola vaccines. To support the development of the assays that will be used in this evaluation, a parasitological survey was conducted in Mambolo between November 2019 and February 2020.
Methods
Healthy individuals aged ≥1 year who were resident in Mambolo Chiefdom were selected using a stratified sampling approach and questionnaires were administered to explore their sociodemographic characteristics. Microscopy was used to detect malaria parasites, intestinal helminths and urinary schistosome infections. Rapid blood tests were used to detect infections with Onchocerca volvulus and Wuchereria bancrofti. We estimated the overall prevalence of these infections and used adjusted logistic regression models to explore risk factors for malaria and hookworm infection.
Results
Eight hundred and fifteen (815) residents, 50.9% of whom were female were surveyed. Overall, 309 (39.1%) of 791 persons tested for malaria had a positive blood slide; Plasmodium falciparum was the dominant species. Helminth infection was detected in 122 (15.0%) of 815 stool samples including three mixed infections. The helminth infections comprised 102 (12.5%) cases of hookworm, 11 (1.3%) cases of Trichuris trichiura, 10 (1.2%) cases of Schistosoma mansoni and two (0.2%) cases of Ascaris lumbricoides. Being male (OR = 2.01, 95% CI 1.15–3.50) and residing in a non-riverine community (OR = 4.02, 95%CI 2.32–6.98) were the factors associated with hookworm infection. Onchocerca volvulus and Wuchereria bancrofti infections were found in 3.3% and 0.4% of participants respectively.
Conclusion
Malaria and hookworm are the most prevalent parasite infections and those most likely to influence long-term immune response to Ebola vaccines among the trial participants.
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Affiliation(s)
- Frank Baiden
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Suzanne Fleck
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Bailah Leigh
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - Philip Ayieko
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Daniel Tindanbil
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Tuda Otieno
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Bolarinde Lawal
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Mattu Tehtor
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - Maariam Rogers
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - Lazarus Odeny
- Kenya Medical Research Institute, Centre for Respiratory Diseases Research, Nairobi, Kenya
| | | | | | - Mohamed Samai
- College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone
| | - David Ishola
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Brett Lowe
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Deborah Watson-Jones
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Brian Greenwood
- London School of Hygiene & Tropical Medicine, London, United Kingdom
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Otache AE, Ezenwosu IL, Ossai EN, Aniwada EC, Nwobi EA, Uzochukwu BSC. Health-related quality of life and associated factors among Onchocerciasis patients in southeast Nigeria: A cross-sectional comparative study. PLoS Negl Trop Dis 2022; 16:e0010182. [PMID: 35139077 PMCID: PMC8827426 DOI: 10.1371/journal.pntd.0010182] [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: 09/20/2021] [Accepted: 01/19/2022] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Onchocerciasis, a neglected tropical disease of public health importance, causes chronic morbidity and severe disability that may impact on health-related quality of life (HRQoL) of the infected people. This study assessed the HRQoL and associated factors among onchocerciasis patients in southeast Nigeria. METHODS This was a community-based cross-sectional comparative study. Using a multistage sampling technique, 340 onchocerciasis patients were selected and matched for age and gender with the healthy population in the same neighbourhood. The respondents were interviewed using the short-form-36 (SF-36) questionnaire to determine their HRQoL. WHO Disability Assessment Schedule 2.0 tool (WHODAS 2.0) was used to assess disability in persons with onchocerciasis. Means were compared with independent student t-test while Chi-square test was used to compare proportions. Also, correlation analysis and logistic regression were used in the analyses. RESULTS A significantly lower proportion of people living with onchocerciasis had a good quality of life when compared with the healthy subjects (69.4% vs 93.5%, p<0.001). Also, an inverse relationship was seen between disability and quality of life in the onchocerciasis group (r = -0.647, p<0.001). Predictors of poor quality of life among respondents with onchocerciasis were: respondents aged ≥48 years (AOR = 2.5, 95% CI: 1.4-5.0), those with some disability associated with onchocerciasis (AOR = 3.33, 95%CI: 1.4-5.0) and respondents who perceived themselves as a burden to people (AOR = 10, 95%CI: 2.5-20). CONCLUSION Onchocerciasis impacted negatively on HRQoL of persons with onchocerciasis when compared with the healthy population. The quality of life of persons affected with onchocerciasis reduces with increasing disability. There is the need to increase community awareness on onchocerciasis to ensure early diagnosis and prompt treatment as this will reduce disability among those affected with the disease thus enhancing their HRQoL.
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Affiliation(s)
- Adah E. Otache
- Department of Community Medicine, University of Nigeria Teaching Hospital, Enugu State, Nigeria
| | - Ifeyinwa L. Ezenwosu
- Department of Community Medicine, University of Nigeria Teaching Hospital, Enugu State, Nigeria
| | - Edmund N. Ossai
- Department of Community Medicine, College of Health Sciences, Ebonyi State University, Abakaliki, Nigeria
| | - Elias C. Aniwada
- Department of Community Medicine, University of Nigeria Teaching Hospital, Enugu State, Nigeria
| | - Emmanuel A. Nwobi
- Department of Community Medicine, University of Nigeria Teaching Hospital, Enugu State, Nigeria
| | - Benjamin SC. Uzochukwu
- Department of Community Medicine, University of Nigeria Teaching Hospital, Enugu State, Nigeria
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Osei FA, Newton S, Nyanor I, Osei-Yeboah E, Amuzu EX, Mensah NK, Nyarko OO, Amanor E, Boadi S, Asare O, Odoom SF, Furu P, Owusu-Dabo E, Meyrowitsch DW. Mass drug administration targeting Onchocerca volvulus in Owabi catchment area in Ashanti Region, Ghana: Determinants of drug coverage and drug uptake. Parasite Epidemiol Control 2022; 16:e00235. [PMID: 35024476 PMCID: PMC8733227 DOI: 10.1016/j.parepi.2021.e00235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 11/24/2022] Open
Abstract
Introduction Achieving high Mass Drug Administration (MDA) coverage and drug uptake are pivotal in the efforts to eradicate onchocerciasis. The present study investigated the extent and predictors of ivermectin MDA coverage and uptake from the individual and healthcare providers' perspectives. The extent of ivermectin distribution and uptake, and the predictors of distribution and uptake were investigated in endemic communities in the Ashanti Region of Ghana. Methods A cross-sectional survey was conducted from August to October 2019 in communities within the Atwima Nwabiagya North District. A total of 2008 respondents were interviewed. Data was collected with REDCap mobile App which had an electronic version of the structured questionnaire. Descriptive data was presented in frequency tables, and bivariate and multivariate logistics regression analysis were performed to measure the associations between exposure variables and outcome variables which were received and uptake of MDA drugs. Results A total of 1284 (63.9%) respondents did not receive ivermectin during the 2019 MDA programme and more than half of them were not aware of the drug distribution (53.3%). The most common reasons for not ingesting the drug were fear of side effects (47.7%) and not trusting the drug distributors (20.0%). Respondents in the age group 48–57 years (AOR = 1.37; 95%CI: 1.01–2.67), Persons in the high wealth index (AOR = 1.40; 95%CI: 1.11–1.77), Being aware of the MDA programme (AOR = 6.67: 95%CI: 4.76–9.35), MDA being beneficial (AOR = 2.12; 95%CI: 1.54–2.92) participating in previous MDA (AOR = 5.44; 95%CI: 4.25–6.98) and having stayed in the communities for 10 years and above significantly increased the odds of receiving MDA drugs. Previous uptake of MDA drugs (AOR = 10.58; 95%CI: 5.78–19.38) and perception of the MDA drug as beneficial (AOR = 5.25; 95%CI: 2.55–10.82) increased the likelihood of ingesting drugs when received. Conclusion The main health system challenge was limited awareness creation regarding MDA. This seems to affect the optimal utilization of the ivermectin MDA intervention. MDA programmes against onchocerciasis eradication should be designed taking into account specific contextual factors to improve implementation outcomes.
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Affiliation(s)
- Francis Adjei Osei
- Department of Global Health, School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Sam Newton
- Department of Global Health, School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | | | | | | | | | | | | | - Ophebia Asare
- Department of Global Health, School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Peter Furu
- Department of Public Health, Global Health Section, University of Copenhagen, Denmark
| | - Ellis Owusu-Dabo
- Department of Global Health, School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Dan Wolf Meyrowitsch
- Department of Public Health, Global Health Section, University of Copenhagen, Denmark
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Hamley JID, Blok DJ, Walker M, Milton P, Hopkins AD, Hamill LC, Downs P, de Vlas SJ, Stolk WA, Basáñez MG. What does the COVID-19 pandemic mean for the next decade of onchocerciasis control and elimination? Trans R Soc Trop Med Hyg 2021; 115:269-280. [PMID: 33515042 PMCID: PMC7928565 DOI: 10.1093/trstmh/traa193] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/16/2020] [Accepted: 12/29/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Mass drug administration (MDA) of ivermectin for onchocerciasis has been disrupted by the coronavirus disease 2019 (COVID-19) pandemic. Mathematical modelling can help predict how missed/delayed MDA will affect short-term epidemiological trends and elimination prospects by 2030. METHODS Two onchocerciasis transmission models (EPIONCHO-IBM and ONCHOSIM) are used to simulate microfilarial prevalence trends, elimination probabilities and age profiles of Onchocerca volvulus microfilarial prevalence and intensity for different treatment histories and transmission settings, assuming no interruption, a 1-y (2020) interruption or a 2-y (2020-2021) interruption. Biannual MDA or increased coverage upon MDA resumption are investigated as remedial strategies. RESULTS Programmes with shorter MDA histories and settings with high pre-intervention endemicity will be the most affected. Biannual MDA is more effective than increasing coverage for mitigating COVID-19's impact on MDA. Programmes that had already switched to biannual MDA should be minimally affected. In high-transmission settings with short treatment history, a 2-y interruption could lead to increased microfilarial load in children (EPIONCHO-IBM) and adults (ONCHOSIM). CONCLUSIONS Programmes with shorter (annual MDA) treatment histories should be prioritised for remedial biannual MDA. Increases in microfilarial load could have short- and long-term morbidity and mortality repercussions. These results can guide decision-making to mitigate the impact of COVID-19 on onchocerciasis elimination.
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Affiliation(s)
- Jonathan I D Hamley
- London Centre for Neglected Tropical Disease Research, 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.,MRC Centre for Global Infectious Disease Analysis, 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
| | - David J Blok
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Martin Walker
- London Centre for Neglected Tropical Disease Research, 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.,London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hatfield AL9 7TA, UK
| | - Philip Milton
- London Centre for Neglected Tropical Disease Research, 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.,MRC Centre for Global Infectious Disease Analysis, 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
| | - Adrian D Hopkins
- Neglected and Disabling Diseases of Poverty Consultant, Kent, UK
| | - Louise C Hamill
- Sightsavers, 35 Perrymount Road, Haywards Heath, RH16 3BW, UK
| | - Philip Downs
- Sightsavers, 35 Perrymount Road, Haywards Heath, RH16 3BW, UK
| | - Sake J de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Wilma A Stolk
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Maria-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research, 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.,MRC Centre for Global Infectious Disease Analysis, 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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9
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Jones RT, Pretorius E, Ant TH, Bradley J, Last A, Logan JG. The use of islands and cluster-randomized trials to investigate vector control interventions: a case study on the Bijagós archipelago, Guinea-Bissau. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190807. [PMID: 33357055 PMCID: PMC7776941 DOI: 10.1098/rstb.2019.0807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2020] [Indexed: 12/30/2022] Open
Abstract
Vector-borne diseases threaten the health of populations around the world. While key interventions continue to provide protection from vectors, there remains a need to develop and test new vector control tools. Cluster-randomized trials, in which the intervention or control is randomly allocated to clusters, are commonly selected for such evaluations, but their design must carefully consider cluster size and cluster separation, as well as the movement of people and vectors, to ensure sufficient statistical power and avoid contamination of results. Island settings present an opportunity to conduct these studies. Here, we explore the benefits and challenges of conducting intervention studies on islands and introduce the Bijagós archipelago of Guinea-Bissau as a potential study site for interventions intended to control vector-borne diseases. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.
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Affiliation(s)
- Robert T. Jones
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
- ARCTEC, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Elizabeth Pretorius
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Thomas H. Ant
- Centre for Virus Research, Bearsden Road, Bearsden, Glasgow G61 1QH, UK
| | - John Bradley
- MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Anna Last
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - James G. Logan
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
- ARCTEC, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
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10
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Bah YM, Paye J, Bah MS, Conteh A, Redwood-Sawyerr V, Sonnie M, Veinoglou A, Koroma JB, Hodges MH, Zhang Y. Achievements and challenges of lymphatic filariasis elimination in Sierra Leone. PLoS Negl Trop Dis 2020; 14:e0008877. [PMID: 33370270 PMCID: PMC7793261 DOI: 10.1371/journal.pntd.0008877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 01/08/2021] [Accepted: 10/13/2020] [Indexed: 11/19/2022] Open
Abstract
Background Lymphatic filariasis (LF) is targeted for elimination in Sierra Leone. Epidemiological coverage of mass drug administration (MDA) with ivermectin and albendazole had been reported >65% in all 12 districts annually. Eight districts qualified to implement transmission assessment survey (TAS) in 2013 but were deferred until 2017 due to the Ebola outbreak (2014–2016). In 2017, four districts qualified for conducting a repeat pre-TAS after completing three more rounds of MDA and the final two districts were also eligible to implement a pre-TAS. Methodology/Principal findings For TAS, eight districts were surveyed as four evaluation units (EU). A school-based survey was conducted in children aged 6–7 years from 30 clusters per EU. For pre-TAS, one sentinel and one spot check site per district (with 2 spot check sites in Bombali) were selected and 300–350 persons aged 5 years and above were selected. For both surveys, finger prick blood samples were tested using the Filariasis Test Strips (FTS). For TAS, 7,143 children aged 6–7 years were surveyed across four EUs, and positives were found in three EUs, all below the critical cut-off value for each EU. For the repeat pre-TAS/pre-TAS, 3,994 persons over five years of age were surveyed. The Western Area Urban had FTS prevalence of 0.7% in two sites and qualified for TAS, while other five districts had sites with antigenemia prevalence >2%: 9.1–25.9% in Bombali, 7.5–19.4% in Koinadugu, 6.1–2.9% in Kailahun, 1.3–2.3% in Kenema and 1.7% - 3.7% in Western Area Rural. Conclusions/Significance Eight districts in Sierra Leone have successfully passed TAS1 and stopped MDA, with one more district qualified for conducting TAS1, a significant progress towards LF elimination. However, great challenges exist in eliminating LF from the whole country with repeated failure of pre-TAS in border districts. Effort needs to be intensified to achieve LF elimination. Lymphatic filariasis or elephantiasis is targeted for elimination in Sierra Leone, with annual mass treatment with ivermectin and albendazole, and required coverage was achieved in all 12 districts annually. In 2017, transmission assessment survey (TAS) was conducted in eight districts to assess whether treatment can be stopped and pre-TAS was conducted in six other districts to assess whether TAS can be conducted. Eight TAS districts were surveyed as four evaluation units (EU), and a school-based survey was conducted in 1703–1926 children aged 6–7 years from 30 clusters per EU. Six pre-TAS districts were surveyed with one sentinel and one/two spot check sites per district and 300–350 persons aged ≥5 years were tested. All tests were using the Filariasis Test Strips with finger prick blood samples. There were 0–7 positive cases in each TAS EU respectively, all below the critical cut-off value, confirming that mass treatment was no longer needed in these eight districts, a significant progress towards LF elimination. One district had prevalence of <1% in two sites and qualified for TAS, while other five districts had sites with prevalence >2%, suggesting that mass treatment needs to continue. Repeated failure of pre-TAS poses great challenge to eliminate LF in Sierra Leone.YMB is the former NTDP manager and coordinated the MDAs with AC and MS. JBK designed and oversaw the early NTDP and baseline surveys. JP, MB designed and led the TAS, pre-TAS field work data collection. MB and VRS conducted the data analysis. VRS and MH reanalysed the coverage data. YZ produced the point prevalence map. MH drafted the manuscript. MH and YZ revised the manuscript. All authors reviewed and approved the final manuscript.
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Affiliation(s)
- Yakuba M. Bah
- Neglected Tropical Disease Program, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | - Jusufu Paye
- Helen Keller International, Freetown, Sierra Leone
| | | | - Abdulai Conteh
- Neglected Tropical Disease Program, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | | | | | - Amy Veinoglou
- Helen Keller International, New York, United States of America
| | | | - Mary H. Hodges
- Helen Keller International, Freetown, Sierra Leone
- * E-mail:
| | - Yaobi Zhang
- Helen Keller International, Regional Office for Africa, Dakar, Senegal
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11
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Gebrezgabiher G, Mekonnen Z, Yewhalaw D, Hailu A. Status of parasitological indicators and morbidity burden of onchocerciasis after years of successive implementation of mass distribution of ivermectin in selected communities of Yeki and Asosa districts, Ethiopia. BMC Public Health 2020; 20:1233. [PMID: 32787813 PMCID: PMC7425055 DOI: 10.1186/s12889-020-09344-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 08/04/2020] [Indexed: 11/23/2022] Open
Abstract
Background Control and elimination of onchocerciasis requires regular follow-up and evaluation of community directed treatment with ivermectin (CDTi) program implementation. This research was aimed to assess the epidemiological status of onchocerciasis in disease endemic communities of Asosa and Yeki districts of Ethiopia after 5 and 15 years of successive CDTi respectively, and to evaluate the decline in infection and morbidity burden. Methods A community-based cross-sectional study was conducted from August 2017 to January 2018 (i.e. within 2–7 months since the last treatment) using interview, physical and parasitological examinations. Pre-CDTi epidemiological data were obtained from studies conducted prior to the launch of CDTi. Results A total of 3002 individuals (1567 from Asosa and 1435 from Yeki) were included. No infection was detected from Yeki. In Asosa, the prevalence of infection was 1.6%. The geometric mean intensity of infection was 0.02 mf/mg of skin snip. The prevalence rates of dermatitis, depigmentation, nodule, and atrophy in Yeki were 33(2.3%), 57(4%), 37(2.6%) and 11(0.7%), respectively. The prevalence rates of papular dermatitis, depigmentation, palpable nodule, atrophy, and blindness in Asosa were 94(6%), 38(2.4%), 30(1.9%), 28(1.8%) and 2(0.1%), respectively. Five years of CDTi had significantly reduced prevalence and intensity of infection by 91.8% (p < 0.001) and 99.7% (p < 0.001), respectively. Moreover, CDTi reduced prevalence of papular dermatitis by 95.9% (p < 0.001), palpable nodule by 90.5% (p < 0.001), and atrophy by 30% (p = 0.6) in Yeki. Similarly, CDTi reduced prevalence of papular dermatitis by 88.6% (p < 0.001), depigmentation by 90.3% (p < 0.001), atrophy by 89.5% (p < 0.001), and blindness by 90% (p < 0.001) in Asosa. Conclusions Fifteen years of successive CDTi had brought the infection from high to zero in Yeki. However, thorough entomological and serological data need to be generated to ascertain whether complete interruption of parasite transmission has been attained, and for considerations of an evidence-based CDTi cessation. Five years of CDTi in Asosa has significantly reduced the infection and morbidity of onchocerciasis to very low level. We, hereby, recommend biannual CDTi to continue in Asosa and its surroundings until the infection transmission is fully interrupted.
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Affiliation(s)
- Gebremedhin Gebrezgabiher
- College of Veterinary Medicine, Samara University, P.O. Box 132, Samara, Ethiopia. .,School of Medical Laboratory Sciences, Institute of Health Sciences, Jimma University, Jimma, Ethiopia.
| | - Zeleke Mekonnen
- School of Medical Laboratory Sciences, Institute of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Institute of Health Sciences, Jimma University, Jimma, Ethiopia.,Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Asrat Hailu
- Department of Microbiology, Immunology, and Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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Cadmus SI, Akinseye VO, Taiwo BO, Pinelli EO, van Soolingen D, Rhodes SG. Interactions between helminths and tuberculosis infections: Implications for tuberculosis diagnosis and vaccination in Africa. PLoS Negl Trop Dis 2020; 14:e0008069. [PMID: 32498074 PMCID: PMC7272205 DOI: 10.1371/journal.pntd.0008069] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Africa is the second most populous continent and has perennial health challenges. Of the estimated 181 million school aged children in sub-Saharan Africa (SSA), nearly half suffer from ascariasis, trichuriasis, or a combination of these infections. Coupled with these is the problem of tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) infection, which is a leading cause of death in the region. Compared to the effect of the human immunodeficiency virus on the development of TB, the effect of chronic helminth infections is a neglected area of research, yet helminth infections are as ubiquitous as they are varied and may potentially have profound effects upon host immunity, particularly as it relates to TB infection, diagnosis, and vaccination. Protection against active TB is known to require a clearly delineated T-helper type 1 (Th1) response, while helminths induce a strong opposing Th2 and immune-regulatory host response. This Review highlights the potential challenges of helminth-TB co-infection in Africa and the need for further research.
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Affiliation(s)
- Simeon I. Cadmus
- Depeartment of Veterinary Public Health & Preventive Medicine, University of Ibadan, Ibadan, Nigeria
- Centre for Control and Prevention of Zoonoses, University of Ibadan, Ibadan, Nigeria
| | - Victor O. Akinseye
- Depeartment of Veterinary Public Health & Preventive Medicine, University of Ibadan, Ibadan, Nigeria
| | - Babafemi O. Taiwo
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Elena O. Pinelli
- Center for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Dick van Soolingen
- Center for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
- Department of Medical Microbiology, Radboud University Medical Center Nijmegen, the Netherlands
| | - Shelley G. Rhodes
- TB Research Group, Animal and Plant Health Agency, Surrey, United Kingdom
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13
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Gebrezgabiher G, Mekonnen Z, Yewhalaw D, Hailu A. Reaching the last mile: main challenges relating to and recommendations to accelerate onchocerciasis elimination in Africa. Infect Dis Poverty 2019; 8:60. [PMID: 31269966 PMCID: PMC6609392 DOI: 10.1186/s40249-019-0567-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 06/10/2019] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Onchocerciasis (river blindness), caused by the filarial worm species Onchocerca volvulus, is a serious vector-borne neglected tropical disease (NTD) of public health and socioeconomic concern. It is transmitted through the bite of black flies of the genus Simulium, and manifested in dermal and ocular lesions. Ninety-nine percent of the total global risk and burden of onchocerciasis is in Africa. This scoping review examines the key challenges related to the elimination of onchocerciasis by 2020-2025 in Africa, and proposes recommendations to overcome the challenges and accelerate disease elimination. To find relevant articles published in peer-reviewed journals, a search of PubMed and Google Scholar databases was carried out. MAIN TEXT Rigorous regional interventions carried out to control and eliminate onchocerciasis in the past four decades in Africa have been effective in bringing the disease burden under control; it is currently not a public health problem in most endemic areas. Notably, transmission of the parasite is interrupted in some hyperendemic localities. Recently, there has been a policy shift from control to complete disease elimination by 2020 in selected countries and by 2025 in the majority of endemic African countries. The WHO has published guidelines for stopping mass drug administration (MDA) and verifying the interruption of transmission and elimination of human onchocerciasis. Therefore, countries have revised their plans, established a goal of disease elimination in line with an evidence based decision to stop MDA and verify elimination, and incorporated it into their NTDs national master plans. Nevertheless, challenges remain pertaining to the elimination of onchocerciasis in Africa. The challenge we review in this paper are: incomplete elimination mapping of all transmission zones, co-endemicity of onchocerciasis and loiasis, possible emergence of ivermectin resistance, uncoordinated cross-border elimination efforts, conflict and civil unrest, suboptimal program implementation, and technical and financial challenges. This paper also proposes recommendations to overcome the challenges and accelerate disease elimination. These are: a need for complete disease elimination mapping, a need for collaborative elimination activities between national programs, a need for a different drug distribution approach in conflict-affected areas, a need for routine monitoring and evaluation of MDA programs, a need for implementing alternative treatment strategies (ATSs) in areas with elimination anticipated beyond 2025, and a need for strong partnerships and continued funding. CONCLUSIONS National programs need to regularly monitor and evaluate the performance and progress of their interventions, while envisaging the complete elimination of onchocerciasis from their territory. Factors hindering the targeted goal of interruption of parasite transmission need to be identified and remedial actions should be taken. If possible and appropriate, ATSs need to be implemented to accelerate disease elimination by 2025.
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Affiliation(s)
- Gebremedhin Gebrezgabiher
- School of Medical Laboratory Sciences, Institute of Health Sciences, Jimma University, P.O. Box 378, Jimma, Ethiopia
- College of Veterinary Medicine, Samara University, Samara, Ethiopia
| | - Zeleke Mekonnen
- School of Medical Laboratory Sciences, Institute of Health Sciences, Jimma University, P.O. Box 378, Jimma, Ethiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Institute of Health Sciences, Jimma University, P.O. Box 378, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Asrat Hailu
- Department of Microbiology, Immunology, and Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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14
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Bah YM, Bah MS, Paye J, Conteh A, Saffa S, Tia A, Sonnie M, Veinoglou A, Amon JJ, Hodges MH, Zhang Y. Soil-transmitted helminth infection in school age children in Sierra Leone after a decade of preventive chemotherapy interventions. Infect Dis Poverty 2019; 8:41. [PMID: 31262367 PMCID: PMC6604471 DOI: 10.1186/s40249-019-0553-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 05/22/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Baseline mapping of soil-transmitted helminth (STH) infections among school age children (SAC) in 2008-2009 found high or moderate prevalence in 13 of the 14 districts in Sierra Leone. Following these surveys, mass drug administration (MDA) of mebendazole/albendazole was conducted biannually at national level targeting pre-school children (PSC) aged 12-59 months and intermittently at sub-national level targeting SAC. In addition, MDA with ivermectin and albendazole for eliminating lymphatic filariasis (LF) has been conducted nationwide since 2010 targeting individuals over 5 years of age. Each MDA achieved high coverage, except in 2014 when all but one round of MDA for PSC was cancelled due to the Ebola emergency. The objective of the current study was to determine the prevalence and intensity of STH infections among SAC after a decade of these deworming campaigns. METHODS Seventy-three schools in 14 districts were purposefully selected, including 39 schools from the baseline surveys, with approximately two sites from each of low, moderate and high prevalence categories at baseline per district. Fresh stool samples were collected from 3632 children aged 9-14 years (male 51%, female 49%) and examined using the Kato Katz technique. RESULTS The prevalence of STH infections in Sierra Leone decreased in 2016 compared to 2008: Ascaris lumbricoides 4.4% (95% confidence interval [CI]: 3.7-5.1%) versus 6.6% (95% CI: 0-25%), Trichuris trichiura 0.7% (95% CI: 0.5-1.1%) versus 1.8% (95% CI: 0-30.2%), hookworm 14.9% (95% CI: 13.8-16.1) versus 38.5% (95% CI: 5.4-95.1%), and any STH 18.3% (95% CI:17.0-19.5%) versus 48.3% (CI: 5.4-96.3%), respectively. In 2016, no district had high hookworm prevalence and four districts had moderate prevalence, compared with eight and four districts respectively in 2008. In 2016, the arithmetic mean hookworm egg count in all children examined was light: 45.5 eggs per gram (EPG) of faeces, (95% CI:\ 35.96-55.07 EPG); three (0.08%) children had heavy infections and nine (0.25%) children had moderate infections. CONCLUSIONS Sierra Leone has made considerable progress toward controlling STH as a public health problem among SAC. As LF MDA phases out (between 2017 and 2021), transition of deworming to other platforms and water and sanitation strategies need to be strengthened to maintain STH control and ultimately interrupt transmission.
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Affiliation(s)
- Yakuba Mohamed Bah
- Neglected Tropical Disease Control Program, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | | | - Jusufu Paye
- Helen Keller International, Freetown, Sierra Leone
| | - Abdulai Conteh
- Neglected Tropical Disease Control Program, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | - Sam Saffa
- Neglected Tropical Disease Control Program, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | - Alie Tia
- Neglected Tropical Disease Control Program, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | | | | | | | | | - Yaobi Zhang
- Helen Keller International, Regional Office for Africa, Yoff-Dakar, Senegal
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15
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Njume FN, Ghogomu SM, Shey RA, Gainkam LOT, Poelvoorde P, Humblet P, Kamgno J, Robert A, Mutesa L, Lelubre C, Edelweiss E, Poterszman A, Anheuser S, Vanhamme L, Souopgui J. Identification and characterization of the Onchocerca volvulus Excretory Secretory Product Ov28CRP, a putative GM2 activator protein. PLoS Negl Trop Dis 2019; 13:e0007591. [PMID: 31329585 PMCID: PMC6675134 DOI: 10.1371/journal.pntd.0007591] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 08/01/2019] [Accepted: 07/01/2019] [Indexed: 11/18/2022] Open
Abstract
Onchocerca volvulus is the nematode pathogen responsible for human onchocerciasis also known as "River blindness", a neglected tropical disease that affects up to 18 million people worldwide. Helminths Excretory Secretory Products (ESPs) constitute a rich repertoire of molecules that can be exploited for host-parasite relationship, diagnosis and vaccine studies. Here, we report, using a range of molecular techniques including PCR, western blot, recombinant DNA technology, ELISA, high performance thin-layer chromatography and mass spectrometry that the 28 KDa cysteine-rich protein (Ov28CRP) is a reliable component of the O. volvulus ESPs to address the biology of this parasite. We showed that (1) Ov28CRP is a putative ganglioside GM2 Activator Protein (GM2AP) conserved in nematode; (2) OvGM2AP gene is transcriptionally activated in all investigated stages of the parasitic life cycle, including larval and adult stages; (3) The full-length OvGM2AP was detected in in-vitro O. volvulus ESPs of adult and larval stages; (4) the mass expressed and purified recombinant OvGM2AP purified from insect cell culture medium was found to be glycosylated at asparagine 173 and lacked N-terminal signal peptide sequence; (5) the recombinant OvGM2AP discriminated serum samples of infected and uninfected individuals; (6) OvGM2AP competitively inhibits MUG degradation by recombinant β-hexosaminidase A but not MUGS, and could not hydrolyze the GM2 to GM3; (7) humoral immune responses to the recombinant OvGM2AP revealed a negative correlation with ivermectin treatment. Altogether, our findings suggest for the first time that OvGM2AP is an antigenic molecule whose biochemical and immunological features are important to gain more insight into our understanding of host-parasite relationship, as well as its function in parasite development at large.
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Affiliation(s)
- Ferdinand Ngale Njume
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Stephen Mbigha Ghogomu
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Robert Adamu Shey
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Lea Olive Tchouate Gainkam
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Philippe Poelvoorde
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Perrine Humblet
- École de santé publique, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Joseph Kamgno
- Department of Epidemiology, Centre for research on filariasis and other tropical diseases, Yaounde, Cameroon
| | - Annie Robert
- Faculté de santé publique, Institut de recherche expérimentale et clinique, Pôle d'épidémiologie et biostatistique, Université Catholique de Louvain, Clos Chapelle-aux-champs, Woluwe-Saint-Lambert, Belgium
| | - Leon Mutesa
- Center for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Christophe Lelubre
- Laboratoire de Médecine Expérimentale, Université Libre de Bruxelles (ULB)—Unité 222, CHU Charleroi (Hôpital André Vésale), Rue de Gozée, Montigny-Le-Tilleul, Belgium
| | - Evelina Edelweiss
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, UMR7104, Illkirch, France
| | - Arnaud Poterszman
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, UMR7104, Illkirch, France
| | - Susi Anheuser
- LIMES Institute, Membrane Biology & Lipid Biochemistry Unit, c/o Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, Germany
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
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16
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Koudou BG, Kouakou MM, Ouattara AF, Yeo S, Brika P, Meite A, Aba E, King CL, Kouakou R, Weil GJ, Fischer PU. Update on the current status of onchocerciasis in Côte d'Ivoire following 40 years of intervention: Progress and challenges. PLoS Negl Trop Dis 2018; 12:e0006897. [PMID: 30352058 PMCID: PMC6214569 DOI: 10.1371/journal.pntd.0006897] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 11/02/2018] [Accepted: 10/04/2018] [Indexed: 12/04/2022] Open
Abstract
Background Onchocerciasis control in Côte d’Ivoire started with aerial insecticide spraying in 1974 and continued with community directed treatment with ivermectin (CDTi) from 1992 to the present. Onchocerciasis and lymphatic filariasis (LF) are co-endemic in 46 of the 81 health districts in the country. Fourteen and 12 districts are endemic for only LF or onchocerciasis, respectively. This paper aims to review the impact of past interventions on onchocerciasis in Côte d’Ivoire between 1975 and 2013, and review plans for disease elimination. Methods We reviewed microfilaria (MF, skin snip) prevalence and community microfilarial load (CMFL) data from published reports from 53 health districts during two major epidemiological assessment periods. Data from 1975 through 1991 provided information on the impact of vector control, and data from 1992 through 2016 provided information on the impact of CDTi. Results Weekly aerial insecticide spraying in 8 endemic districts between 1975 and 1991 reduced the overall MF prevalence by 68.1% from 43.5% to 13.9%. The CMFL also decreased in 7 out of 8 surveyed communities by 95.2% from 9.24 MF/snip to 0.44 MF/snip. Ivermectin distribution started in 1992. The coverage targets for control (65% of the total population) was reached in most endemic districts, and some areas achieved 80% coverage. Two sets of surveys were conducted to assess the impact of CDTi. Results from the first repeat surveys showed a significant decrease in overall MF prevalence (by 75.7%, from 41.6% to 10.1%). The second follow-up evaluation showed further improvement in most endemic districts and also documented major reductions in CMFL compared to baseline. Conclusions Extensive data collected over many years document the very significant impact of interventions conducted by the National Onchocerciasis and other Eyes Diseases Control Programme during challenging times with periods of civil unrest. The Health Ministry has now integrated efforts to control neglected tropical diseases and adopted the goal of onchocerciasis elimination. Onchocerciasis has recently been targeted for elimination in Côte d’Ivoire. With support of international donors the country’s integrated Neglected Tropical Diseases (NTD) program has recently achieved 100% geographical coverage for mass drug administration in districts endemic for lymphatic filariasis and onchocerciasis. From 1975 to 1991 onchocerciasis control in Côte d’Ivoire was based on weekly aerial spraying of insecticide on targeted rivers. From 1992 to present, community directed treatment with ivermectin by community drug distributors was implemented in most endemic areas. Although the country experienced periods of civil disturbance that interrupted distribution of ivermectin for several years, significant progress was made during this time toward onchocerciasis elimination. There have been significant reductions in both microfilarial prevalences and community microfilarial loads in sentinel villages that had implementation of vector control and/or mass drug administration coverage rates of at least 65%. Although onchocerciasis persists in some areas, changes in management of the programme in 2015 together with improved political stability and increased support from key donors may lead to its elimination over the next 10 years.
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Affiliation(s)
- Benjamin G. Koudou
- Laboratory of Biology and Animal Cytology, Training and Research Unit in Natural Sciences, Nangui Abrogoua University, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Research and Development Department, Abidjan, Côte d’Ivoire
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, United Kingdom
| | - Marie-Madeleine Kouakou
- National Onchocerciasis Control Programme, Ministry of Health and Public hygiene in Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Allassane F. Ouattara
- Laboratory of Biology and Animal Cytology, Training and Research Unit in Natural Sciences, Nangui Abrogoua University, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Research and Development Department, Abidjan, Côte d’Ivoire
- * E-mail:
| | - Souleymane Yeo
- National Onchocerciasis Control Programme, Ministry of Health and Public hygiene in Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Pierre Brika
- National Onchocerciasis Control Programme, Ministry of Health and Public hygiene in Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Aboulaye Meite
- National Onchocerciasis Control Programme, Ministry of Health and Public hygiene in Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Elvis Aba
- National Onchocerciasis Control Programme, Ministry of Health and Public hygiene in Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Christopher L. King
- Case Western Reserve University, Center for Global Health and Disease, Cleveland, Ohio, United States of America
| | - Roger Kouakou
- National Onchocerciasis Control Programme, Ministry of Health and Public hygiene in Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Gary J. Weil
- Washington University School of Medicine, Department of Medicine, Infectious Diseases Division, St. Louis, Missouri, United States of America
| | - Peter U. Fischer
- Washington University School of Medicine, Department of Medicine, Infectious Diseases Division, St. Louis, Missouri, United States of America
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Murdoch ME. Onchodermatitis: Where Are We Now? Trop Med Infect Dis 2018; 3:E94. [PMID: 30274490 PMCID: PMC6160948 DOI: 10.3390/tropicalmed3030094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 02/07/2023] Open
Abstract
Onchocerciasis causes debilitating pruritus and rashes as well as visual impairment and blindness. Prior to control measures, eye disease was particularly prominent in savanna areas of sub-Saharan Africa whilst skin disease was more common across rainforest regions of tropical Africa. Mass drug distribution with ivermectin is changing the global scene of onchocerciasis. There has been successful progressive elimination in Central and Southern American countries and the World Health Organization has set a target for elimination in Africa of 2025. This literature review was conducted to examine progress regarding onchocercal skin disease. PubMed searches were performed using keywords 'onchocerciasis', 'onchodermatitis' and 'onchocercal skin disease' over the past eight years. Articles in English, or with an English abstract, were assessed for relevance, including any pertinent references within the articles. Recent progress in awareness of, understanding and treatment of onchocercal skin disease is reviewed with particular emphasis on publications within the past five years. The global burden of onchodermatitis is progressively reducing and is no longer seen in children in many formerly endemic foci.
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Affiliation(s)
- Michele E Murdoch
- Department of Dermatology, West Herts Hospitals NHS Trust, Vicarage Road, Watford, Hertfordshire WD18 0HB, UK.
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18
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Koroma JB, Sesay S, Conteh A, Paye J, Bah M, Sonnie M, Hodges MH, Zhang Y. Progress on elimination of lymphatic filariasis in Sierra Leone. Parasit Vectors 2018; 11:334. [PMID: 29866207 PMCID: PMC5987388 DOI: 10.1186/s13071-018-2915-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 05/24/2018] [Indexed: 11/18/2022] Open
Abstract
Background A baseline survey in 2007–2008 found lymphatic filariasis (LF) to be endemic in Sierra Leone in all 14 districts and co-endemic with onchocerciasis in 12 districts. Mass drug administration (MDA) with ivermectin started in 2006 for onchocerciasis and was modified to add albendazole in 2008 to include LF treatment. In 2011, after three effective MDAs, a significant reduction in microfilaraemia (mf) prevalence and density was reported at the midterm assessment. After five MDAs, in 2013, mf prevalence and density were again measured as part of a pre-transmission assessment survey (pre-TAS) conducted per WHO guidelines. Methods For the pre-TAS survey, districts were paired to represent populations of one million for impact assessment. One sentinel site selected from baseline and one spot check site purposefully selected based upon local knowledge of patients with LF were surveyed per pair (two districts). At each site, 300 people over five years of age provided mid-night blood samples and mf prevalence and density were determined using thick blood film microscopy. Results are compared with baseline and midterm data. Results At pre-TAS the overall mf prevalence was 0.54% (95% CI: 0.36–0.81%), compared to 0.30% (95% CI: 0.19–0.47) at midterm and 2.6% (95% CI: 2.3–3.0%) at baseline. There was a higher, but non-significant, mf prevalence among males vs females. Eight districts (four pairs) had a prevalence of mf < 1% at all sites. Two pairs (four districts) had a prevalence of mf > 1% at one of the two sites: Koinadugu 0.98% (95% CI: 0.34–2.85%) and Bombali 2.67% (95% CI: 1.41–5.00%), and Kailahun 1.56% (95% CI: 0.72–3.36%) and Kenema 0% (95% CI: 0.00–1.21%). Conclusions Compared to baseline, there was a significant reduction of LF mf prevalence and density in the 12 districts co-endemic for LF and onchocerciasis after five annual LF MDAs. No statistically significant difference was seen in either measure compared to midterm. Eight of the 12 districts qualified for TAS. The other four districts that failed to qualify for TAS had historically high LF baseline prevalence and density and had regular cross-border movement of populations. These four districts needed to conduct two additional rounds of LF MDA before repeating the pre-TAS. The results showed that Sierra Leone continued to make progress towards the elimination of LF as a public health problem.
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Affiliation(s)
- Joseph B Koroma
- Family Health International 360, Ghana Country Office, Accra, Ghana
| | - Santigie Sesay
- National Neglected Tropical Disease Control Programme, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | - Abdul Conteh
- National Neglected Tropical Disease Control Programme, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | - Jusufu Paye
- Helen Keller International, Freetown, Sierra Leone
| | - Mohamed Bah
- Helen Keller International, Freetown, Sierra Leone
| | | | | | - Yaobi Zhang
- Helen Keller International, Regional Office for Africa, Dakar, Senegal.
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