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Nyangiri OA, Mulindwa J, Namulondo J, Kitibwa A, Nassuuna J, Elliott A, Kimuda MP, Boobo A, Nerima B, Adriko M, Dunton NJ, Madhan GK, Kristiansen M, Casacuberta-Partal M, Noyes H, Matovu E. Variants of IL6, IL10, FCN2, RNASE3, IL12B and IL17B loci are associated with Schistosoma mansoni worm burden in the Albert Nile region of Uganda. PLoS Negl Trop Dis 2023; 17:e0011796. [PMID: 38033168 PMCID: PMC10715658 DOI: 10.1371/journal.pntd.0011796] [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: 04/01/2023] [Revised: 12/12/2023] [Accepted: 11/14/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND Individuals genetically susceptible to high schistosomiasis worm burden may contribute disproportionately to transmission and could be prioritized for control. Identifying genes involved may guide development of therapy. METHODOLOGY/PRINCIPAL FINDINGS A cohort of 606 children aged 10-15 years were recruited in the Albert Nile region of Uganda and assessed for Schistosoma mansoni worm burden using the Up-Converting Particle Lateral Flow (UCP-LF) test detecting circulating anodic antigen (CAA), point-of-care Circulating Cathodic Antigen (POC-CCA) and Kato-Katz tests. Whole genome genotyping was conducted on 326 children comprising the top and bottom 25% of worm burden. Linear models were fitted to identify variants associated with worm burden in preselected candidate genes. Expression quantitative trait locus (eQTL) analysis was conducted for candidate genes with UCP-LF worm burden included as a covariate. Single Nucleotide Polymorphism loci associated with UCP-LF CAA included IL6 rs2066992 (OR = 0.43, p = 0.0006) and rs7793163 (OR = 2.0, p = 0.0007); IL21 SNP kgp513476 (OR 1.79, p = 0.0025) and IL17B SNP kgp708159 (OR = 0.35, p = 0.0028). A haplotype in the IL10 locus was associated with lower worm burden (OR = 0.53, p = 0.015) and overlapped SNPs rs1800896, rs1800871 and rs1800872. Significant haplotypes (p<0.05, overlapping significant SNP) associated with worm burden were observed in IL6 and the Th17 pathway IL12B and IL17B genes. There were significant eQTL in the IL6, IL5, IL21, IL25 and IFNG regions. CONCLUSIONS Variants associated with S. mansoni worm burden were in IL6, FCN2, RNASE3, IL10, IL12B and IL17B gene loci. However only eQTL associations remained significant after Bonferroni correction. In summary, immune balance, pathogen recognition and Th17 pathways may play a role in modulating Schistosoma worm burden. Individuals carrying risk variants may be targeted first in allocation of control efforts to reduce the burden of schistosomiasis in the community.
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Affiliation(s)
- Oscar Asanya Nyangiri
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Julius Mulindwa
- Department of Biochemistry and Sports Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Joyce Namulondo
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Anna Kitibwa
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Jacent Nassuuna
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Alison Elliott
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Magambo Phillip Kimuda
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Alex Boobo
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Barbara Nerima
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Moses Adriko
- Vector Borne & NTD Control Division, Ministry of Health, Uganda
| | - Nathan J. Dunton
- UCL Genomics core facility, University College London, London, United Kingdom
| | | | - Mark Kristiansen
- UCL Genomics core facility, University College London, London, United Kingdom
| | | | - Harry Noyes
- Centre for Genomic Research, University of Liverpool, Liverpool, United Kingdom
| | - Enock Matovu
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
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Nemungadi TG, Furumele TE, Gugerty MK, Djirmay AG, Naidoo S, Kjetland EF. Establishing and Integrating a Female Genital Schistosomiasis Control Programme into the Existing Health Care System. Trop Med Infect Dis 2022; 7:tropicalmed7110382. [PMID: 36422933 PMCID: PMC9696272 DOI: 10.3390/tropicalmed7110382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/02/2022] [Accepted: 11/09/2022] [Indexed: 11/19/2022] Open
Abstract
Female genital schistosomiasis (FGS) is a complication of Schistosoma haematobium infection, and imposes a health burden whose magnitude is not fully explored. It is estimated that up to 56 million women in sub-Saharan Africa have FGS, and almost 20 million more cases will occur in the next decade unless infected girls are treated. Schistosomiasis is reported throughout the year in South Africa in areas known to be endemic, but there is no control programme. We analyze five actions for both a better understanding of the burden of FGS and reducing its prevalence in Africa, namely: (1) schistosomiasis prevention by establishing a formal control programme and increasing access to treatment, (2) introducing FGS screening, (3) providing knowledge to health care workers and communities, (4) vector control, and (5) water, sanitation, and hygiene. Schistosomiasis is focal in South Africa, with most localities moderately affected (prevalence between 10% and 50%), and some pockets that are high risk (more than 50% prevalence). However, in order to progress towards elimination, the five actions are yet to be implemented in addition to the current (and only) control strategy of case-by-case treatment. The main challenge that South Africa faces is a lack of access to WHO-accredited donated medication for mass drug administration. The establishment of a formal and funded programme would address these issues and begin the implementation of the recommended actions.
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Affiliation(s)
- Takalani Girly Nemungadi
- Discipline of Public Health Medicine, School of Nursing and Public Health, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
- Communicable Disease Control Directorate, National Department of Health, Pretoria 0001, South Africa
- Correspondence:
| | - Tsakani Ernica Furumele
- Communicable Disease Control Directorate, National Department of Health, Pretoria 0001, South Africa
| | - Mary Kay Gugerty
- Evans School of Public Policy & Governance, University of Washington, Seattle, WA 98195-3055, USA
| | - Amadou Garba Djirmay
- Department of the Control of Neglected Tropical Diseases, World Health Organization, 1211 Geneva, Switzerland
| | - Saloshni Naidoo
- Discipline of Public Health Medicine, School of Nursing and Public Health, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Eyrun Flörecke Kjetland
- Discipline of Public Health Medicine, School of Nursing and Public Health, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
- Norwegian Centre for Imported and Tropical Diseases, Department of Infectious Diseases Ullevaal, Oslo University Hospital, 0424 Oslo, Norway
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De Boni L, Msimang V, De Voux A, Frean J. Trends in the prevalence of microscopically-confirmed schistosomiasis in the South African public health sector, 2011-2018. PLoS Negl Trop Dis 2021; 15:e0009669. [PMID: 34529659 PMCID: PMC8445405 DOI: 10.1371/journal.pntd.0009669] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 07/20/2021] [Indexed: 11/25/2022] Open
Abstract
Background Schistosomiasis, also known as bilharzia, is a chronic parasitic blood fluke infection acquired through contact with contaminated surface water. The illness may be mild or can cause significant morbidity with potentially serious complications. Children and those living in rural areas with limited access to piped water and services for healthcare are the most commonly infected. To address the prevalence of the disease in parts of South Africa (SA) effective national control measures are planned, but have not yet been implemented. This study aimed to estimate the prevalence and trends of public sector laboratory-confirmed schistosomiasis cases in SA over an eight-year (2011–2018) period, to inform future control measures. Methodology & principal findings This is a descriptive analysis of secondary data from the National Health Laboratory Service (NHLS). The study included all records of patients for whom microscopic examination detected Schistosoma species eggs in urine or stool specimens from January 2011 to December 2018. Crude estimates of the prevalence were calculated using national census mid-year provincial population estimates as denominators, and simple linear regression was used to analyse prevalence trends. A test rate ratio was developed to describe variations in testing volumes among different groups and to adjust prevalence estimates for testing variations. A total number of 135 627 schistosomiasis cases was analysed with the highest prevalence observed among males and individuals aged 5–19 years. We describe ongoing endemicity in the Eastern Cape Province, and indicate important differences in the testing between population groups. Conclusion While there was no overall change in the prevalence of schistosomiasis during the analysis period, an average of 36 people per 100 000 was infected annually. As such, this represents an opportunity to control the disease and improve quality of life of affected people. Laboratory-based surveillance is a useful method for reporting occurrence and evaluating future intervention programs where resources to implement active surveillance are limited. This is the first paper to describe the prevalence of human schistosomiasis in South Africa using nationally representative data. The prevalence remained consistent during the eight-year period, independent of increasing annual testing volumes. Groups with the highest burden included males and individuals aged 5–19 years. The schistosomiasis-endemic provinces of Limpopo, Mpumalanga and KwaZulu-Natal emerged as the highest-burdened areas, and ongoing endemicity in Eastern Cape Province was demonstrated. Western Cape Province likely reported cases imported from endemic provinces rather than being acquired by local transmission. In summary, schistosomiasis remains an important public health problem in South Africa that needs long-term sustainable, effective standardised interventions to reduce the burden. Passive laboratory-based surveillance is a practical tool for reporting prevalence, and could be used to monitor and evaluate future intervention programs.
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Affiliation(s)
- Liesl De Boni
- South African Field Epidemiology Training Programme, Johannesburg, South Africa
- University of the Witwatersrand, Johannesburg, South Africa
- * E-mail:
| | - Veerle Msimang
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Alex De Voux
- South African Field Epidemiology Training Programme, Johannesburg, South Africa
| | - John Frean
- University of the Witwatersrand, Johannesburg, South Africa
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
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