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Wen Y, Deng S, Wang T, Gao M, Nan W, Tang F, Xue Q, Ju Y, Dai J, Wei Y, Xue F. Novel strategy for Poxviridae prevention: Thermostable combined subunit vaccine patch with intense immune response. Antiviral Res 2024; 228:105943. [PMID: 38909959 DOI: 10.1016/j.antiviral.2024.105943] [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: 05/04/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 06/25/2024]
Abstract
Poxviruses gained international attention due to the sharp rise in monkeypox cases in recent years, highlighting the urgent need for the development of a secure and reliable vaccine. This study involved the development of an innovative combined subunit vaccine (CSV) targeting poxviruses, with lumpy skin disease virus (LSDV) serving as the model virus. To this end, the potential sites for poxvirus vaccines were fully evaluated to develop and purify four recombinant proteins. These proteins were then successfully delivered to the dermis in a mouse model by utilizing dissolvable microneedle patches (DMPs). This approach simplified the vaccination procedure and significantly mitigated the associated risk. CSV-loaded DMPs contained four recombinant proteins and a novel adjuvant, CpG, which allowed DMPs to elicit the same intensity of humoral and cellular immunity as subcutaneous injection. Following immunization with SC and DMP, the mice exhibited notable levels of neutralizing antibodies, albeit at a low concentration. It is noteworthy that the CSV loaded into DMPs remained stable for at least 4 months at room temperature, effectively addressing the storage and transportation challenges. Based on the study findings, CSV-loaded DMPs are expected to be utilized worldwide as an innovative technique for poxvirus inoculation, especially in underdeveloped regions. This novel strategy is crucial for the development of future poxvirus vaccines.
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MESH Headings
- Animals
- Vaccines, Subunit/immunology
- Vaccines, Subunit/administration & dosage
- Mice
- Antibodies, Neutralizing/immunology
- Antibodies, Neutralizing/blood
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Poxviridae Infections/prevention & control
- Poxviridae Infections/immunology
- Female
- Poxviridae/immunology
- Viral Vaccines/immunology
- Viral Vaccines/administration & dosage
- Mice, Inbred BALB C
- Lumpy skin disease virus/immunology
- Vaccination
- Immunity, Cellular
- Immunity, Humoral
- Recombinant Proteins/immunology
- Recombinant Proteins/administration & dosage
- Adjuvants, Vaccine/administration & dosage
- Adjuvants, Immunologic/administration & dosage
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Affiliation(s)
- Yuan Wen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Sanya Institute of Nanjing Agricultural University, Sanya, 572025, China
| | - Shuyue Deng
- College of Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Tianmin Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Sanya Institute of Nanjing Agricultural University, Sanya, 572025, China
| | - Mengtian Gao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Sanya Institute of Nanjing Agricultural University, Sanya, 572025, China
| | - Wenlong Nan
- Laboratory of Diagnostics Development, China Animal Health and Epidemiology Center, 369 Nanjing Road, Qingdao, 266032, China
| | - Fang Tang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qinghong Xue
- China Institute of Veterinary Drug Control, Beijing, 100081, China
| | - Yanmin Ju
- College of Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Jianjun Dai
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; College of Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Yurong Wei
- Xinjiang Key Laboratory of Animal Infectious Diseases, Institute of Veterinary Medicine, Xinjiang Academy of Animal Science, Urumqi, 830099, China
| | - Feng Xue
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Sanya Institute of Nanjing Agricultural University, Sanya, 572025, China.
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El-Shall MN, Aly I, Samen A, Salama WM, Baakdah F. Immunochromatography Lateral Flow Strip Enhancement Based on Passive Gold Nanoparticles Conjugation to Detect Schistosma haematobium Antigens in Human Serum. Acta Parasitol 2024; 69:1267-1274. [PMID: 38753102 PMCID: PMC11182813 DOI: 10.1007/s11686-024-00841-y] [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: 09/20/2023] [Accepted: 03/20/2024] [Indexed: 06/18/2024]
Abstract
PURPOSE This study aimed to develop and evaluate a lateral flow card for the detection of active Schistosoma haematobium infection. METHODS In order to prepare the immunochromatography lateral flow strip (ICLFS), antibodies purified from schistosomiasis were conjugated passively with gold nanoparticles using a potassium carbonate buffer. RESULTS The novel ICLFS was able to correctly identify 64 out of 67 samples of schistosomiasis, 6 out of 90 samples of other parasites, and 0 out of 27 control samples. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were 95.5%, 93.3%, 90%, and 91.4% respectively. Comparatively, the sensitivity, specificity, NPV, and PPV of sandwich enzyme-linked immunosorbent assays (ELISA) conjugated with gold nanoparticles (AuNPs) were 91.1%, 88.8%, 85.9%, and 84.4% respectively. The increased sensitivity and specificity of ICLFS produced superior results to those of sandwich ELISA. CONCLUSION In conclusion, ICLFS is more beneficial and precise than sandwich ELISA for detection of S. haematobium infection at early stage.
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Affiliation(s)
- Mahmoud N El-Shall
- Department of Parasitology, Theodor Bilharz Research Institute, Giza, Egypt
| | - Ibrahim Aly
- Department of Parasitology, Theodor Bilharz Research Institute, Giza, Egypt
| | - Alaa Samen
- Zoology Department, Faculty of Science, Al-Azhar University, Cairo, Egypt
| | - Wesam M Salama
- Zoology Department, Faculty of Science, Tanta University, Tanta, Egypt.
| | - Fadi Baakdah
- Department of Medical Laboratory Science, Faculty of Applied Medical Sciences, King Abdulaziz University, 21589, Jeddah, Saudi Arabia
- Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, 21589, Jeddah, Saudi Arabia
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Gomes BF, Senger MR, Moreira-Filho JT, de Vasconcellos FJ, Dantas RF, Owens R, Andrade CH, Neves BJ, Silva-Junior FP. Discovery of new Schistosoma mansoni aspartyl protease inhibitors by structure-based virtual screening. Mem Inst Oswaldo Cruz 2023; 118:e230031. [PMID: 37672425 PMCID: PMC10481938 DOI: 10.1590/0074-02760230031] [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: 02/15/2023] [Accepted: 08/01/2023] [Indexed: 09/08/2023] Open
Abstract
BACKGROUND Schistosomiasis is a neglected tropical disease caused by trematodes of the genus Schistosoma, with a limited treatment, mainly based on the use of praziquantel (PZQ). Currently, several aspartic proteases genes have already been identified within the genome of Schistosoma species. At least one enzyme encoded from this gene family (SmAP), named SmCD1, has been validated for the development of schistosomicidal drugs, since it has a key role in haemoglobin digestion by worms. OBJECTIVE In this work, we integrated a structure-based virtual screening campaign, enzymatic assays and adult worms ex vivo experiments aiming to discover the first classes of SmCD1 inhibitors. METHODS Initially, the 3D-structures of SmCD1, SmCD2 and SmCD3 were generated using homology modelling approach. Using these models, we prioritised 50 compounds from 20,000 compounds from ChemBridge database for further testing in adult worm aqueous extract (AWAE) and recombinant SmCD1 using enzymatic assays. FINDINGS Seven compounds were confirmed as hits and among them, two compounds representing new chemical scaffolds, named 5 and 19, had IC50 values against SmCD1 close to 100 μM while presenting binding efficiency indexes comparable to or even higher than pepstatin, a classical tight-binding peptide inhibitor of aspartyl proteases. Upon activity comparison against mammalian enzymes, compound 50 was selective and the most potent against the AWAE aspartic protease activity (IC50 = 77.7 μM). Combination of computational and experimental results indicate that compound 50 is a selective inhibitor of SmCD2. Compounds 5, 19 and 50 tested at low concentrations (10 uM) were neither cytotoxic against WSS-1 cells (48 h) nor could kill adult worms ex-vivo, although compounds 5 and 50 presented a slight decrease on female worms motility on late incubations times (48 or 72 h). MAIN CONCLUSION Overall, the inhibitors identified in this work represent promising hits for further hit-to-lead optimisation.
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Affiliation(s)
- Bárbara Figueira Gomes
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Bioquímica Experimental e Computacional de Fármacos, Rio de Janeiro, RJ, Brasil
| | - Mario Roberto Senger
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Bioquímica Experimental e Computacional de Fármacos, Rio de Janeiro, RJ, Brasil
| | - José Teófilo Moreira-Filho
- Universidade Federal de Goiás, Faculdade de Farmácia, Laboratório de Planejamento de Fármacos e Modelagem Molecular, Goiânia, GO, Brasil
| | - Fabio Jorge de Vasconcellos
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Bioquímica Experimental e Computacional de Fármacos, Rio de Janeiro, RJ, Brasil
| | - Rafael Ferreira Dantas
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Bioquímica Experimental e Computacional de Fármacos, Rio de Janeiro, RJ, Brasil
| | - Raymond Owens
- University of Oxford and Rosalind Franklin Institute, Oxfordshire, UK
| | - Carolina Horta Andrade
- Universidade Federal de Goiás, Faculdade de Farmácia, Laboratório de Planejamento de Fármacos e Modelagem Molecular, Goiânia, GO, Brasil
| | - Bruno Junior Neves
- Universidade Federal de Goiás, Faculdade de Farmácia, Laboratório de Quimioinformática, Goiânia, GO, Brasil
| | - Floriano Paes Silva-Junior
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Bioquímica Experimental e Computacional de Fármacos, Rio de Janeiro, RJ, Brasil
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Talipova D, Smagulova A, Poddighe D. Toll-like Receptors and Celiac Disease. Int J Mol Sci 2022; 24:265. [PMID: 36613709 PMCID: PMC9820541 DOI: 10.3390/ijms24010265] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/10/2022] [Accepted: 12/13/2022] [Indexed: 12/28/2022] Open
Abstract
Celiac disease (CD) is an immune-mediated disorder triggered by dietary gluten intake in some genetically predisposed individuals; however, the additional non-HLA-related genetic factors implicated in CD immunopathogenesis are not well-defined. The role of the innate immune system in autoimmunity has emerged in the last few years. Genetic polymorphisms of some pattern-recognition receptors, including toll-like receptors (TLRs), have been associated with several autoimmune disorders. In this review, we summarize and discuss the evidence from basic research and clinical studies as regards the potential role of TLRs in CD immunopathogenesis. The evidence supporting the role of TLRs in CD immunopathogenesis is limited, especially in terms of basic research. However, differences in the expression and activation of TLRs between active CD patients from one side, and controls and treated CD patients from the other side, have been described in some clinical studies. Therefore, TLRs may be part of those non-HLA-related genetic factors implicated in CD etiopathogenesis, considering their potential role in the interaction between the host immune system and some environmental factors (including viral infections and gut microbiota), which are included in the list of candidate agents potentially contributing to the determination of CD risk in genetically predisposed individuals exposed to dietary gluten intake. Further basic research and clinical studies focused on TLRs in the context of CD and other gluten-related disorders are needed.
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Affiliation(s)
- Diana Talipova
- Department of Medicine, Nazarbayev University School of Medicine, Astana 010000, Kazakhstan
| | - Aiganym Smagulova
- Department of Medicine, Nazarbayev University School of Medicine, Astana 010000, Kazakhstan
| | - Dimitri Poddighe
- Department of Medicine, Nazarbayev University School of Medicine, Astana 010000, Kazakhstan
- Clinical Academic Department of Pediatrics, National Research Center for Maternal and Child Health, University Medical Center, Astana 010000, Kazakhstan
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Vianney TJ, Berger DJ, Doyle SR, Sankaranarayanan G, Serubanja J, Nakawungu PK, Besigye F, Sanya RE, Holroyd N, Allan F, Webb EL, Elliott AM, Berriman M, Cotton JA. Genome-wide analysis of Schistosoma mansoni reveals limited population structure and possible praziquantel drug selection pressure within Ugandan hot-spot communities. PLoS Negl Trop Dis 2022; 16:e0010188. [PMID: 35981002 PMCID: PMC9426917 DOI: 10.1371/journal.pntd.0010188] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/30/2022] [Accepted: 07/05/2022] [Indexed: 12/23/2022] Open
Abstract
Populations within schistosomiasis control areas, especially those in Africa, are recommended to receive regular mass drug administration (MDA) with praziquantel (PZQ) as the main strategy for controlling the disease. The impact of PZQ treatment on schistosome genetics remains poorly understood, and is limited by a lack of high-resolution genetic data on the population structure of parasites within these control areas. We generated whole-genome sequence data from 174 individual miracidia collected from both children and adults from fishing communities on islands in Lake Victoria in Uganda that had received either annual or quarterly MDA with PZQ over four years, including samples collected immediately before and four weeks after treatment. Genome variation within and between samples was characterised and we investigated genomic signatures of natural selection acting on these populations that could be due to PZQ treatment. The parasite population on these islands was more diverse than found in nearby villages on the lake shore. We saw little or no genetic differentiation between villages, or between the groups of villages with different treatment intensity, but slightly higher genetic diversity within the pre-treatment compared to post-treatment parasite populations. We identified classes of genes significantly enriched within regions of the genome with evidence of recent positive selection among post-treatment and intensively treated parasite populations. The differential selection observed in post-treatment and pre-treatment parasite populations could be linked to any reduced susceptibility of parasites to praziquantel treatment.
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Affiliation(s)
- Tushabe John Vianney
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Duncan J. Berger
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Stephen R. Doyle
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | | | - Joel Serubanja
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Prossy Kabuubi Nakawungu
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Fred Besigye
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Richard E. Sanya
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
- Health and Systems for Health Unit, African Population and Health Research Center, Nairobi, Kenya
| | - Nancy Holroyd
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Fiona Allan
- Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Emily L. Webb
- MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alison M. Elliott
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Matthew Berriman
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - James A. Cotton
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
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Jiang N, Li SZ, Zhang YWQ, Habib MR, Xiong T, Xu S, Dong H, Zhao QP. The identification of alternative oxidase in intermediate host snails of Schistosoma and its potential role in protecting Oncomelania hupensis against niclosamide-induced stress. Parasit Vectors 2022; 15:97. [PMID: 35313980 PMCID: PMC8935807 DOI: 10.1186/s13071-022-05227-5] [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] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 03/03/2022] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Snail intermediate hosts are mandatory for the transmission of schistosomiasis, which has to date infected more than 200 million people worldwide. Our previous studies showed that niclosamide treatment caused the inhibition of aerobic respiration and oxidative phosphorylation, and the disruption of energy supply, in one of the intermediate hosts of schistosomiasis, Oncomelania hupensis, which eventually led to the death of the snails. Meanwhile, the terminal oxidase in the mitochondrial respiratory chain, alternative oxidase (AOX), was significantly up-regulated, which was thought to counterbalance the oxidative stress and maintain metabolic homeostasis in the snails. The aims of the present study are to identify the AOXs in several species of snails and investigate the potential activation of O. hupensis AOX (OhAOX) under niclosamide-induced stress, leading to enhanced survival of the snail when exposed to this molluscicide. METHODS The complete complementary DNA was amplified from the AOXs of O. hupensis and three species of Biomphalaria; the sequence characteristics were analysed and the phylogenetics investigated. The dynamic expression and localisation of the AOX gene and protein in O. hupensis under niclosamide-induced stress were examined. In addition, the expression pattern of genes in the mitochondrial respiratory complex was determined and the production of reactive oxygen species (ROS) calculated. Finally, the molluscicidal effect of niclosamide was compared between snails with and without inhibition of AOX activity. RESULTS AOXs containing the invertebrate AOX-specific motif NP-[YF]-XPG-[KQE] were identified from four species of snail, which phylogenetically clustered together into Gastropoda AOXs and further into Mollusca AOXs. After niclosamide treatment, the levels of OhAOX messenger RNA (mRNA) and OhAOX protein in the whole snail were 14.8 and 2.6 times those in untreated snails, respectively, but varied widely among tissues. Meanwhile, the level of cytochrome C reductase mRNA showed a significant decrease in the whole snail, and ROS production showed a significant decrease in the liver plus gonad (liver-gonad) of the snails. At 24 h post-treatment, the mortality of snails treated with 0.06-0.1 mg/L niclosamide and AOX inhibitor was 56.31-76.12% higher than that of snails treated with 0.1 mg/L niclosamide alone. CONCLUSIONS AOX was found in all the snail intermediate hosts of Schistosoma examined here. AOX was significantly activated in O. hupensis under niclosamide-induced stress, which led to a reduction in oxidative stress in the snail. The inhibition of AOX activity in snails can dramatically enhance the molluscicidal effect of niclosamide. A potential target for the development of an environmentally safe snail control method, which acts by inhibiting the activity of AOX, was identified in this study.
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Affiliation(s)
- Ni Jiang
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei China
- Joint Inspection Center of Precision Medicine, The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi China
| | - Shi-Zhu Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, National Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
| | - Yang-Wen-Qing Zhang
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei China
| | - Mohamed R. Habib
- Medical Malacology Department, Theodor Bilharz Research Institute, Giza, Egypt
| | - Tao Xiong
- Department of Microbiology, School of Medical Sciences, Hunan University of Chinese Medicine, Changsha, Hunan China
| | - Sha Xu
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei China
| | - Huifen Dong
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei China
| | - Qin-Ping Zhao
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei China
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Prevalence of Schistosoma mansoni and Associated Risk Factors in Human and Biomphalaria Snails in Ethiopia: A Systematic Review and Meta-analysis. Acta Parasitol 2022; 67:31-48. [PMID: 34259986 DOI: 10.1007/s11686-021-00449-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/28/2021] [Indexed: 01/27/2023]
Abstract
PURPOSE Schistosomiasis is one of the leading chronic parasitic diseases in Ethiopia. We aimed to summarize the prevalence of S. mansoni in human and Biomphalaria snails as well as risk factors in Ethiopia. METHODS Literature search was carried out from Scopus, Google Scholar, Science Direct and PubMed which reported Schistosoma mansoni infection in human and Biomphalaria snails in Ethiopia. The overall prevalence was estimated by a random-effect model and heterogeneities among studies were assessed by I2 test. RESULTS A total of 178,251 participants and 1,097 snails were tested for the presence of S. mansoni in the eligible studies. The pooled prevalence of S. mansoni was 32.5% (95% CI 28.0-37.0) and 15.9% (95% CI - 5.6-37.5) in human and Biomphalaria snails in Ethiopia, respectively. The highest pooled prevalence was 43.2% (95% CI 27.3-59.1) in South Nations and National Peoples region while the lowest pooled prevalence was 25% (95% CI 19.3-30.7) observed in the Afar region. Interestingly, the pooled prevalence of S. mansoni declined from 40.7% (95% CI 33-48.4) to 22.4% (95% CI 18.5-26.3) after the launching of mass drug administration (MDA). The analysis of risk factors showed that swimming habit (OR, 2.78; 95% CI 2.35-3.21) and participation in irrigation (OR, 2.69; 95% CI 1.45-3.73) were independent predictors for S. mansoni infection. CONCLUSION This study revealed that about one-third of human and nearly 16% of Biomphalaria snails were infected with S. mansoni in Ethiopia. This review indicated that the prevalence of S. mansoni declined after the implementation of MDA. This study highlights the importance of further integrated approaches for better control of schistosomiasis in Ethiopia.
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Hailegebriel T, Nibret E, Munshea A. Prevalence of Schistosoma mansoni and S. haematobium in Snail Intermediate Hosts in Africa: A Systematic Review and Meta-analysis. J Trop Med 2020; 2020:8850840. [PMID: 32963554 PMCID: PMC7492904 DOI: 10.1155/2020/8850840] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Schistosomiasis is caused by Schistosoma mansoni and S. haematobium in Africa. These schistosome parasites use freshwater snail intermediate hosts to complete their lifecycle. Varied prevalence rates of these parasites in the snail intermediate hosts were reported from several African countries, but there were no summarized data for policymakers. Therefore, this study was aimed to systematically summarize the prevalence and geographical distribution of S. mansoni and S. haematobium among freshwater snails in Africa. METHODS Literature search was carried out from PubMed, Science Direct, and Scopus which reported the prevalence of S. mansoni and S. haematobium among freshwater snails in Africa. The pooled prevalence was determined using a random-effect model, while heterogeneities between studies were evaluated by I 2 test. The meta-analyses were conducted using Stata software, metan command. RESULTS A total of 273,643 snails were examined for the presence of S. mansoni and S. haematobium cercaria in the eligible studies. The pooled prevalence of schistosome cercaria among freshwater snails was 5.5% (95% CI: 4.9-6.1%). The pooled prevalence of S. mansoni and S. haematobium cercaria was 5.6% (95% CI: 4.9-6.3%) and 5.2% (95% CI: 4.6-5.7%), respectively. The highest pooled prevalence was observed from Nigeria (19.0%; 95% CI: 12.7-25.3%), while the lowest prevalence was reported from Chad (0.05%; 95% CI: 0.03-0.13). Higher prevalence of schistosome cercaria was observed from Bulinus globosus (12.3%; 95% CI: 6.2-18.3%) followed by Biomphalaria sudanica (6.7%; 95% CI: 4.5-9.0%) and Biomphalaria pfeifferi (5.1%; 95% CI: 4.1-6.2%). The pooled prevalence of schistosome cercaria obtained using PCR was 26.7% in contrast to 4.5% obtained by shedding cercariae. CONCLUSION This study revealed that nearly 6% of freshwater snails in Africa were infected by either S. haematobium or S. mansoni. The high prevalence of schistosomes among freshwater snails highlights the importance of appropriate snail control strategies in Africa.
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Affiliation(s)
- Tamirat Hailegebriel
- Department of Biology, College of Science, Bahir Dar University, Bahir Dar, Ethiopia
| | - Endalkachew Nibret
- Department of Biology, College of Science, Bahir Dar University, Bahir Dar, Ethiopia
| | - Abaineh Munshea
- Department of Biology, College of Science, Bahir Dar University, Bahir Dar, Ethiopia
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The Potential Role of Schistosome-Associated Factors as Therapeutic Modulators of the Immune System. Infect Immun 2020; 88:IAI.00754-19. [PMID: 32341115 DOI: 10.1128/iai.00754-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The parasites and eggs of helminths, including schistosomes, are associated with factors that can modulate the nature and outcomes of host immune responses, particularly enhancing type 2 immunity and impairing the effects of type 1 and type 17 immunity. The main species of schistosomes that cause infection in humans are capable of generating a microenvironment that allows survival of the parasite by evasion of the immune response. Schistosome infections are associated with beneficial effects on chronic immune disorders, including allergies, autoimmune diseases, and alloimmune responses. Recently, there has been increasing research interest in the role of schistosomes in immunoregulation during human infection, and the mechanisms underlying these roles continue to be investigated. Further studies may identify potential opportunities to develop new treatments for immune disease. In this review, we provide an update on the advances in our understanding of schistosome-associated modulation of the cells of the innate and adaptive immune systems as well as the potential role of schistosome-associated factors as therapeutic modulators of immune disorders, including allergies, autoimmune diseases, and transplant immunopathology. We also discuss potential opportunities for targeting schistosome-induced immunoregulation for future translation to the clinical setting.
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