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Price DRG, Steele P, Frew D, McLean K, Androscuk D, Geldhof P, Borloo J, Albaladejo JP, Nisbet AJ, McNeilly TN. Characterisation of protective vaccine antigens from the thiol-containing components of excretory/secretory material of Ostertagia ostertagi. Vet Parasitol 2024; 328:110154. [PMID: 38490160 DOI: 10.1016/j.vetpar.2024.110154] [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: 11/21/2023] [Revised: 02/21/2024] [Accepted: 02/28/2024] [Indexed: 03/17/2024]
Abstract
Previous vaccination trials have demonstrated that thiol proteins affinity purified from Ostertagia ostertagi excretory-secretory products (O. ostertagi ES-thiol) are protective against homologous challenge. Here we have shown that protection induced by this vaccine was consistent across four independent vaccine-challenge experiments. Protection is associated with reduced cumulative faecal egg counts across the duration of the trials, relative to control animals. To better understand the diversity of antigens in O. ostertagi ES-thiol we used high-resolution shotgun proteomics to identify 490 unique proteins in the vaccine preparation. The most numerous ES-thiol proteins, with 91 proteins identified, belong to the sperm-coating protein/Tpx/antigen 5/pathogenesis-related protein 1 (SCP/TAPS) family. This family includes previously identified O. ostertagi vaccine antigens O. ostertagi ASP-1 and ASP-2. The ES-thiol fraction also has numerous proteinases, representing three distinct classes, including: metallo-; aspartyl- and cysteine proteinases. In terms of number of family members, the M12 astacin-like metalloproteinases, with 33 proteins, are the most abundant proteinase family in O. ostertagi ES-thiol. The O. ostertagi ES-thiol proteome provides a comprehensive database of proteins present in this vaccine preparation and will guide future vaccine antigen discovery projects.
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Affiliation(s)
- Daniel R G Price
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK.
| | - Philip Steele
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
| | - David Frew
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
| | - Kevin McLean
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
| | - Dorota Androscuk
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
| | - Peter Geldhof
- Laboratory of Parasitology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Sciences, Ghent University, Belgium
| | - Jimmy Borloo
- Laboratory of Parasitology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Sciences, Ghent University, Belgium
| | - Javier Palarea Albaladejo
- Biomathematics and Statistics Scotland, JCMB, The King's Buildings, Peter Guthrie Tait Road, Edinburgh, Scotland, UK; Department of Computer Science, Applied Mathematics and Statistics, University of Girona, Girona, Spain
| | - Alasdair J Nisbet
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
| | - Tom N McNeilly
- Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK
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Arroyo G, Lescano AG, Gavidia CM, Lopez-Urbina T, Ara-Gomez M, Gomez-Puerta LA, Bustos JA, Jayashi CM, O’Neal SE, Gonzalez AE, Garcia HH. Antibody Banding Patterns on the Enzyme-Linked Immunoelectrotransfer Blot (EITB) Assay Clearly Discriminate Viable Cysticercosis in Naturally Infected Pigs. Pathogens 2023; 13:15. [PMID: 38251323 PMCID: PMC10820179 DOI: 10.3390/pathogens13010015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 01/23/2024] Open
Abstract
Enzyme-linked immunoelectrotransfer blot (EITB) detects antibodies against seven Taenia solium larvae antigens in three protein families (GP50, T24/42, and 8-kDa) with different structures and functions. EITB banding patterns against these antigens in pigs provide information about the course of infection and may discriminate viable cysticercosis. We analyzed the banding patterns and infection outcomes (presence of viable cysts, degenerated cysts, and any cysts) of 512 rural pigs. Banding patterns were grouped into homogenous classes using latent class analysis, and relationships with infection outcomes were assessed. Four classes were identified: 1 (n = 308, EITB-negative or positive for the GP50 family), 2 (n = 127, positive for GP50 (GP50 family), GP42-39 and GP24 (T24/42 family), but negative for 8-kDa antigens), 3 (n = 22, positive for GP50 and T24/42 antigens (GP42-39 and GP24), as well as to 8-kDa bands GP13, GP14, and GP18, but negative for GP21), and 4 (n = 55, positive for GP50 and T24/42 antigens, as well as to 8-kDa antigens GP21 and GP18 in combination). Pigs in classes 3 and 4 were more likely to have viable cysts (72.6% and 96.4%, respectively) than pigs in classes 1 and 2 (0.7% and 27.6%, respectively; p < 0.001). The number of infections with any cysts was higher in classes 3 and 4 (77.3% and 98.2%, respectively) and lower in classes 2 and 1 (34.7% and 4.9%, respectively; p < 0.001). Pigs with viable cysts represented >90% of pigs with any cysts in classes 3 and 4 (94.1% and 98.2%, respectively), while degenerated cysts were frequent among pigs with any cysts in classes 1, 3, and 2 (86.7%, 47.1%, and 43.2%, respectively; p < 0.001). EITB banding patterns strongly correlate with cysticercosis infection status in rural pigs, with classes 3 and 4 being more predictive of viable infections.
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Affiliation(s)
- Gianfranco Arroyo
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15202, Peru; (J.A.B.); (S.E.O.); (H.H.G.)
| | - Andres G. Lescano
- School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima 15202, Peru;
| | - Cesar M. Gavidia
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Teresa Lopez-Urbina
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Miguel Ara-Gomez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Luis A. Gomez-Puerta
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Javier A. Bustos
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15202, Peru; (J.A.B.); (S.E.O.); (H.H.G.)
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima 15030, Peru
| | - Cesar M. Jayashi
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Seth E. O’Neal
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15202, Peru; (J.A.B.); (S.E.O.); (H.H.G.)
- School of Public Health, Oregon Health & Sciences University-Portland State University, Portland, OR 97207, USA
| | - Armando E. Gonzalez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru; (C.M.G.); (T.L.-U.); (M.A.-G.); (L.A.G.-P.); (C.M.J.); (A.E.G.)
| | - Hector H. Garcia
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15202, Peru; (J.A.B.); (S.E.O.); (H.H.G.)
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima 15030, Peru
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Hossain MS, Shabir S, Toye P, Thomas LF, Falcone FH. Insights into the diagnosis, vaccines, and control of Taenia solium, a zoonotic, neglected parasite. Parasit Vectors 2023; 16:380. [PMID: 37876008 PMCID: PMC10594694 DOI: 10.1186/s13071-023-05989-6] [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: 05/15/2023] [Accepted: 09/28/2023] [Indexed: 10/26/2023] Open
Abstract
Taenia solium taeniasis/cysticercosis (TSTC) is a foodborne, zoonotic neglected tropical disease affecting predominately low- and middle-income countries. Humans are definitive hosts for T. solium, whereas pigs act as intermediate hosts. Taeniasis, i.e. intestinal infection with adult T. solium in the human host, occurs through ingestion of undercooked pork infected with the larval stage (porcine cysticercosis, PCC). Human cysticercosis occurs after humans ingest T. solium eggs, acting as accidental intermediate hosts. Migration of cysticerci to the human brain results in neurocysticercosis (NCC), manifesting in a variety of clinical symptoms, most notably epilepsy. NCC is the leading cause of acquired epilepsy cases in endemic areas. PCC results in reduced pork value because of condemnation or the risk of condemnation of the meat. Available serological diagnostic tests for porcine and human cysticercosis are characterized by low sensitivity and are not cost-effective. An effective vaccine for T. solium cysticercosis in pigs has been developed, although it is not yet commercially available in all endemic countries, and still no vaccine is available for use in humans. This primer highlights the recent development in the field of diagnostic tests and vaccine production and explores possible strategies for future control and eradication of T. solium. In the absence of highly specific diagnostic tests and human vaccines, treatment of infected pigs and tapeworm carriers and prevention of disease transmission remain the principal means to interrupt the zoonotic cycle of T. solium in endemic countries.
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Affiliation(s)
- Md Shahadat Hossain
- Department of Parasitology, Bangladesh Agricultural University, Mymensingh, Bangladesh
- Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany
| | - Shafqat Shabir
- Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany
| | - Philip Toye
- International Livestock Research Institute, Nairobi, Kenya
| | - Lian F Thomas
- International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Neston, UK
| | - Franco H Falcone
- Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany.
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Wang Z, Garcia RM, Huff HV, Niquen-Jimenez M, Marcos LA, Lam SK. Neurocysticercosis control for primary epilepsy prevention: a systematic review. Pathog Glob Health 2022; 116:282-296. [PMID: 34928183 PMCID: PMC9248947 DOI: 10.1080/20477724.2021.2015869] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Neurocysticercosis (NCC) is a leading cause of preventable epilepsy in lower- and upper- middle-income countries (LMICs/UMICs). NCC is a human-to-human transmitted disease caused by ingestion of Taenia solium eggs from a Taenia carrier. T. solium infection control is the key to reduce NCC incidence. This systematic review aims to identify T. solium control programs that can provide frameworks for endemic areas to prevent NCC-related epilepsy. A systematic search was conducted in PubMed/Medline, Embase, Web of Science, and Cochrane Library databases in March 2021. After title and abstract review, full texts were screened for qualitative analysis. Additional articles were identified via citation search. Of 1322 total results, 34 unique studies were included. Six major intervention types were identified: national policy (8.8%), community sanitation improvement (8.8%), health education (8.8%), mass drug administration (29.4%), pig vaccination and treatment (32.4%), and combined human and pig treatment (11.8%). Overall, 28 (82.4%) studies reported decreased cysticercosis prevalence following the intervention. Only health education and combined human and pig treatment were effective in all selected studies. NCC causes preventable epilepsy in LMICs/UMICs and its incidence can be reduced through T. solium control. Most interventions that disrupt the T. solium transmission cycle are effective. Long-term sustained results require comprehensive programs, ongoing surveillance, and collaborative effort among multisectoral agencies.
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Affiliation(s)
- Zhe Wang
- Department of Neurological Surgery, Stony Brook University Renaissance School of Medicine, Stony Brook, NY, USA,Division of Infectious Diseases, Department of Medicine, Stony Brook University Renaissance School of Medicine, Stony Brook, NY, USA,Department of Microbiology and Immunology, Stony Brook University Renaissance School of Medicine, Stony Brook, NY, USA,CONTACT Zhe Wang Department of Neurological Surgery, Stony Brook University Renaissance School of Medicine, HSC T12 Rm 080, 100 Nicolls Rd, Stony Brook, NY11790, USA
| | - Roxanna M. Garcia
- Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Hanalise V. Huff
- Fogarty Fellow, Department of Global Health and Population, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Milagros Niquen-Jimenez
- Facultad de Medicina Humana Alberto Hurtado, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Luis A. Marcos
- Division of Infectious Diseases, Department of Medicine, Stony Brook University Renaissance School of Medicine, Stony Brook, NY, USA,Department of Microbiology and Immunology, Stony Brook University Renaissance School of Medicine, Stony Brook, NY, USA
| | - Sandi K. Lam
- Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA,Division of Pediatric Neurosurgery, Ann & Robert H. Lurie Children’s Hospital, Chicago, IL, USA
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Pray IW, Pizzitutti F, Bonnet G, Gonzales-Gustavson E, Wakeland W, Pan WK, Lambert WE, Gonzalez AE, Garcia HH, O’Neal SE. Validation of a spatial agent-based model for Taenia solium transmission ("CystiAgent") against a large prospective trial of control strategies in northern Peru. PLoS Negl Trop Dis 2021; 15:e0009885. [PMID: 34705827 PMCID: PMC8575314 DOI: 10.1371/journal.pntd.0009885] [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: 01/12/2021] [Revised: 11/08/2021] [Accepted: 10/08/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The pork tapeworm (Taenia solium) is a parasitic helminth that imposes a major health and economic burden on poor rural populations around the world. As recognized by the World Health Organization, a key barrier for achieving control of T. solium is the lack of an accurate and validated simulation model with which to study transmission and evaluate available control and elimination strategies. CystiAgent is a spatially-explicit agent based model for T. solium that is unique among T. solium models in its ability to represent key spatial and environmental features of transmission and simulate spatially targeted interventions, such as ring strategy. METHODS/PRINCIPAL FINDINGS We validated CystiAgent against results from the Ring Strategy Trial (RST)-a large cluster-randomized trial conducted in northern Peru that evaluated six unique interventions for T. solium control in 23 villages. For the validation, each intervention strategy was replicated in CystiAgent, and the simulated prevalences of human taeniasis, porcine cysticercosis, and porcine seroincidence were compared against prevalence estimates from the trial. Results showed that CystiAgent produced declines in transmission in response to each of the six intervention strategies, but overestimated the effect of interventions in the majority of villages; simulated prevalences for human taenasis and porcine cysticercosis at the end of the trial were a median of 0.53 and 5.0 percentages points less than prevalence observed at the end of the trial, respectively. CONCLUSIONS/SIGNIFICANCE The validation of CystiAgent represented an important step towards developing an accurate and reliable T. solium transmission model that can be deployed to fill critical gaps in our understanding of T. solium transmission and control. To improve model accuracy, future versions would benefit from improved data on pig immunity and resistance, field effectiveness of anti-helminthic treatment, and factors driving spatial clustering of T. solium infections including dispersion and contact with T. solium eggs in the environment.
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Affiliation(s)
- Ian W. Pray
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America
| | - Francesco Pizzitutti
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America
| | - Gabrielle Bonnet
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America
| | - Eloy Gonzales-Gustavson
- Tropical and Highlands Veterinary Research Institute, School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, EL Mantaro, Peru
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Wayne Wakeland
- Systems Science Program, Portland State University, Portland, Oregon, United States of America
| | - William K. Pan
- Duke Global Health Institute & Nicholas School of Environment, Duke University, Durham, North Carolina, United States of America
| | - William E. Lambert
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America
| | - Armando E. Gonzalez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Hector H. Garcia
- School of Sciences, Department of Microbiology, Universidad Peruana Cayetano Heredia, Lima, Peru
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru
| | - Seth E. O’Neal
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru
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Vaccination with rEGVac elicits immunoprotection against different stages of Echinococcus granulosus life cycle: A pilot study. Acta Trop 2021; 218:105883. [PMID: 33676937 DOI: 10.1016/j.actatropica.2021.105883] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/16/2022]
Abstract
Vaccination against dog-sheep transmission cycle is necessary to control cystic echinococcosis (CE) infection. A multi-epitope multi-antigenic recombinant vaccine was developed-comprising the three putative vaccine antigens EG95, Eg14-3-3 and EgEnolase-was cloned and expressed. In a pilot experiment, the multi-antigen vaccine was assessed in 15 dogs and 15 sheep (five experimental groups and three animals in each group) by two subcutaneous doses 28 days apart. To evaluate the efficacy of the vaccine candidate first immunological analysis were done comprising IgG and IgE antibodies and the cytokine IL-4 in sera of the immunized dogs and sheep. Serum IgG, IgE, and IL-4, in particular in the dogs, were increased after the two rounds of vaccine candidate injection, while the total number of hydatid cysts was reduced (~85.43%). This pilot trial indicated significant immune protection efficacy against E. granulosus especially in dogs, while its efficacy in sheep was not as high as dogs. The multi-antigenic candidate vaccine is proposed as a protective vaccine modality in both dogs and sheep.
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Ngwili N, Johnson N, Wahome R, Githigia S, Roesel K, Thomas L. A qualitative assessment of the context and enabling environment for the control of Taenia solium infections in endemic settings. PLoS Negl Trop Dis 2021; 15:e0009470. [PMID: 34115758 PMCID: PMC8221787 DOI: 10.1371/journal.pntd.0009470] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 06/23/2021] [Accepted: 05/12/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Taenia solium (T. solium), is a zoonotic helminth causing three diseases namely; taeniasis (in humans), neurocysticercosis (NCC, in humans) and porcine cysticercosis (PCC, in pigs) and is one of the major foodborne diseases by burden. The success or failure of control options against this parasite in terms of reduced prevalence or incidence of the diseases may be attributed to the contextual factors which underpin the design, implementation, and evaluation of control programmes. METHODOLOGY/PRINCIPAL FINDINGS The study used a mixed method approach combining systematic literature review (SLR) and key informant interviews (KII). The SLR focused on studies which implemented T. solium control programmes and was used to identify the contextual factors and enabling environment relevant to successful inception, planning and implementation of the interventions. The SLR used a protocol pre-registered at the International prospective register of systematic reviews (PROSPERO) number CRD42019138107 and followed PRISMA guidelines on reporting of SLR. To further highlight the importance and interlinkage of these contextual factors, KII were conducted with researchers/implementers of the studies included in the SLR. The SLR identified 41 publications that had considerations of the contextual factors. They were grouped into efficacy (10), effectiveness (28) and scale up or implementation (3) research studies. The identified contextual factors included epidemiological, socioeconomic, cultural, geographical and environmental, service and organizational, historical and financial factors. The enabling environment was mainly defined by policy and strategies supporting T. solium control. CONCLUSION/SIGNIFICANCE Failure to consider the contextual factors operating in target study sites was shown to later present challenges in project implementation and evaluation that negatively affected expected outcomes. This study highlights the importance of fully considering the various domains of the context and integrating these explicitly into the plan for implementation and evaluation of control programmes. Explicit reporting of these aspects in the resultant publication is also important to guide future work. The contextual factors highlighted in this study may be useful to guide future research and scale up of disease control programmes and demonstrates the importance of close multi-sectoral collaboration in a One Health approach.
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Affiliation(s)
- Nicholas Ngwili
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya
- College of Agriculture and Veterinary Sciences, University of Nairobi, Nairobi, Kenya
| | - Nancy Johnson
- CGIAR Research program on Agriculture for Nutrition and Health, IFPRI, Washington, DC, United States of America
| | - Raphael Wahome
- College of Agriculture and Veterinary Sciences, University of Nairobi, Nairobi, Kenya
| | - Samuel Githigia
- College of Agriculture and Veterinary Sciences, University of Nairobi, Nairobi, Kenya
| | - Kristina Roesel
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Lian Thomas
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Lea Hurst Campus, Neston, United Kingdom
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Butala C, Brook TM, Majekodunmi AO, Welburn SC. Neurocysticercosis: Current Perspectives on Diagnosis and Management. Front Vet Sci 2021; 8:615703. [PMID: 34041288 PMCID: PMC8141574 DOI: 10.3389/fvets.2021.615703] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 02/26/2021] [Indexed: 11/13/2022] Open
Abstract
Porcine cysticercosis, human taeniasis, and (neuro)cysticercosis are endemic in many low- and middle-income countries (LMIC) where they present a significant health burden to affected communities. Neurocysticercosis (NCC) is one of the leading causes of human epilepsy in many hyperendemic regions in Latin America, Asia, and sub-Saharan Africa. The World Health Organization (WHO) reports an estimated 2.5-8.3 million cases of NCC annually with a disability-adjusted life year (DALY) burden of 2.8 million, but as for all neglected tropical diseases (NTDs), these values are likely to be underestimated. Diagnosis of NCC is complex and most accurately diagnosed using clinical neuroimaging that is unavailable in most hyperendemic regions in LMIC. On January 28, 2021, WHO will launch its road map for the NTDs' "Ending the neglect to attain the Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030." Taeniasis/cysticercosis is targeted for control success considered as steady increase in the number of countries with intensified control in hyperendemic areas [increasing from 2 (3%) in 2020 to 4 (6%) in 2023, to 9 (14%) by 2025, and to 17 (27%) by 2030]. Cross-cutting targets that include 100% access to at least basic water supply, sanitation, and hygiene in areas endemic for NTDs and 75% integrated treatment coverage for preventative chemotherapy will additionally impact on the taeniasis/cysticercosis/NCC complex. With no vaccine available for humans, prevention of infection depends on communication to the public of the life cycle of a complex zoonosis to promote behavior change, underpinned by practical control measures including treatment of human taeniasis and (neuro)cysticercosis with albendazole and praziquantel [widely used as part of the mass drug administration (MDA) deworming programs], surgery where appropriate, and effective vaccination and deworming for pigs supported by meat inspection. Here, we review recent advances in tools and implementation for Taenia solium taeniasis/(neuro)cysticercosis (TSTC) control and milestones on the onward path to elimination.
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Affiliation(s)
- Caitlin Butala
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine & Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - T. M. Brook
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine & Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ayodele O. Majekodunmi
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine & Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Susan Christina Welburn
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine & Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
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Dixon MA, Winskill P, Harrison WE, Basáñez MG. Taenia solium taeniasis/cysticercosis: From parasite biology and immunology to diagnosis and control. ADVANCES IN PARASITOLOGY 2021; 112:133-217. [PMID: 34024358 DOI: 10.1016/bs.apar.2021.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Infection with the pork tapeworm (Taenia solium) is responsible for a substantial global burden of disease, not only restricted to its impact on human health, but also resulting in a considerable economic burden to smallholder pig farmers due to pig cysticercosis infection. The life-cycle, parasitology and immunology of T. solium are complex, involving pigs (the intermediate host, harbouring the larval metacestode stage), humans (the definitive host, harbouring the adult tapeworm, in addition to acting as accidental intermediate hosts) and the environment (the source of infection with eggs/proglottids). We review the parasitology, immunology, and epidemiology of the infection associated with each of the T. solium life-cycle stages, including the pre-adult/adult tapeworm responsible for human taeniasis; post-oncosphere and cysticercus associated with porcine and human cysticercosis, and the biological characteristics of eggs in the environment. We discuss the burden associated, in endemic settings, with neurocysticercosis (NCC) in humans, and the broader cross-sectoral economic impact associated both with NCC and porcine cysticercosis, the latter impacting food-value chains. Existing tools for diagnostics and control interventions that target different stages of the T. solium transmission cycle are reviewed and their limitations discussed. Currently, no national T. solium control programmes have been established in endemic areas, with further work required to identify optimal strategies according to epidemiological setting. There is increasing evidence suggesting that cross-sectoral interventions which target the parasite in both the human and pig host provide the most effective approaches for achieving control and ultimately elimination. We discuss future avenues for research on T. solium to support the attainment of the goals proposed in the revised World Health Organisation neglected tropical diseases roadmap for 2021-2030 adopted at the 73rd World Health Assembly in November 2020.
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Affiliation(s)
- Matthew A Dixon
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom; MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom; Schistosomiasis Control Initiative Foundation (SCI Foundation), London, United Kingdom
| | - Peter Winskill
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom
| | - Wendy E Harrison
- Schistosomiasis Control Initiative Foundation (SCI Foundation), London, United Kingdom
| | - Maria-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom; MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom.
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10
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Nsadha Z, Rutebarika C, Ayebazibwe C, Aloys B, Mwanja M, Poole EJ, Chesang E, Colston A, Donadeu M, Lightowlers MW. Control trial of porcine cysticercosis in Uganda using a combination of the TSOL18 vaccination and oxfendazole. Infect Dis Poverty 2021; 10:34. [PMID: 33743828 PMCID: PMC7981864 DOI: 10.1186/s40249-021-00823-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 03/08/2021] [Indexed: 11/30/2022] Open
Abstract
Background Neurocysticercosis caused by Taenia solium when the parasite lodges in the central nervous system, is an important cause of human seizures and mortality in sub-Saharan Africa. The parasite is prevalent in many regions of Uganda. Pigs are intermediate hosts for T. solium, and we evaluated a T. solium control program in pigs, involving vaccination of pigs with the TSOL18 vaccine and treatment with oxfendazole. Methods The study was conducted in two districts of Eastern Uganda involving the rural village communities of Bukedea (intervention area) and Kumi (control area) during 2016–2017. Seven hundred and thirty-four households were enrolled in the study. Pigs in the intervention area received intramuscular immunizations with TSOL18 (Cysvax™) and an oral medication with 30 mg/kg oxfendazole (Paranthic™) at approximately 3-monthly intervals for 18 months. Porcine cysticercosis was evaluated by post-mortem examination. At the beginning of the study, 111 pigs were examined. In an interim evaluation in the intervention area, 55 pigs were evaluated 12 months after starting the project. At the end of the study approximately 3 months after the final intervention, 55 pigs from the intervention area and 56 pigs from the control area were evaluated. Results The prevalence of porcine cysticercosis for the two sites was 16.2% at the beginning of the study (17.2% in the intervention area and 15.1% in the control area) with no statistically significant difference (P = 0.759) between the two study sites. Among the 110 animals assessed from the intervention site (55 at the interim evaluation and 55 at the final evaluation), no pig with viable T. solium cysts was found. There was a statistically significant difference between the prevalence at baseline (17.2%) and at the end of the study (0%) in the intervention area (P = 0.001) and a statistically significant difference between the intervention (0%) and control areas (5.4%) (P = 0.041) at the end of the study. Conclusions Three-monthly concurrent vaccination of pigs with the TSOL18 vaccine and medication with oxfendazole eliminated T. solium transmission by the animals involved in the study. Application of vaccination with medication in pigs has the potential to reduce transmission of T. solium in Uganda and other endemic countries. ![]()
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Affiliation(s)
- Zachary Nsadha
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P. O. Box 7062, Kampala, Uganda
| | | | - Chrisostom Ayebazibwe
- Ministry of Agriculture, Animal Industry and Fisheries, Department of Animal Health, National Animal Disease Diagnostics and Epidemiology Centre (NADDEC), P.O Box 513, Entebbe, Uganda
| | - Bukenya Aloys
- Malera Sub County Local Government, C/O P.O.BOX 5026, Bukedea, Uganda
| | - M Mwanja
- Ministry of Agriculture, Animal Industry and Fisheries, Department of Animal Health, National Animal Disease Diagnostics and Epidemiology Centre (NADDEC), P.O Box 513, Entebbe, Uganda
| | - E Jane Poole
- International Livestock Research Institute (ILRI), 30709, Nairobi, 0010, Kenya
| | | | | | - Meritxell Donadeu
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, 250 Princes Highway, Werribee, VIC, 3030, Australia.,Initiative for Neglected Animal Diseases (INAND), Midrand, South Africa
| | - Marshall W Lightowlers
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, 250 Princes Highway, Werribee, VIC, 3030, Australia.
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11
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Pray IW, Wakeland W, Pan W, Lambert WE, Garcia HH, Gonzalez AE, O'Neal SE. Understanding transmission and control of the pork tapeworm with CystiAgent: a spatially explicit agent-based model. Parasit Vectors 2020; 13:372. [PMID: 32709250 PMCID: PMC7379812 DOI: 10.1186/s13071-020-04226-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 07/14/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The pork tapeworm, Taenia solium, is a serious public health problem in rural low-resource areas of Latin America, Africa and Asia, where the associated conditions of nuerocysticercosis (NCC) and porcine cysticercosis cause substantial health and economic harms. An accurate and validated transmission model for T. solium would serve as an important new tool for control and elimination, as it would allow for comparison of available intervention strategies, and prioritization of the most effective strategies for control and elimination efforts. METHODS We developed a spatially-explicit agent-based model (ABM) for T. solium ("CystiAgent") that differs from prior T. solium models by including a spatial framework and behavioral parameters such as pig roaming, open human defecation, and human travel. In this article, we introduce the structure and function of the model, describe the data sources used to parameterize the model, and apply sensitivity analyses (Latin hypercube sampling-partial rank correlation coefficient (LHS-PRCC)) to evaluate model parameters. RESULTS LHS-PRCC analysis of CystiAgent found that the parameters with the greatest impact on model uncertainty were the roaming range of pigs, the infectious duration of human taeniasis, use of latrines, and the set of "tuning" parameters defining the probabilities of infection in humans and pigs given exposure to T. solium. CONCLUSIONS CystiAgent is a novel ABM that has the ability to model spatial and behavioral features of T. solium transmission not available in other models. There is a small set of impactful model parameters that contribute uncertainty to the model and may impact the accuracy of model projections. Field and laboratory studies to better understand these key components of transmission may help reduce uncertainty, while current applications of CystiAgent may consider calibration of these parameters to improve model performance. These results will ultimately allow for improved interpretation of model validation results, and usage of the model to compare available control and elimination strategies for T. solium.
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Affiliation(s)
- Ian W Pray
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, OR, USA.
| | - Wayne Wakeland
- Systems Science Program, Portland State University, Portland, OR, USA
| | - William Pan
- Global Health Institute, Duke University, Durham, NC, USA
| | - William E Lambert
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, OR, USA
| | - Hector H Garcia
- School of Sciences, Department of Microbiology, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Armando E Gonzalez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Seth E O'Neal
- School of Public Health, Oregon Health & Science University and Portland State University, Portland, OR, USA
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12
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Mimotope-based antigens as potential vaccine candidates in experimental murine cysticercosis. Parasitology 2020; 147:1330-1337. [DOI: 10.1017/s0031182020001080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractHuman cysticercosis is a public health problem caused by Taenia solium metacestodes; thus, eradication of T. solium transmission by vaccination is an urgent requirement. The Cc48 mimotope from T. solium cysticerci was tested expressed in phage particles (mCc48) and chemically synthesized (sCc48) as a vaccine candidate in experimental murine cysticercosis. For this, BALB/c mice were immunized with mCc48 (G1; n = 40), sCc48 (G2; n = 40) and phosphate-buffered saline (PBS) (G3; n = 40, positive control) and challenged with Taenia crassiceps metacestodes. Another PBS group without parasite challenge was used as a negative control (G4; n = 40). Mice were sacrificed 15, 30, 45 and 60 days post-infection for cysticerci and serum collection. Immunization efficacy was determined by cysticerci counting. Serum samples were tested by ELISA to verify antibody (IgM, IgG, IgA and IgE) and cytokine (IFNγ and IL-4) levels. The sCc48 achieved the highest rates of protection and efficacy (90 and 98%, respectively). The group immunized with mCc48 presented the highest reactivity for IgM, IgG and IgE. All groups presented IL-4, but IFNγ was quite variable among groups. The protection induced by sCc48 synthetic peptide supports further studies of this mimotope as a potential vaccine candidate against cysticercosis.
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13
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Lightowlers MW. Diagnosis of Porcine Cysticercosis at Necropsy: When Is Enough, Enough? Trends Parasitol 2020; 36:575-578. [PMID: 32376114 DOI: 10.1016/j.pt.2020.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 04/09/2020] [Indexed: 10/24/2022]
Abstract
Changes in the incidence of porcine cysticercosis is used commonly in the assessment of efforts to control the transmission of Taenia solium, the cause of human neurocysticercosis. Although cysticerci may occasionally occur in tissues other than the striated muscles, particularly the brain, infection in pigs can be diagnosed reliably by assessment of muscle tissue alone.
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Affiliation(s)
- Marshall W Lightowlers
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, UVet Clinical Centre, 250 Princes Highway, Werribee, Victoria 3030, Australia.
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14
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Kaur R, Arora N, Jamakhani MA, Malik S, Kumar P, Anjum F, Tripathi S, Mishra A, Prasad A. Development of multi-epitope chimeric vaccine against Taenia solium by exploring its proteome: an in silico approach. Expert Rev Vaccines 2020; 19:105-114. [PMID: 31971446 DOI: 10.1080/14760584.2019.1711057] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Objective: Taenia solium is a neglected tropical disease; larvae of this parasite infect central nervous system i.e. Neurocysticercosis, and adults mature and survive into intestine i.e. Taeniasis. Globally more than 50 million people are at the risk of infection. This is one of the main etiological agents for onset of new early epilepsy in developing countries. However, there is no vaccine available to protect human from its infection. Hence, there is an urgent need for a good vaccine.Methods: We applied immune-informatics approach to design a multi-epitope chimeric vaccine consisting of both B and T-cell epitopes.Results: From the whole transcriptome of Taenia, we identified five suitable peptides present on cell membrane, epitope identification on these peptides were done by using various immunoinformatic software. Physiochemical properties were determined and the tertiary structure of vaccine was predicted, validated and refined, and to increase antigenicity we added linker to them. Best-modeled protein-complex was used for docking study with TLR1-2, TLR4, TLR3 and TLR7 and stability of molecular complex was determined by molecular dynamics simulation.Conclusions: Overall, we attempted to design an efficient subunit chimeric vaccine, which could stimulate humoral and cellular immune responses and could protect against both neurocysticercosis and taeniasis.
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Affiliation(s)
- Rimanpreet Kaur
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | - Naina Arora
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | | | - Shelvia Malik
- Department of Bioinformatics, Institute of Bioinformatics and Applied Biotechnology, Bangalore, India
| | - Pramod Kumar
- Biomedical Informatics Centre, ICMR-National Institute of Traditional Medicine, Belagavi, India
| | - Farhan Anjum
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | - Shweta Tripathi
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, India
| | - Amit Prasad
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
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15
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Molehin AJ. Schistosomiasis vaccine development: update on human clinical trials. J Biomed Sci 2020; 27:28. [PMID: 31969170 PMCID: PMC6977295 DOI: 10.1186/s12929-020-0621-y] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 01/16/2020] [Indexed: 01/13/2023] Open
Abstract
Schistosomiasis causes significant levels of morbidity and mortality in many geographical regions of the world. The disease is caused by infections with parasitic blood flukes known as schistosomes. The control of schistosomiasis over the last several decades has been centered on the mass drug administration (MDA) of praziquantel (PZQ), which is the only drug currently available for treatment. Despite the concerted efforts of MDA programs, the prevalence and transmission of schistosomiasis has remained largely unchecked due to the fact that PZQ is ineffective against juvenile schistosomes, does not prevent re-infection and the emergence of PZQ-resistant parasites. In addition, other measures such as the water, sanitation and hygiene programs and snail intermediate hosts control have had little to no impact. These drawbacks indicate that the current control strategies are severely inadequate at interrupting transmission and therefore, implementation of other control strategies are required. Ideally, an efficient vaccine is what is needed for long term protection thereby eliminating the current efforts of repeated mass drug administration. However, the general consensus in the field is that the integration of a viable vaccine with MDA and other control measures offer the best chance of achieving the goal of schistosomiasis elimination. This review focuses on the present status of schistosomiasis vaccine candidates in different phases of human clinical trials and provide some insight into future vaccine discovery and design.
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Affiliation(s)
- Adebayo J Molehin
- Center for Tropical Medicine and Infectious Diseases, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, 79430, USA. .,Department of Internal Medicine, School of Medicine, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, 79430, USA.
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16
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Strategies for tackling Taenia solium taeniosis/cysticercosis: A systematic review and comparison of transmission models, including an assessment of the wider Taeniidae family transmission models. PLoS Negl Trop Dis 2019; 13:e0007301. [PMID: 30969966 PMCID: PMC6476523 DOI: 10.1371/journal.pntd.0007301] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 04/22/2019] [Accepted: 03/13/2019] [Indexed: 01/03/2023] Open
Abstract
Background The cestode Taenia solium causes the neglected (zoonotic) tropical disease cysticercosis, a leading cause of preventable epilepsy in endemic low and middle-income countries. Transmission models can inform current scaling-up of control efforts by helping to identify, validate and optimise control and elimination strategies as proposed by the World Health Organization (WHO). Methodology/Principal findings A systematic literature search was conducted using the PRISMA approach to identify and compare existing T. solium transmission models, and related Taeniidae infection transmission models. In total, 28 modelling papers were identified, of which four modelled T. solium exclusively. Different modelling approaches for T. solium included deterministic, Reed-Frost, individual-based, decision-tree, and conceptual frameworks. Simulated interventions across models agreed on the importance of coverage for impactful effectiveness to be achieved. Other Taeniidae infection transmission models comprised force-of-infection (FoI), population-based (mainly Echinococcus granulosus) and individual-based (mainly E. multilocularis) modelling approaches. Spatial structure has also been incorporated (E. multilocularis and Taenia ovis) in recognition of spatial aggregation of parasite eggs in the environment and movement of wild animal host populations. Conclusions/Significance Gaps identified from examining the wider Taeniidae family models highlighted the potential role of FoI modelling to inform model parameterisation, as well as the need for spatial modelling and suitable structuring of interventions as key areas for future T. solium model development. We conclude that working with field partners to address data gaps and conducting cross-model validation with baseline and longitudinal data will be critical to building consensus-led and epidemiological setting-appropriate intervention strategies to help fulfil the WHO targets. Taenia solium infection in humans (taeniosis and neurocysticercosis) and pigs (cysticercosis) presents a significant global public health and economic challenge. The World Health Organization has called for validated strategies and wider consensus on which strategies are suitable for different epidemiological settings to support successful T. solium control and elimination efforts. Transmission models can be used to inform these strategies. Therefore, a modelling review was undertaken to assess the current state and gaps relating to T. solium epidemiological modelling. The literature surrounding models for other Taeniidae family infections was also considered, identifying approaches to aid further development of existing T. solium models. A variety of different modelling approaches have been used for T. solium including differences in structural and parametric assumptions associated with T. solium transmission biology. Despite these differences, all models agreed on the importance of coverage on intervention effectiveness. Other Taeniidae family models highlighted the need for incorporating spatial structure when necessary to capture aggregation of transmission stages in the environment and movement of animal hosts.
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17
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Beam M, Spencer A, Fernandez L, Atto R, Muro C, Vilchez P, Gamboa R, Olaya S, Ayvar V, Gonzalez AE, Garcia HH, O'Neal SE, For The Cysticercosis Working Group In Peru. Barriers to Participation in a Community-Based Program to Control Transmission of Taenia solium in Peru. Am J Trop Med Hyg 2018; 98:1748-1754. [PMID: 29663901 DOI: 10.4269/ajtmh.17-0929] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Infection of the brain with Taenia solium larvae (neurocysticercosis) is a leading cause of preventable epilepsy worldwide. Effective and sustainable strategies to control parasite transmission in rural endemic communities are needed to prevent the disease. Surveillance and targeted intervention around infected pigs (ring control strategy) have been shown to be effective when carried out by research teams. However, this strategy has not been implemented or tested as a community-based program. In this small trial in northern Peru, eight villages were randomly assigned to community-led surveillance and treatment (five villages, 997 residents) or control (three villages, 1,192 residents). In intervention villages, community-led surveillance and reporting were promoted by community health workers, radio advertisement, and school and household education. Each suspected pig infection was verified, with confirmed cases resulting in treatment with niclosamide for taeniasis and oxfendazole for pigs in clusters of homes nearby. No incentives beyond human and pig treatment were offered. Control villages received basic disease education but no treatment intervention in response to reports. Despite 14 case reports, community-based replication of ring control strategy did not replicate prior results. After 12 months, there was no change in seroincidence in intervention villages between the baseline and study end, and no difference compared with control villages. There was no difference in prevalence of taeniasis or porcine cysticercosis at study end. Community members described lack of knowledge as the main reason for not reporting infected pigs. Further exploration of methods to transfer ring strategy and other control interventions for cysticercosis to the community is needed.
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Affiliation(s)
- Michelle Beam
- School of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Angela Spencer
- School of Public Health, Oregon Health & Science University-Portland State University, Portland, Oregon
| | - Lauralee Fernandez
- School of Public Health, Oregon Health & Science University-Portland State University, Portland, Oregon
| | - Ruth Atto
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Claudio Muro
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Percy Vilchez
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Ricardo Gamboa
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Sandra Olaya
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Viterbo Ayvar
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Armando E Gonzalez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Hector H Garcia
- Department of Microbiology, Universidad Peruana Cayetano Heredia, Lima, Peru.,Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Seth E O'Neal
- Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru.,School of Public Health, Oregon Health & Science University-Portland State University, Portland, Oregon
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18
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Identification and control of sources of Taenia solium infection – the attempts to eradicate the parasite. J Vet Res 2018. [DOI: 10.2478/jvetres-2018-0004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Taenia solium is a parasite causing porcine cysticercosis and human taeniosis and cysticercosis, parasitic zoonoses with a serious public health and economic influence. It has been globally ranked as the top foodborne parasite by the Food and Agriculture Organisation of the United Nations (FAO) and the World Health Organisation (WHO). This parasite is transmitted mainly in countryside regions where animals are free roaming, having access to human faeces, and infected pork is widely available. More developed countries eliminated cysticercosis; nonetheless, there are insufficient data about the current endemicity status of T. solium, due to increased human migration from endemic areas. Formally submitted statistics on cysticercosis in pigs are extremely inadequate. This is the result of not reporting all cases of the disease by some countries and lack of molecular verification during identification of the parasite. There is a need to develop diagnostic tests with increased sensitivity and specificity. The purpose of the present review is to summarise current knowledge about diagnostic and control methods concerning T. solium infection. The article does not address the diagnostics of human cysticercosis, since there is a distinct medical field which should be discussed separately. The paper focuses mainly on identifying the sources of T. solium infection, presenting the methods to detect and control porcine cysticercosis and taeniosis in humans.
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Samorek-Pieróg M, Karamon J, Cencek T. Identification and Control of Sources of Taenia Solium Infection - the Attempts To Eradicate the Parasite. J Vet Res 2018; 62:27-34. [PMID: 29978124 PMCID: PMC5957458 DOI: 10.1515/jvetres-2018-0004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/15/2018] [Indexed: 11/15/2022] Open
Abstract
Taenia solium is a parasite causing porcine cysticercosis and human taeniosis and cysticercosis, parasitic zoonoses with a serious public health and economic influence. It has been globally ranked as the top foodborne parasite by the Food and Agriculture Organisation of the United Nations (FAO) and the World Health Organisation (WHO). This parasite is transmitted mainly in countryside regions where animals are free roaming, having access to human faeces, and infected pork is widely available. More developed countries eliminated cysticercosis; nonetheless, there are insufficient data about the current endemicity status of T. solium, due to increased human migration from endemic areas. Formally submitted statistics on cysticercosis in pigs are extremely inadequate. This is the result of not reporting all cases of the disease by some countries and lack of molecular verification during identification of the parasite. There is a need to develop diagnostic tests with increased sensitivity and specificity. The purpose of the present review is to summarise current knowledge about diagnostic and control methods concerning T. solium infection. The article does not address the diagnostics of human cysticercosis, since there is a distinct medical field which should be discussed separately. The paper focuses mainly on identifying the sources of T. solium infection, presenting the methods to detect and control porcine cysticercosis and taeniosis in humans.
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Affiliation(s)
- Małgorzata Samorek-Pieróg
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, 24-100 Pulawy, Poland
| | - Jacek Karamon
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, 24-100 Pulawy, Poland
| | - Tomasz Cencek
- Department of Parasitology and Invasive Diseases, National Veterinary Research Institute, 24-100 Pulawy, Poland
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20
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Bobes RJ, Navarrete-Perea J, Ochoa-Leyva A, Anaya VH, Hernández M, Cervantes-Torres J, Estrada K, Sánchez-Lopez F, Soberón X, Rosas G, Nunes CM, García-Varela M, Sotelo-Mundo RR, López-Zavala AA, Gevorkian G, Acero G, Laclette JP, Fragoso G, Sciutto E. Experimental and Theoretical Approaches To Investigate the Immunogenicity of Taenia solium-Derived KE7 Antigen. Infect Immun 2017; 85:e00395-17. [PMID: 28923896 PMCID: PMC5695116 DOI: 10.1128/iai.00395-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/11/2017] [Indexed: 11/20/2022] Open
Abstract
Taenia solium cysticercosis, a parasitic disease that affects human health in various regions of the world, is preventable by vaccination. Both the 97-amino-acid-long KETc7 peptide and its carboxyl-terminal, 18-amino-acid-long sequence (GK-1) are found in Taenia crassiceps Both peptides have proven protective capacity against cysticercosis and are part of the highly conserved, cestode-native, 264-amino-acid long protein KE7. KE7 belongs to a ubiquitously distributed family of proteins associated with membrane processes and may participate in several vital cell pathways. The aim of this study was to identify the T. solium KE7 (TsKE7) full-length protein and to determine its immunogenic properties. Recombinant TsKE7 (rTsKE7) was expressed in Escherichia coli Rosetta2 cells and used to obtain mouse polyclonal antibodies. Anti-rTsKE7 antibodies detected the expected native protein among the 350 spots developed from T. solium cyst vesicular fluid in a mass spectrometry-coupled immune proteomic analysis. These antibodies were then used to screen a phage-displayed 7-random-peptide library to map B-cell epitopes. The recognized phages displayed 9 peptides, with the consensus motif Y(F/Y)PS sequence, which includes YYYPS (named GK-1M, for being a GK-1 mimotope), exactly matching a part of GK-1. GK-1M was recognized by 58% of serum samples from cysticercotic pigs with 100% specificity but induced weak protection against murine cysticercosis. In silico analysis revealed a universal T-cell epitope(s) in native TsKE7 potentially capable of stimulating cytotoxic T lymphocytes and helper T lymphocytes under different major histocompatibility complex class I and class II mouse haplotypes. Altogether, these results provide a rationale for the efficacy of the KETc7, rTsKE7, and GK-1 peptides as vaccines.
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Affiliation(s)
- Raúl J Bobes
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
| | - José Navarrete-Perea
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
- Instituto Nacional de Medicina Genómica, México City, México
| | - Adrián Ochoa-Leyva
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Víctor Hugo Anaya
- Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
| | - Marisela Hernández
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
| | | | - Karel Estrada
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Filiberto Sánchez-Lopez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Xavier Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- Instituto Nacional de Medicina Genómica, México City, México
| | - Gabriela Rosas
- Facultad de Medicina, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México
| | - Cáris Maroni Nunes
- UNESP, Universidade Estadual Paulista, Department of Animal Health and Production, Araçatuba, SP, Brazil
| | - Martín García-Varela
- Instituto de Biología, Universidad Nacional Autónoma de México, México City, México
| | - Rogerio Rafael Sotelo-Mundo
- Laboratorio de Estructura Biomolecular, Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora, México
| | - Alonso Alexis López-Zavala
- Laboratorio de Estructura Biomolecular, Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora, México
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Hermosillo, Sonora, México
| | - Goar Gevorkian
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
| | - Gonzalo Acero
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
| | - Juan P Laclette
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
| | - Gladis Fragoso
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
| | - Edda Sciutto
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México
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21
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A hyperendemic focus of Taenia solium transmission in the Banke District of Nepal. Acta Trop 2017; 176:78-82. [PMID: 28739367 PMCID: PMC5644834 DOI: 10.1016/j.actatropica.2017.07.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/20/2017] [Accepted: 07/20/2017] [Indexed: 01/06/2023]
Abstract
The prevalence of porcine cysticercosis was determined in pigs from the Banke District of Nepal. Slaughter-age animals were selected at random and underwent detailed necropsy examination. Thirty two of 110 animals were found to harbour T. solium cysticerci. This is one of the highest levels of porcine cysticercosis described for any region in the world. Measures are warranted to control this zoonotic disease in Nepal.
Neurocysticercosis is a major cause of epilepsy in countries where Taenia solium is endemic and the parasite is a major cause of food-borne disease globally. Pigs are the natural intermediate host involved in transmission of the parasite. T. solium is known to be endemic in Nepal, however there is limited reliable data about the prevalence of the disease in Nepal. The aim of this study was to determine accurately the prevalence of porcine cysticercosis in slaughter age pigs in an area of Nepal where pigs are known to be free-roaming. Pigs were obtained from the Udaypur Village Development Committee (VDC) and Hirminiya & Betahani VDC of the Banke district in Nepal. One hundred and ten animals of slaughter age (approximately 8–16 months old) were purchased, slaughtered and the heart, liver, brain and half the body skeletal musculature were sliced using hand knives and the number and viability of T. solium cysts determined. Thirty two of the 110 animals were found to harbour T. solium cysticerci (29%), of which 30 (27%) were found to have viable cysticerci (93% of the infected animals). This is one of the highest prevalences of porcine cysticercosis that has been reported to date from the results of necropsy on randomly selected animals. This study highlights a high rate of transmission of T. solium in the Banke District of Nepal. It encourages further investigation of human and porcine cysticercosis in Nepal, as well as implementation of efforts to reduce transmission of the parasite and the associated human disease.
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Agustina KK, Swacita IBN, Oka IBM, Dwinata IM, Traub RJ, Cargill C, Damriyasa IM. Reducing zoonotic and internal parasite burdens in pigs using a pig confinement system. Vet World 2017; 10:1347-1352. [PMID: 29263598 PMCID: PMC5732342 DOI: 10.14202/vetworld.2017.1347-1352] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/04/2017] [Indexed: 12/21/2022] Open
Abstract
Aim This study was designed to validate the effectiveness of the pig confinement system (PCS) in reducing the prevalence of zoonotic and internal parasite burdens in pigs. Materials and Methods Ten PCS households were selected together with 10 households practising traditional scavenging systems. Five pigs were monitored per household every 3 months for 15 months and blood and feces collected. Pigs received a single dose of oxfendazole at 30 mg/kg at baseline. Qualitative fecal examinations for intestinal parasite stages were performed, and serum was tested for antibodies to cysticercus of Taenia solium, Trichinella spp., and Toxoplasma gondii. Results Based on fecal examination, the prevalence of pigs positive for parasite eggs was reduced in PCS pigs over consecutive samplings (Ascaris suum [14.3% to 0%], Trichuris suis [46.9% to 8.3%], Strongyle-type eggs [81.6% to 8.3%], Physocephalus spp. [6.1% to 0%], and Metastrongylus apri [20.8% to 0%]) compared with increases in the number of pigs positive for parasite eggs in non-PCS pigs (T. suis [20-61.5%], Strongyle-type [60.4-80.8%], Physocephalus spp. [8.3-15.4%], and M. apri [20.8-34.6%]) and little change in pigs positive for A. suum (18.8-19.2%). While the prevalence of pigs with antibodies against to cysticerci of T. solium reduced in PCS pigs from 18% to 14%, the prevalence in non-PCS pigs increased from 42% to 52%. Antibodies to Trichinella were not detected, but the prevalence of T. gondii antibodies increased from 6% to 10% in PCS pigs and from 7% to 24% in non-PCS pigs. Conclusion These data demonstrate the potential of a PCS to reduce the prevalence of pigs infected with zoonotic and internal parasites and thus the risk to human and pig health.
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Affiliation(s)
- Kadek Karang Agustina
- Department of Veterinary Public Health, Faculty of Veterinary Medicine Udayana University, PB. Sudirman St. Campus, Denpasar, Bali 80223, Indonesia.,Department of Parasitology, Center Studies on Animal Diseases Udayana University, Markisa Alleyway of Sesetan St. No. 8 Denpasar, Bali 80223, Indonesia
| | - Ida Bagus Ngurah Swacita
- Department of Veterinary Public Health, Faculty of Veterinary Medicine Udayana University, PB. Sudirman St. Campus, Denpasar, Bali 80223, Indonesia
| | - Ida Bagus Made Oka
- Department of Veterinary Public Health, Faculty of Veterinary Medicine Udayana University, PB. Sudirman St. Campus, Denpasar, Bali 80223, Indonesia
| | - I Made Dwinata
- Department of Veterinary Public Health, Faculty of Veterinary Medicine Udayana University, PB. Sudirman St. Campus, Denpasar, Bali 80223, Indonesia
| | - Rebecca Justin Traub
- Department of Parasitology, Faculty of Veterinary Science University of Melbourne, Melbourne, Victoria, Australia
| | - Colin Cargill
- Department of Livestock Production, South Australian Research and Development Institute, Hartley Grove, Urrbrae SA 5064, Australia
| | - I Made Damriyasa
- Department of Veterinary Public Health, Faculty of Veterinary Medicine Udayana University, PB. Sudirman St. Campus, Denpasar, Bali 80223, Indonesia.,Department of Parasitology, Center Studies on Animal Diseases Udayana University, Markisa Alleyway of Sesetan St. No. 8 Denpasar, Bali 80223, Indonesia
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23
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Okello AL, Thomas LF. Human taeniasis: current insights into prevention and management strategies in endemic countries. Risk Manag Healthc Policy 2017; 10:107-116. [PMID: 28615981 PMCID: PMC5461055 DOI: 10.2147/rmhp.s116545] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Human taeniasis is a zoonotic condition resulting from infection with the adult stages of Taenia saginata ("beef tapeworm"), Taenia solium ("pork tapeworm") or Taenia asiatica ("Asian tapeworm"). Although these parasites have a worldwide distribution, the overwhelming burden is felt by communities in low- and middle-income countries. This is particularly true for T. solium, whereby infection of the central nervous system with the larval stage of the parasite (neurocysticercosis) is a major cause of acquired epilepsy in low-resource settings. With a focus on endemic countries, this review provides an insight into the prevention and management of human taeniasis, concluding with some recent case studies describing their implementation. Discussion of the opportunities and challenges regarding current fecal and serological diagnostic assays for detecting Taenia spp. highlights the importance of accurate and accessible diagnostic options for the field situation. The lack of long-term impact on the parasites' lifecycle from human anthelmintic treatment, coupled with the propensity for adverse reactions, highlights the importance of a "two-pronged" approach that considers the relevant animal hosts, particularly in the case of T. solium. Aside from the therapeutic options, this review reiterates the importance of adequate assessment and consideration of the associated behavioral and policy aspects around sanitation, hygiene and meat inspection that have been shown to support parasite control, and potential elimination, in endemic regions.
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Affiliation(s)
- Anna L Okello
- Division of Infection and Pathway Medicine, Edinburgh Medical School, Biomedical Sciences College of Medicine and Veterinary Medicine, University of Edinburgh, Scotland
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24
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Goulart LR, da S. Ribeiro V, Costa-Cruz JM. Anti-parasitic Antibodies from Phage Display. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1053:155-171. [DOI: 10.1007/978-3-319-72077-7_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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25
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Wu HW, Ito A, Ai L, Zhou XN, Acosta LP, Lee Willingham A. Cysticercosis/taeniasis endemicity in Southeast Asia: Current status and control measures. Acta Trop 2017; 165:121-132. [PMID: 26802488 DOI: 10.1016/j.actatropica.2016.01.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/02/2015] [Accepted: 01/10/2016] [Indexed: 12/26/2022]
Abstract
The parasitic zoonoses cysticercosis/taeniasis is among the 17 major Neglected Tropical Diseases (NTDs) identified by the WHO as a focus for research and control. It is caused by a larval stage (cysticercus) infection of Taenia solium tapeworm in both humans and pigs. Cysticercosis occurs in many resource-poor countries, especially those with warm and mild climates in the regions of Latin America (LA), Asia and Sub-Saharan Africa (SSA). The prevalence of human cysticercosis is marked in those areas where individuals are traditionally keen to consume raw or insufficiently cooked pork and/or where the husbandry of pigs is improper. The worldwide burden of cysticercosis is unclear and notably, large-scale control initiatives are lacking in all regions. This review focuses on the current endemic status of cysticercosis caused by T. solium infection in both humans and pigs living in 13 Southeast Asian countries. We will also emphasize epidemiological data as well as prevention and control of human neurocysticercosis.
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Affiliation(s)
- Hai-Wei Wu
- Center for International Health Research, Rhode Island Hospital, Brown University Medical School, Providence, RI, USA; Department of Pediatrics, Rhode Island Hospital, Brown University Medical School, Providence, RI, USA.
| | - Akira Ito
- Department of Parasitology and Neglected Tropical Diseases Research Laboratory, Asahikawa Medical University, Asahikawa, Japan
| | - Lin Ai
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China
| | - Luz P Acosta
- Department of Immunology, Research Institute for Tropical Medicine, Alabang, Muntinlupa, Philippines
| | - Arve Lee Willingham
- One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Basseterre, St. Kitts, West Indies
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26
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Gabriël S, Dorny P, Mwape KE, Trevisan C, Braae UC, Magnussen P, Thys S, Bulaya C, Phiri IK, Sikasunge CS, Makungu C, Afonso S, Nicolau Q, Johansen MV. Control of Taenia solium taeniasis/cysticercosis: The best way forward for sub-Saharan Africa? Acta Trop 2017; 165:252-260. [PMID: 27140860 DOI: 10.1016/j.actatropica.2016.04.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 04/22/2016] [Accepted: 04/23/2016] [Indexed: 11/15/2022]
Abstract
Taenia solium taeniasis/cysticercosis is a neglected parasitic zoonosis with significant economic and public health impacts. Control measures can be broadly grouped into community health education, improvements in hygiene and sanitary conditions, proper meat handling at household and community level, improved standards of meat inspection, pig management, treatment of individual patients and possibly human populations, and treatment and/or vaccination of porcine populations. This manuscript looks critically into currently existing control options and provides suggestions on which (combination of) tools would be most effective in the control of T. solium taeniasis/cysticercosis in sub-Saharan Africa. Field data and disease transmission simulations suggest that implementation of a single intervention control strategy will not lead to a satisfactory reduction of disease morbidity or transmission. A feasible strategy to combat T. solium taeniasis/cysticercosis would include a combination of approaches focussing on both human (health education and treatment) and animal host (management, treatment and vaccination), which can vary for different communities and different geographical locations. Selection of the specific strategy depends on cost-effectiveness analyses based on solid field data, currently unavailable, though urgently needed; as well as on health priorities and resources of the country. A One Health approach involving medical, veterinary, environmental and social sectors is essential for T. solium to be controlled and eventually eliminated. Finally the success of any intervention is largely dependent on the level of societal and political acceptance, commitment and engagement.
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Affiliation(s)
- S Gabriël
- Institute of Tropical Medicine, Antwerp, Belgium.
| | - P Dorny
- Institute of Tropical Medicine, Antwerp, Belgium; Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - K E Mwape
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - C Trevisan
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - U C Braae
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - P Magnussen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - S Thys
- Institute of Tropical Medicine, Antwerp, Belgium
| | - C Bulaya
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - I K Phiri
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - C S Sikasunge
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - C Makungu
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - S Afonso
- Faculty of Veterinary Medicine, Eduardo Mondlane University, Maputo, Mozambique
| | - Q Nicolau
- Faculty of Veterinary Medicine, Eduardo Mondlane University, Maputo, Mozambique
| | - M V Johansen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
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Braae UC, Devleesschauwer B, Gabriël S, Dorny P, Speybroeck N, Magnussen P, Torgerson P, Johansen MV. CystiSim - An Agent-Based Model for Taenia solium Transmission and Control. PLoS Negl Trop Dis 2016; 10:e0005184. [PMID: 27984581 PMCID: PMC5161321 DOI: 10.1371/journal.pntd.0005184] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 11/14/2016] [Indexed: 11/19/2022] Open
Abstract
Taenia solium taeniosis/cysticercosis was declared eradicable by the International Task Force for Disease Eradication in 1993, but remains a neglected zoonosis. To assist in the attempt to regionally eliminate this parasite, we developed cystiSim, an agent-based model for T. solium transmission and control. The model was developed in R and available as an R package (http://cran.r-project.org/package=cystiSim). cystiSim was adapted to an observed setting using field data from Tanzania, but adaptable to other settings if necessary. The model description adheres to the Overview, Design concepts, and Details (ODD) protocol and consists of two entities—pigs and humans. Pigs acquire cysticercosis through the environment or by direct contact with a tapeworm carrier's faeces. Humans acquire taeniosis from slaughtered pigs proportional to their infection intensity. The model allows for evaluation of three interventions measures or combinations hereof: treatment of humans, treatment of pigs, and pig vaccination, and allows for customary coverage and efficacy settings. cystiSim is the first agent-based transmission model for T. solium and suggests that control using a strategy consisting of an intervention only targeting the porcine host is possible, but that coverage and efficacy must be high if elimination is the ultimate goal. Good coverage of the intervention is important, but can be compensated for by including an additional intervention targeting the human host. cystiSim shows that the scenarios combining interventions in both hosts, mass drug administration to humans, and vaccination and treatment of pigs, have a high probability of success if coverage of 75% can be maintained over at least a four year period. In comparison with an existing mathematical model for T. solium transmission, cystiSim also includes parasite maturation, host immunity, and environmental contamination. Adding these biological parameters to the model resulted in new insights in the potential effect of intervention measures. Taenia solium is the leading cause of preventable epilepsy and the highest ranking foodborne parasite in terms of disease burden worldwide. Currently there are no large scale control programmes implemented against T. solium, but efficacious intervention tools are there, making control programmes the next step forward. Because of the zoonotic properties of the parasite, existing in both humans and pigs, a combination of intervention tools is likely to be needed. cystiSim is an agent-based disease model that provides insight into which intervention tools, and the frequency of administration of these tools, are needed to yield an effect on disease prevalence. cystiSim is a valuable tool in designing future control programmes and will assist in the elimination of T. solium as a public health problem.
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Affiliation(s)
- Uffe Christian Braae
- Section for Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- * E-mail:
| | - Brecht Devleesschauwer
- Department of Public Health and Surveillance, Scientific Institute of Public Health (WIV-ISP), Brussels, Belgium
| | - Sarah Gabriël
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Pierre Dorny
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Niko Speybroeck
- Institute of Health and Society (IRSS), Université catholique de Louvain, Brussels, Belgium
| | - Pascal Magnussen
- Section for Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Paul Torgerson
- Section of Epidemiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Maria Vang Johansen
- Section for Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
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28
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Lightowlers MW, Garcia HH, Gauci CG, Donadeu M, Abela-Ridder B. Monitoring the outcomes of interventions against Taenia solium: options and suggestions. Parasite Immunol 2016; 38:158-69. [PMID: 26538513 PMCID: PMC4819694 DOI: 10.1111/pim.12291] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 10/26/2015] [Indexed: 11/27/2022]
Abstract
There is an increasing interest in reducing the incidence of human neurocysticercosis, caused by infection with the larval stage of Taenia solium. Several intervention trials are currently assessing various options for control of T. solium transmission. A critical aspect of these trials will be the evaluation of whether the interventions have been successful. However, there is no consensus about the most appropriate or valuable methods that should be used. Here, we undertake a critical assessment of the diagnostic tests which are currently available for human T. solium taeniasis and human and porcine cysticercosis, as well as their suitability for evaluation of intervention trial outcomes. Suggestions are made about which of the measures that are available for evaluation of T. solium interventions would be most suitable, and which methodologies are the most appropriate given currently available technologies. Suggestions are also made in relation to the most urgent research needs in order to address deficiencies in current diagnostic methods.
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Affiliation(s)
- M W Lightowlers
- Veterinary Clinical Centre, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic., Australia
| | - H H Garcia
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurológicas, Lima, Peru.,Department of Microbiology, School of Sciences, Centre for Global Health-Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - C G Gauci
- Veterinary Clinical Centre, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic., Australia
| | - M Donadeu
- Veterinary Clinical Centre, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic., Australia
| | - B Abela-Ridder
- Department of Control of Neglected Tropical Diseases, World Health Organization, Genève 27, Switzerland
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29
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Molehin AJ, Rojo JU, Siddiqui SZ, Gray SA, Carter D, Siddiqui AA. Development of a schistosomiasis vaccine. Expert Rev Vaccines 2016; 15:619-27. [PMID: 26651503 PMCID: PMC5070536 DOI: 10.1586/14760584.2016.1131127] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Schistosomiasis is a neglected tropical disease (NTD) of public health importance. Despite decades of implementation of mass praziquantel therapy programs and other control measures, schistosomiasis has not been contained and continues to spread to new geographic areas. A schistosomiasis vaccine could play an important role as part of a multifaceted control approach. With regards to vaccine development, many biological bottlenecks still exist: the lack of reliable surrogates of protection in humans; immune interactions in co-infections with other diseases in endemic areas; the potential risk of IgE responses to antigens in endemic populations; and paucity of appropriate vaccine efficacy studies in nonhuman primate models. Research is also needed on the role of modern adjuvants targeting specific parts of the innate immune system to tailor a potent and protective immune response for lead schistosome vaccine candidates with the long-term aim to achieve curative worm reduction. This review summarizes the current status of schistosomiasis vaccine development.
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Affiliation(s)
- Adebayo J. Molehin
- Department of Internal Medicine, Texas Tech University School of Medicine, Lubbock, Texas, USA
- Center of Tropical Medicine and Infectious Diseases, Texas Tech University School of Medicine, Lubbock, Texas, USA
| | - Juan U. Rojo
- Department of Internal Medicine, Texas Tech University School of Medicine, Lubbock, Texas, USA
- Center of Tropical Medicine and Infectious Diseases, Texas Tech University School of Medicine, Lubbock, Texas, USA
| | - Sabrina Z. Siddiqui
- Department of Internal Medicine, Texas Tech University School of Medicine, Lubbock, Texas, USA
- Center of Tropical Medicine and Infectious Diseases, Texas Tech University School of Medicine, Lubbock, Texas, USA
| | | | - Darrick Carter
- PAI Life Sciences, Washington, USA
- Infectious Disease Research Institute, Seattle, Washington, USA
| | - Afzal A. Siddiqui
- Department of Internal Medicine, Texas Tech University School of Medicine, Lubbock, Texas, USA
- Center of Tropical Medicine and Infectious Diseases, Texas Tech University School of Medicine, Lubbock, Texas, USA
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30
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Singhi P, Saini AG. Pediatric neurocysticercosis: current challenges and future prospects. Pediatric Health Med Ther 2016; 7:5-16. [PMID: 29388588 PMCID: PMC5683283 DOI: 10.2147/phmt.s79058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Neurocysticercosis (NCC) is an acquired infection of the nervous system caused by encysted larvae of Taenia solium. It is a major cause of epilepsy in the tropics and the commonest cause of focal seizures in North Indian children. T. solium teniasis-cysticercosis is considered a parasitic "Neglected Tropical Diseases" endemic throughout Southeast Asia. NCC in children has pleomorphic manifestations depending on the location, number and viability of the cysts, and host response. Even with advancing knowledge of the disease manifestations, many aspects related to diagnosis and treatment, particularly in children, still remain controversial and pose challenges to clinical practice. There is no gold standard test to diagnose NCC and the management recommendations are still emerging. This review provides an overview of diagnosis of NCC in children and its management with special focus on current challenges and future prospects.
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Affiliation(s)
- Pratibha Singhi
- Department of Pediatrics, Pediatric Neurology and Neurodevelopment Unit, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Arushi Gahlot Saini
- Department of Pediatrics, Pediatric Neurology and Neurodevelopment Unit, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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31
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Lightowlers MW, Assana E, Jayashi CM, Gauci CG, Donadeu M. Sensitivity of partial carcass dissection for assessment of porcine cysticercosis at necropsy. Int J Parasitol 2015; 45:815-8. [PMID: 26385439 PMCID: PMC4655835 DOI: 10.1016/j.ijpara.2015.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Revised: 08/27/2015] [Accepted: 08/28/2015] [Indexed: 12/01/2022]
Abstract
Taenia solium cyst distribution was determined in the carcass musculature of 209 naturally exposed pigs. 81% of the infected animals had cysts in the tongue, masticatory muscles and/or heart muscles. Dissection of a limited proportion of the muscles of pigs could be used to assess the outcomes of cysticercosis control.
Many interventions against Taenia solium are evaluated by assessing changes in the prevalence of porcine cysticercosis ascertained by carcass dissection. Financial and logistical difficulties often prohibit dissection of entire pig carcasses. We assessed 209 pigs from rural areas of Cameroon and Peru for the presence of T. solium cysticerci and determined the distribution of parasites within the musculature of infected animals. Considering the presence of cysts in the tongue, masticatory muscles and heart, 31 of the 38 (81%) naturally infected animals were identified as having cysts. Dissection of only the tongue, masticatory muscles and heart provides a relatively sensitive and highly specific method for diagnosis of porcine cysticercosis.
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Affiliation(s)
- M W Lightowlers
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Veterinary Clinical Centre, 250 Princes Highway, Werribee, Victoria 3030, Australia.
| | - E Assana
- The University of Ngaoundere, School of Veterinary Medicine and Sciences, P.O. Box 454, Ngaoundere, Cameroon
| | - C M Jayashi
- The University of Queensland, AIBN, Building 75, Cnr College Road & Old Cooper Road, Brisbane, Queensland 4072, Australia
| | - C G Gauci
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Veterinary Clinical Centre, 250 Princes Highway, Werribee, Victoria 3030, Australia
| | - M Donadeu
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Veterinary Clinical Centre, 250 Princes Highway, Werribee, Victoria 3030, Australia
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32
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Kungu JM, Dione MM, Ocaido M, Ejobi F. Status of Taenia solium cysticercosis and predisposing factors in developing countries involved in pig farming. INTERNATIONAL JOURNAL OF ONE HEALTH 2015. [DOI: 10.14202/ijoh.2015.6-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
Helminth parasites infect over one fourth of the human population and are highly prevalent in livestock worldwide. In model systems, parasites are strongly immunomodulatory, but the immune system can be driven to expel them by prior vaccination. However, no vaccines are currently available for human use. Recent advances in vaccination with recombinant helminth antigens have been successful against cestode infections of livestock and new vaccines are being tested against nematode parasites of animals. Numerous vaccine antigens are being defined for a wide range of helminth parasite species, but greater understanding is needed to define the mechanisms of vaccine-induced immunity, to lay a rational platform for new vaccines and their optimal design. With human trials underway for hookworm and schistosomiasis vaccines, a greater integration between veterinary and human studies will highlight the common molecular and mechanistic pathways, and accelerate progress towards reducing the global health burden of helminth infection.
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Mackey TK, Liang BA, Cuomo R, Hafen R, Brouwer KC, Lee DE. Emerging and reemerging neglected tropical diseases: a review of key characteristics, risk factors, and the policy and innovation environment. Clin Microbiol Rev 2014; 27:949-79. [PMID: 25278579 PMCID: PMC4187634 DOI: 10.1128/cmr.00045-14] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern.
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Affiliation(s)
- Tim K Mackey
- Department of Anesthesiology, University of California, San Diego, School of Medicine, San Diego, California, USA Division of Global Public Health, University of California, San Diego, Department of Medicine, San Diego, California, USA
| | - Bryan A Liang
- Department of Anesthesiology, University of California, San Diego, School of Medicine, San Diego, California, USA
| | - Raphael Cuomo
- Joint Doctoral Program in Global Public Health, University of California, San Diego, and San Diego State University, San Diego, California, USA
| | - Ryan Hafen
- Department of Anesthesiology, University of California, San Diego, School of Medicine, San Diego, California, USA Internal Medicine, University of California, San Diego, School of Medicine, San Diego, California, USA
| | - Kimberly C Brouwer
- Division of Global Public Health, University of California, San Diego, Department of Medicine, San Diego, California, USA
| | - Daniel E Lee
- Department of Anesthesiology, University of California, San Diego, School of Medicine, San Diego, California, USA Pediatrics Department, University of California, San Diego, School of Medicine, San Diego, California, USA
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Carabin H, Traoré AA. Taenia solium taeniasis and cysticercosis control and elimination through community-based interventions. CURRENT TROPICAL MEDICINE REPORTS 2014; 1:181-193. [PMID: 25544938 DOI: 10.1007/s40475-014-0029-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Taenia solium was declared potentially eradicable by the International Task Force for Disease Eradication in 1992. Yet, very few well-designed community-based randomized controlled trials have been conducted to measure the effectiveness of alternative control strategies. Most strategies have been tested in pre-post intervention designs in very few communities, often without a control group. The only two community-based randomized controlled trials suggest that an educational program alone or a combination of human and porcine mass treatment reduce porcine cysticercosis in the short term. A transmission dynamics model suggests that improved sanitation and pig management are more effective and sustainable than pig vaccination, human or porcine mass treatment. Current evidence does not support the eradication of Taenia solium in the foreseeable future. Investigators should follow international recommendations on the conduct of community-based randomized control trials to provide more valid estimates of the effect and cost-effectiveness of alternative control strategies for cysticercosis.
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Affiliation(s)
- Hélène Carabin
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104
| | - Aminata A Traoré
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104. Tel: 405 271-2229.
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Jayashi CM, Gonzalez AE, Castillo Neyra R, Rodríguez S, García HH, Lightowlers MW. Validity of the Enzyme-linked Immunoelectrotransfer Blot (EITB) for naturally acquired porcine cysticercosis. Vet Parasitol 2014; 199:42-9. [PMID: 24183647 PMCID: PMC5448663 DOI: 10.1016/j.vetpar.2013.10.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 09/20/2013] [Accepted: 10/07/2013] [Indexed: 11/25/2022]
Abstract
The Enzyme-linked Immunoelectrotransfer Blot (EITB) has been used widely as a screening test for Taenia solium cysticercosis in swine. However, the relation between seropositivity and infection in pig populations from endemic areas has not been well defined. The aim of this study is to relate EITB seropositivity with infection and infection burden, analyse the trade-off between sensitivity and specificity with various cut-off points for the EITB assay, and finally describe the serology changes in a cohort of rural pigs raised under natural conditions. A group of 107 pigs that were used as controls during a vaccination field trial in Peru was our study population. The prevalence of porcine cysticercosis determined by necropsy examination was 16.82% (18/107) in these animals. Using EITB reactivity to ≥ 1 band as a cut-off point for the assay, the sensitivity was 88.89% (65.29-98.62, 95% CI) and the specificity was 48.31% (37.59-59.16, 95% CI). Comparing other cut-off points, involving up to as many as 7 reactive bands, a reactivity of ≥ 3 bands provided the best trade-offs in sensitivity and specificity. Using this cut-off point for the assay, the sensitivity was 77.77% (52.36-93.59, 95% CI) and the specificity was 76.40% (66.22-84.76, 95% CI). A significant association was found between cyst counts over 100 cysts and reactivity to ≥ 3 bands in the EITB assay (Fisher's exact test, p<0.05). The results of this study suggest that the use of the EITB assay to study porcine cysticercosis may require setting different cut-offs under field and experimental conditions, and depending upon the objective of the screening process.
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Affiliation(s)
- César M Jayashi
- Veterinary Clinical Centre, The University of Melbourne, 250 Princes Hwy, Werribee, Victoria 3030, Australia.
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37
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Impacts of globalisation on foodborne parasites. Trends Parasitol 2014; 30:37-52. [DOI: 10.1016/j.pt.2013.09.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 09/18/2013] [Accepted: 09/19/2013] [Indexed: 11/21/2022]
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Control of Taenia solium taeniasis/cysticercosis: past practices and new possibilities. Parasitology 2013; 140:1566-77. [DOI: 10.1017/s0031182013001005] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYNeurocysticercosis continues to be a major health burden on humans living in many regions of the world, despite the availability of highly effective taeniacides and identification of the cause, Taenia solium, as being potentially eradicable. Several T. solium control trials have been undertaken, generally achieving limited success and none that has been fully documented has achieved what was demonstrated to be a sustainable level of disease control. Pigs act as intermediate hosts for T. solium and two new control tools have become available for application in pigs – single-dose oxfendazole treatment of porcine cysticercosis and the TSOL18 vaccine. Three potential intervention scenarios for pigs are compared for control of cysticercosis, using either oxfendazole or vaccination. A control scenario involving vaccination plus oxfendazole treatment delivered at 4 monthly intervals was predicted to achieve the best outcome, with no pigs slaughtered at 12 months of age having viable T. solium cysticerci. Now that new control tools are available, there are opportunities to concentrate research attention on evaluation of novel control scenarios leading to the implementation of effective and sustainable control programmes and a reduction in the global burden of neurocysticercosis.
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Assana E, Lightowlers MW, Zoli AP, Geerts S. Taenia solium taeniosis/cysticercosis in Africa: Risk factors, epidemiology and prospects for control using vaccination. Vet Parasitol 2013; 195:14-23. [DOI: 10.1016/j.vetpar.2012.12.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 12/04/2012] [Accepted: 12/11/2012] [Indexed: 10/27/2022]
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40
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Gilman RH, Gonzalez AE, Llanos-Zavalaga F, Tsang VCW, Garcia HH. Prevention and control of Taenia solium taeniasis/cysticercosis in Peru. Pathog Glob Health 2013; 106:312-8. [PMID: 23265557 DOI: 10.1179/2047773212y.0000000045] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Taenia solium is endemic in most of the world, causing seizures and other neurological symptoms. Transmission is mainly maintained in rural areas by a human to pig cycle. Despite claims on its eradicability, sustainable interruption of transmission has not yet been reported. This manuscript reviews the conceptual basis for control, available diagnostic and control tools, and recent experiences on control in the field performed in Peru along the past decade.
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Affiliation(s)
- Robert H Gilman
- Department of Microbiology, and Center for Global Health-Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru
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Ding J, Zheng Y, Wang Y, Dou Y, Chen X, Zhu X, Wang S, Zhang S, Liu Z, Hou J, Zhai J, Yan H, Luo X, Cai X. Immune responses to a recombinant attenuated Salmonella typhimurium strain expressing a Taenia solium oncosphere antigen TSOL18. Comp Immunol Microbiol Infect Dis 2013; 36:17-23. [DOI: 10.1016/j.cimid.2012.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 07/31/2012] [Accepted: 09/01/2012] [Indexed: 11/16/2022]
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Gauci C, Jayashi C, Lightowlers MW. Vaccine development against the Taenia solium parasite: the role of recombinant protein expression in Escherichia coli. Bioengineered 2012. [PMID: 23196744 DOI: 10.4161/bioe.23003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Taenia solium is a zoonotic parasite that causes cysticercosis. The parasite is a major cause of human disease in impoverished communities where it is transmitted to humans from pigs which act as intermediate hosts. Vaccination of pigs to prevent transmission of T. solium to humans is an approach that has been investigated to control the disease. A recombinant vaccine antigen, TSOL18, has been remarkably successful at reducing infection of pigs with T. solium in several experimental challenge trials. The vaccine has been shown to eliminate transmission of naturally acquired T. solium in a field trial conducted in Africa. We recently reported that the vaccine was also effective in a field trial conducted in Peru. The TSOL18 recombinant antigen for each of these trials has been produced by expression in Escherichia coli. Here we discuss research that has been undertaken on the TSOL18 antigen and related antigens with a focus on improved methods of preparation of recombinant TSOL18 and optimized expression in Escherichia coli.
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Affiliation(s)
- Charles Gauci
- University of Melbourne; Faculty of Veterinary Science; Werribee, Australia; Australian Institute for Bioengineering and Nanotechnology; University of Queensland; Queensland, Australia
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Jayashi CM, Gonzalez AE, Castillo Neyra R, Kyngdon CT, Gauci CG, Lightowlers MW. Characterisation of antibody responses in pigs induced by recombinant oncosphere antigens from Taenia solium. Vaccine 2012; 30:7475-80. [PMID: 23116696 DOI: 10.1016/j.vaccine.2012.10.057] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 09/11/2012] [Accepted: 10/16/2012] [Indexed: 10/27/2022]
Abstract
Recombinant antigens cloned from the oncosphere life cycle stage of the cestode parasite Taenia solium (T. solium) have been proven to be effective as vaccines for protecting pigs against infections with T. solium. Previous studies have defined three different host protective oncosphere antigens, TSOL18, TSOL16 and TSOL45. In this study, we evaluated the potential for combining the antigens TSOL16 and TSOL18 as a practical vaccine. Firstly, in a laboratory trial, we compared the immunogenicity of the combined antigens (TSOL16/18) versus the immunogenicity of the antigens separately. Secondly, in a field trial, we tested the ability of the TSOL16/18 vaccine to induce detectable antibody responses in animals living under environmental stress and traditionally reared in areas where T. solium cysticercosis is endemic; and finally, we characterised the immune response of the study population. Pigs of 8-16 weeks of age were vaccinated with 200 μg each of TSOL16 and TSOL18, plus 5mg of Quil-A. Specific total IgG, IgG(1) and IgG(2) antibody responses induced by TSOL16 and TSOL18 were determined with ELISA. The immunogenicity of both antigens was retained in the combined TSOL16/18 vaccine. The combined vaccine TSOL16/18 induced detectable specific anti-TSOL18 antibody responses in 100% (113/113) and specific anti-TSOL16 in 99% (112/113) of the vaccinated animals measured at 2 weeks following the booster vaccination. From the two IgG antibody subtypes analysed we found there was stronger response to IgG(2).
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Affiliation(s)
- César M Jayashi
- Veterinary Clinical Centre, The University of Melbourne, Werribee, Victoria 3030, Australia.
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