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Zulu G, Sikasunge CS, Welte TM, Simuunza MC, Stelzle D, Schmidt V, Hachangu A, Mutale W, Masuku M, Chembensofu M, da Costa CP, Mwape KE, Winkler AS, Phiri IK. Epidemiology of intestinal helminthiasis with an emphasis on taeniasis in Chipata district of the Eastern province of Zambia. PLoS Negl Trop Dis 2023; 17:e0011561. [PMID: 37983246 PMCID: PMC10695371 DOI: 10.1371/journal.pntd.0011561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 12/04/2023] [Accepted: 11/06/2023] [Indexed: 11/22/2023] Open
Abstract
BACKGROUND Intestinal helminth infections are among the most common infections worldwide and have a negative impact on the health, education, nutrition and economic development of affected populations. This study aimed to estimate the prevalence of intestinal helminthiasis, including T. solium taeniasis, using a large-scale community-based study in Chiparamba area of Chipata District in the Eastern province of Zambia. METHODS/PRINCIPAL FINDINGS A cross-sectional study was conducted between June 2019 and December 2022 in a rural community of 25 randomly selected villages known to be at risk for T. solium infection. Stool samples were examined for intestinal helminths using the formol-ether concentration technique and further tested for taeniasis by copro antigen-ELISA (copro Ag-ELISA). Descriptive statistical analyses were conducted, and associations between the disease prevalence of active infections and individual- and village-level variables were determined using the chi-square or Fisher's exact test. Predictors of an individual being positive for either taeniasis or other soil-transmitted helminths were determined using binary logistic regression. A total of 2762 stool samples were examined. One hundred ninety-five (7.1%) tested positive for at least one helminthic parasite on microscopy, with hookworm being the most frequent 84 (3.0%), followed by S. mansoni, 66 (2.4%). For taeniasis, 11 (0.4%) participants were positive for Taenia spp. microscopically, while 241 (8.7%) tested positive via copro Ag-ELISA. On bivariate analysis, male sex was significantly associated with the prevalence of intestinal parasites (p = 0.012) but not with that of taeniasis based on copro Ag-ELISA results. Village level differences were significant for infection with intestinal helminths as well as for taeniasis positivity on copro Ag-ELISA (p <0.001). CONCLUSION Intestinal helminths, including T. solium taeniasis, are prevalent in Chiparamba area of Chipata district in the eastern province of Zambia, supporting the clear need for further targeted public health interventions for surveillance and control.
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Affiliation(s)
- Gideon Zulu
- Ministry of Health, Government of the Republic of Zambia, Lusaka, Zambia
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Chummy S. Sikasunge
- Department of Para-clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Tamara M. Welte
- Department of Neurology, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Epilepsy Centre, Department of Neurology, University Hospital Erlangen, Erlangen, Germany
- Centre for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
| | - Martin C. Simuunza
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Dominik Stelzle
- Department of Neurology, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Centre for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
| | - Veronika Schmidt
- Department of Neurology, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Centre for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
| | - Alex Hachangu
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Wilbroad Mutale
- Department of Public Health, School of Medicine, University of Zambia, Lusaka, Zambia
| | - Maxwell Masuku
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Mwelwa Chembensofu
- Department of Para-clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Clarissa Prazeres da Costa
- Centre for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
- German Center for Infection Research (DZIF), Munich site, Munich, Germany
- Institute for Medical Microbiology, Immunology and Hygiene, School of Medicine and Health, Technical University of Munich, Munich, Germany
| | - Kabemba E. Mwape
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Andrea S. Winkler
- Department of Neurology, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Centre for Global Health, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Department of Community Medicine and Global Health, Institute of Health and Society, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Isaac K. Phiri
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
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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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Nguemnang Kamdem C, Soubgwi Fogue P, Zebaze Tiofack AA, Mezajou Mewamba E, Tekeu Mengoue LE, Womeni MH, Simo G. Assessment of the capacity of Whatman filter papers as support to store stools for the molecular diagnostic testing of soil-transmitted helminthiasis. J Microbiol Methods 2023; 213:106824. [PMID: 37717625 DOI: 10.1016/j.mimet.2023.106824] [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: 07/25/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/19/2023]
Abstract
Storage of stools for the detection of soil-transmitted helminths (STH) remains challenging for the molecular diagnostic testing of STH infections. This study aimed to overcome this challenge by assessing the capacity of Whatman filter papers to store stools for the molecular detection of STHs. Stool samples were collected from school-aged children of soil-transmitted helminthiasis endemic areas of Cameroon and then, analysed using Kato Katz technique. For this study, 128 and 40 stool samples respectively with and without STH eggs were analysed. From each sample, 10, 20, 40 and 80 mg of stool were weighted and spread on 6 grades of Whatman filter papers that were stored at room temperature from one to ten weeks. DNA was extracted from spread stool using CTAB based-method. The amount of stool to spread on filter papers and the grade of filter paper offering good storage were determined by amplifying specific DNA fragments of Ascaris lumbricoides. The capacity of filter papers to store stool samples for several weeks before the molecular detection of STH species was assessed by amplifying specific DNA fragments of different STHs. The amplification rates of A. lumbricoides were significantly higher (P < 0.0001) for 10 and 20 mg of stored stools. Stools spread on Whatman paper grade 2 yielded the highest amplification rate of 100% for A. lumbricoides, T. trichiura and hookworm. PCR revealed STH infections in all the 128 spread stools carrying STH eggs. It also revealed Necator americanus and Ancylostoma duodenale respectively in 10 and 13 of 15 spread stools contained hookworm eggs. PCR confirmed the co-infections of these hookworm species as well as that of A. lumbricoides and Trichuris trichiura in 7 spread stools. Out of 40 stools without STH eggs, PCR revealed that 5 (12.5%) and 9 (22.5%) had respectively A. lumbricoides and T. trichiura infections. The amplification rate of each STH species was 100% from one to 8 weeks and decreased to 86.7% after 10 weeks of storage. This study highlighted the capacity of filter papers to store stools for the molecular detection of STHs. Storing stools on these papers will enable to monitor and evaluate control programs and ensure post-elimination surveillance.
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Affiliation(s)
- Cyrille Nguemnang Kamdem
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Pythagore Soubgwi Fogue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Auvaker Arnol Zebaze Tiofack
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Estelle Mezajou Mewamba
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Loic Edmond Tekeu Mengoue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Macaire Hilaire Womeni
- Unité de Recherche de Biochimie, des plantes Médicinales, des Sciences alimentaires et Nutrition, University of Dschang, Dschang, Cameroon
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon.
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The prevalence of Taenia spp. in pigs slaughtered in Kinshasa. Vet Parasitol Reg Stud Reports 2022; 36:100794. [PMID: 36436903 DOI: 10.1016/j.vprsr.2022.100794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 09/30/2022] [Accepted: 10/01/2022] [Indexed: 11/07/2022]
Abstract
Taenia hydatigena is a non-zoonotic worm that has dogs and wild canids as definitive hosts. Its presence induces cross reactions in certain diagnostic tests for porcine cysticercosis caused by T. solium, the occurrence of which has a considerable public health and economic impact. In the Democratic Republic of the Congo (DR Congo), T. solium is considered endemic, however, the prevalence of T. hydatigena has not been estimated yet. The objective of the study was therefore to estimate the prevalence of T. hydatigena cysticercosis by serological and molecular diagnostic tools in pigs slaughtered in DR Congo. A total of 480 pigs slaughtered in 6 slaughter slabs in Kinshasa, DR Congo, were examined. The thoracal and abdominal cavity organs were inspected for cysts, which were analyzed using PCR-RFLP. Furthermore, 480 sera were collected, and analyzed for the presence of circulating Taenia spp. cysticercus antigens, using the B158/B60 Ag-ELISA. Upon inspection of the carcass, 41 cysts suspected to be metacestodes of Taenia spp. were collected, from the following viscera: spleen (24/41, 59%), liver (13/41, 32%), intestine (3/41, 7%) and lung (1/41, 2%). Molecular analyses revealed a T. hydatigena prevalence of 0.2% (95% CI: 0.0001-0.0116), based on a single lesion (1/480), taken from the spleen. Out of the 480 sera collected, the presence of circulating Taenia spp. cysticerci antigens was detected in 32 (6.7%; 95% CI: 4.5-11.2). The results of this study revealed that T. hydatigena is present in pigs sold in markets in the city of Kinshasa in DR Congo, albeit at a very low prevalence, thus the impact on the interpretation of the B158/B60 seems low in this setting. Detection of circulating antigens in porcine sera by Ag-ELISA, shows that pigs slaughtered in Kinshasa, DR Congo, were infected with viable cysticerci of Taenia spp. which in turn can infect humans.
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Dixon MA, Winskill P, Harrison WE, Whittaker C, Schmidt V, Flórez Sánchez AC, Cucunuba ZM, Edia-Asuke AU, Walker M, Basáñez MG. Global variation in force-of-infection trends for human T aenia solium taeniasis/cysticercosis. eLife 2022; 11:76988. [PMID: 35984416 PMCID: PMC9391040 DOI: 10.7554/elife.76988] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 08/07/2022] [Indexed: 12/01/2022] Open
Abstract
Infection by Taenia solium poses a major burden across endemic countries. The World Health Organization (WHO) 2021–2030 Neglected Tropical Diseases roadmap has proposed that 30% of endemic countries achieve intensified T. solium control in hyperendemic areas by 2030. Understanding geographical variation in age-prevalence profiles and force-of-infection (FoI) estimates will inform intervention designs across settings. Human taeniasis (HTT) and human cysticercosis (HCC) age-prevalence data from 16 studies in Latin America, Africa, and Asia were extracted through a systematic review. Catalytic models, incorporating diagnostic performance uncertainty, were fitted to the data using Bayesian methods, to estimate rates of antibody (Ab)-seroconversion, infection acquisition and Ab-seroreversion or infection loss. HCC FoI and Ab-seroreversion rates were also estimated across 23 departments in Colombia from 28,100 individuals. Across settings, there was extensive variation in all-ages seroprevalence. Evidence for Ab-seroreversion or infection loss was found in most settings for both HTT and HCC and for HCC Ab-seroreversion in Colombia. The average duration until humans became Ab-seropositive/infected decreased as all-age (sero)prevalence increased. There was no clear relationship between the average duration humans remain Ab-seropositive and all-age seroprevalence. Marked geographical heterogeneity in T. solium transmission rates indicate the need for setting-specific intervention strategies to achieve the WHO goals.
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Affiliation(s)
- Matthew A Dixon
- Department of Infectious Disease Epidemiology and London Centre for Neglected Tropical Disease Research (LCNTDR), 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.,SCI Foundation, Edinburgh House, 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
| | | | - Charles Whittaker
- Department of Infectious Disease Epidemiology and London Centre for Neglected Tropical Disease Research (LCNTDR), 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
| | - Veronika Schmidt
- Department of Neurology, Center for Global Health, Technical University Munich (TUM), Munich, Germany.,Centre for Global Health, Institute of Health and Society, University of Oslo, Oslo, Norway
| | | | - Zulma M Cucunuba
- Department of Infectious Disease Epidemiology and London Centre for Neglected Tropical Disease Research (LCNTDR), 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
| | | | - Martin Walker
- Department of Pathobiology and Population Sciences and London Centre for Neglected Tropical Disease Research (LCNTDR), Royal Veterinary College, Hatfield, United Kingdom
| | - María-Gloria Basáñez
- Department of Infectious Disease Epidemiology and London Centre for Neglected Tropical Disease Research (LCNTDR), 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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Diaz MM, Sokhi D, Noh J, Ngugi AK, Minja FJ, Reddi P, Fèvre EM, Meyer ACL. Prevalence of Epilepsy, Human Cysticercosis, and Porcine Cysticercosis in Western Kenya. Am J Trop Med Hyg 2022; 106:1450-1455. [PMID: 38223984 PMCID: PMC9128686 DOI: 10.4269/ajtmh.21-0594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 12/21/2021] [Indexed: 01/16/2024] Open
Abstract
Cysticercosis is the leading cause of acquired epilepsy worldwide and has been shown to be highly prevalent in pig populations in western Kenya. We conducted a community-based door-to-door survey in a region of western Kenya with a high proportion of pig-keeping households. Persons with epilepsy (PWE) were determined using a screening questionnaire followed by a neurologist evaluation. Cysticercosis serum apDia antigen ELISAs and Western blot for LLGP and rT24h antigen were performed on all PWE and 2% of screen-negative patients. All PWE or people with positive apDia underwent contrast-enhanced brain computed tomography (CT). Of a sample of 810 village residents, 660 (81%) were present in the homestead, of whom 648 (98%) participated. Of these, 17 were confirmed to have lifetime epilepsy, an estimated crude prevalence of 2.6%. No humans with (N = 17) or without (N = 12) epilepsy had serological evidence of cysticercosis infection. Fourteen PWE and one individual with borderline positive apDia antigen ELISA underwent brain CT; none had radiographic findings consistent with neurocysticercosis. Nearly 30% of households kept pigs, with 69% always tethered in both wet and dry seasons. More than 8% (6/72) of pigs had palpable lingual cysts; these pigs all originated from homesteads with latrines, one-third of which were free-ranging at least some of the time. Epilepsy prevalence in our study was greater than the national prevalence, but we found no individuals with epilepsy attributable to cysticercosis. Additional studies are required to identify causes of epilepsy, human and porcine cysticercosis, the role of spatial clustering, and protective factors like host-pathogen immunity.
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Affiliation(s)
- Monica M. Diaz
- Yale University, New Haven, Connecticut
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Dilraj Sokhi
- International Livestock Research Institute, Nairobi, Kenya
| | - John Noh
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | - Prabhakhar Reddi
- Aga Khan University East Africa, Nairobi, Kenya
- Aga Khan Hospital, Kisumu, Kenya
| | - Eric M. Fèvre
- International Livestock Research Institute, Nairobi, Kenya
- University of Liverpool, Liverpool, United Kingdom
| | - Ana-Claire L. Meyer
- Yale University, New Haven, Connecticut
- Johns Hopkins University School of Medicine, Baltimore, Maryland
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Rahantamalala A, Rakotoarison RL, Rakotomalala E, Rakotondrazaka M, Kiernan J, Castle PM, Hakami L, Choi K, Rafalimanantsoa AS, Harimanana A, Wright P, Grandjean Lapierre S, Schoenhals M, Small PM, Marcos LA, Vigan-Womas I. Prevalence and factors associated with human Taenia solium taeniosis and cysticercosis in twelve remote villages of Ranomafana rainforest, Madagascar. PLoS Negl Trop Dis 2022; 16:e0010265. [PMID: 35404983 PMCID: PMC9064101 DOI: 10.1371/journal.pntd.0010265] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/03/2022] [Accepted: 02/17/2022] [Indexed: 11/18/2022] Open
Abstract
Background Infections with the tapeworm Taenia solium (taeniosis and cysticercosis) are Neglected Tropical Diseases (NTD) highly endemic in Madagascar. These infections are however underdiagnosed, underreported and their burden at the community level remains unknown especially in rural remote settings. This study aims at assessing the prevalence of T. solium infections and associated risk factors in twelve remote villages surrounding Ranomafana National Park (RNP), Ifanadiana District, Madagascar. Methodology A community based cross-sectional survey was conducted in June 2016. Stool and serum samples were collected from participants. Tapeworm carriers were identified by stool examination. Taenia species and T. solium genotypes were characterised by PCR and sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Detection of specific anti-cysticercal antibodies (IgG) or circulating cysticercal antigens was performed by ELISA or EITB/Western blot assays. Principal findings Of the 459 participants with paired stool and blood samples included ten participants from seven distinct villages harbored Taenia spp. eggs in their stools samples DNA sequencing of the cox1 gene revealed a majority of T. solium Asian genotype (9/10) carriage. The overall seroprevalences of anti-cysticercal IgGs detected by ELISA and EITB were quite similar (27.5% and 29.8% respectively). A prevalence rate of 12.4% of circulating cysticercal antigens was observed reflecting cysticercosis with viable cysts. Open defecation (Odds Ratio, OR = 1.5, 95% CI: 1.0–2.3) and promiscuity with households of more than 4 people (OR = 1.9, 95% CI: 1.1–3.1) seem to be the main risk factors associated with anticysticercal antibodies detection. Being over 15 years of age would be a risk factor associated with an active cysticercosis (OR = 1.6, 95% CI: 1.0–2.7). Females (OR = 0.5, 95% CI: 0.3–0.9) and use of river as house water source (OR = 0.3, 95% CI: 0.1–1.5) were less likely to have cysticercosis with viable cysts. Conclusions/Significance This study indicates a high exposure of the investigated population to T. solium infections with a high prevalence of cysticercosis with viable cysts. These data can be useful to strengthen public health interventions in these remote settings. Taenia solium infections in humans (taeniosis and neurocysticercosis) and in pigs (cysticercosis) are endemic in Madagascar presenting a significant public health burden. Neurocysticercosis with localization of the parasite in the Central Nervous System is the most severe and frequent form of parasitic brain diseases in humans and responsible of thousands of worldwide deaths per year. Madagascar is a T. solium endemic country where poor sanitation, free roaming pigs and outdoor defecation are common, and maintain the parasite transmission cycle. Little information is available regarding taeniosis/cysticercosis epidemiology in Madagascar. We carried out a community-based study to investigate the prevalence of human taeniosis/cysticercosis and associated risk factors in 12 rural remote villages of Ranomafana and Kelilalina townships (Ifanadiana district, Madagascar). Our results reveal that in 7/12 villages investigated, a high number of participants had teaniosis. Moreover, a high number of active cysticercosis cases were detected. Open defecation and promiscuity were seemed to be the main risk factors associated to T. solium infections. The results of this study will be useful to guide interventions in these remote settings surrounding the Ranomafana National Park.
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Affiliation(s)
- Anjanirina Rahantamalala
- Institut Pasteur de Madagascar, Immunology of Infectious Diseases Unit, Antananarivo, Madagascar
- * E-mail:
| | | | - Emma Rakotomalala
- Institut Pasteur de Madagascar, Immunology of Infectious Diseases Unit, Antananarivo, Madagascar
| | | | - Jaydon Kiernan
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
| | - Paul M. Castle
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
| | - Lee Hakami
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
| | - Koeun Choi
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
| | | | - Aina Harimanana
- Institut Pasteur de Madagascar, Epidemiology and Clinical Research Unit, Antananarivo, Madagascar
| | - Patricia Wright
- Centre ValBio, Ranomafana, Ifanadiana, Madagascar
- Department of Anthropology, Stony Brook University, Stony Brook, New York, United States of America
| | - Simon Grandjean Lapierre
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
| | - Matthieu Schoenhals
- Institut Pasteur de Madagascar, Immunology of Infectious Diseases Unit, Antananarivo, Madagascar
| | - Peter M. Small
- Centre ValBio, Ranomafana, Ifanadiana, Madagascar
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
| | - Luis A. Marcos
- Global Health Institute, Stony Brook University, Stony Brook, New York, United States of America
- Division of Infectious Diseases, Department of Medicine, Department of Microbiology and Molecular Genetics, Stony Brook University, Stony Brook, New York, United States of America
| | - Inès Vigan-Womas
- Institut Pasteur de Madagascar, Immunology of Infectious Diseases Unit, Antananarivo, Madagascar
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Kusolsuk T, Chaisiri K, Poodeepiyasawad A, Sa-Nguankiat S, Homsuwan N, Yanagida T, Okamoto M, Watthanakulpanich D, Waikagul J, Dekumyoy P, Komalamisra C, Ito A. Risk factors and prevalence of taeniasis among the Karen people of Tha Song Yang District, Tak Province, Thailand. ACTA ACUST UNITED AC 2021; 28:53. [PMID: 34142955 PMCID: PMC8212811 DOI: 10.1051/parasite/2021041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 04/26/2021] [Indexed: 11/15/2022]
Abstract
Taeniasis remains a prevalent public health problem in Thailand. National helminthiasis surveys report only the incidence of Taenia spp. eggs. The ability to differentiate Taenia species using morphological and molecular techniques is vital for epidemiological surveys. This study detected taeniasis carriers and other helminthic infections by Kato's thick smear technique and identified the Taenia species by multiplex PCR. The study subjects were the ethnic Karen people in Tha Song Yang District, Tak Province, Thailand, bordering Myanmar. In total, 983 faecal samples from villagers were examined for helminthiases. Interview-based questionnaires were used to gather information on possible risk factors for infection. The prevalence of helminth infections was 42.7% (420/983), including single (37.3%, 367/983) and mixed infections (5.4%, 53/983). The most common infection (19.23%, 189/983) was Ascaris lumbricoides, whereas taeniasis carriers comprised 2.8% (28/983). Multiplex PCR of Cox1 was used for species identification of Taenia tapeworms, eggs, or both in 22 taeniasis carriers. Most of the parasites (20 cases) were Taenia solium, with two cases of Taenia saginata. Taenia saginata asiatica was not found in the villagers examined. The analysis of 314 completed questionnaires showed that a statistically significant (p < 0.05) risk of taeniasis was correlated with being male, a history of being allowed to forage during childhood, a history of seeing tapeworm proglottids, and a history of raw or undercooked pork consumption. Health education programmes must seek to reduce and prevent reinfection in these communities.
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Affiliation(s)
- Teera Kusolsuk
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Kittipong Chaisiri
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Akkarin Poodeepiyasawad
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Surapol Sa-Nguankiat
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Nirundorn Homsuwan
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Tetsuya Yanagida
- Laboratory of Veterinary Parasitology, Joint Faculty of Veterinary Medicine, 1677-1 Yoshida, Yamaguchi City, Yamaguchi, 753-8511, Japan
| | - Munehiro Okamoto
- Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan
| | - Dorn Watthanakulpanich
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Jitra Waikagul
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Paron Dekumyoy
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Chalit Komalamisra
- Mahidol Bangkok School of Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi 10400, Bangkok, Thailand
| | - Akira Ito
- Department of Parasitology, Asahikawa Medical University, Midorigaoka-Higashi 2-1-1-1, Asahikawa 078-8510, Hokkaido, Japan
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Li T, Chen X, Budke CM, Zhou Y, Duan M, Wang C, Zhong B, Liu Y, Luo J, He W, Shang J, Ito A. New insights on the Taenia solium tapeworm using molecular tools: age-based human definitive host prevalence and deliberation on parasite life span. Pathog Glob Health 2021; 116:99-106. [PMID: 34029172 PMCID: PMC8933036 DOI: 10.1080/20477724.2021.1928869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Information on age-based Taenia solium taeniasis prevalence is crucial for control of cysticercosis. T. solium taeniasis prevalence was determined for a village in Liangshan Prefecture, Sichuan Province, China that was co-endemic for T. solium, Taenia saginata asiatica, and Taenia saginata. Individuals who were Taenia egg-positive by stool microscopy and/or expelled tapeworms or proglottids post-treatment were diagnosed as having taeniasis. Infecting species was identified via multiplex PCR on tapeworm specimens or coproPCR followed by sequencing. In addition, initial stool samples from 10 children with taeniasis suspected of having spontaneous expulsion of tapeworms within the period between diagnosis and treatment were subject to species confirmation via coproPCR and sequencing. Of the 389 study subjects, 194 (49.9%) were diagnosed with taeniasis. Children (< 16 years of age) had a higher T. solium taeniasis prevalence (8.8%) than older individuals (2.5%) (P = 0.0127). Molecular analysis of initial stool samples from 7 of 10 children suspected of spontaneously passing tapeworms indicated 6 infections due to T. solium and 1 infection due to T. saginata. This study found that young children had a higher T. solium taeniasis prevalence than older individuals, providing additional support for the belief that adult T. solium likely has a relatively short lifespan compared to other Taenia species with human definitive hosts.
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Affiliation(s)
- Tiaoying Li
- Institute of Parasitic Diseases, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Xingwang Chen
- Institute of Parasitic Diseases, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Christine M Budke
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Yuangui Zhou
- Department of Endemic Diseases, Muli County Center for Disease Control and Prevention, Muli, China
| | - Mianchuan Duan
- Department of Endemic Diseases, Muli County Center for Disease Control and Prevention, Muli, China
| | - Celine Wang
- Williamsville School District, Buffalo, NY, USA
| | - Bo Zhong
- Institute of Parasitic Diseases, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Yang Liu
- Institute of Parasitic Diseases, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Jianying Luo
- Department of Endemic Diseases, Muli County Center for Disease Control and Prevention, Muli, China
| | - Wei He
- Institute of Parasitic Diseases, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Jingye Shang
- Institute of Parasitic Diseases, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Akira Ito
- Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan
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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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Hendrickx E, Thomas LF, Dorny P, Bobić B, Braae UC, Devleesschauwer B, Eichenberger RM, Gabriël S, Saratsis A, Torgerson PR, Robertson LJ, Dermauw V. Epidemiology of Taenia saginata taeniosis/cysticercosis: a systematic review of the distribution in West and Central Africa. Parasit Vectors 2019; 12:324. [PMID: 31248445 PMCID: PMC6598244 DOI: 10.1186/s13071-019-3584-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/24/2019] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The zoonotic tapeworm Taenia saginata, although causing only minor discomfort in humans, is responsible for considerable economic losses in the livestock sector due to condemnation or downgrading of infected beef carcasses. An overview of current knowledge on the distribution and prevalence of this parasite in West and Central Africa is lacking. METHODS We conducted a systematic review, collecting information on published and grey literature about T. saginata taeniosis and bovine cysticercosis from 27 countries/territories in West and Central Africa, published between January 1st, 1990 and December 31st, 2017. RESULTS The literature search retrieved 1672 records, of which 51 and 45 were retained for a qualitative and quantitative synthesis, respectively. Non-specified human taeniosis cases were described for Nigeria, Cameroon, Senegal, Burkina Faso, Democratic Republic Congo, Guinea, and Ivory Coast (seven out of 27 countries/territories), while T. saginata taeniosis specifically was only reported for Cameroon. Most prevalence estimates for taeniosis ranged between 0-11%, while three studies from Nigeria reported prevalence estimates ranging between 23-50%. None of the studies included molecular confirmation of the causative species. The presence of bovine cysticercosis was reported for Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Democratic Republic Congo, Ghana, Guinea, Ivory Coast, Mali, Niger, Nigeria, Senegal, and Tristan da Cunha (14 out of 27 countries/territories). Prevalence estimates ranged between 0-29%. CONCLUSIONS Our systematic review has revealed that human taeniosis and bovine cysticercosis are seriously understudied in West and Central Africa. The high prevalence estimates of both conditions suggest an active dissemination of this parasite in the region, calling for a concerted One Health action from public health, veterinary health and food surveillance sectors.
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Affiliation(s)
- Emilie Hendrickx
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Lian F. Thomas
- International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi, Kenya
- Institute for Infection & Global Health, University of Liverpool, Neston, UK
| | - 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
| | - Branko Bobić
- Centre of Excellence for Food and Vector-borne Zoonoses, Institute for Medical Research, University of Belgrade, Dr Subotića 4, Belgrade, 11000 Serbia
| | - Uffe Christian Braae
- One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, Saint Kitts and Nevis
- Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, 2300 Copenhagen, Denmark
| | - Brecht Devleesschauwer
- Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
- Department of Epidemiology and Public Health, Sciensano, Brussels, Belgium
| | - Ramon M. Eichenberger
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Sarah Gabriël
- Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Anastasios Saratsis
- Veterinary Research Institute, Hellenic Agricultural Organisation Demeter, Thermi, 57001 Greece
| | - Paul R. Torgerson
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Lucy J. Robertson
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Veronique Dermauw
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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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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Ng-Nguyen D, Traub RJ, Nguyen VAT, Breen K, Stevenson MA. Spatial distribution of Taenia solium exposure in humans and pigs in the Central Highlands of Vietnam. PLoS Negl Trop Dis 2018; 12:e0006810. [PMID: 30235251 PMCID: PMC6168177 DOI: 10.1371/journal.pntd.0006810] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 10/02/2018] [Accepted: 09/01/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Taenia solium, a pork-borne parasitic zoonosis, is the cause of taeniasis and cysticercosis in humans. In Vietnam, poor sanitation, the practice of outdoor defecation and consumption of raw/undercooked pork have been associated with infection/exposure to T. solium in both humans and pigs. The broad-scale geographic distribution of the prevalence of T. solium varies throughout the country with infection restricted to isolated foci in the north and a more sporadic geographic distribution in the Central Highlands and the south. While cross-sectional studies have allowed the broad-scale geographic distribution of T. solium to be described, details of the geographic distribution of T. solium at finer spatial scales have not been described in detail. This study provides a descriptive spatial analysis of T. solium exposure in humans and pigs and T. solium taeniasis in humans within individual households in village communities of Dak Lak in the Central Highlands of Vietnam. METHODOLOGY/PRINCIPAL FINDINGS We used Ripley's K-function to describe spatial dependence in T. solium exposure positive and negative human and pig households and T. solium taeniasis exposure positive and negative households in villages within the districts of Buon Don, Krong Nang and M'Drak of Dak Lak province in the Central Highlands of Vietnam. The prevalence of exposure to T. solium in pigs in Dak Lak province was 9 (95% CI 5 to 17) cases per 1000 pigs at risk. The prevalence of exposure to the parasite in humans was somewhat higher at 5 (95% CI 3 to 8) cases per 100 individuals at risk. Spatial aggregations of T. solium exposure-positive pig and human households occurred in some, but not all of the villages in the three study districts. Human exposure-positive households were found to be aggregated within a distance of 200 to 300 m in villages in Krong Nang district compared with distances of up to 1500 m for pig exposure-positive households in villages in M'Drak district. Although this study demonstrated the aggregation of households in which either T. solium exposure- or taeniasis-positive individuals were present, we were unable to identify an association between the two due to the very low number of T. solium taeniasis-positive households. CONCLUSIONS Spatial aggregations of T. solium exposure-positive pig and human households occurred in some, but not all of the villages in the three study districts. We were unable to definitively identify reasons for these findings but speculate that they were due to a combination of demographic, anthropological and micro-environmental factors. To more definitively identify characteristics that increase cysticercosis risk we propose that cross-sectional studies similar in design to that described in this paper should be applied in other provinces of Vietnam.
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Affiliation(s)
- Dinh Ng-Nguyen
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Dak Lak, Vietnam
| | - Rebecca Justine Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Van-Anh Thi Nguyen
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Dak Lak, Vietnam
| | - Kathleen Breen
- Department of Livestock, Montana Veterinary Diagnostic Lab, Bozeman, Montana, United States of America
| | - Mark Anthony Stevenson
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
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Mushonga B, Habarugira G, Birori A, Kandiwa E, Samkange A, Bhebhe E. An epidemiological survey of the magnitude and local perceptions of porcine cysticercosis by two methods in Nyaruguru district, Rwanda. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2018; 14:18-24. [PMID: 31014726 DOI: 10.1016/j.vprsr.2018.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 07/28/2018] [Accepted: 07/30/2018] [Indexed: 10/28/2022]
Abstract
This study investigated the magnitude of porcine cysticercosis (PC), its risk factors, economic effects and the perceptions of 80 pig farmers from Nyabimata (n = 38) and Muganza (n = 42) and 20 registered butchers in the Nyaruguru district of Rwanda. January to December 2013 slaughter records from Kamirabagenzi market were also analysed for PC diagnoses based on the tongue test and meat inspection. During this period, the responding farmers' records showed a tongue test-based PC magnitude (3.9%, n = 984) which was lower than the collective tongue test-based PC magnitude of 9.2% (n = 1720) at Kamirabagenzi (p < .05). The overall magnitude of PC based on routine meat inspection diagnosis at Kamirabagenzi was 4%. The overall magnitude of PC for respondents using Free-range production systems (7.9%) was significantly greater than for those in Semi-intensive (2.1%) and Intensive production systems (1.5%) (p < .05). Though most farmers (90%) knew that PC is zoonotic, only 22.5% of the farmers opted for treatment of PC-infected pigs and 52.5% were willing to seek veterinary inspection while the rest (25%) opted to circumvent veterinary inspection (P > .05). Most butchers (70%) indicated they would circumvent veterinary inspection and continue to slaughter PC-positive animals whilst the rest (30%) indicated they would resell PC positive animals to defray costs (P < .05). The low sensitivity and specificity of methods used for PC detection in the study, implies that this may just be the tip of an iceberg and the actual magnitude is most likely to be much higher. In conclusion, PC is endemic in the Nyaruguru district of Rwanda with a high proportion of positive animals. The condition has public health implications and is worsening the economic plight of the impoverished Nyaruguru community.
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Affiliation(s)
- Borden Mushonga
- Department of Biomedical Sciences, School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, Neudamm Campus, University of Namibia, P. Bag 13301, Pioneerspark, Windhoek, Namibia
| | - Gervais Habarugira
- School of Animal Sciences and Veterinary Medicine, University of Rwanda, P.O. Box 57, Nyagatare, Rwanda.
| | - Aloys Birori
- School of Animal Sciences and Veterinary Medicine, University of Rwanda, P.O. Box 57, Nyagatare, Rwanda
| | - Erick Kandiwa
- Department of Biomedical Sciences, School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, Neudamm Campus, University of Namibia, P. Bag 13301, Pioneerspark, Windhoek, Namibia
| | - Alaster Samkange
- Department of Clinical Veterinary Studies, School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, Neudamm Campus, University of Namibia, P. Bag 13301, Pioneerspark, Windhoek, Namibia
| | - Evison Bhebhe
- Department of Animal Science, School of Agriculture, University of Venda, Thohoyandou 0950, South Africa
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15
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Oliveira FLP, Cançado ALF, de Souza G, Moreira GJP, Kulldorff M. Border analysis for spatial clusters. Int J Health Geogr 2018; 17:5. [PMID: 29454357 PMCID: PMC5816564 DOI: 10.1186/s12942-018-0124-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 01/21/2018] [Indexed: 12/21/2022] Open
Abstract
Background The spatial scan statistic is widely used by public health professionals in the detection of spatial clusters in inhomogeneous point process. The most popular version of the spatial scan statistic uses a circular-shaped scanning window. Several other variants, using other parametric or non-parametric shapes, are also available. However, none of them offer information about the uncertainty on the borders of the detected clusters. Method We propose a new method to evaluate uncertainty on the boundaries of spatial clusters identified through the spatial scan statistic for Poisson data. For each spatial data location i, a function F(i) is calculated. While not a probability, this function takes values in the [0, 1] interval, with a higher value indicating more evidence that the location belongs to the true cluster. Results Through a set of simulation studies, we show that the F function provides a way to define, measure and visualize the certainty or uncertainty of each specific location belonging to the true cluster. The method can be applied whether there are one or multiple detected clusters on the map. We illustrate the new method on a data set concerning Chagas disease in Minas Gerais, Brazil. Conclusions The higher the intensity given to an area, the higher the plausibility of that particular area to belong to the true cluster in case it exists. This way, the F function provides information from which the public health practitioner can perform a border analysis of the detected spatial scan statistic clusters. We have implemented and illustrated the border analysis F function in the context of the circular spatial scan statistic for spatially aggregated Poisson data. The definition is clearly independent of both the shape of the scanning window and the probability model under which the data is generated. To make the new method widely available to users, it has been implemented in the freely available SaTScan\documentclass[12pt]{minimal}
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\begin{document}$$^\mathrm{TM}$$\end{document}TM software www.satscan.org.
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Affiliation(s)
- Fernando L P Oliveira
- Department of Statistics, UFOP, Morro do Cruzeiro, Campus Universitário, Ouro Preto, MG, 35400-000, Brazil.
| | | | | | | | - Martin Kulldorff
- Division of Pharmacoepidemiology and Pharmacoeconomics, Harvard Medical School, Boston, MA, USA
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Frew PM, Lutz CS, Ofotokun I, Marconi VC, del Rio C. Geospatial mapping to identify feasible HIV prevention and treatment strategies that target specific settings. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:59. [PMID: 29610750 PMCID: PMC5879532 DOI: 10.21037/atm.2017.12.20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 12/05/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Paula M. Frew
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
- Hubert Department of Global Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
- Department of Behavioral Sciences and Health Education, Emory University Rollins School of Public Health, Atlanta, GA, USA
- Emory Center for AIDS Research, Atlanta, GA, USA
| | - Chelsea S. Lutz
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Ighovwerha Ofotokun
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
- Emory Center for AIDS Research, Atlanta, GA, USA
| | - Vincent C. Marconi
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
- Hubert Department of Global Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
- Emory Center for AIDS Research, Atlanta, GA, USA
| | - Carlos del Rio
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
- Hubert Department of Global Health, Emory University Rollins School of Public Health, Atlanta, GA, USA
- Emory Center for AIDS Research, Atlanta, GA, USA
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Abstract
PURPOSE OF REVIEW Cestodes infections in humans are among the most prevalent parasitosis worldwide. Although tapeworm infection is often asymptomatic, they can be associated with a range of symptoms. The landscape of cestode infections is changing with rapid diagnosis techniques and advanced molecular diagnosis aiding in identification of species specific epidemiology. RECENT FINDINGS Traditional descriptions of species by location have been challenged with molecular diagnostic techniques, which show variation in distribution of species, thought to be because of globalization and importation of disease. MAIN THEMES IN LITERATURE Epidemiology, molecular diagnostic techniques. SUMMARY Infection by tapeworms is often asymptomatic or accompanied by mild symptoms though can occasionally cause severe disease and contribute to anemia and malnutrition. Tapeworm infection is most prevalent in resource-poor countries but the distribution is worldwide. Epidemiology of infection is changing because of molecular diagnostics, which allow more accurate tracking of species.
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Affiliation(s)
- Camille Webb
- Division of Infectious Disease Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
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Madinga J, Polman K, Kanobana K, van Lieshout L, Brienen E, Praet N, Kabwe C, Gabriël S, Dorny P, Lutumba P, Speybroeck N. Epidemiology of polyparasitism with Taenia solium, schistosomes and soil-transmitted helminths in the co-endemic village of Malanga, Democratic Republic of Congo. Acta Trop 2017; 171:186-193. [PMID: 28336269 DOI: 10.1016/j.actatropica.2017.03.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 03/10/2017] [Accepted: 03/18/2017] [Indexed: 11/27/2022]
Abstract
Helminth co-infections are common in sub-Saharan Africa. However, little is known about the distribution and determinants of co-infections with Taenia solium taeniasis/cysticercosis. Building on a previous community-based study on human cysticercosis in Malanga village, we investigated co-infections with Taenia solium, soil-transmitted helminths (STHs) and Schistosoma spp and associated risk factors in a random subsample of 330 participants. Real time PCR assays were used to detect DNA of soil-transmitted helminths (STHs), T. solium and Schistosoma in stool samples and Schistosoma DNA in urine samples. Serum samples were tested for T. solium cysticercosis using the B158/B60 monoclonal antibody-based antigen ELISA. Bivariate analysis and logistic regression were applied to assess associations of single and co-infections with common risk factors (age, sex, area, hygiene) as well as pair wise associations between helminth species. Overall, 240 (72.7%) participants were infected with at least one helminth species; 128 (38.8%) harbored at least two helminth species (16.1% with STHs-Schistosoma, 14.5% with STHs-T. solium taeniasis/cysticercosis and 8.2% with Schistosoma-T. solium taeniasis/cysticercosis co-infections). No significant associations were found between Schistosoma-T. solium taeniasis/cysticercosis co-infection and any of the risk factors studied. Males (OR=2 (95%CI=1.1-5), p=0.03) and open defecation behavior (OR=3.8 (95%CI=1.1-6.5), p=0.04) were associated with higher odds of STHs-T. solium taeniasis/cysticercosis co-infection. Village districts that were found at high risk of T. solium taeniasis/cysticercosis were also at high risk of co-infection with STHs and T. solium taeniasis/cysticercosis (OR=3.2 (95%CI=1.1-7.8), p=0.03). Significant pair-wise associations were found between T. solium cysticerci and Necator americanus (OR=2.2 (95%CI=1.2-3.8), p<0.01) as well as Strongyloides stercoralis (OR=2.7 (95%CI=1.1-6.5), p=0.02). These findings show that co-infections with T. solium are common in this polyparasitic community in DRC. Our results on risk factors of helminth co-infections and specific associations between helminths may contribute to a better integration of control within programmes that target more than one NTD.
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