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Julius RS, Zengeya TA, Schwan EV, Chimimba CT. Geospatial Modelling and Univariate Analysis of Commensal Rodent-Borne Cestodoses: The Case of Invasive spp. of Rattus and Indigenous Mastomys coucha From South Africa. Front Vet Sci 2021; 8:678478. [PMID: 34179170 PMCID: PMC8226005 DOI: 10.3389/fvets.2021.678478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/18/2021] [Indexed: 11/23/2022] Open
Abstract
Poor socio-economic and unsanitary conditions are conducive to commensal rodent infestations, and these conditions are widespread in South Africa. Cestode species of zoonotic interest are highly prevalent in commensal rodents, such as invasive Rattus norvegicus, Rattus rattus, Rattus tanezumi, and indigenous Mastomys coucha, and have been frequently recovered from human stool samples. These cestode species have similar transmission dynamics to traditional soil-transmitted helminths (STHs), which ties them to infections associated with poverty and poor sanitation. Univariate analysis was used in the present study to determine the association between rodent-related factors and cestode prevalence, while ecological niche modelling was used to infer the potential distribution of the cestode species in South Africa. Cestode prevalence was found to be associated with older rodents, but it was not significantly associated with sex, and ectoparasite presence. The predicted occurrence for rodent-borne cestodes predominantly coincided with large human settlements, typically associated with significant anthropogenic changes. In addition, cestode parasite occurrence was predicted to include areas both inland and along the coast. This is possibly related to the commensal behaviour of the rodent hosts. The study highlights the rodent-related factors associated with the prevalence of parasites in the host community, as well as the environmental variables associated with parasite infective stages that influence host exposure. The application of geospatial modelling together with univariate analysis to predict and explain rodent-borne parasite prevalence may be useful to inform management strategies for targeted interventions.
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Affiliation(s)
- Rolanda S Julius
- Department of Zoology and Entomology, Department Science & Technology (DST)- National Research Foundation (NRF) Centre of Excellence for Invasion Biology (CIB), University of Pretoria, Pretoria, South Africa
| | - Tsungai A Zengeya
- Department of Zoology and Entomology, Department Science & Technology (DST)- National Research Foundation (NRF) Centre of Excellence for Invasion Biology (CIB), University of Pretoria, Pretoria, South Africa.,Kirstenbosch Research Centre, South African Biodiversity Institute, Cape Town, South Africa
| | - E Volker Schwan
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - Christian T Chimimba
- Department of Zoology and Entomology, Department Science & Technology (DST)- National Research Foundation (NRF) Centre of Excellence for Invasion Biology (CIB), University of Pretoria, Pretoria, South Africa
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Gastrointestinal Helminths in Slaughtered Cattle in Ibadan, South-Western Nigeria. J Vet Med 2014; 2014:923561. [PMID: 26464944 PMCID: PMC4590849 DOI: 10.1155/2014/923561] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/30/2014] [Accepted: 10/08/2014] [Indexed: 11/25/2022] Open
Abstract
As part of an ongoing project to investigate the epidemiology of gastrointestinal helminths of cattle in Nigeria, we carried out a systematic random sampling of cattle slaughtered in a major abattoir in Ibadan, south-western Nigeria. Using sedimentation and floatation methods, we analyzed fecal samples from 397 animals between March and May 2013. Overall, 163 (41.6%) of the animals had at least one gastrointestinal helminth egg, comprising a total of eight helminths from different genera (i.e., four nematodes, three trematodes, and one cestode), with nematode infection being the highest (71.54%). In addition, eggs of four helminths of zoonotic importance were also obtained. Among the cattle examined, the Bunaji breed was the most infected (46%; 69/150). Furthermore, female animals (OR = 1.1; 95% CI: 0.60–1.84) and animals with moderate body condition (OR = 1.2; 95% CI: 0.80–1.79) are more likely to be positive to helminth infection. Our findings reveal that there were helminth infections of both zoonotic and socioeconomic importance among the cattle screened. Considering the impact of the infections on animal production and public health, we advocate that effective prophylactic measures be adopted as a first step to curtail helminth infections of cattle in Nigeria.
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Pullan RL, Smith JL, Jasrasaria R, Brooker SJ. Global numbers of infection and disease burden of soil transmitted helminth infections in 2010. Parasit Vectors 2014; 7:37. [PMID: 24447578 PMCID: PMC3905661 DOI: 10.1186/1756-3305-7-37] [Citation(s) in RCA: 863] [Impact Index Per Article: 86.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 01/06/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Quantifying the burden of parasitic diseases in relation to other diseases and injuries requires reliable estimates of prevalence for each disease and an analytic framework within which to estimate attributable morbidity and mortality. Here we use data included in the Global Atlas of Helminth Infection to derive new global estimates of numbers infected with intestinal nematodes (soil-transmitted helminths, STH: Ascaris lumbricoides, Trichuris trichiura and the hookworms) and use disability-adjusted life years (DALYs) to estimate disease burden. METHODS Prevalence data for 6,091 locations in 118 countries were sourced and used to estimate age-stratified mean prevalence for sub-national administrative units via a combination of model-based geostatistics (for sub-Saharan Africa) and empirical approaches (for all other regions). Geographical variation in infection prevalence within these units was approximated using modelled logit-normal distributions, and numbers of individuals with infection intensities above given thresholds estimated for each species using negative binomial distributions and age-specific worm/egg burden thresholds. Finally, age-stratified prevalence estimates for each level of infection intensity were incorporated into the Global Burden of Disease Study 2010 analytic framework to estimate the global burden of morbidity and mortality associated with each STH infection. RESULTS Globally, an estimated 438.9 million people (95% Credible Interval (CI), 406.3 - 480.2 million) were infected with hookworm in 2010, 819.0 million (95% CI, 771.7 - 891.6 million) with A. lumbricoides and 464.6 million (95% CI, 429.6 - 508.0 million) with T. trichiura. Of the 4.98 million years lived with disability (YLDs) attributable to STH, 65% were attributable to hookworm, 22% to A. lumbricoides and the remaining 13% to T. trichiura. The vast majority of STH infections (67%) and YLDs (68%) occurred in Asia. When considering YLDs relative to total populations at risk however, the burden distribution varied more considerably within major global regions than between them. CONCLUSION Improvements in the cartography of helminth infection, combined with mathematical modelling approaches, have resulted in the most comprehensive contemporary estimates for the public health burden of STH. These numbers form an important benchmark upon which to evaluate future scale-up of major control efforts.
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Affiliation(s)
- Rachel L Pullan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Jennifer L Smith
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Rashmi Jasrasaria
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, USA
- Stanford University School of Medicine, Stanford, CA, USA
| | - Simon J Brooker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
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Nxasana N, Baba K, Bhat V, Vasaikar S. Prevalence of intestinal parasites in primary school children of mthatha, eastern cape province, South Africa. Ann Med Health Sci Res 2013; 3:511-6. [PMID: 24380000 PMCID: PMC3868115 DOI: 10.4103/2141-9248.122064] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background: The presence of intestinal parasites in a population group is indicative of lack of proper sanitation, low economic standards and poor educational background. Aim: To determine the prevalence of intestinal parasites in primary school children of Mthatha, South Africa and relate this to their socio-economic status. Subjects and Methods: The study population was randomly selected from four governmental schools, rural and urban, from April 2009 to September 2009. A total of 162 learners (85 boys and 77 girls) participated in this survey. Parasitological data were collected by analyzing stool samples using Formalin ethyl-acetate concentration technique. Socio-economic and epidemiologic data were collected by means of a pre-tested structured questionnaire, covering the important relevant aspects, in this descriptive, cross sectional and analytical study. Data were analyzed descriptively and inferentially with SPSS satistical software, and P values of <0.05 were considered as significant. Results: Out of 162 learners analyzed, 64.8% (105/162) stool samples were positive for ova and cysts of which 57.4% (93/162) were known pathogenic parasites. The most common parasite was Ascaris lumbricoides 29.0% (47/162), followed by Giardia lamblia 9.9% (16/162) and Entamoeba histolytica/dispar 6.8% (11/162) (Other parasites observed but at lower rates of occurrence were Iodamoeba butschlii, Trichuris trichiura, Hymenolepis nana, Taenia spp, Chilomastix mesnili, and Fasciola spp. Our findings showed no significant difference in parasitic infections between urban and rural learners, gender and the age of these learners. Significant associations between parasitic infections and parents’ unemployment and lower education were observed. Conclusion: Prevalence of worm infestation was more than 50%; therefore, there was a need for mass de-worming of school children in these communities and also a need for other public health interventions like health education programs and improvement of sanitation.
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Affiliation(s)
- N Nxasana
- Department of Medical Microbiology, Walter Sisulu University, Mthatha, Eastern Cape Province, South Africa
| | - K Baba
- TAD - NHLS/University of Pretoria, South Africa
| | - Vg Bhat
- Department of Microbiology, Advanced Center for Treatment Research, and Education in Cancer, Tata Memorial Center, Navi Mumbai, India
| | - Sd Vasaikar
- Department of Medical Microbiology, Walter Sisulu University, Mthatha, Eastern Cape Province, South Africa
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van Soelen N, Mandalakas AM, Kirchner HL, Walzl G, Grewal HMS, Jacobsen M, Hesseling AC. Effect of Ascaris Lumbricoides specific IgE on tuberculin skin test responses in children in a high-burden setting: a cross-sectional community-based study. BMC Infect Dis 2012; 12:211. [PMID: 22966931 PMCID: PMC3482567 DOI: 10.1186/1471-2334-12-211] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 08/06/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND M.tuberculosis (M.tb) is associated with enhanced T helper cell type 1 (Th1) immune responses while helminth infection is associated with T helper cell type 2 (Th2) immune responses. Our aim was to investigate whether helminth infection could influence the ability to generate an appropriate Th1 immune response that is characterized by a positive tuberculin skin test (TST), in M.tb exposed children. METHODS We completed a community-based, cross sectional household contact tracing study, using matched enrolment of HIV negative children with and without documented household M.tb exposure. We documented demographics, clinical characteristics, HIV status, M.tb exposure (using a standard contact score) and M.tb infection status (TST > = 10 mm). Ascaris lumbricoides-specific IgE was used as proxy for Ascaris infection/exposure. RESULTS Of 271 children (median age 4 years (range: 4 months to 15 years)) enrolled, 65 participants (24%) were serum positive for Ascaris IgE. There were 168 (62%) children with a documented household tuberculosis contact and 107 (40%) were (TST) positive overall.A positive TST was associated with increasing age (Odds Ratio (OR) =1.17, p < 0.001), increasing M.tb contact score (OR = 1.17, p < 0.001), previous tuberculosis treatment (OR = 4.8, p = 0.06) and previous isoniazid preventive treatment (OR = 3.16, p = 0.01). A visible bacillus Calmette-Guérin (BCG) scar was associated with reduced odds of being TST positive (OR = 0.42, p = 0.01).Ascaris IgE was not associated with TST status in univariate analysis (OR = 0.9, p = 0.6), but multivariable logistic regression analysis suggested an inverse association between Ascaris IgE status and a positive TST (OR = 0.6, p = 0.08), when adjusted for age, and M.tb contact score. The addition of an age interaction term to the model suggested that the age effect was stronger among Ascaris IgE positive children; the effect of being Ascaris IgE positive significantly reduced the odds of being TST positive amongst younger children while this effect weakened with increasing age. CONCLUSIONS Our preliminary findings highlight a high prevalence of both Ascaris exposure/infection and M.tb infection in children in an urban setting. Helminth exposure/infection may reduce the immune response following M.tb exposure when controlling for epidemiological and clinical covariates. These findings might be relevant to the interpretation of immunological tests of M.tb infection in children.
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Affiliation(s)
- Nelda van Soelen
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Anna M Mandalakas
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Health Sciences, Stellenbosch University, Tygerberg, South Africa
- Section on Retrovirology and Global Health, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Center for Global Health, Texas Children’s Hospital, Houston, TX, USA
| | | | - Gerhard Walzl
- Immunology Research Group, Department of Biomedical Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Harleen M S Grewal
- Section of Microbiology and Immunology, The Gade Institute, University of Bergen and Department of Microbiology, Haukeland University Hospital, Bergen, Norway
| | - Marc Jacobsen
- Deptartment of General Pediatrics and Neonatology, University Childrens Hospital, Duesseldorf, 40225, Germany
| | - Anneke C Hesseling
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Health Sciences, Stellenbosch University, Tygerberg, South Africa
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Ravasi DF, O’Riain MJ, Davids F, Illing N. Phylogenetic evidence that two distinct Trichuris genotypes infect both humans and non-human primates. PLoS One 2012; 7:e44187. [PMID: 22952922 PMCID: PMC3429462 DOI: 10.1371/journal.pone.0044187] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 07/30/2012] [Indexed: 11/18/2022] Open
Abstract
Although there has been extensive debate about whether Trichuris suis and Trichuris trichiura are separate species, only one species of the whipworm T. trichiura has been considered to infect humans and non-human primates. In order to investigate potential cross infection of Trichuris sp. between baboons and humans in the Cape Peninsula, South Africa, we sequenced the ITS1-5.8S-ITS2 region of adult Trichuris sp. worms isolated from five baboons from three different troops, namely the Cape Peninsula troop, Groot Olifantsbos troop and Da Gama Park troop. This region was also sequenced from T. trichiura isolated from a human patient from central Africa (Cameroon) for comparison. By combining this dataset with Genbank records for Trichuris isolated from other humans, non-human primates and pigs from several different countries in Europe, Asia, and Africa, we confirmed the identification of two distinct Trichuris genotypes that infect primates. Trichuris sp. isolated from the Peninsula baboons fell into two distinct clades that were found to also infect human patients from Cameroon, Uganda and Jamaica (named the CP-GOB clade) and China, Thailand, the Czech Republic, and Uganda (named the DG clade), respectively. The divergence of these Trichuris clades is ancient and precedes the diversification of T. suis which clustered closely to the CP-GOB clade. The identification of two distinct Trichuris genotypes infecting both humans and non-human primates is important for the ongoing treatment of Trichuris which is estimated to infect 600 million people worldwide. Currently baboons in the Cape Peninsula, which visit urban areas, provide a constant risk of infection to local communities. A reduction in spatial overlap between humans and baboons is thus an important measure to reduce both cross-transmission and zoonoses of helminthes in Southern Africa.
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Affiliation(s)
- Damiana F. Ravasi
- Department of Zoology, University of Cape Town, Rondebosch, South Africa
| | - Mannus J. O’Riain
- Department of Zoology, University of Cape Town, Rondebosch, South Africa
| | - Faezah Davids
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, South Africa
| | - Nicola Illing
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, South Africa
- * E-mail:
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