Allergic sensitization and work related asthma among poultry workers in South Africa

dc.contributor.advisorJeebhay, Mohameden_ZA
dc.contributor.advisorBaatjies, Roslynnen_ZA
dc.contributor.authorNgajilo, Dorothyen_ZA
dc.date.accessioned2017-06-06T09:44:57Z
dc.date.available2017-06-06T09:44:57Z
dc.date.issued2016en_ZA
dc.description.abstractObjective: The aim of the study was to determine the risk factors associated with allergic sensitisation and various asthma phenotypes in poultry workers. Methods: A cross-sectional study of 230 currently employed poultry workers used a modified ECRHS questionnaire, spirometry, fractional exhaled nitric oxide, Phadiatop and ImmunoCAP for specific IgE to poultry farming associated allergens (chicken meat, feathers, serum protein, droppings, sunflower seeds, storage mite) and mould mix to investigate workrelated asthma. Results: The mean dust particulate concentration (geometric mean (GM) =11.04mg/m³) was highest in the rearing department while mean (1-3)-ß-D-glucan (GM=148 ng/ m³) and endotoxin levels (GM=2298 EU/m³) were highest in the catching department. Worker's mean age was 37±9 years, 68% were male, 43% current smokers, 34% atopic and 5% casual workers. The prevalence of non-atopic asthma (NAA=10%) was higher than atopic asthma (AA=6%) or probable occupational asthma (OA=5%). Sensitisation to at least one poultry work related allergen was 24%, with sunflower seed and storage mite sensitisation being the most prevalent (13%). In multivariate adjusted models, workers sensitised to chicken specific allergens were more likely to be atopic (OR=20.9, 95% CI: 4.7-93.2) or have casual job status (OR=6.0, 95% CI: 1.1-35.9). Workers with work-related chest symptoms were more likely to work in the rearing department (OR=3.2, 95% CI: 1.2-8.3) and to report episodes of high gas/dust/fume exposures causing asthma symptoms (OR=4.8, 95%CI: 2.4-9.6). Reversible obstructive airway obstruction was more strongly associated with employment in small broiler farms (OR=11.6, 95% CI: 1.0-129.0) as well as casual work (OR=6.4, 95% CI: 1.4-28.0). Furthermore, NAA was strongly associated with casual work (OR=5.0, 95% CI: 1.3-19.0) as well as working in the automated egg laying system (OR=8.0, 95% CI: 1.0-68.6). Further analysis revealed that the proportion of workers sensitised to at least one poultry work related allergen declined with increasing years of service (chi-square trend p=0.023), with workers having <2 years employment demonstrating a higher risk compared to those with >6 years employment (OR=4.0, 95% CI: 1.2-13.8). Conclusion: Non-atopic asthma is the most common asthma phenotype among poultry workers with work in the rearing department demonstrating an increased respiratory risk. The increased risk of reversible airway obstruction among workers in small broiler farms and the declining prevalence of sensitisation with increasing employment duration suggests a healthy worker effect. Preventive measures, including appropriate training, are recommended to reduce respiratory health risks, particularly in novice workers.en_ZA
dc.identifier.apacitationNgajilo, D. (2016). <i>Allergic sensitization and work related asthma among poultry workers in South Africa</i>. (Thesis). University of Cape Town ,Faculty of Health Sciences ,Department of Public Health and Family Medicine. Retrieved from http://hdl.handle.net/11427/24503en_ZA
dc.identifier.chicagocitationNgajilo, Dorothy. <i>"Allergic sensitization and work related asthma among poultry workers in South Africa."</i> Thesis., University of Cape Town ,Faculty of Health Sciences ,Department of Public Health and Family Medicine, 2016. http://hdl.handle.net/11427/24503en_ZA
dc.identifier.citationNgajilo, D. 2016. Allergic sensitization and work related asthma among poultry workers in South Africa. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Ngajilo, Dorothy AB - Objective: The aim of the study was to determine the risk factors associated with allergic sensitisation and various asthma phenotypes in poultry workers. Methods: A cross-sectional study of 230 currently employed poultry workers used a modified ECRHS questionnaire, spirometry, fractional exhaled nitric oxide, Phadiatop and ImmunoCAP for specific IgE to poultry farming associated allergens (chicken meat, feathers, serum protein, droppings, sunflower seeds, storage mite) and mould mix to investigate workrelated asthma. Results: The mean dust particulate concentration (geometric mean (GM) =11.04mg/m³) was highest in the rearing department while mean (1-3)-ß-D-glucan (GM=148 ng/ m³) and endotoxin levels (GM=2298 EU/m³) were highest in the catching department. Worker's mean age was 37±9 years, 68% were male, 43% current smokers, 34% atopic and 5% casual workers. The prevalence of non-atopic asthma (NAA=10%) was higher than atopic asthma (AA=6%) or probable occupational asthma (OA=5%). Sensitisation to at least one poultry work related allergen was 24%, with sunflower seed and storage mite sensitisation being the most prevalent (13%). In multivariate adjusted models, workers sensitised to chicken specific allergens were more likely to be atopic (OR=20.9, 95% CI: 4.7-93.2) or have casual job status (OR=6.0, 95% CI: 1.1-35.9). Workers with work-related chest symptoms were more likely to work in the rearing department (OR=3.2, 95% CI: 1.2-8.3) and to report episodes of high gas/dust/fume exposures causing asthma symptoms (OR=4.8, 95%CI: 2.4-9.6). Reversible obstructive airway obstruction was more strongly associated with employment in small broiler farms (OR=11.6, 95% CI: 1.0-129.0) as well as casual work (OR=6.4, 95% CI: 1.4-28.0). Furthermore, NAA was strongly associated with casual work (OR=5.0, 95% CI: 1.3-19.0) as well as working in the automated egg laying system (OR=8.0, 95% CI: 1.0-68.6). Further analysis revealed that the proportion of workers sensitised to at least one poultry work related allergen declined with increasing years of service (chi-square trend p=0.023), with workers having <2 years employment demonstrating a higher risk compared to those with >6 years employment (OR=4.0, 95% CI: 1.2-13.8). Conclusion: Non-atopic asthma is the most common asthma phenotype among poultry workers with work in the rearing department demonstrating an increased respiratory risk. The increased risk of reversible airway obstruction among workers in small broiler farms and the declining prevalence of sensitisation with increasing employment duration suggests a healthy worker effect. Preventive measures, including appropriate training, are recommended to reduce respiratory health risks, particularly in novice workers. DA - 2016 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - Allergic sensitization and work related asthma among poultry workers in South Africa TI - Allergic sensitization and work related asthma among poultry workers in South Africa UR - http://hdl.handle.net/11427/24503 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/24503
dc.identifier.vancouvercitationNgajilo D. Allergic sensitization and work related asthma among poultry workers in South Africa. [Thesis]. University of Cape Town ,Faculty of Health Sciences ,Department of Public Health and Family Medicine, 2016 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/24503en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Public Health and Family Medicineen_ZA
dc.publisher.facultyFaculty of Health Sciencesen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherOccupational Medicineen_ZA
dc.titleAllergic sensitization and work related asthma among poultry workers in South Africaen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMMeden_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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