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

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 ni...

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Main Author: Ngajilo, Dorothy
Other Authors: Jeebhay, Mohamed
Format: Thesis
Language:English
Published: Department of Public Health and Family Medicine 2017
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access_status_str Open Access
author Ngajilo, Dorothy
author2 Jeebhay, Mohamed
author_browse Jeebhay, Mohamed
Ngajilo, Dorothy
author_facet Jeebhay, Mohamed
Ngajilo, Dorothy
author_sort Ngajilo, Dorothy
collection Thesis
description 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.
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:42:04.133Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2017
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spelling oai:open.uct.ac.za:11427/24503 Allergic sensitization and work related asthma among poultry workers in South Africa Ngajilo, Dorothy Jeebhay, Mohamed Baatjies, Roslynn Occupational Medicine 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. 2017-06-06T09:44:57Z 2017-06-06T09:44:57Z 2016 Master Thesis Masters MMed http://hdl.handle.net/11427/24503 eng application/pdf Department of Public Health and Family Medicine Faculty of Health Sciences University of Cape Town
spellingShingle Occupational Medicine
Ngajilo, Dorothy
Allergic sensitization and work related asthma among poultry workers in South Africa
thesis_degree_str Master's
title Allergic sensitization and work related asthma among poultry workers in South Africa
title_full Allergic sensitization and work related asthma among poultry workers in South Africa
title_fullStr Allergic sensitization and work related asthma among poultry workers in South Africa
title_full_unstemmed Allergic sensitization and work related asthma among poultry workers in South Africa
title_short Allergic sensitization and work related asthma among poultry workers in South Africa
title_sort allergic sensitization and work related asthma among poultry workers in south africa
topic Occupational Medicine
url http://hdl.handle.net/11427/24503
work_keys_str_mv AT ngajilodorothy allergicsensitizationandworkrelatedasthmaamongpoultryworkersinsouthafrica