Possible respiratory infection due to Aspergillus in workers from swineries and poultries

Introduction: Aspergillus is among a growing list of allergens that can aggravate asthmatic responses. Significant pulmonary pathology is associated with Aspergillus-induced allergic and asthmatic lung disease. Environments with high levels of exposure to fungi are found in animal production facilities like swineries and poultry which farmers are at increased risk of occupational respiratory diseases. Purpose: Seven Portuguese poultries and seven swineries were analyzed in order to estimate the prevalence, amount and distribution of Aspergillus species, as well as to evaluate the existence of clinical symptoms associated with asthma and other allergy diseases in these highly contaminated settings. Methods: A total of 83 air samples (through impaction method), 66 surface samples (swab sampling) and 28 samples of different material covering their floor were analyzed. Results: The collected fungal isolates (699) were distributed by 40 different genus, Aspergillus presented a prevalence of 17.6% (average) and regarding poultries only, its prevalence showed a higher value (22.7%). The most frequently isolated Aspergillus species were A. versicolor, A. flavus and A. fumigatus. In poultries, A. flavus presented the highest level of airborne spores (>2000 ufc/m3) whereas in swineries was A. versicolor, with a prevalence four times higher than the other referred species. Eighty workers of these settings were analyzed, with ages ranging from 17 to 93 years old. Seven of these workers were medical diagnosed with asthma and four of them reported the first attack after the age of 40 years old, which possibly could be related with their occupational exposure. A high prevalence of respiratory symptoms in professionals without asthma was observed, namely wheezing associated with dyspnea (23.8%) and dyspnea after strenuous activities (12.3%), suggesting an under diagnosed respiratory problem. Moreover, 32.5% of all the inquired workers refer an improvement of their respiratory ability during the resting days and holiday. Conclusions: Considering the strong association between fungal sensitization and severity of asthma and that Aspergillus species are one of the most important fungal agents causing sensitization of the individual, this study contributes to the knowledge of Aspergillus prevalence and distribution in Portuguese poultries and swineries. These data, together with data regarding determinations of specific IgE levels and monitorization of mycotoxin exposure using biomarkers will also help to understand how and which Aspergillus species can affect workers of these settings