Respiratory symptoms, lung function and precipitin tests in two farming communities in Iceland

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn Skoða/Opna(view/open)The aim of this study was to find prevalence of respiratory symptoms, do spirometries and measure precipitins against M. faeni, T. vulgaris and A. fumigatus in farmers in two different communities in Iceland. Area A is located at the southern tip of Iceland where the heaviest rainfall occurs (2-4000 mm/year). In spite of this, regular haymaking with outdoor drying of the hay is the most common method. Area B is located in the northwestern part of the country. Here the rainfall is less (1-2000 mm/year) but the summers are very short. Therefore farmers cannot risk a wet summer and make silage from most of their harvest. A farmer living in area A therefore usually has great haydust exposure but one living in area B little. We selected everyone living in these areas 16 years or older who listed livestock farming as their main occupation in the Icelandic National Registry. A questionnaire based on the British Medical Research Council questionnaire for respiratory symptoms, with questions related to haydust exposure added, was used. Spirometry was performed and blood drawn for precipitin tests against M. faeni, T. vulgaris and A. fumigatus. These were done with double gel diffusion technique. In area A, 325 (99,1% of cohort) were studied, but 126 (84,0% of cohort) in area B. In area A, 3,4% made silage from more than half of their harvest compared to 92,9% in area B. In area A, 12,3% had cough for 3 months per year or longer, 11,4% had phlegm for same length of time, 13,6% had dyspnea walking on level ground and 2,8% had wheezing on most days. Comparable figures for area B were 14,3%, 14,3%, 5,6% and 2,4% respectively. Only dyspnea was significantly different in these two areas (p<0,05). In area A, 19,1% experienced cough after working in haydust, 14,2% shortness of breath and 18,5% had experienced fever after such exposure. Comparable figures for area B were 14,3%, 13,5% and 7,9% respectively. Only the febrile episodes were significantly different (p<0,01). In area 72,9% had precipitins against M. faeni compared to 23,0% in area B (p<0,001). As many asymptomatic individuals have this test positive, it is not a valuable diagnotstic tool. No one had precipitins against T. vulgaris, and only 5 against A. fumigatus. Cough of phlegm for 3 months or longer, wheezing on most days or shortness of breath after working in haydust did not correlate with precipitins against M. faeni. However, dyspnea walking on level ground (p<0,05), cough working in haydust (p<0,02) and febrile reactions (p<0,001) did correlate with positive precipitins against M. faeni. Non-smokers were more likely to form precipitins against M. faeni than smokers (p<0,01). In area A, 24,8% had FEV1/FVC% less than 70% compared to 9,5% in area B (p