[Epidemiological study on the demonstration of precipitating antibodies against Micropolyspora faeni in agricultural workers].

The authors report on the frequency (as determined by the double diffusion test according to Ouchterlony) of circulating precipitating antibodies against thermophil actinomycetes of the genus Micropolyspora faeni in 1666 blood samples from 1376 agricultural workers. These workers belonged to the main professional categories in two districts of the German Democratic Republic and were examined by members of the Research Group on Occupational Medicine in Agriculture of the Ernst Moritz Arndt University during the years 1972-1975. 290 workers were examined twice or three times in a longitudinal study. Positive serological findings were obtained from 5.1% of the subjects under investigation. There were no statistically significant differences with regard to occupational category, sex, age, and season. Nevertheless, there were marked regional differences. The results obtained show that there is no need for special medical supervision of the agricultural workers with regard to thoracic actinomycosis (farmers' lung). Further examinations are of course necessary in case of suspected or clinically manifest affection.