RESUMO
A study of farmer's lung (FL) disease was carried out in 197 subjects engaged in farming and having respiratory complaints of varying duration. It revealed that 13.2% of the subjects had precipitating antibodies against thermophilic actinomycetes, with Faenia rectivirgula (Micropolyspora faeni) alone accounting for 85% of the positive reactions. Precipitating antibodies against Thermoactinomyces vulgaris and T. thalpophilus were observed only in 1.5% and 0.5% of the subjects, respectively. Two subjects concomitantly demonstrated F. rectivirgula and T. vulgaris-specific serum precipitins. Sixty (30%) of the subjects related their respiratory symptoms to exposure to wheat straw/thresher's dust or other vegetable substrata in the working environment. Based upon a suggestive clinical history, roentgenography, pulmonary function studies and demonstration of serum precipitins against F. rectivirgula, FL was diagnosed in 4 subjects whose salient features are presented and discussed. To the best of our knowledge, this is the first authentic report on FL from India. A comprehensive epidemiological survey is indicated to determine the prevalence of FL in different geo-climatic regions of the country.