Farmer's lung disease in Somerset.

A survey of laboratory records was made to assess the value of the precipitin test and isolation methods in the diagnosis of farmer9s lung disease and also to determine its prevalence in the farming population of Somerset. A link was established between the clinical diagnosis as written on the form that accompanied the specimen and the actual number of positive laboratory diagnoses made. Fifty (43%) of the clinically diagnosed patients were serologically positive for farmer9s lung during a four-year period. If the clinically diagnosed but serologically negative cases of farmer9s lung disease are added to this number, a prevalence of about 23 per 1000 of the farming population of Somerset is obtained.