Etiological Investigation of Farmer's Lung - Serological Study.
Shen-E; Shan-L; Tao-G; Chen-X; Wu-L; Hong-R
NIOSH 1990 Sep:722-723
An etiological study of farmer's lung was carried out by measuring precipitins in sera of 30 hay grinders with the disease. Antigens were prepared from (M-faeni), Aspergillus-fumigatus (A-fumigatus), Thermoactinomycetes-vulgaris (T-vulgaris) and Thermoactinomycetes- candidus (T-candidus) and from moldy hay isolates of four strains of T-vulgaris and two strains of thermophilic Nocardia. Subjects' sera were collected 1 month after they ground moldy hay and were compared with sera from 30 unexposed sex and age matched referents from the same area and with sera from 29 healthy university students. Precipitins were detected using Ouchterlony's agar gel double diffusion assay. Reactions against two laboratory strains of T- vulgaris were noted in 46.7% and 66.7% of patients, significantly higher than in comparisons. Reactions against T-candidus were 80% higher in patients than in comparison students but did not differ much from those in local comparisons. Reactions against two strains of M-faeni and A-fumigatus were observed in 16.7%, 3.3% and 9.1% of patients, not significantly higher than either comparison group. For moldy hay isolates, patients revealed a 36.7% reaction rate against one T-vulgaris strain, significantly increased over both comparison groups. Reactions against two other strains occurred in 80.0% and 33.3% of patients, significantly higher than student comparisons. Reaction rates to Nocardia did not differ among groups. The authors conclude that in the area studied, farmer's lung is due to several strains of T-vulgaris, and that several strains should be used for diagnostic precipitin tests.
Farmers; Agricultural-workers; Lung-disease; Respiratory-system-disorders; Immunology; Microbiology; Epidemiology; Antibody-response; Occupational-diseases;
Asthma and Chronic Obstructive Pulmonary Disease; Disease and Injury; Respiratory-system-disorders;
Proceedings of the VIIth International Pneumoconioses Conference