Coccidioidomycosis in San Fernando Valley; report of a study carried out in 1951-1952.

Four cases of benign pulmonary coccidioidomycosis occurred during May 1951 among some 35 teenage students at a boarding school and farm for boys that occupies 30 acres in the northwestern section of the San Fernando Valley within the City of Los Angeles. Epidemiological and serological study of the patients yielded evidence that exposure had occurred on the farm or nearby. Correlation of results of skin testing for sensitivity to coccidioidin among students over the subsequent months and of serologic studies in cases in which there was positive reaction to skin tests indicated exposure to coccidioides during the time the subjects were in residence at the school. In addition, two boys had conversion from negative to positive reaction to coccidioidin while they were in residence.