An outbreak of recurrent acute and chronic hypersensitivity pneumonitis in office workers

Three episodes of an acute, flu-like illness, one studied in detail, were associated with manipulations on the central air handling system of an office building in Tennessee in the summer and early fall of 1981. Symptoms were compatible with acute hypersensitivity pneumonitis, although the time of onset revealed a biphasic epidemic curve. Breathing air not supplied through the central air handling system protected against disease. Ill persons had significantly more precipitins to agents cultured from the building than did controls. Symptoms suggestive of chronic hypersensitivity pneumonitis were also found. Chronic disease was associated with the presence of humidifiers at home, asthma, and longer work in the building. Acute disease occurred less frequently in smokers and persons who had previously worked in the building before 1976. Persons with acute disease were more likely to have chronic disease. No single etiologic agent could be identified. Because of difficulties with demonstrating safety for reoccupancy, the building was vacated and remains empty at this time.