[Five cases of tuberculosis occurring in an accounting office during 5-year period]

Five cases of pulmonary tuberculosis occurred in an accounting office during 5-year period. Patients 1 and 2 were hospitalized in January and March respectively in 1984. Patients 3 and 4 were found to have abnormal shadows in 1987. Patient 5 was admitted to our hospital in July, 1988. Patients 1 and 2 showed a similar pattern of drug resistance. The desk of Patient 3 was located in front of the desk of Patient 1. Retrospective review of chest X-ray film of Patient 3 taken two years before admission revealed that active contagious tuberculosis had been misdiagnosed as inactive type, resulting in delayed treatment. Patients 4 and 5 worked near to Patient 3 for the past two years. PPD skin test was carried out on 47 workers in the same room and other rooms as well. The distribution of maximum diameters of erythema for workers in the same room did not show a bimodal distribution, but the mean diameter (30.6 +/- 16.4 mm) was larger than that (22.3 +/- 17.2 mm) for workers in other rooms. Preventive administration of Isonicotinic acid hydrazide (INH) was made for 10 workers. These observations suggest that routine chest X-ray film should be carefully checked, and PPD skin test should be performed to those at risk of tuberculosis infection.