... Therefore for economic reasons,41 fl uorescence microscopy is currently recom-mended only in district laboratories that process more than 30 smears per day2 or in regional laboratories ... Health2044 www.thelancet.com Vol 369 June 16, 2007sputum collection, storage, and staining, reading errors, or poor laboratory services. In children, the diagnosis of pulmonary tuberculosis is ... high laboratory workload;43 however, fl uorescence microscopy can greatly reduce the time needed for examination of smears. About 15 times as many fi elds of view can be scanned by fl uorescence...