Introduction - Transmission of tuberculosis in hospital settings can occur. This study reports on the investigation conducted following the diagnosis of active pulmonary tuberculosis in a nurse. Materials and Methods - An extraordinary CLIN meeting decided to recall patients and staff. The two screening rounds (T0 and at 3 months) included chest X-rays (CXR) and tuberculin skin tests (TST). Results - A total of 810 patients were recalled: 46% had an initial consultation, and 3.8% had a second consultation. 96.2% underwent chest X-rays and showed no signs of tuberculosis. 58.7% underwent an intradermal test; 8.7% had a reaction ≥14 mm but without indications for treatment. 211 employees were contacted: 67% had an initial consultation, 59% a second. In cases of enlarged indurations or indurations ≥14 mm, 8 specialist consultations were requested. Three courses of anti-tuberculosis treatment were initiated. No source patients were identified. Discussion and conclusion - The failure to detect tuberculosis infection or disease in patients may be related to the characteristics of the screened population, factors favoring transmission, the characteristics of the disease, and screening conditions. Compliance with the second consultation is low. The question of evidence for the nosocomial nature of a tuberculosis infection arises. (R.A.)