Risk factors for non-isolation of patients admitted for pulmonary tuberculosis in a high-incidence department: a single-centre retrospective study

Background Pulmonary tuberculosis (PTB) is an airborne disease, warranting the identification of suspected cases on admission, and their hospitalization in individual rooms with the implementation of airborne supplementary precautions (ASPs). Aim To identify the frequency of non-isolated PTB and the factors associated with the delay in implementing ASPs in a high-prevalence hospital. Methods This retrospective observational study included patients with at least one Mycobacterium tuberculosis-positive specimen. Patient demographic and clinical data, as well as data related to the mode of admission, were collected. Univariate and multi-variate statistical analyses were performed. Findings During the study period, 256 patients were included. Among them, 134 (52.3%) had PTB (75% males, median age 39 years, 70% foreign-born). Among these patients, 46 (34%) were isolated beyond 24 h of admission. The average time to implement ASPs was 4.3 days, and seven patients (5.2%) were not isolated throughout their hospital stay. Multi-variate analysis indicated that three factors were associated with isolation. Previous consultation with a general practitioner was associated with greater likelihood of isolation, whereas admission through the emergency department was not. The presence of so-called 'cardinal clinical signs' and a suggestive chest x-ray were also associated with greater likelihood of isolation. Finally, European patients were isolated less frequently than foreign-born patients. Conclusion In this study, 34% of patients admitted with PTB were not isolated on admission. The likelihood of non-isolation was three times higher in cases admitted via the emergency department, and European patients were isolated less frequently than foreign-born patients. The presence of cardinal signs and prior consultation with a general practitioner were associated with greater likelihood of isolation.