Screening for Latent Tuberculosis Infection among Students of Healthcare Professions and Postgraduates of the Faculty of Medicine of the University of Palermo

Abstract

Introduction and objective: Italy is a country with a low incidence of tuberculosis and in the last fifty years the annual number of TB cases decreased from 12,247 to 4,418, showing a reduction of approximately 64% in the number of cases and 71% in incidence. Despite of this encouraging trend, in the last years the epidemiology of tuberculosis changed and today it is a re-emerging infectious. The aim of this study is to measure the prevalence of positivity to tuberculosis infection (latent TB) in students, without any obvious manifestation of disease, attending degree courses of the health care professions and postgraduate medical courses of the School of Medicine of the University of Palermo, Italy. Materials and methods: A cross-sectional observational study in students of nursing, midwifery, dentistry degree courses and in resident physicians of postgraduate medical schools was carried out from January 2012 to July 2016. Mantoux test was performed and all positive cases were tested with Interferon-Gamma Release Assay (IGRA). Results: The 1,351 subjects evaluated, 25 (1.8%) resulted positive to Mantoux test; in 17 students (1.2%) the diagnosis was confirmed with IGRA. Positive cases were significantly more frequent among students attending Postgraduated Medical School Courses (p<0.001) and were older than negative cases (p<0.001). Conclusion: This study suggests that in our geographic area, latent TB shows a relatively low prevalence among students of medical schools. Despite of this evidence, and considering that several students have been found to be positive for TB, this infectious disease has to be considered a re-emerging biohazard that requires preventive strategies for the containment of the risk in exposed workers as well as in the general population.