Evaluation of Tuberculin Skin Test Results among Students of the University of Medical Sciences and Technology, Sudan

Abstract

Introduction: Tuberculosis is an endemic infectious disease in Sudan and other developing countries. Healthcare workers, including students, are at a great risk of exposure and possible infection. This study is conducted to determine the pattern and prevalence of positive tuberculin skin test (TST) among students of the University of Medical Sciences and Technology during distinct periods of their training, and to study the influencing factors for positive results. Design and Setting: A cross-sectional study conducted among 100 students in the period between October 2010 to March 2011 using questionnaires, and administration of the Tuberculin Skin Test (TST) by a licensed professional. Students were divided into two groups, high risk group (medical students), and low risk group (non-medical students) according to their level of exposure. Demographics, BCG vaccination, potential exposure to TB patients and symptomatology were obtained and analyzed. Results: The overall prevalence of positive TST was 19%, 2% were strongly positive, 17% being moderately positive. The high risk group exhibited a significantly higher rate of positive TST (26%). Positive TST was found to correlate significantly with contact with TB patients (P 0.08). No significant correlation was found between positive TST and gender (P 0.834), country of residence (P 0.242), vaccination (P 0.094), presence of BCG scar (P 0.793), drinking unpasteurized milk (p 0.647), immunosuppressive therapy (P 0.674) and crowding (P 0.872). Conclusion: The TST positivity rate was high among our students; it correlates with in-hospital training stage. More attention should be paid to prevention strategies in medical students prior to and during their clinical training.