Prevalence of Positive Tuberculin Skin Test (TST) Results among Pre-clinical and Clinical Medical Students during their Educational Course in Mashhad, Iran

Background: Tuberculosis is an endemic and critical public health issue in Iran and many developing countries. Healthcare workers, including medical students are at a great risk of exposure. This study is conducted in order to determine the prevalence of latent tuberculosis infection in medical student in different stages.

Materials and Methods: This is a cross sectional study, conducted between August and December 2013. 195 medical students from different stages (preclinical, externship and internship) enrolled in this study. Tuberculin skin testing (TST) was used to determine the prevalence of infection with TB and the induration was measured. A standardized questionnaire was collected for risk-assessment analysis.

Results: Among the 195 participant, 118 (60.5%) had indurations lower than 10 mm and 77 (39.5%) had indurations more than 10 mm. Induration ≥10 mm was taken as positive (P-value<0.0001).

Conclusion: TST positive results increase among medical students as they advance in their training program. The screening programs of healthcare student before clinical training can be useful for early identification and treatment of the sporadic cases of latent tuberculosis.