Level of exposure to Mycobacterium tuberculosis in medical students at a university in southern Minas

Abstract

Objectives. To verify the level of exposure to Mycobacterium tuberculosis and the associated risk factors, using the tuberculin test as a marker for latent tuberculosis in the university's medical school in UNIVÁS, Pouso Alegre, MG, Brazil. Methods. Cross-sectional study with 120 students divided into three groups: basic, intermediate and boarding. Information regarding gender, age, presence of BCG scar, the second dose of BCG, previous contact with tuberculosis patients and personal history of tuberculosis were obtained by questionnaire. The tuberculin test was performed by a skilled professional was defined as positive when the induration was greater than 5mm. Results. The prevalence of exposure to Mycobacterium tuberculosis was 28,3%, being more frequent in the boarding school students. There was a greater positivity in females(p > 0.05). The tuberculin test was positive in those over 21 years, with the scars (BCG) and who had no contact with a person with tuberculosis (p > 0.05). Students who received the second dose of BCG were more likely to have positive test when compared with those not vaccinated (RC = 0.35, 95% CI = 0.1 to 0.9, p = 0.023). Conclusions. The higher prevalence of latent tuberculosis at the end of medical school suggests that medical students are probably exposed to nosocomial transmission of Mycobacterium tuberculosis. This study showed the vulnerability of this population in relation to tuberculosis and revealed the need for implementation of biosafety programs for medical students and alerts for the use of control measures