The aim of our study was to determine the risk of tb infection in students of medical and non-medical faculties of Charles University during their studies.
Students of Charles University were repeatedly tested with tuberculin skin test (TST) at the beginning of their studies, in the 3rd year and in the 5th or 6th year depending on the length of studies. The increase of TST for 10 mm or more was considered as the conversion of TST. The annual risk of infection (ARI) was calculated according to Styblo method.
3116 students were tested with TST during the years 1993-2003. 1224 were medical students, 1892 were students of other faculties. At the beginning of their studies no significant differencies were observed concerning the results of TST between these two groups. 35% were TST negative, 62% had TST between 6-15 mm and 3% had TST 16 mm and more. Median of TST was 7 mm. In the 3rd year of studies the medical students showed a significant increase in TST results (14% TST negative, 74% TST 6-15 mm, 12% TST 16 mm and more, median TST 12 mm). There was no significant change in TST results in students of other faculties. The conversion of TST in the 3rd year of medical studies was detected in 22% of medical students and in 6.5% of students of other faculties (p≤ 0.01).The annual risk of infection (ARI) was higher in medical students during the first three years of their studies (ARI 0.081)compared to the second three years (ARI 0.042). The ARI in students of other faculties was 0.011.
Medical students are at significantly higher risk for tb infection compared to the students of other faculties of Charles University. The risk seems to be most prominent during the first three years of medical studies.
Study of medicine carries a significat risk for acquiring tuberculosis even in countries with low prevalence of tuberculosis and functional system of tb control.
Jiri Homolka, None.