High Prevalence of tuberculosis infection among medical students in Makerere University, Kampala: results of a cross sectional study

BACKGROUND: Uganda’s Ministry of Health registered a 12% increase in new Tuberculosis (TB) cases between 2001 and 2005. Of these, 20% were from Kampala district and most from Mulago national referral hospital where the largest and the oldest medical school is found. Medical students are likely to have an increased exposure to TB infection due to their training in hospitals compared to other university students. The study compared the prevalence of TB infection and associated factors among undergraduate medical and veterinary students in Makerere University, Uganda. METHODS: This was a cross-sectional study with 232 medical and 250 veterinary undergraduate students. Socio-demographic and past medical history data was collected using questionnaires. A tuberculin skin test was performed on the volar aspect of the left forearm. An induration ≥10 mm in diameter after 48-72 hrs was considered positive. Logistic regression was used to determine association of independent variables with TB infection. RESULTS: The prevalence of TB infection was higher in medical students (44.8%, 95% C.I= 38.4-51.3%) compared to veterinary students (35.2%, 95% C.I = 29.3-41.1%). The significant predictors of TB infection were: being a medical student (aOR=1.56, 95% CI = 1.05-2.31), male sex (aOR=1.75, 95% CI = 1.17-2.63), history of contact with a confirmed TB case (aOR=1.57, 95% CI = 1.06-2.31) and residing at home (aOR=2.08, 95% CI = 1.20-3.61). Among the medical students, having gone to a day compared to boarding high school (aOR=2.31, 95% CI = 1.06-5.04), involvement in extracurricular clinical exposure (aOR=3.39 95% CI = 1.60-7.16), male sex, residence at home, and history of contact with a TB case predicted TB infection. CONCLUSION: Medical students have a higher prevalence of TB infection than veterinary students probably due to increased exposure during training. There is a need to emphasize TB infection control measures in hospitals and the general community.