Tuberculosis outbreak in a grammar school, Serbia, 2016.

Serbia has a low incidence of tuberculosis (TB), with a decreasing trend in the last decade. The purpose of this manuscript is to describe an outbreak of TB infection that occurred in 2016 among students of a grammar school in Novi Pazar. A 17-year-old girl, third-grade student of a grammar school (the index case), was diagnosed with smear-positive tuberculosis. Contact investigation was conducted, including chest X-ray examinations of over 1100 persons. After the index case was detected, a total of 16 (10 pulmonary and 6 extrapulmonary) tuberculosis patients were newly diagnosed during 2016. Among 11 culture positive cases, MIRU-VNTR method revealed that all Mycobacterium tuberculosis isolates were identical. Diagnostic delay contributed to the transmission of infection.

Tuberculosis outbreak among high school students in Novi Pazar, Serbia 2016: a retrospective-cohort study.

INTRODUCTION: Between February and November 2016, 17 tuberculosis (TB) cases were identified among high school students in Novi Pazar, Serbia. The objectives of our study were to describe the outbreak, to identify potential risk factors and to evaluate the applied control measures. METHODOLOGY: The outbreak was described by time, person and place. A retrospective cohort study was conducted. Attack rates, unadjusted relative risks (RR) and 95% confidence intervals (CI) were calculated. Multiple log-binomial regression analysis was performed to calculate adjusted RR. RESULTS: Sixteen of the total 17 cases occurred among grade 3 students, AR 5.5%. Previous TB family history, (RR = 5.29; 95% CI = 1.63-17.12), spending time with a known TB case at school (RR = 5.38; 95% CI = 1.48-19.55) and exposure to secondhand smoke (RR = 3.37; 95% CI = 1.11-10.29) were all significantly and independently associated with the occurrence of TB. CONCLUSIONS: Delayed diagnosis and reporting resulted in delayed initiation of the contact investigation and non-identification of latent TB cases probably favored the occurrence of this outbreak in a low incidence country. Public health authorities should consider revising the existing guidelines, promoting inter-sectorial collaboration and increasing awareness of public health professionals.