The school has notified fellow students of the contagious infection, which is spread through airborne bacteria. Finnish law demands that the source of the infection is pinpointed to prevent more people from falling ill.
Fellow classmates could contract TB simply by being in the same room as the infected person. Tuberculosis is commonly transmitted by inhaling contaminated droplets of coughs and sneezes.
The disease remains latent in most carriers, meaning it never becomes active. Some 300 tuberculosis infections are reported in Finland every year, mostly among adults.