TB is a disease of the lungs that can be fatal if left untreated. It's spread through coughing or sneezing which sends the germs airborne.
The Cumberland County Health Department is testing students and staff who may have been exposed. Anyone who comes back with a positive result will get antibiotic treatment.
TB was largely stamped out in western countries by the middle of the 20th century thanks to the discovery of antibiotics, but new drug resistant strains began cropping up in the 1980s, and now the disease is much more common.
Every year, about a half million new cases are reported worldwide.