GWINNETT COUNTY, GA — A student at South Gwinnett High School is diagnosed with tuberculosis and now over a hundred students and staff will undergo testing after being exposed.

Tuberculosis is caused by bacteria that usually attack the lungs, and it is spread through the air when an infectious person coughs or sneezes.

Gwinnett health officials are set to test approximately 150 students at South Gwinnett High School next week. If a test is positive, the individual will need to have a chest x-ray to ensure that they did not have an active disease. In October, a single case at Cobb County’s Walton High School also triggered a need for large scale testing.