Health officials say that with the bulk of the investigation complete, about 120 students and staff at Longmont High School have tested positive for latent tuberculosis.
Dr. Randall Reves, director of the Denver Metro Tuberculosis Clinic, says "this is an unusual percentage, but it's not unheard of."
After a student was diagnosed with active TB in December, everyone in that student's classes was tested. The Denver Post reports testing was expanded to the entire school because of a high rate of latent infection in the class. About 40 percent of those who shared a classroom with the student tested positive.
About 1,200 students attend Longmont High, and the school employs about 120 staff.
Tuberculosis is caused by bacteria spread through the air. The disease is easily treated by antibiotics but can be fatal.
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