Underlying

Twenty students at Chester’s Science and Discovery High School have tested positive for latent TB. The school tested 200 students for tuberculosis after a classmate became exposed to the infection, and only a fraction proved to be carrying the germ.

According to an Associated Press report, latent TB presents itself in 5 to 10 percent of the population, and is not contagious. The Chester student exposed to TB will have follow-up chest x-rays and will likely take anti-tuberculosis medication.