SHEBOYGAN, Wis. (AP) — Health officials say a Sheboygan South High School student has an active case of tuberculosis and has been isolated and treated. Sheboygan County Health and Human Services supervisor Jean Beinemann says about two dozen students are being tested because they were in close contact with the infected person. Beinemann says Sheboygan County residents in general are at low risk of contracting the disease. The Sheboygan Area School District sent letters home to parents of students who were at greatest risk. Beinemann says the TB case was discovered when one of the student's family members visited a clinic and was identified with tuberculosis.