Public health officials will head back to Phoenix Slementary School in Grand Forks today for follow-up testing of students for TB. Students and staff were screened back in November after two students showed signs of the illness. The health department’s Debbie Swanson says those tests were negative and they would expect similar results this time around. Health officials will conduct a secondary check of 78 students and staff at Valley Middle School next week after a student came down with an active TB case eight weeks ago. Grand Forks has identified 15 cases of TB since September -- 17 going back to March.