On Friday, August 22, 2014, Sacramento County, in collaboration with Twin Rivers Unified School District, conducted TB screenings for 345 students and staff at Grant Union High School. This was done as part of a continuing investigation following the diagnosis of a student with active TB disease in February 2014.
Earlier screening in 2014 focused on those who shared the same classes (periods) with the index case and those who were in adjacent classrooms (at the same time as the index case) that shared the same air circulation system. This round of testing was targeted for an additional 300 students who attended classes in the same classrooms as the index case, but not during the same period. The testing was also open to other students and staff who had not been identified, but voluntarily wanted to get tested.
According to Sacramento Public Health Officer, Olivia Kasirye, MD, the results summarized below indicate, “The TB exposures occurred in the classrooms of the index case (and those classrooms that shared the same circulation system) and not throughout the entire school.”
Of the 345 screened on Friday, 215 were identified as having been in the same classrooms as the index case, but not in the same period. Among this group, 29 tested positive for exposure (14%). They will be further evaluated with chest x-rays and offered preventive treatment.
Of the remaining 130 students and staff who were voluntarily screened, seven had a positive test (approximately 5%) which is more typical of the general population.
This last clinic revealed a 14% exposure rate in the identified students, which is significantly less than the earlier screenings. This indicates that as the screenings expanded to include greater numbers of students who were further removed from the index case, the percentage of positive cases decreased.
At this time, there are no known infectious students/staff at the school and no evidence of any exposures after March 2014.