TB screenings for some students began on April 11 at Deer Valley High School in Contra Costa County, Calif., after a fellow classmate tested positive for TB. Contra Costa Health Services offered testing only to students who may have come into contact with the diagnosed student by sharing a classroom or by being fellow club members. The county determined last month that the student was ill with TB. Although no longer infectious, the student could have been infectious in January. The TB screenings held on April 11 are the first in the county since 2009 when an Antioch High School student was diagnosed with TB.