Eric Tretten, the principal of Armijo High School, where the illness was reported, said that the Solano County Public Health Department was working with school officials to “mitigate the risk to students and staff.” Tretten did not specify whether a student or staff member contracted the tuberculosis, a respiratory disease that attacks the tissue of the host. Trettten, in another letter, a joint communication with Michael Stacey of the county’s public health department, said school officials within the week would notify parents whether their child needed to be tested for exposure to the tuberculosis germ. “We understand that this notification may cause concerns and questions,” the letter said, adding that administrators were working to identify students and staff who could have been exposed to the disease.