Sacramento County public health officials will test 500 more students and staff members at Grant Union High School for tuberculosis Monday.
The decision was made after the number of people who tested positive for latent tuberculosis at the school grew from 21 last month to 47. Latent tuberculosis has no symptoms and is not infectious, but it can become active after a long period of dormancy.
Those diagnosed were among 200 tested for tuberculosis at Grant since March. The screenings were given after a student at the school tested positive in February for active tuberculosis, which attacks the lungs and can be fatal.
The student has since been treated, has been medically cleared and has returned to school, said Olivia Kasirye, Sacramento County public health officer. No new cases of active tuberculosis have been found.
“While there are no confirmed active TB cases at Grant Union High School, we are proactively investigating and screening any potential exposure,” Kasirye said in a statement. “It is standard practice to systematically investigate in this manner, expanding testing based on results, and assuring that nobody is at risk in the meantime.”
Students and staff with immediate exposure to the student were tested first. Testing will now be expanded to include students who attended classes immediately after the infected student, as well as students in classrooms that shared a ventilation system with classrooms frequented by the student.
Students and staff will be tested Monday and the tests will be read on May 8.
Tuberculosis is spread through the air when people cough, laugh, sneeze or sing. It cannot be spread through hand-shaking or touching objects such as doorknobs or railings. Risk of infection depends on a number of factors, including proximity and duration of exposure.
The 47 people diagnosed with latent TB are being treated. Latent TB can become active after remaining dormant in a person for years. Both active and latent tuberculosis can be treated successfully, according to health officials.
About 80 cases of tuberculosis are reported in Sacramento County each year, but the patients are usually adults. The rare incidents at schools usually result in a low number of students who have been exposed to the disease, Kasirye said. The number of students diagnosed with latent TB at the school is “higher then we have gotten in previous testing” at county schools, although other counties have had similar numbers, Kasirye said.
A letter recently sent to the families of students targeted for testing has caused some confusion. The letter, which explains the testing, comes with an opt-out form and no consent form, according to parents.
“We have gotten a few calls about that,” Kasirye said. She said students who are affected will get more information at the school, including a consent form for parents to sign. “If they accidentally sign the refusal form we won’t turn them away if they show up.”
For more information about tuberculosis, call the health department at (916) 875-5881.