California public health officials in Sacramento County say a total of 111 students and staff at Grant Union High School have been diagnosed with latent tuberculosis since February.
“It is higher than what we expected,” Sacramento County public health officer Olivia Kasirye told the Sacramento Bee. “At this time there are no plans of expanding (testing). We haven’t identified any other factors that would put any other students or teachers at a reasonable exposure to warrant testing.”
Tuberculosis can be diagnosed through a skin test. A skin reaction to the test means the person has antibodies to tuberculosis, meaning they have been exposed to infectious disease. If that person shows no symptoms – confirmed through a chest X-ray – they are diagnosed with a latent form of TB.
One in 10 latent infections progresses into active tuberculosis, and it can become active after a long period of dormancy.
TB is spread though the air when an infected person coughs or sneezes. Patient X at Grant Union High School turned out to be a student.
Where do people pick up this infection? When this humble writer was diagnosed with latent TB at age 14, I was told I had probably gotten it from a sick passenger on an airplane. After 16 years, my infection has never evolved into active TB.
Latent TB is not infectious.
"The person is not contagious, is not sick, they can be around other people," Kasirye told News 10 ABC.
"A person can stay in that latent phase for a long, long time," she added. "In fact, the majority of people never actually come down with disease. But a certain percentage, about 10 percent do."
Initially, all 200 people who had direct contact with the sick student were tested and 47 were diagnosed with latent TB.
County officials ordered 500 more students and teachers to be tested on May 5. Many of these had been in classrooms used by the sick student or rooms that shared ventilation with those classrooms.
Only 260 showed up to be screened, 64 of whom tested positive for latent TB.
Kasirye urges the 240 people who did not show up for the TB test to be screened by their private physicians. She told the Sacramento Bee that treatment with antibiotics greatly decreases the chances of developing active TB.