4th Tuberculosis Case In 2 Years Prompts Mass Testing At San Diego County School

SAN DIEGO, CA — A fourth tuberculosis case in two years at a San Diego County high school has prompted health officials to offer free testing to all students and staff amid concerns about further spread.

The latest exposure occurred between June 23, 2025, and March 6, 2026, at Southwest High School in San Diego, according to county health officials. Officials are working with the Sweetwater Union High School District to notify students and staff who may have been exposed.

Officials have already contacted people at the highest risk of infection. Free tuberculosis testing will be offered to all current students and staff at the school during the first week of November. A mobile unit providing chest X-rays will also be available.

Former students are being notified and can receive free testing from 1:30 to 6 p.m. Dec. 4 in the school's South Lot student parking area.

Officials are investigating whether the latest case is connected to previous cases at the school. Testing showed that two earlier cases involved different strains of tuberculosis. Genetic testing of the latest case is pending.

Although no connection has been confirmed, health officials said four active TB cases within two years prompted additional testing to prevent further spread.

All staff and nearly 90% of students exposed to earlier cases were tested and found not to have active TB.

"Bringing testing to the school is crucial to identify any latent TB infections and stop potential spread given the high number of cases in such a short timespan," County Public Health Officer Dr. Sayone Thihalolipavan said. "We will continue to closely monitor the school."

Tuberculosis spreads through the air when someone with active TB coughs, speaks, sings or breathes. People with prolonged or frequent indoor exposure are at greater risk of infection.

People who test positive but have no symptoms should get a chest X-ray and consult a health care provider, officials said. They may have a dormant form of tuberculosis that is not contagious but can develop into active disease without preventive treatment.

San Diego County recorded 265 active tuberculosis cases in 2025, up from 247 in 2024, according to county data. An estimated 175,000 people in the county have latent tuberculosis and are at risk of developing active TB without preventive treatment, according to officials.

For more information, contact the county's TB Control Program at 619-692-8621.