TB Outbreak Reported at San Francisco High School

Officials warn of 'moderate' risk as they investigate cases and implement testing and safety measures.

Jan. 28, 2026 at 6:47pm by Ben Kaplan

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The San Francisco Department of Public Health is investigating an active outbreak of tuberculosis at Archbishop Riordan High School, where at least three individuals have been sickened. All students and staff are being tested, and the school has implemented contact tracing and other measures to stop the outbreak from spreading further.

Why it matters

TB outbreaks are relatively rare in the U.S., and three cases at a high school are considered 'really bad' by infectious disease experts. TB can be easily transmitted in closed settings, and the outbreak raises concerns about public health and safety at the school.

The details

The initial TB case was reported on November 17, and due to the slow-growing nature of the bacterial infection, testing on students and staff started on January 20. The San Francisco Department of Public Health said the risk of TB transmission at the high school was 'moderate' during the testing phase. The school has implemented measures such as requiring all students and staff to undergo TB testing by February 20 or be barred from campus, and any student or staff member wanting to attend off-campus indoor activities will need to have tested negative. Masks are also strongly recommended.

  • The initial TB case was reported on November 17, 2025.
  • Testing on students and staff started on January 20, 2026.

The players

San Francisco Department of Public Health

The local public health department investigating the TB outbreak and implementing measures to stop the spread of the disease.

Archbishop Riordan High School

The high school where the TB outbreak has occurred, and where the school administration is working with the health department to address the situation.

Dr. Monica Gandhi

An infectious disease expert at the University of California, San Francisco, who commented on the rarity of TB outbreaks in the U.S. and the challenges of containing the disease in a school setting.

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What they’re saying

“SFDPH is also providing ongoing medical and public health guidance to reduce the risk of transmission, including recommendations for symptom monitoring, masking indoors, and adjustments to certain indoor activities while screening continues.”

— San Francisco Department of Public Health, Department officials (sfgate.com)

“It's quite easily transmitted in closed settings, and none of us are immune in the United States.”

— Dr. Monica Gandhi, Infectious disease expert at UC San Francisco (sfgate.com)

What’s next

The judge in the case will decide on Tuesday whether or not to allow Walker Reed Quinn out on bail.

The takeaway

This TB outbreak at a San Francisco high school highlights the need for vigilant public health measures and the challenges of containing infectious diseases in close-knit school communities, where the risk of transmission is heightened.