TB Outbreak Reported at San Francisco High School

Archbishop Riordan High School investigating multiple active tuberculosis cases among students and staff.

Jan. 27, 2026 at 11:15pm by Ben Kaplan

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The San Francisco Department of Public Health is investigating an outbreak of active tuberculosis (TB) at Archbishop Riordan High School after a third confirmed case was reported on Tuesday. The campus had its first confirmed case back in November, leading to required testing for all students and staff. The school is now dealing with two more confirmed cases, meeting the definition of a TB outbreak.

Why it matters

TB is a serious infectious disease that can spread easily through coughing and sneezing, especially in close-knit school communities. This outbreak raises concerns about public health and the ability to quickly identify and contain TB cases before they spread further.

The details

After the first confirmed TB case in November, Archbishop Riordan High School required all 1,150 students and 100 faculty/staff members to undergo testing between January 20 and February 13. The school has now reported two additional confirmed cases, meeting the criteria for a TB outbreak. The San Francisco Department of Public Health is working closely with school officials to monitor for symptoms, recommend masking indoors, and make changes to indoor activities while screening continues.

  • The first confirmed TB case at Archbishop Riordan High School was reported in November 2025.
  • The school required all students and staff to undergo TB testing between January 20 and February 13, 2026.
  • A third confirmed TB case was reported at the school on January 28, 2026.

The players

Archbishop Riordan High School

A Catholic high school in San Francisco with an enrollment of around 1,150 students and 100 faculty/staff members.

San Francisco Department of Public Health

The local public health agency responsible for investigating the TB outbreak at Archbishop Riordan High School and providing guidance to the school community.

Tim Reardon

The president of Archbishop Riordan High School, who has committed to taking every measure to ensure the safety of the school community.

Alejandro Rosales

A junior student at Archbishop Riordan High School who shared details about the school's response, including required testing and cancellation of events.

Karla Rivas

A parent of a sophomore student at Archbishop Riordan High School who expressed confidence in the school's handling of the situation.

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What they’re saying

“We will take every measure available to ensure the safety and wellbeing of faculty, staff, students, and their families, and we are committed to providing frequent, consistent updates to members of the Riordan community.”

— Tim Reardon, School President (KTVU)

“Everybody's kind of around everybody. All of us have to get tests. I got it last Friday, I came out negative.”

— Alejandro Rosales, Junior Student (KTVU)

“I'm not worried, I think everything will be fine.”

— Karla Rivas, Parent of Sophomore Student (KTVU)

What’s next

The San Francisco Department of Public Health is continuing to work closely with Archbishop Riordan High School to monitor the situation and provide guidance on further testing and safety protocols. The school has committed to following all recommendations from the health department.

The takeaway

This TB outbreak at Archbishop Riordan High School highlights the importance of vigilant disease monitoring and rapid response in close-knit school communities. The school's proactive approach to testing and communication with families is crucial to containing the spread and ensuring the health and safety of students and staff.