TB outbreak at Archbishop Riordan High School

SAN FRANCISCO, Calif. - The San Francisco Department of Public Health is investigating an outbreak of active tuberculosis (TB) at Archbishop Riordan High School after a third case was confirmed on Tuesday.

What we know:

The campus dealt with its first confirmed case back in November and after requiring testing for all students and staff. It now has two more confirmed cases, according to SFDPH.

An outbreak is defined by the National Institute of Health as 3 or more cases of active TB. 

Testing underway for all students and staff

It’s an average-sized high school with just about 1,150 students, and another hundred faculty and staff.

"Everybody’s kind of around everybody," said junior Alejandro Rosales. "All of us have to get tests. I got it last Friday, I came out negative."

Rosales said students who were near an infected person received an email and school-wide events have been canceled. 

"They also said we can’t be going to the basketball games if we haven’t gotten tested yet, also they canceled the rally today," he said.

The backstory:

After the first confirmed case back in November, students and staff were required to test between January 20 and February 13.

The health department said it is working closely with school officials to reduce the risk of spread by monitoring students and staff for symptoms, recommending masks indoors, and making changes to indoor activities while screening continues.

What they're saying:

The school’s president Tim Reardon sent us a statement, saying in part, "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."

Parents at the pick-up line on Tuesday said the school is doing a good job of keeping parents informed.

Karla Rivas, the mother of a sophomore, said she has a newborn at home. "I’m not worried, I think everything will be fine," she said.

Symptoms mirror cold and flu

TB presents like a cold or flu, and spreads easily through coughs and sneezes, so medical experts say it can be tough to detect.

It takes up to 10 weeks to incubate, meaning the test could take that long to be positive, likely why the school community is testing now after the first case.

"That's why it's so hard to control TB because it's still so slow growing and so quiet," said Dr. Peter Chin-Hong, infectious disease specialist at UCSF.

Most times, TB stays latent 

It only becomes active in about 5-10% of people, but it’s a higher risk for babies and folks who are immunocompromised. 

Chin-Hong added, "If you get infected, most of the time, 90% of the time or 95% of time, you wouldn't feel anything."

In most recent data from 2023, SFDPH recorded 63 cases of active TB in San Francisco. 

SFDPH wrote in a statement, in part, "The health and safety of the school community remain our top priority, and we will continue working together to ensure students and staff have the guidance and support they need to stay healthy."

The good news is, if an exposed person tests positive, it’s treatable with antibiotics. 

The school said it’s following all recommendations from DPH.

"SFDPH just finalized the updated guidance based on the latest test results and data. We have shared with our community those specific recommendations and protocols, which we will be following moving forward," said Reardon.