Tuberculosis Outbreak at Archbishop Riordan High School
San Francisco health officials have issued an advisory concerning a tuberculosis (TB) outbreak at Archbishop Riordan High School. Over 50 members of the school community have tested positive for latent TB, with three confirmed cases of active TB.
Public Health Response and School Measures
The San Francisco Department of Public Health (SFDPH) has alerted healthcare providers to monitor for TB symptoms in individuals connected to the school. The initial active TB case was identified in November.
Individuals with active TB are required to isolate at home. Testing efforts at the school will continue every eight weeks until the outbreak is declared over.
Archbishop Riordan High School has temporarily transitioned to remote learning until February 9, followed by a hybrid model through February 20. After this period, campus access will be restricted to students and staff who have tested negative for TB.
Participation in indoor off-campus activities, such as sports competitions, also requires a negative TB test result.
The SFDPH has indicated that the risk to the broader San Francisco population is low.
Understanding Tuberculosis
TB is a bacterial infection that primarily affects the lungs. It exists in two forms:
- Active TB: Causes symptoms like fever, chills, coughing, weight loss, and coughing up blood. It is transmissible to others.
- Latent TB: Asymptomatic and not transmissible, but it can progress to active TB at any time.
Both latent and active TB are treatable with antibiotics, although treatment typically spans several months. The SFDPH reports that some cases may necessitate hospitalization, and San Francisco experiences a case fatality rate exceeding 10%.
Broader Context
California's TB incidence rate (5.4 cases per 100,000 people) is higher than the national average (approximately 3 cases per 100,000 in 2024). Despite this, outbreaks of four or more people remain relatively uncommon, with 17 new or ongoing outbreaks reported in California for 2024.
Dr. Monica Gandhi, an infectious disease expert at UC San Francisco, noted an increase in U.S. TB cases since 2022.
Dr. Gandhi emphasized the significance of the current outbreak and supported the school's response.