Tuberculosis Outbreak Linked to San Francisco High School
A tuberculosis (TB) outbreak has been reported at Archbishop Riordan High School in San Francisco. The local health department issued a warning on January 29, highlighting the situation in the school community.
TB is a bacterial infection that primarily affects the lungs, but it can also impact other parts of the body. It spreads through the air when an infected person coughs, sneezes, or otherwise releases droplets into the air.
Since November 2025, health officials have confirmed three active cases of TB connected to the school, along with over 50 individuals showing latent TB infections. A latent TB infection means the bacteria are present but inactive, meaning those individuals aren’t contagious. However, there is a chance that latent infections could develop into active TB in about 5% to 10% of cases.
The advisory states that actions are being taken to ensure that everyone involved receives preventive treatment. School staff and students are being asked to stay home if they feel ill and to get a doctor’s approval before returning.
Moreover, everyone connected to the school must undergo a TB evaluation, regardless of whether they show symptoms. Follow-up assessments will take place every eight weeks until the outbreak is under control.
Currently, the general public’s risk of contracting TB from this outbreak is considered low, so no additional measures are necessary for those unrelated to the school cases.
Health experts remind us that TB is a risk for everyone, as noted by Dr. Masae Kawamura, a former TB control director in San Francisco. She points out that since TB spreads through the air, it’s often found in crowded places like schools, hospitals, and shelters.
In the U.S., TB remains a serious health concern, with more than 565 reported deaths in the last year, according to the CDC. In San Francisco, the case fatality rate is over 10%.
Understanding TB Symptoms and Treatment
While many people have been exposed to TB bacteria, only a small percentage will develop symptoms. Common signs include a persistent cough, chest pain, fatigue, weight loss, fever, and night sweats. Some patients may even cough up blood as the illness worsens.
TB affects the lungs in about 80% of cases, but it can also impact other organs like the kidneys, spine, and brain. Diagnosing TB can be done through rapid testing, and treatment typically involves a course of antibiotics taken daily for four to six months. It’s crucial to complete the full treatment to prevent the bacteria from becoming resistant to medication.
If untreated, TB can be lethal in about half of cases, with a portion of patients recovering on their own.
Who Is Most at Risk?
Dr. Kawamura highlights that anyone can catch TB, especially in crowded environments where airflow is limited. Individuals most at risk include those with weakened immune systems, malnutrition, or underlying conditions like diabetes. Children and babies are also more susceptible.
The best way to protect against TB is through early testing and treatment for latent infections, the doctor emphasizes.
For now, health officials continue to monitor the situation at Archbishop Riordan High School while ensuring the wellbeing of its community.
