Public Health – Seattle & King County is following up on the confirmation of an individual associated with Rainier Beach High School, in Seattle, who was diagnosed with active tuberculosis (TB). Public Health is working with Rainier Beach High School to define the extent of any potential TB exposures and supporting the school as Public Health conducts evaluations for those exposed and provides guidance and information to staff, students and families.
TB is not easy to spread
TB is an infectious disease caused by bacteria that are passed from person to person through the air. TB is not easily spread; it’s much harder to spread than COVID-19, a cold or flu. It typically takes repeated and prolonged exposure in a confined indoor space to become infected with TB. Even in households with one person who is contagious with TB, only about 1-in-3 close household members become infected.
Details about the evaluation
As a precaution, Public Health is recommending that about 130 people associated with the school be evaluated for TB, based on the amount of time they were exposed to the person with TB in indoor spaces. Rainier Beach High School will be directly contacting those who need TB evaluation, which includes a medical risk assessment and a TB test.
All students, staff and families are being informed this week of the situation, regardless of their level of exposure.
If anyone associated with the school is identified to be infected with latent TB infection, Public Health will help connect them with treatment that will kill the TB germs and prevent them from developing TB disease in the future. Latent TB infection can be treated in three to four months.
The person associated with the school who has active TB disease is receiving treatment from Public Health and is no longer considered contagious. Most cases of active TB are readily treatable with antibiotics that are commonly available; treatment typically takes six to nine months.
Active TB versus latent TB infection
Unlike active TB disease, people with latent (or dormant) TB infection can’t spread it to others and are not ill with the disease. Approximately 100,000 people in King County have latent TB infection. While they aren’t contagious now, they could potentially have active TB in the future and also infect others.
Approximately five percent of those who acquire latent TB infection develop active TB within two years and an additional five percent develop active TB over the rest of their lifetime.
More about TB
TB usually affects the lungs, but can affect lymph nodes, bones, joints, and other parts of the body. A person with active TB in the lungs can spread the disease by coughing or sneezing. In King County, 110 new cases of TB disease were reported in 2024. On average, about two cases of TB disease are diagnosed in King County each week.
To learn more about signs, symptoms, and transmission of TB, visit the Centers for Disease Control and Prevention’s TB website.
TB program protects the community
Public Health – Seattle & King County’s TB Control Program ensures that people with active TB are diagnosed and cured, and that others in contact with them who are at highest risk of infection are screened, so that infections do not spread.
This essential public health work improves the community’s health and saves money by controlling the spread of TB, preventing outbreaks, and preventing the development of multi-drug resistant TB that can be very expensive to treat.
TB is a global threat, with over two million deaths every year, as people in many parts of the world do not have access to treatment and effective TB control programs like we do in the United States.
Originally published on February 24, 2026.