Public Health – Seattle & King County is following up on the report of a Kentridge High School community member who was diagnosed with active tuberculosis (TB). Public Health is working with Kent School District officials to define the extent of any potential TB exposures, conduct evaluations for those exposed, and provide guidance and information to the school communities affected.
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 the cold or flu. It typically takes repeated and prolonged exposure in a confined indoor space to become infected with TB. Even in households with a contagious TB case, only about 1-in-3 close household contacts become infected.
Details on the evaluation
As a precaution, approximately 135 people from Kentridge High School, are recommended to be evaluated for TB, based on the amount of time they were exposed to the person with TB in indoor spaces. This exposure occurred from March through September 2023. Kent School District will be directly contacting these individuals who need TB evaluation. If you are not contacted, you are not considered to be exposed, and no action is required.
People at the schools who are identified to be infected with latent TB infection may be recommended for treatment, so that they do not develop the disease in the future. Latent TB infection can be treated in 3-4 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 5% of those who acquire latent TB infection develop active TB within two years and an additional 5% of them develop active TB over the rest of their lifetime. For that reason, we will be conducting TB evaluation in the Kentridge High School community in a timely manner to identify those who are recently infected with TB and offer preventive treatment to stop the spread of TB.
The person at Kentridge High School with active TB disease is receiving treatment and is currently not a risk for infecting others. Most cases of active TB are readily treatable with antibiotics that are commonly available; treatment typically takes six to nine months.
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, 111 new cases of TB disease were reported in 2022. 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.
Originally published September 26, 2023