135 people evaluated after active tuberculosis case discovered at Kentridge High School

KENT, Wash. — Public Health – Seattle & King County is investigating a case of tuberculosis at a Kent high school.

Health officials say someone at Kentridge High School was diagnosed with active TB.

About 135 people at the high school were told they should be evaluated based on how long they were exposed to the person with TB while indoors.

The exposure happened from March through September.

Kent School District officials contacted those who need to be evaluated on Tuesday. If you were not contacted, you were not considered to have been exposed and no action needs to be taken.

Those with a latent — or dormant — TB infection may be recommended to have treatment so they don’t get the disease in the future. A latent infection can be treated in three to four months.

So what’s the difference between active TB and a latent TB infection?

A latent TB infection can’t be spread to others, and the person with a latent infection is not sick with the disease, according to public health officials.

However, those with latent infections could get active TB in the future, which could then be spread to others. About 100,000 people in King County have latent TB infections.

“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,” Public Health – Seattle & King County said in a blog post.

The person at Kentridge High School who had active tuberculosis is being treated. Most active cases are treated with antibiotics, usually for six to nine months.

But how is the disease spread?

According to Public Health’s blog post:

“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.”