The person had contact with nearly 150 other vendor employees at a Microsoft facility in Redmond.

REDMOND, Wash. — A vendor at a Microsoft facility in Redmond was recently diagnosed with active tuberculosis (TB), according to officials with Public Health - Seattle & King County.

The person had contact with nearly 150 other vendor employees, officials said. Those employees must now undergo testing as a precaution to rule out any TB infection.

The vendor companies are reaching out to their affected employees to notify them about the testing. Public health officials have been on site this week to evaluate those employees and test those who were exposed.

TB is an infectious disease caused by bacteria that are passed from person to person through the air. Health officials said TB is not easily spread. It typically takes repeated and prolonged exposure in a confined indoor space to become infected.

The cold or flu is much more easily spread, officials said.

The person diagnosed with active TB is being treated. Health officials said most TB cases are readily treatable with antibiotics and the treatment usually takes six to nine months.

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, according to officials.