State health officials are investigating a “positive, active” case of tuberculosis at Concord High School, officials said Wednesday.

Concord Superintendent Kathleen Murphy notified the community Wednesday via social media, saying the district is working to identify anyone who came in contact with the person.

“High school and district staff are working closely with public health officials, including Dr. Elizabeth Talbot, and Dr. James Noble, our infectious disease consultant,” state health officials said in a statement. “This person with TB is no longer in the school environment. If students or staff have had prolonged contact with this person since September 1, 2021, they may have been exposed to the bacteria that causes TB and benefit from testing and treatment.”

No further information was released.

Tuberculosis is a rare but contagious bacterial infection. It spreads through droplets released into the air by coughing and sneezing.

Not everyone infected with TB bacteria becomes sick, officials said. Tests are available to determine if someone who was exposed was infected.

A person who is infected but does not show any symptoms has what is called “latent” TB infection (LTBI). They are not considered infectious and cannot give TB to others, including family members, officials said.

Active TB disease causes symptoms such as persistent cough, fever, and unexplained weight loss.

There were 12 cases of tuberculosis in New Hampshire in 2020, according to state health officials.