For the second time in two months, a case of tuberculosis in a public school has state Department of Health officials testing students and taking precautions to contain the spread of the disease.

Last week students, faculty and parents learned that a Kahuku High & Intermediate School teacher had tested positive for TB after visiting a doctor because of an illness. The teacher has not returned to campus, DOH said.

Health officials will test 106 people at Kahuku Feb. 19.

In December a Roosevelt High School student also tested positive, triggering a DOH investigation and testing of 132 people who came into contact with the student at the school.

New tuberculosis cases in the state have increased slightly over the past two years. Hawai'i has the highest rate in the nation, due in part to a relatively high percentage of foreign-born residents. As many as 40 percent of the foreign-born people tested in Hawai'i have positive TB results, compared to 6 percent of U.S.-born residents, said Dr. Jessie Wing, chief of the DOH Tuberculosis Control Branch.

The Kahuku case has the department rethinking its strategies.

"It's unusual for us to have a new case with a teacher, so we're trying to ask if there are problems with our screening system," Wing said. "We're asking how this can be prevented."

Teachers used to be tested for TB every two years, but now they are tested when they begin working in the schools. Students are tested only when they first enter the public school system. Some private schools require TB testing every year, but Wing said the frequent testing proved to be unnecessary and costly.

From 2000 to 2006, there have been five new cases of Hawai'i public school employees with TB, she said.

"We don't find a lot of TB among students," Wing said. "We don't find a lot of TB among teachers."

Kahuku principal Lisa De Long said the school is working with the Department of Health. Letters were sent to parents and public information briefings were scheduled, De Long said.

"I don't want to downplay this, but the DOH considers this routine," she said. "Student health and safety is our priority, so we're taking appropriate steps to address the case."

One parent said she's not worried and is confident that the school is handling the problem correctly. But she said her daughter had concerns and showed how little people know about the disease.

"My daughter was saying, 'Mom, can we die from that? If we can die from that we don't want to go back to school,' " Leslie Llanos said.

The bacterial infection usually attacks the lungs but can affect other body parts, and if left untreated, could be fatal.

At Roosevelt, of the 132 people tested, two people were found to have a positive TB test, Principal Ann Mahi said.

"We're way below the percentage rate for the general population," Mahi said.

But the incident had a positive effect in that it provided an opportunity to educate students and faculty about the disease, which is treatable, she said.

Reach Eloise Aguiar at eaguiar@honoluluadvertiser.com.