AUBURN – Six of the 150 people tested for tuberculosis at Edward Little High School have a latent form of the disease, a percentage that is consistent with the general population, the school physician said Thursday.
One student was diagnosed with active tuberculosis in April, but so far no one else at the school has developed the illness, said Dr. Douglas Smith.
There’s a big difference between “active” and “latent” TB, he stressed. Active TB is contagious under prolonged exposure. The victim is sick with coughing and fever. Once treatment begins, it continues to be contagious from three weeks to three months.
Latent TB is less serious. It is not contagious. It does, however, require antibiotics for nine months.
The small number of latent cases at Edward Little indicates the disease is not spreading, Smith said.
“It’s going well. I applaud our community,” Smith said. “There hasn’t been a groundswell of panic, there’s been appropriate concern. Overall, it’s being handled well by school staff, local and state health staff.”
The six who have latent TB may not have caught it from the infected student, said Dr. Dora Mills, director of Maine’s Center for Disease Control.
“They may have other risk factors for TB,” Mills said. “It may very well be they contracted it in other ways.” One risk factor is traveling outside the country, she said.
If people with latent TB are not treated, they could come down with the more serious active TB, Smith said. Latent TB means you have the germ in your body.
People with latent TB are prescribed a special antibiotic, isoniazid, for nine months. It takes that long to kill the bacteria because, in part, it grows slowly. When a person with latent TB is treated and takes the medicine, he or she will be cured, Smith said.
The cost of the tests for EL students and faculty is covered by public health budgets, Smith said. Further testing and treatment done outside the public health arena would be covered by the individual’s insurance, he said.
Only those identified as having possible prolonged exposure to the infected student, such as those in the same classrooms or on the same bus, were tested for the disease, Mills said.
At Edward Little, the positive numbers from the testing are low, which indicates there is not a need to continuing testing more who had casual contact with the infected student, Smith said. “It’s not like the common cold.” A person with latent TB cannot spread latent TB.
It’s not uncommon to take 100 people off the street and get a few positives, he said. “Every community’s different, but it’s not uncommon to find 5 percent who test positive.” In most cases, a positive screening means someone has latent TB and needs treatment, Smith said.
While it appears the disease has been contained, Smith cautioned that more tests will be given because the disease can take a while to appear. More testing at EL is scheduled for June and testing outside the high school is ongoing, Mills said.
Someone with latent TB will test positive for the rest of his or her life, even if they’ve taken medicine for the nine months, Smith said. That’s because someone with latent TB will always carry the antibodies, even though they’re cured.
Some countries use a vaccine to inoculate against TB. Because that vaccine is not effective, it isn’t used in this country, Smith said.
“In the United States, we never really have inoculated’ students or anyone else against TB,” Smith said.
In the earlier part of the century tuberculosis, which was also called “consumption,” was a dangerous disease that killed thousands. Development of antibiotics brought about cures. Today there are 15 to 20 active cases in Maine a year.
For several decades youngsters were routinely tested for TB by being pricked. Routine testing is no longer done, Smith said.