Tuberculosis Found In Pittsburgh Public Schools: Doctors Warn How To Prevent Spreading

PITTSBURGH (KDKA) -- A student at Arsenal 6-8 has tuberculosis.

This bacterial infection is spread through the air. It can affect any part of the body, but usually the lungs, with a person developing a cough, fever, night sweats, and weight loss.

Symptoms last longer than three weeks.

"TB is only transmitted if a person with active TB coughs or spits or talks forcefully to someone in very close contact for a prolonged period of time," Allegheny County Health Department epidemiologist Dr. Kristen Mertz explains.

Transmission in a school setting is extremely rare. The bacteria is not spread through casual contact or on surfaces.

To control any further infection, the county health department is conducting an investigation.

"We notify and evaluate the people who have the closest contact to the case and we look to see if those people are infected. And if so, we expand to the second most amount of contact," said Dr. Mertz, "Rarely do we get beyond the first tier."

Fortunately, TB is on the decline in the United States, only 20 cases per year in Allegheny County and only 200 cases for all of Pennsylvania.

"Those are at historical lows," said Allegheny Health Network internal medicine specialist Dr. Marc Itskowitz, "The most common patient that we will see with tuberculosis is someone who comes from another country where tuberculosis is much more common."

He has taken care of some of these few cases over the years.

"Fortunately we have good detection tools today and antibiotics," he said.

A PPD, the skin test, a tiny shot of noninfectious protein associated with tuberculosis, goes just under the surface of the skin. Two to three days after the shot, the doctor will take a look.

If there's a red hard lump, the test is positive for TB.

Another diagnostic tool is a blood test, which does not require a return visit.

"It is a common test now, and that is the preferred test," says Dr. Mertz.

The health department says that Arsenal is notifying a small number of contacts out of an abundance of caution.

The case is a surprise.

"This is an unusual situation, especially here in Pittsburgh, where we don't have a lot of tuberculosis, to begin with," says Dr. Itskowitz. "The student would only pass the infection along if they were coughing or sneezing those droplets and someone was directly exposed. Even for those students who were in the classroom, with the infected patient, the actual risk of infection is quite low."

WATCH: Doctors Discuss How To Prevent Spread Of Tuberculosis

It's more common in other parts of the world.

"If you look over the last 50-60 years, there has been a significant decrease, fortunately, in the United States," Dr. Itszkowitz said.

Dr. Itzkowitz says watching for symptoms in close contacts is the best strategy.

"It does get a little complicated because we're in flu season, right? So fever and cough are common this time of year. but the key is the duration."

Flu symptoms last about one week.

For cough, fever, and weight loss lasting longer than three weeks, doctors may consider TB testing.

In the United States, there are so few cases, vaccination is not routine. Immunization of infants is more common in other countries where TB is widespread.

The Allegheny County Health Department does not expect more cases at Arsenal 6-8.

"In general, people at highest risk for becoming infected are people who live with a case, and who spend prolonged periods of time with a person who is symptomatic," says Dr. Martz, "But for just the general public, there is very little risk at all."

The student with tuberculosis is not in school and is getting medication to treat the infection.

The Allegheny County Health Department is identifying close contacts to make sure they are tested and treated.