The recent tuberculosis outbreak at Ennis High School and a possible case at Denton High School has many North Texans asking questions about the bacterial infection.
NBC 5 is taking questions sent to newstips@nbcdfw.com and answering them on-air and in this story.
Doctors say awareness and taking action keep tuberculosis from spreading.
"We are able to control it by recognizing the disease and isolating those individuals effectively and quickly," said Dr. Robert Guillinese of Texas Health Harris Methodist.
How It's Spread
Tuberculosis is an airborne bacterial infection.
"If someone coughs or someone sneezes in the room or even talks in the room and you inhale the air, you can be infected with someone else's tuberculosis," said Dr. Garry Woo, the Dallas County medical director for Tuberculosis Control.
But exposure to tuberculosis does not mean a person will contract it. People are only at risk for contracting the infection if they are in close proximity to a person with an active case for a prolonged period of time -- 40 to 80 hours over the course of several weeks.
Casual contact such as a conversation, sports or a car ride should not lead to infection.
Who Is at Risk
Doctors say that healthy people should not worry.
Local
The latest news from around North Texas.
"Generally it's an at risk population," Guillinese said.
He said people with normal immune systems can fight off the tuberculosis bacteria fairly easily.
People with poor immune systems or kidney disease, severe diabetics and drug users should be concerned "but even their chances of becoming infected are very, very low," Guillinese said.
Symptoms
Parents who worry that their child was exposed to tuberculosis or could have it should be tested by their pediatrician. Symptoms to look out for are a chronic cough that lasts longer than three weeks, a high fever (around 104 degrees) and night sweats.
Why Texas Doesn't Routinely Test for TB
The Texas health department dropped required tuberculosis testing in 1987.
State health officials say they stopped routine testing primarily because so few people were testing positive.
The testing was also expensive, especially for parents and children with false positive results.
TB Vaccine
Guillinese said the tuberculosis vaccine is only effective half of the time.
Typically, the World Health Organization only recommends the vaccine be used in areas of that have a high endemic incident of tuberculosis.
Texas had only 1,385 cases of tuberculosis in 2010 and 1,500 cases in 2009. According to the Centers for Disease Control and Prevention, nearly 9 million around the world become sick with tuberculosis each year.
Length of Isolation for Active TB Cases
The Denton County Health Department says people diagnosed with an active case of tuberculosis are typically isolated -- either at home or in a hospital -- for two weeks.
After two weeks of isolation and medication, they are no longer considered contagious.
