What parents need to know about tuberculosis, according to experts

Tuberculosis close-up in purple and red
Tuberculosis is a disease that most commonly causes an infection of the lungs. (Photo: Getty Images)

With cases of tuberculosis (TB) cropping up at schools in different parts of the country — including a person at a middle school in Pennsylvania, and a student or staff member at a Las Vegas elementary school — parents may have some questions about the infectious disease. What exactly causes tuberculosis? What are the symptoms to look out for? And how common is it?

Here’s what parents need to know about tuberculosis.

What is tuberculosis and what are the symptoms?

“Tuberculosis is a disease that most commonly causes an infection of the lungs, and is caused by a bacterium that is transmitted from person to person,” Dr. Alexander Kay, assistant professor of pediatrics-global immigrant health at Baylor College of Medicine, tells Yahoo Life.

Most infections in children cause no symptoms, because their body controls the infection before it spreads too far, according to Dr. Rachel Martin-Blais, a pediatric infectious disease expert at Nationwide Children’s Hospital. “But we treat them to keep the infection from causing problems in the future,” she tells Yahoo Life.

When children do have symptoms, Martin-Blais explains, they usually come on slowly. “The most common things we see are a cough lasting several weeks, fevers and/or severe sweating at night, weight loss or poor growth and swollen glands,” she says. “Sometimes, children can have other forms of tuberculosis that show up as bone pain or headaches and behavior changes.”

Symptoms can also include “failure to thrive and decreased appetite and playfulness,” notes Kay.

However, infected individuals don’t necessarily get sick right away. “People can become sick from tuberculosis long after being infected, and in some cases, symptoms don’t develop for a few months or even years after the infection occurred,” notes Martin-Blais.

How is tuberculosis spread?

Tuberculosis is airborne, “meaning it is spread through tiny droplets that are suspended in the air when a person coughs, sneezes, sings, etc.,” explains Martin-Blais. “Because these droplets are so small, they can travel long distances in the air.”

Adults generally have more TB bacteria in their lungs than children, notes Kay, and are typically more infectious with TB than children are. Martin-Blais agrees, adding that, in general, children are “very poor” transmitters of tuberculosis.In fact, we usually consider children under 10 not to be contagious unless they have really severe disease or they’re having devices like breathing tubes being inserted or removed,” she says.

That said, Martin-Blais points out that identifying a child infected with TB is a red flag. “A case of tuberculosis in a child is a really important signal to our public health teams that there is probably an infected adult in that child’s social circle.”

Kay points out that tuberculosis can be transmitted “any time there is a person with tuberculosis disease in close proximity to other people.”

Who is most at risk for the disease?

Infants and children under 5 years of age, as well as people with weakened immune systems — such as those receiving cancer chemotherapy, those with HIV or people who have undergone an organ transplant — are at the highest risk for severe TB, says Kay.

People with compromised immune systems can develop “very severe disease if they are exposed to tuberculosis, because their bodies have a harder time controlling its spread,” explains Martin-Blais. “The same goes for very young children — under 4 — who may become sicker than older children with more mature immune systems would.”

In these populations, “it is more common for TB to infect parts of the body outside of the lungs, such as the fluid around the brain,” Kay says. “TB infections of the central nervous system can result in significant disability when not treated promptly.”

Although anyone can get tuberculosis if exposed to it, Martin-Blais notes that exposure is “quite rare” in the U.S. and Canada. “Many people who get tuberculosis came into contact with it while living or spending an extended period of time — usually more than 3 weeks — in a country where tuberculosis is more common,” she says.

How is tuberculosis typically treated?

When treating tuberculosis, Martin-Blais explains that physicians draw a distinction between infection and illness. “A huge majo1`rity of people with TB have infection without disease, so they have been exposed and have the bacteria in their bodies, but the bugs haven’t yet caused any problems,” she says.

Typically, though, tuberculosis is treated with four antibiotics used in tandem, to prevent the bacteria from developing resistance, explains Kay. “These medications can be reduced over time, and treatment generally lasts six months,” he says. “There is newer evidence that children with less severe TB disease only need to be treated for four months.”

The bacterium that causes tuberculosis (M. tuberculosis, if you really want to know) grows “very slowly and is good at adapting to antibiotics,” says Martin-Blais, “so physicians usually need long courses of treatment with multiple medications to make sure that they take care of it the first time.”

However, if physicians can find and treat infected individuals before they become sick, says Martin-Blais, they can use fewer antibiotics and can help to prevent them both from developing disease and from spreading the infection to others. “That is why health care professionals provide tuberculosis screening, which tells physicians if someone has been exposed to tuberculosis before they develop symptoms,” she says. “In the U.S., physicians screen people based on their risk for coming in contact with an infected person.”

She adds that health care professionals are now better at treating TB. “The World Health Organization (WHO) just updated guidelines to say that physicians can do even shorter courses for straightforward cases,” she says, “and can give oral treatments for many cases of resistant infections.”

There is a tuberculosis vaccine, which many other countries give to newborns to try to prevent tuberculosis disease, but it's rarely used in the U.S.

“The vaccine is effective at preventing severe TB in infants, but is not effective at preventing TB disease over the long term in adults,” Kay explains. “In general, the risk of acquiring TB is low for infants in most parts of the United States, and that is why the vaccine is not routinely used. Infants and children in the U.S. that visit places with higher rates of tuberculosis or who have exposure to people with tuberculosis are at risk for TB and should speak to their doctor.”

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