Preventing Tuberculosis: Treating Inactive TB, Stopping Spread, and Travel

The main points

• Inactive TB (also called latent TB infection) can be treated, which keeps it from becoming active TB disease.
• People with active TB of the lungs or throat may need to take steps so they do not pass the germs on.
• Taking every TB medicine exactly as prescribed is essential.
• Health care settings need infection control plans to limit exposure and spread.

A health care worker in a respirator with a masked patient. Image from CDC's page.

How TB spreads

TB travels through the air. A person with TB disease of the lungs or throat puts germs into the air by coughing, speaking or singing, and they can hang there for several hours, depending on the surroundings. Spread is likelier indoors or wherever air moves poorly — a closed vehicle, for instance — than outdoors.

Breathing the air can infect someone, but not everyone infected falls ill. That gives two conditions: inactive TB and active TB disease. Active disease spreads most to the people someone sees every day: family, friends, coworkers and schoolmates.

If you think you have been exposed, contact your health care provider or health department, and say when you spent time with the person who has active TB.

Who is at higher risk

Anyone can get TB. Higher risk comes in two kinds.

More likely to be exposed — people who:

• were born in, or often travel to, countries where TB is common, including some in Asia, Africa and Latin America;
• live or have lived in large group settings such as homeless shelters, prisons or jails;
• have recently spent time with someone who has active TB;
• work where TB spreads more easily — hospitals, homeless shelters, correctional facilities, nursing homes.

More likely to fall ill once infected — people who:

• were recently infected;
• have a weaker immune system from certain medicines or conditions such as diabetes, cancer or HIV.

More: TB risk factors.

Symptoms of active TB in the lungs

A cough lasting 3 weeks or longer, chest pain, coughing up blood or sputum (phlegm), weakness or fatigue, weight loss, loss of appetite, chills, fever and night sweats. People with inactive TB have no symptoms — but without treatment they can go on to develop active disease. More: signs and symptoms.

Treat inactive TB

Treating inactive TB is the best way to prevent active TB disease. Left untreated, 1 in 10 people with inactive TB will fall ill with active disease, which can spread and can kill. The risk is much higher with a weakened immune system, diabetes, cancer or HIV, and for such people treatment is especially important. More than 80% of people who develop active TB in the United States each year got it from untreated inactive TB. More: treating inactive TB.

If you have active TB of the lungs or throat

You may be infectious, and you and your provider will talk about protecting others. The most important step is to take all your medicines exactly as directed — no missed doses, no stopping early; stopping or taking them irregularly can be very dangerous. Tell your provider if you are having trouble with them, or if anything seems wrong.

Keep every clinic appointment. Your provider needs to follow your progress, often with another chest x-ray or a sputum test, which show whether the medicines are working and whether you can still spread the germs.

In the hospital, you may be placed in a special room whose air vents keep germs from reaching other rooms; staff wear a special mask, and you stay in the room.

At home:

• take your medicines as directed — this matters most;
• cover your mouth with a tissue when you cough or laugh, and throw it away in a closed bag;
• stay away from work or school until your provider says it is safe, and avoid close contact with anyone;
• sleep in a separate bedroom from the rest of the family;
• air out your room often, if it is not too cold — TB spreads in small closed spaces where air does not move;
• put a fan in the window blowing outward; with other windows open, it also draws in fresh air, lowering the chance that germs linger.

Your provider will tell you when you can go back to work or school, or see friends. More: treating active TB.

Prevent drug-resistant TB

Drug-resistant TB means the germs resist at least one of the most effective TB medicines, which can no longer kill them. It is hard and costly to treat. It comes from catching resistant germs, or from TB medicines being misused or mismanaged, and is more common in people who:

• have spent time with someone known to have drug-resistant TB;
• come from parts of the world where it is common;
• develop TB again after earlier treatment;
• do not take all their TB medicines, or do not take them regularly.

The best protection is again to take all TB medicine exactly as prescribed. More: drug-resistant TB.

In health care settings

Health care settings — especially those where exposure is likelier — should have a TB infection control plan covering administrative measures (such as facility risk assessments, screening of staff and education), environmental controls, and respiratory protective equipment.

Travel

TB occurs worldwide but is far more common in some places: most TB disease is in sub-Saharan Africa, Eastern Europe and Asia. The chance of catching TB on a plane is very low.

Travelers going to work in a clinic, hospital or other health care setting where TB patients are likely should consult infection control or occupational health experts, ask about procedures that prevent exposure, and consider personal respiratory protection. Anyone expecting prolonged exposure to people with TB disease should have a TB blood test or skin test before leaving the United States:

• if it is negative, repeat it 8 to 10 weeks after returning;
• yearly testing may be advised for repeated or prolonged exposure, or a stay of several years;
• people with HIV should talk to their provider, since HIV can blunt the response to TB tests.

More: CDC's Travelers' Health, Questions and Answers About TB, the TB fact sheet and Think. Test. Treat TB.

Sources

Based on "Preventing Tuberculosis," Tuberculosis (TB), Centers for Disease Control and Prevention; a work of the United States government in the public domain.