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Understanding Tuberculosis: Information, Symptoms, and Treatment
The Basics | Symptoms | Treatment
The Basics
What Is Tuberculosis?
Tuberculosis, commonly known as TB, is a bacterial infection that can spread through the lymph nodes and bloodstream to any organ in your body -- and most often is found in the lungs. Most people who are exposed to TB never develop symptoms, since the bacteria can live in an inactive form in the body. But if the immune system weakens, such as in people with HIV or elderly adults, TB bacteria can become active. In their active state, TB bacteria cause death of tissue in the organs they infect. Active TB disease can be fatal if left untreated.
Because the bacteria that cause tuberculosis are transmitted through the air, the disease can be quite contagious. But it's nearly impossible to catch TB by a single, social contact with an infected person. To be at risk of being infected, you must be exposed to TB bacteria constantly, by living or working in close quarters with someone who has the active disease. Even then, because the bacteria generally stay latent (inactive) after they invade the body, only 10% of people infected with TB will ever have the active disease. The remaining 90% have what's called latent TB infection -- they show no signs of infection and won't be able to spread the disease to others.
These latent infections can eventually become active, though, so even people without symptoms should receive medical treatment. Medication can help get rid of the inactive bacteria before they become active.
Once a widespread disease, TB became relatively rare with the help of antibiotics developed in the 1950s. Two decades ago, the U.S. Surgeon General announced that tuberculosis was a disease of the past. He spoke too soon: The disease has since resurfaced in a potent new form called multidrug-resistant TB. Today, this new and dangerous form of TB -- resistant to some of the commonly used drug treatments -- has created a public health crisis in many large cities worldwide. If you have TB -- in its active or dormant state -- you must seek medical treatment.
What Causes Tuberculosis?
Tuberculosis is generally caused by exposure to microscopic airborne droplets containing the bacterium Mycobacterium tuberculosis. The disease is almost never transmitted through clothes, bedding, or other personal items. Because most people with TB exhale only a few of these bacteria with each breath, you can contract the disease only if you're exposed to an infected person for a long time. If you spend 8 hours a day for 6 months -- or 24 hours a day for 2 months -- with someone with an active case of TB, you have a 50% chance of getting infected.
People who are malnourished or who live or work in close quarters stand the greatest chance of contracting tuberculosis. Healthcare workers, long-term hospital patients, and prison workers and inmates face a greater-than-normal risk of becoming infected with TB. The conditions of poverty also contribute to its spread.
The active form of TB infection is more likely to occur in people with weakened immune systems, such as those with HIV/AIDS or blood cancers such as leukemia.
The Basics | Symptoms | Treatment
