Toning Down Tuberculosis

Your chest feels tight every time you cough. You feel weak and tired. You sweat at night something awful. And your cough won’t let up. You could have tuberculosis.

Tuberculosis (TB) is an infectious disease that affects mainly the lungs, but also other parts of the body such as the spine, brain, or kidneys. Everyone infected with this disease doesn’t get sick but if you do get sick you need prompt treatment. The bacteria that causes tuberculosis is spread from person to person through tiny droplets released in the air through coughs and sneezes.

Once rare in developed nations, cases of tuberculosis started rising because of HIV infected patients. HIV weakens a person’s immune system and makes one vulnerable to tuberculosis.

According to the Centers for Disease Control and Prevention, in 2018, 1.7 billion people were infected with TB bacteria—roughly 23 percent of the world’s population. TB is the leading infectious disease killer in the world, claiming 1.5 million lives per year. Of the 10 million that became ill with TB in 2018, approximately three million were missed by health systems and did not get the care they truly needed, allowing the disease to be further transmitted.

TB is caused by the bacterium Mycobacterium tuberculosis. Although TB is infectious, it doesn’t spread easily. Usually, you have to spend a lot of time in contact with someone who is contagious in order to catch it. Only people with an active pulmonary infection are contagious. Most people who breathe in TB bacteria are able to fight the bacteria and stop it from growing. The bacteria becomes inactive in these individuals, and is referred to as a latent TB infection.

Although the bacteria is inactive, they can still remain alive in the body, and become active later. Some people can have a latent TB infection for a lifetime, without it later becoming active and developing into TB disease. However, TB can become active if the immune system is weakened and cannot stop the bacteria from growing. This is when the latent TB infection becomes TB disease.

People with inactive TB don’t show symptoms. Those with TB disease can show bad cough (lasting longer than 2 weeks); pain in the chest; coughing up blood or sputum (mucus); fatigue or weakness; loss of appetite; weight loss; chills; fever; and night sweats.

Many TB strains resist the drugs most used to treat the disease. People with active TB must take several types of medications for months to get rid of the infection and prevent antibiotic resistance.

The Centers for Disease Control and Prevention recommends that people who have an increased risk of tuberculosis be screened for latent TB infection. This recommendation includes people who have HIV/AIDS, use IV drugs; are in contact with infected people; are from a country where TB is common such as several countries in Latin America, Africa, or Asia; live or work in areas where TB is common such as prisons or nursing homes; work in health care and treat people with a high risk of TB; and are children who are exposed to adults at risk of TB.

Although TB is contagious, it is not easy to catch. You are much more likely to catch a strain of TB from someone you live with or work with than a stranger. Most people with active TB who have had appropriate drug treatment for at least two weeks are no longer contagious.

Since the 1980s, TB cases have risen dramatically due to the spread of HIV, the virus that causes AIDS. HIV suppresses the immune system, making it vulnerable to TB bacteria. As a result, people with HIV are more likely to have active TB than people who aren’t HIV positive.

TB can still be deadly because of the increase in drug resistant strains. Some TB bacteria have survived despite medications. This is because people don’t take their drugs as directed and don’t complete the necessary course of treatment.

Anyone can get TB, but certain things raise your risk of acquiring the disease including a weakened immune system from other conditions such as HIV, diabetes, certain cancers, cancer treatment like chemotherapy, drugs to treat other conditions like rheumatoid arthritis, Crohn’s disease, and psoriasis, malnutrition or body weight, and very young or advanced age.

You can also increase your risk of getting TB depending on where you live or where you work. If you live in Africa, Asia, or Latin America you can significantly increase your risk. If you work in a residential care facility like a homeless shelter or prison, you can also raise your risk of having TB.  

The most common diagnostic tool for TB is a skin test, but blood tests are becoming common. A small amount of a substance called tuberculin is injected just below the skin on the inside of your forearm. Within 48 to 72 hours, your doctor will check your arm for swelling at the injection site. A hard raised red bump indicates TB infection. The size of the bump determines whether the test results are significant. No test is perfect and sometimes you can get a false positive or test that indicates that you don’t have TB when you do.

Blood tests can confirm or rule out latent or active TB. These tests measure your immune system’s reaction to TB bacteria. These tests require only one office visit. A blood test may be useful if you’re high risk of TB infection but have a negative response to the skin test.

If you have a positive skin test, your doctor is likely to order a chest X-ray or a computed tomography (CT) scan. This might show white spots in your lungs where your immune system has walled off TB bacteria or it might reveal changes in your lungs caused by active TB.

If your chest X-ray shows signs of TB, your doctor may take a sample of your sputum, the mucus you cough up in order to test it for TB bacteria. Sputum samples can also be used to test for drug resistant strains of TB. This helps your doctor narrow in on the medications that are more likely to work. The results will come in four to eight weeks.

If you have latent TB, your doctor may recommend treatment with medication if you’re at high risk for developing active TB. For active TB, you must take medication for at least six to nine months.

The exact drugs and length of treatment depend on your age, overall health, possible drug resistance and where the infection is in your body.

If you have latent TB, you might need to take one or two types of drugs. Active TB, especially if it is a drug-resistant strain, require several drugs at once. The most common drugs for TB are isoniazid, rifampin (Rifadin, Rimactane), ethambutol (Myambutol), and pyrazinamide.

If you have drug-resistant TB, a combination of antibiotics called fluoroquinolones and injectable medications, such as amikacin or capreomycin (Capastat), are generally used for 20 to 30 months. Some drugs may be added to counteract drug resistance such as bedaquiline (Sirturo) and linezolid (Zyvox).

You can experience notable side effects from these medications. Please note that all TB medication can be toxic to your liver. When taking these drugs, contact your doctor if you have nausea and vomiting; loss of appetite; a yellow color to your skin (jaundice); dark urine; easy bruising or bleeding; and blurred vision.

It is important that you take the prescribed treatment for the amount of time specified by your doctor. In a few weeks, you will be feeling much better and no longer contagious. Stopping treatment too soon or skipping doses may result in drug-resistant bacteria.

TB is curable even in weakened immune systems. To learn more about TB, talk to your health provider or visit the CDC website.