Tuberculosis: Treating TB
Most of the time TB can be cured with antibiotics. If you have TB, you will need to take several drugs. This is because there are many bacteria to be killed. Taking multiple drugs also helps to prevent the bacteria from becoming drug resistant and, thus, much more difficult to cure.
If you have TB of the lungs, or pulmonary TB, you are probably infectious. This means that you can spread the disease by coughing or sneezing. Fortunately, after a couple of weeks of taking medicine, most people are no longer infectious and they begin to feel better. Usually they can return to life as usual. But that doesn't mean all the bacteria are killed. People often have to take TB medicine for six to nine months before all the bacteria are killed.
Why Is It Important to Take TB Medicine for So Long?
Cure rates for TB are above 90 percent if medicine is taken properly and to completion. For patients with multi-drug resistant TB, cure rates are only 50 percent.
TB bacteria die very slowly. Even when patients start to feel better, the bacteria are alive in their bodies. They have to keep taking medicine until all the bacteria are dead, otherwise they can get sick again and infect others.
Another danger of not completing the whole course of therapy is the rise of drug-resistant TB. If you stop taking your medicine and some of the bugs are still alive, they may become resistant to the drugs you were taking, so that if you get sick again, you will need different drugs to kill the bacteria because the old ones won't work. These additional drugs, called second-line drugs, must be taken for a very long time, sometimes up to two years, and their side effects can be quite serious.
Statistics have shown that income level has nothing to do with who takes their TB medicine to completion. Doctors and wealthy people are just as likely to stop taking their medicine as those who are less fortunate.
The only way to get better is to take your medicine as prescribed by the doctor. Most public health officials advocate Directly Observed Therapy (DOTS), which is when a health-care worker meets with the patient every day, or several times a week, to be sure they take their medicine. Sometimes they meet at the patient's home or at a hospital or TB clinic. Some DOTS programs provide medicine that can be taken only two or three times a week instead of every day. In addition to ensuring that the patient takes their medication as prescribed, the health care worker also monitors side effects.
DOTS works and it is used in many countries. It is the World Health Organization's recommended method for successfully treating TB.
Patients with active TB who have to go to the hospital may be put in special rooms with negative air pressure. This keeps TB from spreading from room to room, or out into hospital hallways. People who enter the rooms will wear special facemasks to protect themselves.
Multi-Drug-Resistant TB (MDR-TB)
DNA fingerprinting of TB strains can track the spread of a particular strain, confirm that an outbreak has occurred, and show the difference between cases in which a latent infection has been reactivated from those that are caused by recent infection.
When TB patients don't take their medicine properly, the TB bacteria may become resistant to certain drugs. This means the drugs can no longer kill the bacteria. Drug resistance is most likely to occur when people …
- Have spent time with someone with drug-resistant TB.
- Don't take their medicine regularly.
- Don't take all their medicine.
- Develop TB after they've taken TB drugs before.
- Come from areas where drug-resistant TB is common.
Multi-drug-resistant TB (MDR-TB) is a form of tuberculosis that is resistant to two or more of the first-line drugs used to treat the disease. When the bacteria resist the antibiotics used to attack them, they relay that ability to new bacteria that is produced. People with multi-drug-resistant TB must be treated with special second-line drugs. These drugs don't kill the bacteria as well as the first-line drugs, and they often cause more severe side effects.
If a person with MDR-TB spreads the disease to someone else and that person comes down with active disease, it will be multi-drug-resistant from the beginning. In the early 1990s, there were several outbreaks of multi-drug-resistant TB in New York City hospitals that were caused primarily by the spread of one strain, strain W, that went from patient to patient to patient. This strain was resistant to between seven and nine drugs. A large number of these patients died, and many health-care workers now have latent infections with this highly resistant strain.
A strain of MDR-TB originally develops when a case of drug-susceptible TB is improperly or incompletely treated. This occurs when a doctor doesn't prescribe the right drugs or when a patient doesn't take the drugs properly. This allows individual bacteria that have natural resistance to a drug to multiply. Over time, the majority of bacteria in the body become resistant.
The success in treating MDR-TB depends on how quickly it is identified and whether effective drugs can be found. Unfortunately, tests to determine whether a particular strain is resistant usually take several weeks to complete. During the delay, the patient may be improperly treated and therefore remain infectious. In populations at high risk for MDR-TB, this danger is combated by starting treatment without waiting for susceptibility results to confirm which drugs will be most effective.
TB is difficult to diagnose and drug resistance takes a long time to determine because the bacteria grows so slowly. Most bacteria double in 20 minutes—TB takes 24 hours. So it takes 24 hours to get 2 bacteria, 48 hours to get 4, and so on.
Treatment for MDR-TB can take up to two years and cost up to $250,000. The cure rate is only 50 percent, while the vast majority of drug-sensitive TB is curable. The World Health Organization estimates that over 50 million people worldwide are infected with MDR-TB. Given the difficulty of treating MDR-TB, this is a very frightening statistic.
Excerpted from The Complete Idiot's Guide to Dangerous Diseases and Epidemics © 2002 by David Perlin, Ph.D., and Ann Cohen. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.