Tuberculosis (TB) is a bacterial infection caused by a germ called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but they can also damage other parts of the body. TB spreads through the air when a person with TB of the lungs or throat coughs, sneezes or talks. If you think you have been exposed, you should go to your doctor for tests as soon as possible. You are more likely to get TB if you have a weak immune system.
Cause
All types of TB (see “Drug-resistant TB” below) are spread the same way. TB germs are put into the air when a person with TB disease of the lungs or throat coughs, sneezes, speaks, or sings. These germs can float in the air for several hours, depending on the environment. Persons who breathe in air containing these TB germs can become infected.TB is not spread by:
Symptoms
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Abdominal pain
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Blurred vision
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Continued loss of appetite
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Dark (coffee-colored) urine
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Fever
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Nausea
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Rash or itching
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Tingling or burning in your hands or feet
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Tiredness without reason
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Vomiting
If you think you have been exposed to someone who has TB, call your doctor immediately to schedule a skin test.
Diagnosis
The most commonly used method to check for tuberculosis is a test referred to as the PPD or TST skin test. The Mantoux tuberculin skin test (TST) is the standard method of determining whether a person is infected with Mycobacterium tuberculosis. The TST is performed by injecting 0.1 ml of tuberculin purified protein derivative (PPD) into the inner surface of the forearm. If you have a positive PPD, it means you have been exposed to a person who has tuberculosis and you are now infected with the bacteria that cause the disease.
Treatment
TB infection and TB disease are not treated the same way. If you have TB infection, you will probably just take INH (Isoniazid) for 6 to 9 months. It is very important that you take all of the medication and not stop because you are feeling better. You should not skip a single dose. If you have TB disease you will take several medicines when you start your treatment to kill the TB germs in your body. These include: Isoniazid (INH), Rifampin, Ethambutol, and Pyrazinamide.
What is Drug-Resistant TB?
TB can usually be treated with a course of four standard, or first-line, anti-TB drugs. If these drugs are misused or mismanaged, multidrug-resistant TB (MDR-TB) can develop. MDR-TB takes longer to treat with second-line drugs, which are more expensive and have more side-effects. If these second-line drugs are also misused or mismanaged and therefore also become ineffective, extensively drug-resistant tuberculosis (XDR-TB) can develop. Because XDR-TB is resistant to both first- and second-line drugs, treatment options are seriously limited.
Drug-resistant TB is caused by inconsistent or partial treatment:
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When patients do not take all their medicines regularly for the required period because they start to feel better, or
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Because doctors and health workers prescribe the wrong treatment regimens, or
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Because the drug supply is unreliable.
It is vital that TB control is managed properly by both healthcare professional and their patients.
What is XDR TB?
Extensively drug-resistant tuberculosis (XDR TB) is a relatively rare type of multidrug-resistant tuberculosis (MDR TB). It is resistant to almost all drugs used to treat TB, including the two best first-line drugs: isoniazid and rifampin. XDR TB is also resistant to the best second-line medications: fluoroquinolones and at least one of three injectable drugs (i.e., amikacin, kanamycin, or capreomycin).
Cause of XDR TB
Drug-susceptible (regular) TB and XDR TB are spread the same way. TB germs are put into the air when a person with TB disease of the lungs or throat coughs, sneezes, speaks, or sings. These germs can float in the air for several hours, depending on the environment. Persons who breathe in the air containing these TB germs can become infected.
TB is not spread by
Why is XDR TB so serious?
Because XDR TB is resistant to the most powerful first-line and second-line drugs, patients are left with treatment options that are much less effective and often have worse treatment outcomes. XDR TB is of special concern for persons with HIV infection or other conditions that can weaken the immune system. These persons are more likely to develop TB disease once they are infected, and also have a higher risk of death once they develop TB disease.
Risks of XDR TB?
Drug-resistant TB (MDR or XDR) is more common in people who:
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Do not take their TB medicine regularly
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Do not take all of their TB medicines as told by their doctor or nurse
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Develop active TB disease again, after having taken TB medicine in the past
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Come from areas of the world where drug-resistant TB is common
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Have spent time with someone known to have drug-resistant TB disease
XDR TB Treatment
Yes, in some cases. Some TB control programs have shown that cure is possible for an estimated 30% of affected people. Successful outcomes depend greatly on the extent of the drug resistance, the severity of the disease, and whether the patient’s immune system is weakened.
Symptoms of XDR TB
The general symptoms of TB disease include feelings of sickness or weakness, weight loss, fever, and night sweats. The symptoms of TB disease of the lungs may also include coughing, chest pain, and coughing up blood. Symptoms of TB disease in other parts of the body depend on the area affected. If you have these symptoms, you should contact your doctor or local health department.
Prevention of XDR TB
Health care providers can help prevent MDR and XDR TB by quickly diagnosing cases, following recommended treatment guidelines, monitoring patients’ response to treatment, and making sure therapy is completed.
Providers should also ensure proper implementation of infection control procedures to prevent exposure to TB in hospitals or health-care settings where TB patients are likely to be seen.
