These are reasons you might need this test:

• You have symptoms of a lung infection, such as chronic cough, coughing up blood, weight loss, fever, chills, and tiredness.

• You have a positive TB skin or blood test and you are at high risk for exposure to TB or its progression to active disease. This includes those with HIV/AIDS or another condition that weakens your immune system. People who have been in hospitals, nursing homes, or prisons are also at high risk.

• You have symptoms of TB outside the lungs, a condition called extrapulmonary TB. These symptoms vary based on the site of infection. Most people think of TB as only a lung disease. But it can show up in other parts of the body. If it infects the spinal cord, for example, it can cause back pain and paralysis. In the kidneys, it often causes blood in the urine.

• You have a condition like HIV/AIDS that puts you at increased risk of getting TB. If you have also been in close contact with someone who has TB, healthcare providers will want to test you for the disease.

Your doctor may also give you this test from time to time if you are being treated for TB. This is to see if the treatment is working and to find out whether you are still infectious.

There are several tests for tuberculosis with each one having their advantages and disadvantages. Some of the other tests which are routinely done to diagnose tuberculosis are :

• Mantoux Test
• TB PCR
• Quantiferon TB Gold
• X-Ray / CT Scan

Tuberculosis is a disease of the third world countries. India has made rapid progress on all fronts but unfortunately the number of tuberculosis patients in India is still very high. Almost 20% patients of tuberculosis in the world are Indians. Tuberculosis is an infection caused by bacteria called Mycobacterium and malnourished people are more prone to the disease. Till the 70;s tuberculosis was the biggest killer in the country. Even now TB results in the death of many people in the remote areas of the country where the system of early diagnosis is not in place. The government has a big programme called DOTS for the eradication of TB in the country.

TB is treatable and curable; however, people with TB can die if they do not get proper treatment. Sometimes drug-resistant TB occurs when bacteria become resistant to the drugs used to treat TB. This means that the drug can no longer kill the TB bacteria.

Drug-resistant TB can occur when the drugs used to treat TB are misused or mismanaged. Examples of misuse or mismanagement include

• People do not complete a full course of TB treatment
• Health care providers prescribe the wrong treatment (the wrong dose or length of time)
• Drugs for proper treatment are not available
• Drugs are of poor quality

Drug-resistant TB is more common in people who

• Do not take their TB drugs regularly
• Do not take all of their TB drugs
• Develop TB disease again, after being treated for TB disease in the past
• Come from areas of the world where drug-resistant TB is common
• Have spent time with someone known to have drug-resistant TB disease