Q: I had tuberculosis in the year 2000. I have been treated successfully with regular medicine and there was no sign of weight loss and other symptoms. But the scars in the lungs have remain unchanged. How these scars will go. If the scar is there, is there any chances that the disease may reappear?

A:Don't worry about the scar, and since 6-7 years have elapsed after successful treatment, the chances of a recurrence or a relapse are quite low. However, because of the life-long risk of relapse, you should return to your doctor if symptoms of TB recur. Studies have shown that rather than being protected from recurrent tuberculosis after a new episode, patients who are successfully treated for tuberculosis are at higher risk for developing tuberculosis again as compared to the general population. A patient is said to relapse, if he improves while on treatment, but becomes ill again after stopping treatment. The majority of relapses occur within 6 months of finishing treatment. Patients who are more likely to relapse are those who were took their medication in an unreliable and irregular fashion. There is a small relapse rate (up to 7%) associated with all treatment regimens, even if the treatment has been taken religiously with 100% compliance (the standard regimen has a relapse rate of 2 to 3%), requiring re-treatment within a couple of years. The probability of resistance is higher in patients who relapse and in such patients it is important to submit a good specimen for culture and drug susceptibility for mycobacteria. However, most patients who relapse do so with a fully sensitive strain and it is possible that these patients have instead been reinfected and can therefore be retreated with the same regimen as before.