1. Need for Category 4: We agree that with DOTS, resistant TB can be decreased significantly. However, it will not disappear completely. Drug resistant TB in children is reflection of drug resistant TB in adult patients. As long as there are adults with multidrug resistant tuberculosis, there will be cases of MDR tuberculosis in children and that justifies need for category 4 in the treatment strategies.

2. Decision to change regimen if no response by 3 months of intensive phase: No response after the 3 months of intensive phase may be due to poor compliance, drug resistance or wrong diagnosis. The compliance in children is likely to be better as parents or guardians supervise the drug administration. Involving household members for drug administration has been documented to show efficacy similar to that of health care workers in DOTS centers(1). The disease in children is more likely to be disseminated than adults. It is not desirable to delay changing the regimen beyond three months in children who are not responding to a regimen they are adhering to. Delay may cause serious disease in form of CNS tuberculosis. Of course it does not mean that one will forget about the adherence and microbiological documentation of drug resistance in M. tuberculosis.

3. We have already clarified this in our article(2). We add that an evidence-based guideline is required for the management of patients who continues to develop new lymhnodes/tuberculoma or non-resolution of X-ray findings.

4. Preventive chemotherapy (chemo-prophylaxis): We agree with Dr. Joshi regarding the existence of the guidelines. The recommendations for childhood tuberculosis by RNTCP(3) has included 6 months of daily isoniazid as preventive therapy. However, it remains grossly underutilized in the program. Efficacy of 12 months daily therapy with isoniazid as chemoprophylaxis in developed countries has been well established. Data about efficacy of chemoprophylaxis in developing countries are limited and recommendations of professional bodies are not uniform. The British Thoracic Society recommends either 6 months of isoniazid alone or 3 months of isoniazid and rifampicin for chemo-prophylaxis in children(4). The Indian Academy of Pediatrics recommended 6 months of isoniazid and rifampicin for preventive therapy(5). However, the efficacy and feasibility of these have not been studied. Therefore we feel there is need to develop an effective and shorter duration of chemoprophylaxis.