Surveillance of drug resistance in tuberculosis in the State of Tamil Nadu.

Summary: Surveillance of drug resistance was carried out at State level to obtain data which are standardised and comparable using guidelines prescribed by the WHO/IUATLD Working Group on Anti-tuberculosis Drug Resistance Surveillance. Objective: To determine the proportion of initial and acquired drug resistance in cases of pulmonary tuberculosis in Tamilnadu, in order to use the level of drug resistance as a performance indicator of the National Tuberculosis Programme. Methods: Two specimens of sputum from each of a total of 713 patients attending 145 participating centres all over the state were tested by smear and culture examination and drug susceptibility tests of Isoniazid, Rifampicin, Ethambutol and Streptomycin. Results: Out of 400 patients for whom drug susceptibility results were available, 384 (96%) had no history of previous anti-tuberculosis treatment. Of these, 312 (81%) were susceptible to all the drugs tested. Resistance to isoniazid was seen in 15.4% of patients and to Rifampicin in 4.4% including resistance to Isoniazid and Rifampicin in 3.4%. Conclusion: There has been a gradual increase in initial drug resistance over the years in this part of the country.