Prevalence of Rifampicin resistance in newly diagnosed and previously treated cases of pulmonary tuberculosis by Xpert MTB / RIF assay

Dr. Badrunnesa Khatun; Dr. Swapna Kanade; Dr. Gita Nataraj; Dr. Preeti Mehta

Volume : VI, Issue : V, May - 2017

Prevalence of Rifampicin resistance in newly diagnosed and previously treated cases of pulmonary tuberculosis by Xpert MTB / RIF assay

Dr. Badrunnesa Khatun, Dr. Swapna Kanade, Dr. Gita Nataraj, Dr. Preeti Mehta

Abstract :

Badrunnesa Khatun, Swapna Kanade, Gita Nataraj, Preeti Mehta. Department of Microbiology, Tertiary care hospital, Mumbai. Objective: � To determine the prevalence of Rifampicin resistance in new and previously treated PTB, � To compare Rifampicin resistance obtained by Xpert and proportion method � To determine the prevalence of Isoniazid mono–resistance by proportion method. Design: This cross–sectional study was carried over a period of one year (January – December 2015). Results: In 100 new TB suspects, smear positivity was 21% and culture positivity was 49%. Xpert assay detected MTB in 46% cases. In 100 previously treated cases, smear positivity was 40% and culture as well as Xpert MTB/RIF assay positivity was 47%. Xpert MTB/RIF assay has a sensitivity of 93.75% and specificity of 97.11% as compared to culture. Six (12.24%) Rifampicin resistant cases were observed in new TB cases & 19 (40.42%) in previously treated cases. All Rifampicin resistant cases were Isoniazid resistant also. INH mono–resistance was observed in nine cases. Conclusion: Rifampicin resistance, a surrogate marker of MDR–TB is more prevalent in previously treated cases. Xpert MTB/RIF assay provide the much–needed diagnostic capacity for effective identification of MDR TB cases in lesser time.