Pattern of drug resistance among patients of pulmonary tuberculosis

Abstract

Background: Drug resistant tuberculosis (DR-TB), particularly multidrug resistance (MDR-TB) and extensive drug resistance (XDR-TB) pose a serious threat to public health. This study aimed to identify drug resistance in pulmonary tuberculosis patients and to see their association with diabetes, human immunodeficiency virus (HIV), previous history of tuberculosis (TB) and family history of TB.

Method: Sputum specimens obtained from 11,874 pulmonary tuberculosis patients were subjected to smear microscopy, cartridge based nucleic acid amplification test (CBNAAT) and liquid culture (LC). Smear positive isolates were subjected to first line Line probe assay (FL-LPA) for isoniazid and rifampicin resistance. FL- LPA positive isolates were subjected to second line Line probe assay (SL-LPA) for fluoroquinolones and second line injectable drug resistance.

Result: Out of 11,874 microbiologically confirmed cases of pulmonary tuberculosis, 976 (8.2%) had a drug resistant tuberculosis. Five patterns of drug resistance were identified monoisoniazid; 394 (3.32%), rifampicin; 461 (3.88%) (monorifampicin; 383 (3.22%)), multidrug; 73 (0.61), extensivedrug; 11 (0.09) and others; 37 (0.31). Previous history of tuberculosis was significantly associated with rifampicin resistance and MDR-TB. Family history of tuberculosis contact was strongly associated with rifampicin resistance, MDR-TB and XDR-TB.

Conclusion: There has been an increasing trend in drug resistance in the recent years, particularly in retreatment cases. This study highlights the pattern of drug resistance and need to detect resistance among all tuberculosis cases, in order to interrupt transmission and control this emerging epidemic.

Keywords: Drug resistance; Extensive drug resistance; Multidrug resistance; Tuberculosis.