Detection of drug resistant Mycobacterium tuberculosis among patients with and without HIV infection in a rural setting.

Abstract

OBJECTIVE To analyse the sensitivity of Mycobacterium tuberculosis by nitrate reductase assay (NRA) and the Hain molecular line probe assay (LPA) in sputa of tuberculosis (TB)/HIV co-infected patients in Guyana. DESIGN Sputum samples were collected from known TB patients at Georgetown Chest Clinic and were analysed at the Reference Laboratory, Guyana, over the period April 2010 to April 2011. RESULTS Both methods recorded greater sensitivity for rifampin (RIF) than of isoniazid (INH). Both methods detected four RIF resistant, two INH resistant and two multi-drug resistant (MDR) strains and they had greater negative agreement indices than positive agreement indices. CONCLUSION It was established that the sensitivity of Mycobacterium tuberculosis by the NRA and Hain LPA in TB/HIV co-infected patients has acceptable correlation and that HIV infection does not affect drug susceptibility testing.