Rapid molecular assay gene Xpert in detection of multi-drug resistant tuberculosis (MTB/Rif)

Background: Tuberculosis (TB) is one of the deadliest threats today; TB due to Mycobacterium tuberculosis (MTB) remains a major public health issue: the infection affects up to one third of the world population, and almost two million people are killed by TB each year. However, in many areas of the world, TB diagnosis still relies on insensitive, poorly standardized sputum microscopy methods. Antibiotic resistance is a growing problem with increasing rate of drug-resistant tuberculosis (MDRTB) which is a serious public health problem in many developing countries. Treatment of MDTB takes longer and requires more expensive drugs. GeneXpert assay is a molecular technique that simultaneously detects (MTB) and Rifampicin resistant Tuberculosis (RR-TB) in approximately 2 h. Methods and materials: A retrospective cross sectional review of patients screened for TB with GeneXpert assay at TB Reference Laboratory,Khartoum State,Sudan from 20th June 2017 and 30th November 2017 (n = 583). Data analysis was done using Epi-Info Software, version 7.2 and Microsoft Office Excel 2007. Results: The total number of specimens collected from patients with symptoms of pulmonary TB was 583 (Males 402/Females 181). One hundred and fifty nine (159) (27.3%) of the screened samples had positive results for MTB, (Males 123/Females 36) of which 63 has history of past TB treatment, 71 New and 25 has un known past history of TB treatment. Among the positive MTB there is one case positive for HIV. Out of 159 there were 26 (4.4%) had rifampicin resistant MDR TB (22 males/4 females), all of MDR TB were more than 14 years, 16 has previous treatment of TB, 9 new and 1 has un known history of TB treatment. The male patients were more resistant to rifampicin when compared to the female patients.MTB was not detected in 424 (279 males 145 females). These despite the usefulness of GeneXpert assay method in early MTB/MDRTB diagnosis. Conclusion: Its simplicity, high sensitivity and specificity for RIF resistance detection make this technique a attractive tool for diagnostic of MTB and RIF resistance in MDR suspects.