1. Evaluation of GeneXpert MTB/RIF system performances in the diagnosis of extrapulmonary tuberculosis
- Author
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Fatna Bssaibis, Youness Mechal, Nadia Touil, Mariama Chadli, Yassine Benlahlou, Mostafa Elouennass, Elmostafa Benaissa, Ahmed Abid, Yashpal Singh Malik, Nadia El mrimar, Adil Maleb, and A. Zegmout
- Subjects
0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Tuberculosis ,Adolescent ,Genotype ,Extra-pulmonary tuberculosis ,030106 microbiology ,Multidrug-resistance ,Sensitivity and Specificity ,lcsh:Infectious and parasitic diseases ,Mycobacterium tuberculosis ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Medical microbiology ,Tuberculosis diagnosis ,Drug Resistance, Multiple, Bacterial ,Medicine ,Humans ,lcsh:RC109-216 ,030212 general & internal medicine ,Aged ,Retrospective Studies ,Microscopy ,GeneXpert MTB/RIF ,biology ,business.industry ,Diagnostic Tests, Routine ,Incidence ,Gold standard (test) ,Middle Aged ,biology.organism_classification ,medicine.disease ,bacterial infections and mycoses ,Virology ,Morocco ,Infectious Diseases ,Parasitology ,Female ,Rifampin ,business ,Research Article ,Molecular diagnostic techniques - Abstract
BackgroundTuberculosis represents a serious public health problem and a significant diagnostic and therapeutic challenge worldwide. Molecular diagnostic techniques are crucial in the World Health Organization’s new tuberculosis control strategy.This study aims to evaluate the performance of GeneXpert MTB/RIF (Cepheid Sunnyvale, CA, United States) in diagnosis of extra-pulmonary tuberculosis then compare it’s performance in detecting Rifampicin resistance to GenoType MTBDRplus (HAIN Life Sciences, Nehren, Germany).MethodsSamples from pulmonary and/or extra-pulmonary origins were analysed in a 21 months retrospective study. Samples were sent to the bacteriology laboratory forMycobacterium tuberculosisdetection using conventional bacteriological and molecular methods (GeneXpert MTB/RIF and MTBDRplus). Sensitivity and specificity were calculated for the stained smear and GeneXpert according to culture (Gold Standard) as well as for GeneXpert MTB/RIF in both negative and positive microscopy tuberculosis cases. Data’s statistical analysis was performed with SPSS13.0 software.ResultsSeven hundred fourteen patients’ samples were analysed; the average age was 47.21 ± 19.98 years with a male predominance (66.4%). Out of 714 samples: 285 were from pulmonary and 429 were from extra-pulmonary origins. The positivity rates for microscopy, GeneXpert MTB/RIF and culture were 12.88, 20.59 and 15.82%, respectively. These rates were 18.9, 23.85 and 20.35% for pulmonary samples and 9.71, 18.41 and 12.82% for extra-pulmonary samples, respectively. The sensitivity and specificity of GeneXpert MTB/RIF were almost the same in both pulmonary and extra-pulmonary samples (78.2 and 90.4%) and (79,3 and 90.3%) respectively.Rifampicin resistance rate found by GeneXpert MTB/RIF was 0.84%. Comparison of Rifampicin resistance obtained by GeneXpert MTB/RIF and Genotype MTBDRplus, showed 100% agreement between the two techniques for studied samples.ConclusionsThis confirms GeneXpert MTB/RIF advantage for tuberculosis diagnosis, particularly extra-pulmonary tuberculosis with negatively stained smear. The performance of GeneXpert and Genotype MTBDRplus are similar in detection of Rifampicin resistance. However, variability of detection performance according to tuberculosis endemicity deserves more attention in the choice of screening techniques of Rifampicin resistance, hence the interest of conducting comparative studies of detection performance under low and medium endemicity on large samples of tuberculosis populations.
- Published
- 2019