title: GeneXpert polymerase chain reaction for spinal tuberculosis: an accurate and rapid diagnostic test.
abstract: The lack of an accurate, rapid diagnostic test for mycobacterium tuberculosis (TB) is a major handicap in the management of spinal TB. GeneXpert, a new, rapid molecular diagnostic test is recommended as the first line investigation for suspected pulmonary TB in areas with a high prevalence of HIV or drug resistance, yet it has not been validated for the diagnosis of musculoskeletal TB. The aim of this study was to assess the accuracy of GeneXpert in diagnosing spinal TB. A prospective clinical study of 69 consecutive adults with suspected spinal TB was conducted at a tertiary hospital in an area with the highest incidence and prevalence of TB in the world. GeneXpert was used on tissue samples of the enrolled patients and its diagnostic accuracy compared with a reference standard of tissue in liquid culture. A total of 71 spine samples from 69 patients (two re-biopsies) were included in the study. The GeneXpert test showed a sensitivity of 95.6% and specificity of 96.2% for spinal TB. The results of the GeneXpert test were available within 48 hours compared with a median of 35 days (IQR 15 to 43) for cultures. All cases of multi-drug resistant TB (MDR TB) were diagnosed accurately with the GeneXpert test. The MDR TB rate was 5.8%.
authors.affiliation: Department of Orthopaedic Surgery, University of Cape Town, H49 Old Main Building, Groote Schuur Hospital, Observatory 7925, South Africa.
authors.forename: M
authors.initials: M
authors.lastname: Held
authors.affiliation: Department of Orthopaedic Surgery, University of Cape Town, H49 Old Main Building, Groote Schuur Hospital, Observatory 7925, South Africa.
authors.forename: M
authors.initials: M
authors.lastname: Laubscher
authors.affiliation: Department of Pediatrics and Child Health, Red Cross War Memorial Children's Hospital, University of Cape Town, South Africa.
authors.forename: H J
authors.initials: HJ
authors.lastname: Zar
authors.affiliation: Department of Orthopaedic Surgery, University of Cape Town, H49 Old Main Building, Groote Schuur Hospital, Observatory 7925, South Africa.
authors.forename: R N
authors.initials: RN
authors.lastname: Dunn
mesh_terms: D000328:Adult; D001706:Biopsy; D002555:Cerebrospinal Fluid / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods*; D015995:Prevalence; D011446:Prospective Studies; D015203:Reproducibility of Results; D013019:South Africa / Q000453:epidemiology; D013904:Thoracic Vertebrae; D018088:Tuberculosis, Multidrug-Resistant / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000453:epidemiology; D014399:Tuberculosis, Spinal / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial
keywords: GeneXpert MTB/RIF; Musculoskeletal tuberculosis; PCR; Polymerase chain reaction; Spinal tuberculosis