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%. Cite this article:
