Publication:

Estimation of prevalence of multidrug resistance in spinal tuberculosis, antibiotic susceptibility patterns and clinical outcomes

Background There are no adequate data in literature referring to the early diagnosis and treatment (especially surgical) of MDR tuberculosis of spine and evaluation of its clinical outcome. We aimed to address this lacunae, by using gene expert test (CBNAAT) and drug sensitivity/susceptibility tests (DST) and by studying subsequent actual clinical outcomes.

Methods Forty patients with clinico-radiological scenario of spinal tuberculosis were evaluated using biochemical, radiological and histo-pathological studies. Anti-tuberculosis treatment was empirically started based on initial clinico-radiological suspicion of spinal tuberculosis. All tissue specimen and intra-operative samples were subjected to CBNAAT, MGIT culture and histopathological examination. Culture of those samples which showed rifampicin resistance on CBNAAT were followed up for DST (Drug Susceptibility Test) and the treatment modified accordingly, if required. All cases were followed up at 3, 6, 9 and 12 months interval.

Results Out of 40 patients, mycobacterium tuberculosis was detected in 23 patients by CBNAAT. Out of these 23 cases, 20 showed mycobacterium tuberculosis sensitivity to rifampicin and 3 were resistant. Out of these 3 cases, one had culture positive. Sensitivity and negative predictive value of gene expert test in comparison with the culture were 100%. Specificity and positive predictive value were calculated at 58.6% and 47.8% respectively. Accuracy of gene expert in our study was found to be 70%.

Conclusions Early detection of MDR spinal tuberculosis using highly sensitive CBNAAT test would be helpful to avoid consequences of inappropriate chemotherapy and would result in favourable outcomes.