Osteoarticular tuberculosis--diagnostic solutions in a disease endemic region

We conducted a study of osteoarticular tuberculosis in patients from private and public settings in a disease endemic area. Our objective was to assess the role of mycobacterial culture and polymerase chain reaction (PCR) in the diagnosis of osteoarticular tuberculosis (TB) in settings where only clinical and imaging diagnosis form the basis for treatment.

Ninety-three consecutive specimens collected from clinically suspected patients of osteoarticular TB were screened for bacterial culture, mycobacterial culture and in-house nested PCR. In addition, specimens were examined by imaging and histopathology. Ten specimens collected from patients suffering from other bone diseases were included as negative controls.

Of the 93 clinically suspected TB patients, mycobacterial culture was positive for Mycobacterium tuberculosis (MTB) in 47 (51%) patients who were confirmed as definite TB cases. Of the remaining patients, 16 (17%) were diagnosed as probable, 19 (20%) as possible, and 11 (12%) as only clinically suspected TB cases. In-house nested PCR was positive in 65 (70%) cases. Fifteen patients were resistant to one or more anti-tuberculous drugs; twelve patients were multi-drug resistant, two of whom were extensively drug resistant.

Mycobacterial cultures using liquid media with susceptibility should form the backbone of management of osteoarticular TB. Nested PCR enhances the sensitivity if performed in addition to culture.