Utility and diagnostic performance of Mycobacterium tuberculosis complex by two immunochromatographic assays as compared with the molecular Genotype assay in Nigeria.

Abstract : Among the disadvantages of smear microscopy for detection of tuberculosis cases is its inability to differentiate between Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacteria (NTM). This study evaluated two, new immunochromatographic assays - Capilia TB-Neo and SD Bioline - on unheated and heated cultures at 80 C for 30 min respectively for their ability to discriminate between MTB complex and NTM as compared with the molecular Genotype assay. Mycobacteria used in the study were obtained from smear-positive specimens collected from patients at four major hospitals in Cross River State, Nigeria. Capilia TB-Neo and SD Bioline showed sensitivities of 98.8% and 93.8% respectively and 100% specificity for both assays. Heating the isolates did not significantly impact the test performance. Both tests are recommended for use in rapid differentiation of strains isolated in Nigeria.