Comparison between ELISA and ICT-MycoDot in childhood tuberculosis

Diagnosis of childhood tuberculosis (TB) is a difficult job. Keeping this fact in mind, the present study was designed to detect serum anti-TB IgG antibody in childhood TB cases by Enzyme Linked Immunosorbent Assay (ELISA) and Immunochromatography test (ICT) method using commercially available diagnostic kit (Pathozyme TB complex and MycoDot test respectively). This case-control study, were done on 52 cases of childhood TB within the age range of 4(+)-14 years. Among them, 15 (28.8%) were AFB positive confirmed cases, 25 (48.1%) were AFB negative clinically diagnosed cases before treatment and 12 (23.1%) were clinically diagnosed cases on treatment. Age and sex matched 36 controls were also included of which 21 (58.3%) were healthy children and 15 (41.7%) were sick children with non-specific pulmonary infection. Overall sensitivity and specificity of ELISA were 34.62% and 97.20% (p<0.001) and those of MycoDot as 48.08% and 96.92% (p<0.001). Rate of both ELISA and MycoDot positive were higher among. clinically diagnosed cases on treatment with respective values as 71.42% and 85.71%. Respective values among AFB positive confirmed TB cases were 40% and 72.72%. Different aspects of immune response in TB were discussed. Since, both method yielded negative results in confirmed TB cases, so none of the methods should be considered as a confirmatory test method for TB.