Clinical utility of Polymerase Chain Reaction for improved diagnosis of Pulmonary Tuberculosis in children.

ABSTRACT

Background: Conventional bacteriological methods rarely detect M. tuberculosis in clinical samples from children and, hence are of limited use in the diagnosis of active tuberculosis in them. There is need for an alternative detection method which is rapid, specific and sensitive. Aim: The efficacy of Polymerase Chain Reaction (PCR) was evaluated in the diagnosis of pulmonary tuberculosis in children. Methods: Sixty two (62) hospitalized children were included in the study. Thirty-one were suffering from active tuberculosis, 11 children had tuberculous infection but no active disease and 20 children had other unrelated diagnosis. Early morning gastric aspirates and sputum samples were processed using conventional techniques of mycobacterial isolation and PCR for M. tuberculosis complex specific MPB64 gene. Favorable response to anti- tubercular treatment (ATT) was taken as the gold standard. Results: In the active tuberculosis group 12 out 31 children were positive by PCR while microscopy and culture were positive in 3 and 6 children respectively. All samples positive by microscopy and culture were positive by PCR giving a sensitivity of 100% for culture confirmed cases. Conclusion: Benefit of rapid and reliable results with PCR offers an appreciable advantage over traditional techniques when used in conjunction with clinical profile and epidemiological factors such as age, socio-economic and nutritional status, contact history and any other intercurrent illness.