Abstract:

Objective To investigate the diagnostic efficacy of three molecular diagnostic techniques for children pulmonary tuberculosis in order to find a simple, rapid and accurate method for the diagnosis of tuberculosis in children.Methods A total of 186 children from 2 months to 14 years old with suspected pulmonary tuberculosis who were admitted to the Children’s Tuberculosis Department of Harbin Chest Hospital, Respiratory Department of Harbin Children’s Hospital, Department of Pediatrics, the First Affiliated Hospital of Harbin Medical University from September 2016 to June 2018. Finally 119 cases were diagnosed as tuberculosis, including 54 cases (45.4%) of younger children, 65 cases (54.6%) of elderly children, compared with 31 cases (42.3%) of younger children and 36 cases (53.7%) of elderly children in 67 non-tuberculosis children. Real-time fluorescence quantitative PCR (FQ-PCR), simultaneous amplification and testing (SAT) and drug-resistant gene chip technology were used to detect Mycobacterium tuberculosis in gastric juice and sputum (older children) respectively to observe the diagnostic efficacy of each method.Results According to the clinical diagnosis, the sensitivity of FQ-PCR, SAT and drug-resistant gene chip detection of gastric juice were 81.51% (97/119), 78.15% (93/119), 73.11% (87/119), and the specificity were 86.57% (58/67), 98.51% (66/67), 92.54% (62/67) respectively, Kappa values were 0.653, 0.709, 0.603. The sensitivity of the three methods for detecting gastric juice in elderly children was 80.00% (52/65), 73.85% (48/65) and 67.69% (44/65), and the specificity was 75.00% (27/36), 97.22%(35/36) and 88.89% (32/36) respectively. The sensitivity of detecting sputum in elderly children was 47.69% (31/65), 41.54% (27/65), 36.92% (24/65), and the specificity was 88.89% (32/36), 97.22% (35/36) and 91.67% (33/36) respectively. The sensitivity of gastric juice detected by each method was higher than that of sputum, and the difference was statistically significant (χ ² values were 14.696, 13.898, 12.334, P values were 0.000). The specificity of each detection method was not statistical significance between gastric juice and sputum (χ ² values were 2.347, 0.000, 0.158, respectively, P values were 0.126, 1.000, 0.691). The total positive rate of gastric juice was 87.69% (57/65), and the sputum was 58.46% (38/65), the difference was statistically significant (χ ²=14.114, P=0.000). Conclusion FQ-PCR, SAT and drug-resistant gene chip detection methods have high sensitivity and specificity in the detection of Mycobacterium tuberculosis in gastric juice and sputum of children with suspected pulmonary tuberculosis, which is of great value in the diagnosis of tuberculosis in children.

Key words: Tuberculosis, pulmonary, Molecular diagnostic techniques, Child, Gastric juice, Sputum, Efficiency, Comparative study