RESULTS
A total of 800 clinically TB suspects were initially included in the study. 84 (10.5%) samples of clinically TB suspects were discarded due to technical shortcomings (insufficient in quantity, errors in diagnostic modalities, culture contamination). 716 clinically TB suspects samples were included in the final analysis of the study. All the samples were subjected to ZN staining, GeneXpert assay and culture inoculation.
The mean age ± SD of the clinically TB suspects was 43.6 ± 20.9, of which 48.7% (N = 349) were males and 51.3% (N = 367) were females. Characteristics of study participants are presented in table 1 which also shows the comparison of TB positive and TB negative individuals.
[Table 1 about here]
Out of total 716 samples, 51.4% (N = 368) were GeneXpert negative and 48.6% (N = 348) were GeneXpert positive. 47.3% (N = 339) were screened positive and 52.7% (N = 377) as negative by MGIT culture method. Whereas, 57.4% (N = 411) were detected as negative by ZN staining and 42.6% (N = 305) as positive (Table 2).
[Table 2 about here]
Results of both GeneXpert and ZN staining were compared with MGIT culture. MGIT culture results were used as reference. In comparative analysis, the sensitivity and specificity of GeneXpert with 95% confidence interval (CI) was comparatively higher (99.7%, CI 0.98 - 0.99) and (97.3%, CI 0.95 - 0.98) respectively than that of ZN staining (85.5%, CI 0.81 - 0.89) and (96.0%, CI 0.93 - 0.97) respectively (Table 3).
[Table 3 about here]