Which sample type is better for Xpert MTB/RIF to diagnose adult and pediatric pulmonary tuberculosis?

OBJECTIVE

This review aimed to identify proper respiratory-related sample types for adult and pediatric pulmonary tuberculosis (PTB), respectively, by comparing performance of Xpert MTB/RIF when using bronchoalveolar lavage (BAL), induced sputum (IS), expectorated sputum (ES), nasopharyngeal aspirates (NPAs), and gastric aspiration (GA) as sample.

METHODS

Articles were searched in Web of Science, PubMed, and Ovid from inception up to 29 June 2020. Pooled sensitivity and specificity were calculated, each with a 95% confidence interval (CI). Quality assessment and heterogeneity evaluation across included studies were performed.

RESULTS

A total of 50 articles were included. The respective sensitivity and specificity were 87% (95% CI: 0.84-0.89), 91% (95% CI: 0.90-0.92) and 95% (95% CI: 0.93-0.97) in the adult BAL group; 90% (95% CI: 0.88-0.91), 98% (95% CI: 0.97-0.98) and 97% (95% CI: 0.95-0.99) in the adult ES group; 86% (95% CI: 0.84-0.89) and 97% (95% CI: 0.96-0.98) in the adult IS group. Xpert MTB/RIF showed the sensitivity and specificity of 14% (95% CI: 0.10-0.19) and 99% (95% CI: 0.97-1.00) in the pediatric ES group; 80% (95% CI: 0.72-0.87) and 94% (95% CI: 0.92-0.95) in the pediatric GA group; 67% (95% CI: 0.62-0.72) and 99% (95% CI: 0.98-0.99) in the pediatric IS group; and 54% (95% CI: 0.43-0.64) and 99% (95% CI: 0.97-0.99) in the pediatric NPA group. The heterogeneity across included studies was deemed acceptable.

CONCLUSION

Considering diagnostic accuracy, cost and sampling process, ES was a better choice than other sample types for diagnosing adult PTB, especially HIV-associated PTB. GA might be more suitable than other sample types for diagnosing pediatric PTB. The actual choice of sample types should also consider the needs of specific situations.