Effect of the Xpert MTB/RIF on the detection of pulmonary tuberculosis cases and rifampicin resistance in Shanghai, China

Abstract

Background: Xpert MTB/RIF (Xpert) is an automated molecular test recommended by World Health Organization (WHO) for diagnosis of tuberculosis (TB). This study evaluated the effect of Xpert implementation on the detection of pulmonary TB (PTB) and rifampicin-resistant TB (RR-TB) cases in Shanghai, China.Methods: Xpert was routinely implemented in 2018 for all presumptive PTB patients. All PTB patients above 15 years-old identified within the Provincial TB Control Program during the first half of each of 2017 and 2018, were enrolled to compare the difference in proportions of bacteriological confirmation, patients with drug susceptibility test (DST) results for rifampicin (ie, DST coverage) and RR-TB detection before and after Xpert's implementation. Results: A total of 6047 PTB patients were included in the analysis with 1691 tested by Xpert in 2018. Percentages of bacteriological confirmation, DST coverage and RR-TB detection in 2017 and 2018 were 50% vs. 59%, 36% vs. 49% and 2% vs. 3%, respectively (all p-values < 0.05). Among 1103 PTB patients who completed sputum smear, culture and Xpert testing in 2018, Xpert detected an additional 121 (11%) PTB patients who were negative by smear and culture, but missed 248 (23%) smear and/or culture positive patients. Besides, it accounted for an increase of 9% in DST coverage and 1% in RR-TB detection. The median time from first visit to a TB hospital to RR-TB detection was 62 days (interquartile range -IQR 48-84.2) in 2017 vs. 9 days (IQR 2-45.7) in 2018 (p-value < 0.001). In the multivariate model, using Xpert was associated with decreased time to RR-TB detection (adjusted hazard ratio = 4.62, 95% confidence interval: 3.18-6.71). Conclusions: Integrating Xpert with smear, culture and culture-based DST in a routine setting significantly increased bacteriological confirmation, DST coverage and RR-TB detection with a dramatic reduction in the time to RR-TB diagnosis in Shanghai, China. Our findings can be useful for other regions that attempt to integrate Xpert into routine PTB and RR-TB case-finding cascade. Further study should focus on the identification and elimination of operational level challenges to fully utilize the benefit of rapid diagnosis by Xpert.

Characteristics of rifampicin-resistant tuberculosis detection in China, 2015–2019

“…In 2019 the median time for RR-TB cases to obtain RR results have been significantly reduced to 15 days, which is lower than the 26 days in the Republic of Korea [ 25 ]. In Shanghai, China, a metropolis with a population of 30 million, the diagnosis time has been as short as 9 days [ 26 ].…”

Prevalence of active tuberculosis disease among healthcare workers and support staff in healthcare settings of the Amhara region, Ethiopia

“…This study evaluated the healthcare workers active disease status using laboratory based molecular Xpert 1MTB/RIF method, which is a more sensitive method to detect active TB cases [34] then used in several other studies [35][36][37]. However, this study was not without limitations.…”

Thin-Layer-Agar-Based Direct Phenotypic Drug Susceptibility Testing on Sputum in Eswatini Rapidly Detects Mycobacterium tuberculosis Growth and Rifampicin Resistance Otherwise Missed by WHO-Endorsed Diagnostic Tests

“…The tests used most commonly to detect drug resistance are Xpert MTB/RIF (Cepheid, USA), which simultaneously detects Mycobacterium tuberculosis complex (MTB) and RR, and line probe assays (LPA) such as GenoType MTBDRplus, (Hain Lifescience, Germany) for isoniazid (INH) and RMP and MTBDRsl for fluoroquinolone (FQ) and second-line injectables ( 2 ). The rollout of Xpert MTB/RIF, also in peripheral laboratories, substantially decreased diagnostic delay ( 3 , 4 ). However, these rapid molecular techniques miss specific rpoB mutants at positions outside the RR-determining region of the rpoB gene (RRDR), which are associated with equally poor treatment outcomes, as “common” rpoB mutants ( 5 ).…”