Evidence map›Paper›PMID 41772459›Full record

ArticleBMC infectious diseases2026

Evaluation of Xpert MTB/RIF assay accuracy for diagnosing TB and detecting rifampin resistance in patients with very low bacterial loads results: a retrospective study in Hunan, China.

Xuan Zeng, Peilei Hu, Xinyun Tan, Hua Bai, Jue Wang, Daofang Gong, Jingwei Guo, Hengzhong Yi, Yi Liu, Yi Wu and 1 more

Abstract readEvaluation Study
In one paragraph

Article in BMC infectious diseases, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Xuan Zeng *Hunan Chest Hospital, Changsha, Hunan province, 410005, China.
Peilei Hu *Hunan Chest Hospital, Changsha, Hunan province, 410005, China.
Xinyun TanXiangya School of Nursing, Central South University, Changsha, Hunan province, 410005, China.
Hua BaiHunan Chest Hospital, Changsha, Hunan province, 410005, China.
Jue WangHunan Chest Hospital, Changsha, Hunan province, 410005, China.
Daofang GongHunan Chest Hospital, Changsha, Hunan province, 410005, China.
Jingwei GuoHunan Chest Hospital, Changsha, Hunan province, 410005, China.
Hengzhong YiHunan Chest Hospital, Changsha, Hunan province, 410005, China.
Yi LiuHunan Chest Hospital, Changsha, Hunan province, 410005, China.
Yi WuHunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, Hunan province, 410005, China. wuyi19701210@sina.com.
Yunhong TanHunan Chest Hospital, Changsha, Hunan province, 410005, China. 1220163360@qq.com.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThere is widespread use of Xpert MTB/RIF for tuberculosis (TB) diagnosis and rifampin resistance (RIF-R) detection. Despite this, concerns have been raised about false-positive results, which are more prevalent in patients with very low bacterial loads.

methodsWe performed a retrospective analysis of 717 patients at Hunan Chest Hospital from January 2022 to January 2023, all of whom had Xpert MTB/RIF results indicating very low bacterial loads. The accuracy of Xpert in diagnosing TB was evaluated against a composite reference standard (CRS), which classified cases via symptom, liquid culture, imaging assessments, immunological tests, and therapeutic response. In addition, rifampicin resistance was adjudicated using a composite reference standard of pDST and rpoB sequencing, with pDST as the primary reference for Xpert MTB/RIF results and sequencing used to resolve discrepancies.

resultsOf 717 patients with Xpert detected very low bacterial loads, 175 (24.4%) yielded positive cultures, while 16 cases identified as non-tuberculous mycobacteria (NTM). The positive predictive value (PPV) of Xpert for bacteriologically confirmed TB was 90.8% (159/175). For 542 culture-negative patients, Xpert’s PPV was 81.7% (443/542) in clinically diagnosed TB (80.4% pulmonary TB, 88.9% extrapulmonary TB). In 121 patients with pDST, Xpert for RIF-R had 68.4% sensitivity (13/19), 88.2% specificity (90/102), respectively. Among the 6 patients who were RIF-R by pDST but rifampin susceptible by Xpert, four cases harbored mutations inside the 81-bp Rifampicin Resistance-Determining Region (RRDR) region of rpoB.

conclusionXpert demonstrates good performance in diagnosing TB among the patients with results showing very low bacterial loads, especially in the culture-positive group and extrapulmonary tuberculosis group. However, its performance in detecting rifampicin resistance is not reliable. Our findings emphasize that Xpert results showing very low bacterial loads should be confirmed when diagnosing rifampin resistance tuberculosis.

Indexed as

Drug Resistance, BacterialMolecular Diagnostic TechniquesMycobacterium tuberculosisRifampinTuberculosisAdultAgedAntibiotics, AntitubercularBacterial LoadChinaFemaleHumansMaleMiddle AgedRapid Diagnostic TestsRetrospective StudiesAntibiotics, AntitubercularRifampinRifampin resistanceTuberculosisVery low bacterial loadsXpert MTB/RIF

Identifiers

PMID41772459
PMCPMC13059202

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.