We present a field evaluation of the diagnostic accuracy of Xpert MTB/RIF ("Xpert") and Xpert MTB/RIF Ultra ("Ultra") using two cohorts in a high tuberculosis/HIV burden setting in Southern Mozambique.

Single respiratory specimens from symptomatic adults accessing healthcare services (passive case finding (PCF) cohort) and from household and community close contacts (active case finding (ACF) cohort) were tested by smear microscopy, culture, Xpert and Ultra. Liquid and solid culture served as a composite reference standard. We explored the impact of trace results on specificity via their recategorisation to negative (in all and just among those previously treated individuals).

1419 and 252 participants were enrolled in the PCF and ACF cohorts, respectively. For the PCF cohort, Ultra showed higher sensitivity than Xpert overall (0.95 (95% CI 0.90–0.98) versus 0.88 (96% CI 0.82–0.93); p<0.001) and among smear-negative patients (0.84 (96% CI 0.71–0.93) versus 0.63 (96% CI 0.48–0.76)). Ultra's specificity was lower than Xpert's (0.96 (96% CI 0.95–0.97) versus 0.98 (96% CI 0.97–0.99); p=0.008). For ACF, sensitivities were the same (0.67 (95% CI 0.22–0.96) for both tests), although Ultra detected a higher number of microbiologically confirmed samples than Xpert (4.7% (12 out of 252) versus 2.7% (seven out of 252)). Conditional recategorisation of trace results among previously treated participants maintained differences in specificity in the PCF cohort.

These results add evidence on the improved sensitivity of Ultra and support its use in different case finding scenarios.

我们使用莫桑比克南部结核病/艾滋病毒高负担环境中的两个队列，对 Xpert MTB/RIF（“Xpert”）和 Xpert MTB/RIF Ultra（“Ultra”）的诊断准确性进行了现场评估。

通过涂片显微镜检查、培养、Xpert 和 Ultra 对来自有症状的成年人获得医疗保健服务（被动病例发现 (PCF) 队列）和家庭和社区密切接触者（主动病例发现 (ACF) 队列）的单个呼吸道样本进行了测试。液体和固体培养物用作复合参考标准。我们通过将追踪结果重新分类为阴性（在所有且仅在那些先前接受过治疗的个体中）来探索追踪结果对特异性的影响。

分别有 1419 名和 252 名参与者参加了 PCF 和 ACF 队列。对于 PCF 队列，Ultra 显示出比 Xpert 整体更高的敏感性（0.95（95% CI 0.90–0.98）与0.88（96% CI 0.82–0.93）；p<0.001）和涂片阴性患者（0.84（96% CI 0.71） –0.93)与0.63 (96% CI 0.48–0.76))。Ultra 的特异性低于 Xpert（0.96（96% CI 0.95–0.97）与0.98（96% CI 0.97–0.99）；p=0.008）。对于 ACF，灵敏度是相同的（两种测试均为 0.67（95% CI 0.22–0.96）），尽管 Ultra 检测到的微生物确认样本数量高于 Xpert（4.7%（252 个中的 12 个）与2.7%（252 人中有 7 人））。在先前治疗的参与者中对追踪结果进行有条件的重新分类保持了 PCF 队列中特异性的差异。

这些结果增加了 Ultra 灵敏度提高的证据，并支持其在不同病例发现场景中的使用。