Clinical Infection Medicine, Department of Translational Medicine, Lund University, Malmö, Sweden.
Adama Hospital Medical College, Adama, Ethiopia.
Trop Med Int Health. 2019 Mar;24(3):356-362. doi: 10.1111/tmi.13201. Epub 2019 Jan 24.
Restricted capacity for viral load (VL) testing is a major obstacle for antiretroviral therapy (ART) programmes in high-burden regions. Algorithms for targeted VL testing could help allocate laboratory resources rationally. We validated the performance of the Viral Load Testing Criteria (VLTC), an algorithm with satisfactory performance in derivation (sensitivity 91%, specificity 43%).
HIV-positive adults who had been receiving first-line ART for ≥12 months at three Ethiopian public ART clinics were included. Healthcare providers collected data on variables of the VLTC: current CD4 count, mid-upper arm circumference (MUAC) and self-reported treatment interruption. VL testing was performed in parallel. Performance of the algorithm for identification of patients with VL ≥ 1000 copies/ml was evaluated.
Of 562 patients (female 62%, median ART duration 92 months), 33 (6%) had VL ≥ 1000 copies/ml. Sensitivity for the VLTC was 85% (95% CI, 68-95), specificity 60% (95% CI, 55-64), positive predictive value 12% (95% CI, 10-14) and negative predictive value 98% (95% CI, 97-99). Use of the algorithm would reduce the number of VL tests required by 57%. Misclassification occurred in 5/33 (15%) of subjects with VL ≥ 1000 copies/ml.
In validation, the VLTC performed similarly well as derivation. Use of the VLTC may be considered for targeted VL testing for ART monitoring in high-burden regions.
在高负担地区，病毒载量（VL）检测能力受限是抗逆转录病毒疗法（ART）项目的主要障碍。针对 VL 检测的算法可以帮助合理分配实验室资源。我们验证了 Viral Load Testing Criteria（VLTC）的性能，该算法在推导中表现良好（敏感性 91%，特异性 43%）。
在埃塞俄比亚的三个公共艾滋病治疗诊所中，纳入了已经接受一线 ART 治疗≥12 个月的 HIV 阳性成年人。医疗保健提供者收集了 VLTC 的变量数据：当前 CD4 计数、上臂中部周长（MUAC）和自我报告的治疗中断情况。同时进行 VL 检测。评估了该算法识别 VL≥1000 拷贝/ml 的患者的性能。
在 562 名患者（女性占 62%，ART 治疗持续时间中位数为 92 个月）中，有 33 名（6%）患者的 VL≥1000 拷贝/ml。VLTC 的敏感性为 85%（95%CI，68-95），特异性为 60%（95%CI，55-64），阳性预测值为 12%（95%CI，10-14），阴性预测值为 98%（95%CI，97-99）。使用该算法可将所需的 VL 检测数量减少 57%。VLTC 对 33 名 VL≥1000 拷贝/ml 的患者中的 5 名（15%）出现了分类错误。
在验证中，VLTC 的表现与推导时相似。在高负担地区，针对 ART 监测的靶向 VL 检测，可以考虑使用 VLTC。
