Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Clinical Microbiology Laboratory, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
J Clin Microbiol. 2021 Apr 20;59(5). doi: 10.1128/JCM.00110-21.
Community-based health care clinics and hospital outreach services have the potential to expand coronavirus disease 2019 (COVID-19) diagnostics to rural areas. However, reduced specimen stability during extended transport, the absence of a cold chain to centralized laboratories, and biosafety concerns surrounding specimen handling have limited this expansion. In the following study, we evaluated eNAT (Copan Italia, Brescia, Italy) as an alternative transport system to address the biosafety and stability challenges associated with expanding COVID-19 diagnostics to rural and remote regions. In this study, we demonstrated that high-titer severe acute respiratory virus syndrome coronavirus 2 (SARS-CoV-2) lysate placed into eNAT medium cannot be propagated in cell culture, supporting viral inactivation. To account for off-site testing in these settings, we assessed the stability of contrived nasopharyngeal (NP) specimens stored for up to 14 days in various transport media (eNAT, eSwab, viral transport medium [VTM], saline, and phosphate-buffered saline [PBS]) at 4°C, 22 to 25°C, and 35°C. The molecular detection of SARS-CoV-2 was unaffected by sample storage temperature over the 2 weeks when stored in eNAT or PBS (change in cycle threshold, ≤1). In contrast, variable stability was observed across test conditions for other transport media. As eNAT can inactivate SARS-CoV-2, it may support COVID-19 diagnostics at the point of care. Evaluation of compatibility of eNAT with Cepheid Xpert Xpress SARS-CoV-2 assay demonstrated diagnostic accuracy and sensitivity equivalent to those of VTM. Taken together, these findings suggest that the implementation of eNAT as a collection device can expand COVID-19 testing to areas with limited health care access.
社区医疗保健诊所和医院外展服务有可能将 2019 年冠状病毒病(COVID-19)诊断扩展到农村地区。然而,在延长的运输过程中样本稳定性降低、缺乏到集中实验室的冷链以及样本处理方面的生物安全问题限制了这种扩展。在下面的研究中,我们评估了 eNAT(意大利科潘,布雷西亚)作为替代运输系统的潜力,以解决将 COVID-19 诊断扩展到农村和偏远地区所面临的生物安全和稳定性挑战。在这项研究中,我们证明了高滴度严重急性呼吸综合征冠状病毒 2(SARS-CoV-2)裂解液放入 eNAT 培养基中不能在细胞培养物中繁殖,支持病毒失活。为了在这些环境中进行现场外检测,我们评估了在各种运输介质(eNAT、eSwab、病毒运输介质[VTM]、生理盐水和磷酸盐缓冲盐水[PBS])中储存长达 14 天的模拟鼻咽(NP)样本在 4°C、22-25°C 和 35°C 下的稳定性。当储存在 eNAT 或 PBS 中时,SARS-CoV-2 的分子检测在 2 周内不受样本储存温度变化的影响(循环阈值变化,≤1)。相比之下,在其他运输介质的测试条件下,观察到不同的稳定性。由于 eNAT 可以灭活 SARS-CoV-2,因此它可能支持在护理点进行 COVID-19 诊断。评估 eNAT 与 Cepheid Xpert Xpress SARS-CoV-2 检测试剂盒的兼容性表明,其诊断准确性和灵敏度与 VTM 相当。总之,这些发现表明,实施 eNAT 作为收集装置可以将 COVID-19 检测扩展到医疗服务有限的地区。