Institut Louis Malardé, Papeete, Tahiti, French Polynesia.
PLoS One. 2021 Sep 2;16(9):e0256877. doi: 10.1371/journal.pone.0256877. eCollection 2021.
In French Polynesia, the first case of SARS-CoV-2 infection was detected on March 10th, 2020, in a resident returning from France. Between March 28th and July 14th, international air traffic was interrupted and local transmission of SARS-CoV-2 was brought under control, with only 62 cases recorded. The main challenge for reopening the air border without requiring travelers to quarantine on arrival was to limit the risk of re-introducing SARS-CoV-2. Specific measures were implemented, including the obligation for all travelers to have a negative RT-PCR test for SARS-CoV-2 carried out within 3 days before departure, and to perform another RT-PCR testing 4 days after arrival. Because of limitation in available medical staff, travelers were provided a kit allowing self-collection of oral and nasal swabs. In addition to increase our testing capacity, self-collected samples from up to 10 travelers were pooled before RNA extraction and RT-PCR testing. When a pool tested positive, RNA extraction and RT-PCR were performed on each individual sample. We report here the results of COVID-19 surveillance (COV-CHECK PORINETIA) conducted between July 15th, 2020, and February 15th, 2021, in travelers using self-collection and pooling approaches. We tested 5,982 pools comprising 59,490 individual samples, and detected 273 (0.46%) travelers positive for SARS-CoV-2. A mean difference of 1.17 Ct (CI 95% 0.93-1.41) was found between positive individual samples and pools (N = 50), probably related to the volume of samples used for RNA extraction (200 μL versus 50 μL, respectively). Retrospective testing of positive samples self-collected from October 20th, 2020, using variants-specific amplification kit and spike gene sequencing, found at least 6 residents infected by the Alpha variant. Self-collection and pooling approaches allowed large-scale screening for SARS-CoV-2 using less human, material and financial resources. Moreover, this strategy allowed detecting the introduction of SARS-CoV-2 variants of concern in French Polynesia.
在法属波利尼西亚，2020 年 3 月 10 日发现首例 SARS-CoV-2 感染病例，为一名从法国返回的居民。3 月 28 日至 7 月 14 日，国际航空停飞，本地 SARS-CoV-2 传播得到控制，仅记录到 62 例病例。重新开放边境而无需旅行者抵达时隔离的主要挑战是限制引入 SARS-CoV-2 的风险。为此实施了具体措施，包括要求所有旅行者在出发前 3 天内进行 SARS-CoV-2 的 RT-PCR 检测，结果为阴性，并在抵达后 4 天进行另一次 RT-PCR 检测。由于医务人员有限，旅行者可以获得一个试剂盒，自行采集口腔和鼻腔拭子。除了增加检测能力外，还可以将最多 10 名旅行者的自行采集样本混合，然后进行 RNA 提取和 RT-PCR 检测。如果一个样本池呈阳性，则对每个个体样本进行 RNA 提取和 RT-PCR 检测。本文报告了 2020 年 7 月 15 日至 2021 年 2 月 15 日期间旅行者使用自行采集和混合方法进行的 COVID-19 监测（COV-CHECK PORINETIA）结果。我们共检测了 5982 个样本池，包含 59490 个个体样本，发现 273 名（0.46%）旅行者 SARS-CoV-2 检测阳性。阳性个体样本与样本池之间的 Ct 值平均差异为 1.17（95%CI 0.93-1.41）（N=50），可能与 RNA 提取使用的样本量有关（分别为 200 μL 和 50 μL）。对 2020 年 10 月 20 日以来自行采集的阳性样本进行基于变异体特异性扩增试剂盒和刺突基因测序的回溯性检测，发现至少有 6 名居民感染了 Alpha 变异株。自行采集和混合方法可利用较少的人力、物力和财力对 SARS-CoV-2 进行大规模筛查。此外，该策略还可以检测到 SARS-CoV-2 变体在法属波利尼西亚的引入。
