Self-sampling kit delivered to travelers for COVID-19 testing 4 days after arrival in French Polynesia, July 2020–February 2021

1. Text

French Polynesia (FP), ≈280,000 inhabitants, 74 inhabited islands, is a French overseas collectivity in the South Pacific. The first SARS-CoV-2 infection was detected in March 2020 and during the following three months, 62 SARS-CoV-2 infections including 32 imported-cases were reported. In May 2020, after two months of population lockdown and closure of international borders, FP achieved total clearance of SARS-CoV-2 transmission [1,2].

In mid-July 2020, to reactivate tourism-related economy and prevent a social crisis at the queue of the COVID-19 public health crisis, the government decided the re-opening of borders and the leverage of quarantine measures. Specific measures for visitors and residents arriving by air were implemented. Before departure, in addition to the request for a negative SARS-CoV-2 RT-PCR result, travelers had to register online on Electronic Travel Information System (ETIS, https://www.etis.pf/) to provide travel itinerary and contact information. Moreover, as part of a new testing protocol for travelers, called CoV-Check Porinetia, every traveler aged ≥6 arriving at Tahiti-Faa'a airport, was provided a kit allowing self-collection of nasal and oral samples to be performed 4 days after arrival (Self-sampling instructions and video tutorial, https://www.ilm.pf/covcheck/). Each self-sampling kit was tagged with a barcode linked to travelers' personal ETIS number. Once performed, self-collected samples had to be deposited to a health center in any of the islands connected by airline or boat to Tahiti. Once received at the Institut Louis Malardé (ILM, Tahiti) samples were pooled by ten and submitted to SARS-CoV-2 RT-PCR. If the result was positive, samples were re-tested individually. The barcode of each positive sample was communicated to the surveillance office from the Ministry of Health that accessed travelers' information on ETIS platform. A confirmatory RT-PCR test done by medical staff was organized and if SARS-CoV-2 infection was confirmed, the traveler was requested to isolate.

In August 2nd, 2020, the first SARS-CoV-2 infected case after the re-opening of borders was a tourist on a cruise ship whose self-collected samples were found positive by RT-PCR [3]. As soon as the information was given to health authorities, the boat was required to make its way back to Tahiti. The tourist tested positive and another closely-related passenger were immediately disembarked from the boat. All other passengers and crew members (340) were isolated for 7 days, and none of them tested positive. Between July 2020 and February 2021, a total of 59,490 self-collected samples were tested and 273 were found positive (Suppl1).

Although the self-testing protocol did not prevent the re-introduction of SARS-CoV-2 in FP, it allowed limiting the emergence or expansion of traveler-related clusters. While COVID-19 incidence increased in Tahiti, the protocol was maintained to help preserving other islands (Fig. 1 ) [4]. With the emergence of SARS-CoV-2 variants of concern, re-testing of self-collected samples using variants-specific amplification kit, and spike gene sequencing has been implemented. Retrospective investigation over the past three months found B1.1.7 UK variant in six travelers coming from France (Suppl2). In February 2021, quarantine measures were re-implemented, and self-testing at day 4 was maintained [5].

Fig. 1.

Weekly confirmed Sars-CoV-2 cases, COV-CHECK self-tests and positive COV-CHECK self-tests reported in French Polynesia between July 15, 2020, and February 14, 2021. Grey bar: weekly number of confirmed Sars-CoV-2 cases (Source: Mallet HP et al., 2020) [4]; light orange bar: weekly number of analyzed COV-CHECK self-tests; dark orange bar: weekly positive COV-CHECK self-tests.

Declaration of competing interest

The authors have declared no conflicts of interest.

Authors contribution

VMCL, MA, IT conceived the surveillance protocol; VMCL, MA, IT, VR and AT designed the surveillance protocol; MA, IT supervised the distribution and the collection of self-testing kits; AT and VR developed, performed and interpreted the virological analyses and the genetic sequencing experiments; VMCL wrote the first version of the manuscript; IT produced the Figure and SupplTable1; VR produced SupplTable 2; all authors critically reviewed and approved the final version of the manuscript.

Funding

This work was supported by the Government of French Polynesia. Funding source had no role in the writing of the manuscript or the decision to submit it for publication. All authors had full access to the full data in the study and accept responsibility to submit for publication.

Appendix A. Supplementary data

The following are the Supplementary data to this article: