In the face of a more contagious virus, we must break the chains of transmission as quickly as possible

The detection and management of COVID-19 cases infected with the VOC 202012/01 UK variant in France must be carried out as quickly as possible in order to slow its spread across the country. Guidelines have been prepared by Santé publique France, the National Reference Center for Respiratory Infections, and the Ministry of Health. They were distributed on December 31 to healthcare professionals and are updated as resources and knowledge evolve to detect possible cases of new variants and confirm them through sequencing.

As soon as a case is detected, all healthcare stakeholders are mobilized to assist those affected in tracing their potential contacts and ensuring their strict isolation to break the chains of transmission.

Enhanced sequencing and a Flash survey to estimate the circulation of the UK variant within the country

In France, genomic surveillance of SARS-CoV-2 viruses falls under the remit of the National Reference Center (CNR) for Respiratory Infections. Its objective is to monitor the genetic evolution of viruses to identify the emergence and spatiotemporal distribution of viruses with mutations likely to affect their characteristics, such as infectivity, transmissibility, and virulence. This surveillance is conducted using representative samples of viruses circulating in the population, collected from various sources established in collaboration with Santé publique France and several partners, such as clinical laboratories, the Sentinelles Network, social and medical-social institutions, and hospitals.

Regarding the VOC 202012/01 UK variant, a rapid investigation was launched by the CNR (Laboratory of the Hospices Civils de Lyon) in collaboration with Santé publique France and the ANRS Emerging Infectious Diseases Unit, to estimate the level of circulation of the British variant in France. It consists of screening via ThermoFisher® RT-PCR followed by sequencing of viruses isolated from samples processed over two days by laboratories within a network of hospital virologists coordinated by the ANRS and several private laboratories. This investigation is currently underway.

With the aim of strengthening surveillance of these variants and better describing their characteristics, other projects are under consideration, including the regular submission to CNR laboratories of a sample of positive specimens processed in certain clinical laboratories, derived from investigations of specific clusters in school settings or from certain large-scale screening campaigns.

Monitoring epidemiological indicators, which remains essential for detecting a signal

At the same time, Santé publique France and health authorities are maintaining heightened vigilance regarding the epidemiological indicators produced daily at the national and regional levels. Any sudden change in these indicators—particularly an unexplained increase in incidence within a defined geographic area or a higher frequency of clusters—may signal a potential emerging variant, which can be investigated in collaboration with the CNR.

In the event of a suspected infection with a SARS-CoV-2 variant, since viral sequencing takes longer than RT-PCR, measures to investigate and isolate cases and their contacts must be implemented immediately to limit the spread of the virus.