Summary

What is currently known about the situation in Réunion?

In Réunion, the majority of cases identified since March 11 were imported; local transmission has remained limited. Thanks to an early reduction in incoming flights, the start of lockdown (March 17) a few days after the first imported cases (March 11), combined with a mandatory 14-day quarantine upon arrival (mandatory quarantine facilities from March 30 to May 14), the number of potentially infected arrivals who could spread the virus on the island was limited. The implementation of early detection measures (screening at the airport and expanded testing guidelines in community healthcare settings, with drive-through testing stations established by late March) enabled the identification of cases, contact tracing, and thus a significant reduction in local transmission.

What’s new in this Update for the region?

A new contact tracing system has been in place since May 12, involving healthcare professionals (Level 1), health insurance providers (Level 2), the Réunion Health Agency, and Public Health France (Level 3). This structure is designed to identify cases and their at-risk contacts as quickly as possible in order to implement measures to limit the spread (home isolation, testing, case and contact follow-up, etc.). Laboratory technicians are responsible for reporting cases using the Sidep tool.
Individual case investigations are now conducted by the Health Insurance Agency; case characteristics (description: age, sex, onset date, type of transmission, etc.) are no longer included in this section.
The analysis of the epidemiological situation is supplemented by virological indicators from the Sidep tool (number of new confirmed cases over the past week, positivity rate previously reported).
During week 22, a virus transmission cluster was identified. At this stage, investigations are ongoing; however, this situation confirms the island’s vulnerability and the possibility of local viral circulation beginning, particularly from imported cases.

What are the public health implications for the region?

To date, the epidemiological situation (low-level viral circulation) remains fragile and depends on our collective ability to continue the control measures that have been put in place.
A new introduction of the virus is possible due to the increased frequency of flights and the number of passengers entering Réunion, coupled with the continued circulation of the virus (more than 4,000 weekly cases in mainland France in S21). Therefore, the continuation of preventive measures (including mask-wearing) is necessary, even for people who have been infected with COVID-19 (risk of transmission via contaminated hands). Compliance with the 14-day quarantine for arrivals (with strict isolation at home or in a quarantine facility) is imperative to limit the risk of establishing new local transmission chains.
The steps for detecting and managing transmission chains and clusters of COVID-19 infections are essential to limit the spread of the virus. These steps are carried out by the Regional Health Agencies (ARS) in coordination with the regional units of Santé publique France, using data from the National Health Insurance system.