Key Points

In early 2021, Mayotte faced a second major wave of the epidemic. Epidemiological indicators pointed to a relatively severe wave (high hospitalization rate), which strained the island’s healthcare capacity. Starting in mid-February, the spread of the virus gradually declined. The incidence rate has been below the alert threshold of 10 per 100,000 inhabitants since Week 23, and the positivity rate has been below the alert threshold of 5% since Week 17. Currently, SARS-CoV-2 transmission is low on the island. Since early June, 3 cases per day have been reported, with an average of 440 tests conducted. Testing activity is, however, much lower than what was observed during the second wave (peaking at 3,314 tests per 100,000 inhabitants in Week 5 of 2021).

The start of the southern winter is marked by people leaving for vacations and the organization of large events conducive to gatherings. Air travel, which will continue until the start of the school year, exposes the territory to the risk of introducing new variants, particularly the Delta variant, which is approximately 40% to 60% more transmissible than the historical variants (Alpha, Beta, and Gamma). This variant is actively circulating in the United Kingdom, Russia, Indonesia, Europe, and also in South Africa, where it is now dominant. This variant was identified on June 25 in Réunion; since then, several local transmission chains have been identified in the neighboring department, including three clusters.

In this fragile context, it is essential to continue efforts to implement preventive measures. Contact tracing and targeted testing operations must be maintained, particularly for cases of infection with variants of concern (VOCs) or in unusual situations (high incidence in a neighborhood). Finally, screening and sequencing capacities are being strengthened in collaboration with laboratories to enable detailed and responsive virological surveillance.