Key Points

• COVID-19 Surveillance

  • Multi-source, consisting of systems designed to be comprehensive and/or descriptive

  • Enabling the tracking and description of the epidemic in all its aspects

  • First-time implementation of a system to centralize all diagnostic tests for a disease in real time

• Study period for the completion of this BSP

  • March 2020 to May 2021

  • Covering the two epidemic waves and an inter-epidemic period

• Epidemic dynamics in Mayotte (March 2020 – May 2021)

  • Influenced by regional characteristics (testing policy, underserved neighborhoods, high hospital strain, insufficient vaccination coverage)

  • Epidemic dynamics reflected in all data sources

  • A ^first wave of limited scale and shorter duration than in other regions, but with a healthcare system already under pressure

  • A second wave of greater intensity but shorter duration, linked to widespread circulation of the Beta variant, which was particularly severe among those aged 40–59.

  • A second wave associated with a high excess mortality rate, with an estimated excess mortality of +42% (9–85%) for the period from January 1 to May 31, 2021.

  • A decrease in incidence observed in mid-February 2021 to varying degrees across several age groups, as vaccination coverage began to increase in the general population.

  • During the third period, an increase in case severity, as well as an increase in the prevalence of comorbidities, particularly obesity and diabetes. This period was also marked by an increase in case fatality among people aged 65 and older with comorbidities.

• Key figures in Mayotte (March 2020 – May 2021)

  • 144,041 people tested and 19,358 cases identified

  • 1,500 hospitalizations, including 318 in intensive care

  • 268 cases reported by the CHM’s sentinel intensive care units; median age of 56; male-to-female ratio of 1.7; presence of comorbidities in over 80% of cases; median length of stay of 6 days

  • 173 deaths in total, including 158 in hospitals (29 medical evacuations)

  • 2,508 emergency department visits for suspected COVID-19

  • 9.3% of the general population had received one dose of the vaccine and 5.2% had completed the full vaccination series by the end of May 2021