Key Points

• In Mayotte, flu outbreaks generally occur during the hot and humid season, between December and March.

• This year, surveillance data confirm relatively early circulation of the influenza virus:

  • onset of virus circulation biologically confirmed in S32-2021

  • epidemic phase: from S42-2021 to S01-2022. End of the post-epidemic phase in S05-2022

  • 482 samples positive for influenza virus since S32-2021, predominantly type A(H3N2)

  • 315 emergency department visits since week 32 of 2021 and 71 subsequent hospitalizations

  • 14 severe cases hospitalized in intensive care since Week 37, including one death in Week 46-2021

• Special context for the 2021/2022 epidemic season:

  • No influenza epidemic in 2020/2021: reduced immunity in the general population

  • co-circulation of SARS-CoV-2 with possible viral competition. The third wave of SARS-CoV-2 in Mayotte coincides with a decline in influenza surveillance indicators