ECDC recorded 171 cases of Plasmodium falciparum malaria in Mayotte, the French territory in the Indian Ocean, from January to 21 May, averaging 25 a week in weeks 18 to 20 against 6 a week the year before, a 4.2-fold rise concentrated in the southern municipalities 1. P. falciparum is the most lethal of the human malaria species, responsible for most malaria deaths worldwide. Mayotte sits administratively within France but inside the Indian Ocean malaria transmission zone, between Madagascar and the Mozambique coast.
Of the 171, 63 were autochthonous, locally acquired rather than imported, which means the parasite is circulating on the island and not merely arriving with travellers. ECDC rates onward transmission to mainland Europe as very low; the immediate risk sits with Mayotte's own population and with travellers, WHO are now sensibly advised to consider prophylaxis rather than treating it as over-cautious.
Mayotte borders the Comoros inside a known transmission zone, and the mosquito vector that carries the parasite thrives in warmer, wetter conditions that do not respect the line between an endemic Indian Ocean territory and the European mainland it belongs to. The 63 locally acquired cases matter for that reason: the longer-run signal is the parasite's range establishing on French soil, not the size of this season's count. ECDC ran the surge in its Week 23 bulletin beside a reassuring mpox clade I trend , the agency's early-warning layer catching a vector range shift while an established threat held flat.
