Plasmodium falciparum
The most lethal human malaria parasite species, now surging fourfold on the French island of Mayotte.
Last refreshed: 9 June 2026 · Appears in 1 active topic
Why is the world's deadliest malaria parasite now surging on a French island?
Timeline for Plasmodium falciparum
Malaria surges fourfold on a French island
Pandemics and BiosecurityBackground
ECDC recorded 171 cases of Plasmodium falciparum malaria in Mayotte from January to 21 May 2026, of which 63 were autochthonous (locally acquired rather than imported from travellers). Weekly incidence surged to an average of 25 cases per week in weeks 18 to 20 against 6 per week the prior year, a 4.2-fold rise concentrated in the southern municipalities, particularly Chirongui. ECDC rates the likelihood of Onward transmission to mainland Europe as very low. Travellers to Mayotte are advised to consider prophylaxis.
Plasmodium falciparum is the most lethal of the five human malaria parasite species and is responsible for the vast majority of malaria deaths worldwide. Unlike P. vivax, it can cause cerebral malaria and severe anaemia, with untreated severe cases carrying a mortality rate above 20%. It is transmitted by Anopheles mosquitoes and, unlike P. vivax, does not form dormant liver stages (hypnozoites), meaning all active transmission is via the mosquito vector. The parasite has developed resistance to multiple drug classes; artemisinin-based combination therapies (ACTs) remain the front-line treatment.
Mayotte sits within the Indian Ocean malaria transmission zone, bordering the Comoros archipelago, and has never been fully free of P. falciparum transmission. The 63 autochthonous cases in 2026 signal active local parasite circulation, not merely imported cases arriving with travellers. The longer-run concern is that warming and wetter conditions in the Indian Ocean expand the range and breeding season of the Anopheles vector, potentially deepening endemic transmission on French-administered territory.