First evidence of plasmodium falciparum-plasmodium ovale co-infection with delayed clinical presentation in an Ivorian patient: observations and diagnostic challenges

Malaria remains highly endemic in Côte d’Ivoire, where repeated exposure to infective mosquito bites increases the risk of both mono- and mixed-species Plasmodium infections. While Plasmodium falciparum predominates and accounts for most acute clinical cases, co-infections with non- falciparum species are under-recognized due to diagnostic limitations and complex interspecies interactions. Unlike previous reports of concomitant mixed infections, we report the first case of P. falciparum and P. ovale infection in a 69-year-old Ivorian patient residing in France, who experienced latent recurrent malaria episodes following travel to the Man District in the western part of the country. Initial episodes were attributed to P. falciparum , whereas a subsequent episode, occurring in the absence of any re-exposure, was diagnosed as P. ovale infection. This report highlights the critical role of a putative co-infection and species-specific incubation strategies in malaria pathophysiology. The temporal dissociation between P. falciparum and P. ovale detection strongly suggests an initial co-infection, with P. ovale likely remaining subclinical due to low parasitemia (0.02%) and plausible interspecies competition. Unlike P. falciparum , P. ovale is capable of forming dormant hepatic stages (hypnozoites), leading to delayed clinical recurrence 4 months after the primary infection. The late clinical presentation observed in this patient, without recent travel and new exposure, supports the hypothesis of hypnozoite reactivation rather than reinfection. This report underscores the importance of considering mixed-species malaria infections and variable incubation periods in diagnostic and clinical management. It also highlights the importance of sensitive molecular diagnostic tools and appropriate radical treatment strategies targeting both blood-stage parasites and dormant hepatic forms.