Résumé
Context: Since Cameroon joined the global Roll Back Malaria initiative two decades ago, considerable advances have been made in the fight against malaria. However, the spread of vector resistance to insecticides and parasite resistance to antimalarial drugs are still holding back control of the disease. In order to optimise control strategies, we studied the epidemiological profile of malaria in two different parts of Cameroon.Material and method: Two cross-sectional surveys (entomological and parasitological) were carried out in 2018 and 2019 in 9 and 13 neighbourhoods/villages in the Mfou and Tibati; respectively. Malaria was diagnosed using rapid diagnostic tests (RDTs) and microscopy on blood collected from the fingertips of each participant. Molecular identification of Plasmodium species and study of polymorphism of genes associated with Plasmodium falciparum genetic diversity (MSP2) and antimalarial drug resistance (Pfcrt, Pfmdr1, Pfdhr and Pfdhps) were carried out by PCR on blood spotted on wathman paper. Anopheles collected by human approach from 6pm to 9am in households were identified morphologically and their ovarian tracheoles were dissected for parity rate determination. Molecular identification of anopheline species and determination of infection rate were carried out by PCR. Insecticide sensitivity tube tests were carried out on local Anopheles strains.Results: Malaria was hyper-endemic (Plasmodium Index >50%) in both localities, and Plasmodium falciparum was responsible for over 96% of infections. More than 60% of the persons had polyclonal infections and the multiplicity of infection was 2.07 and 1.80 at Mfou and Tibati, respectively. The frequency of the Pfcrt K76 allele (chloroquino-sensitive) was close to 80%, and those of the Pfdhfr (51I, 59R, 108N) and Pfdhps (437G) alleles associated with resistance to Sulphadoxine-Pyriméthamine (SP) were alsmost 100% in both localities. An. gambiae, An.coluzzii, An.funestus, An.leesoni, An. moucheti, An. nili, An. ziemanni, An.paludis and An.phaorensis were identified. The entomological inoculation rate was 0.54 and 0.15 infecting bites/man/night in Mfou and Tibati, respectively. An. gambiae s.l. and An. funestus species were most aggressive after midnight, with peaks occurring at dawn (4-5 am). These vectors were resistant to several classes of insecticides, with a high level of resistance to pyrethroids at both localities.Conclusion: This study shows the hyper-endemicity of malaria and the great diversity of Plasmodium strains. A re-emergence of chloroquino-sensitive isolates, high resistance of parasites to SP and of vectors to insecticides were observed in both study localities. The data generated in this work could contribute to the optimization of malaria control tools.