Molecular epidemiology of non-falciparum Plasmodium infestations in different areas of the Ivory Coast

Malaria is a major public health problem, particularly in the tropical regions of America, Africa and Asia. Plasmodium falciparum is not only the most widespread but also the most deadly species. The share of Plasmodium infestations caused by the other species (P. ovale and P. malariae) is clearly underestimated. General objective was to determine the molecular epidemiology of plasmodial infestations due to P. malariae and P. ovale in Côte d'Ivoire. This is a cross-sectional study which took place from February to March 2021 at the Centre de Recherche et de Lutte contre le Paludisme (CRLP) of the Institut National de Santé Publique (INSP). The collection of samples took place from May 2015 to April in different malaria epidemiological facies in Côte d'Ivoire. Analysis of the collected samples was performed. In each patient, we collected blood by venipuncture at the elbow on EDTA tubes. These samples were used to make confetti on Wathman paper for the molecular diagnosis of malaria. Molecular diagnosis as well as differential diagnosis of plasmodial species using the nested PCR technique. A total of 360 samples were tested with a success rate of 72.5% (261 out of 360). The sex ratio was 0.84. The overall plasmodic index was 72.5%. The specific index was 77.4%; 1.5% and 0% for P. falciparum, P. malariae and P. ovale in mono-infestation, respectively. There was also 15% P. falciparum and P. malariae co-infestation, 3.4% P. falciparum and P. ovale co-infestation and 2.3% P. falciparum, P. malariae and P. ovale triple-infestation. After exclusion of P. falciparum monoinfestation cases, 59 samples were finally retained to evaluate the molecular epidemiology of non-falciparum Plasmodium infestations. Typing of Plasmodium ovale subspecies showed a clear predominance of Plasmodium ovale curtisi (81.2% of cases). Plasmodium falciparum remains the most prevalent malaria species in Côte d'Ivoire, but P. malariae and P. ovale are endemic at a low rate. The elimination of malaria requires a better understanding of the specific epidemiological characteristics of P. malariae and P. ovale with a particular emphasis on the identification of asymptomatic carriers.