Molecular epidemiology of non-falciparum Plasmodium infections in three different areas of the Ivory Coast.

BACKGROUND: 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 infections caused by the other species (Plasmodium ovale and Plasmodium malariae) is clearly underestimated. The objective of the study was to determine the molecular epidemiology of plasmodial infection due to P. malariae and P. ovale in Côte d'Ivoire. METHODS: The study was cross-sectional. The study participants were recruited from Abengourou, San Pedro and Grand-Bassam. Sample collection took place from May 2015 to April 2016. Questionnaires were administered and filter paper blood samples were collected for parasite DNA extraction. The molecular analysis was carried out from February to March 2021. A nested PCR was used for species diagnosis. The data was presented in frequencies and proportions. RESULTS: A total of 360 patients were recruited, including 179 men (49,7%) for 181 women (50,3%). The overall Plasmodium positive rate was 72.5% (261/360). The specific index was 77.4% and 1.5% for P. falciparum and P. malariae in mono-infection, respectively. There was also 15% P. falciparum and P. malariae co-infection, 3.4% P. falciparum and P. ovale co-infection and 2.3% P. falciparum, P. malariae and P. ovale triple-infection. Typing of P. ovale subspecies showed a significant predominance of P. ovale curtisi (81.2% of cases). CONCLUSION: Plasmodium falciparum remains the most prevalent malaria species in Côte d'Ivoire, but P. malariae and P. ovale are also endemic mostly in co-infection. Malaria elimination 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.

Assessment of the performance of five malaria rapid diagnostic tests in health facilities in Abidjan (Côte d'Ivoire).

Regular monitoring of malaria rapid diagnostic tests (RDTs) for the management of uncomplicated malaria in healthcare facilities is a key factor in improving diagnostic quality and ensuring better case management. This study aimed to assess the performance of five RDTs (Standard Q Malaria P.f Ag and Standard Q Malaria P.f/Pan (SD Biosensor, Korea), One Step Malaria HRP2/pLDH (P.f/Pan) (Guangzhou Wondfo Biotech Co., Ltd., China), Malaria Pf/Pan (B&O Pharm, France), and Malaria test P.f/pan (Das Labor, Germany)) in two healthcare facilities in Abidjan. This cross-sectional study was conducted between September and October 2022. Overall, 250 patients suffering from uncomplicated malaria were included with a predominance of female patients (56.6%). The mean age was 22.3 years (SD = 20.6; range, 0.17-73). Of the patients tested, forty-six (46) tested positive for thick smears, reflecting a prevalence of 18.5%. Plasmodium falciparum was the most commonly detected species (93.5%). The geometric mean parasitemia was 6,111.80 parasites/µl (SD = 80,026.93) (range: 116-412461). The sensitivity ranged from 95.24% to 95.65%, whereas the specificity ranged from 93.07 to 94.09% for all five tests evaluated. The false positive rate of the tests was less than 10%. No invalid test results were reported. Two-thirds of P. malariae cases detected by microscopy showed also positive results with all the RDTs. All five RDTs showed 100% sensitivity at low parasitemia levels (< 1,000 parasites/µl blood) including three cases of parasites < 200 parasites/µl blood. This study demonstrated the importance of monitoring the performance of RDTs in clinical samples.