Dynamics of Plasmodium falciparum genetic diversity among asymptomatic and symptomatic children in three epidemiological areas in Cote d’Ivoire

Abstract

Asymptomatic carriers of Plasmodium are considered a reservoir of the parasite in humans. Therefore, in order to be effective, new malaria elimination strategies must take these targets into account. The aim of this study was to analyse genetic diversity of Plasmodium falciparum among schoolchildren in three epidemiological areas in Côte d'Ivoire. This was a crosssectional study carried out from May 2015 to April 2016 in a primary school in rural and urban areas of San Pedro, Grand-Bassam and Abengourou, during the rainy season and the dry season. A total of 282 Plasmodium falciparum isolates were genotyped using Nested PCR of Pfmsp1 and Pfmsp2 genes. The overall frequency of K1, Mad20 and RO33 alleles was 81.6%, 53.4% and 57% for Pfmsp1 respectively. For Pfmsp2, this frequency was 84.3% and 72.2% for 3D7 and FC27. K1, Mad20 and FC27 Frequencies were significantly higher in Abengourou compared to other sites. Overall, the frequency of MIs was significantly higher in Abengourou for Pfmsp1 and Pfmsp2. However, Mad20 and RO33 alleles were significantly higher in the rainy season. No significant difference was observed between Pfmsp2 alleles in both seasons. Frequency of the 3D7 allele was significantly higher in symptomatic patients. MIs and COI increased with parasitemia for Pfmsp1and Pfmsp2. The data can be added to that available for monitoring and control of P. falciparum malaria. Further studies combining the entomological inoculation rate and the genetic diversity of P. falciparum will allow us to shed light on our understanding of the epidemiology of this parasite.

Maintenance of high temporal Plasmodium falciparum genetic diversity and complexity of infection in asymptomatic and symptomatic infections in Kilifi, Kenya from 2007 to 2018

“…The IC/3D7 family has been associated with asymptomatic infections and is thought to protect against clinical malaria [ 16 , 37 , 38 ]. However, contradictory findings have reported that parasites carrying FC27 like alleles are more prevalent among asymptomatic carriers [ 15 , 39 ]. There is no clear consensus on whether the two msp2 allelic families are likely to be found in asymptomatic or symptomatic infections.…”

“…The polymorphic block 3 contains repeats that vary in number, length and sequence that are grouped into two allelic families i.e. IC/3D7 and FC27 [ 14 ] that are associated with different malaria outcomes [ 15 , 16 ].…”

Drought correlates with reduced infection complexity and possibly prevalence in a decades-long study of the lizard malaria parasite Plasmodium mexicanum

“…Thus far, much empirical research on the impacts of drought on parasite ecology has focused on disease prevalence/incidence as well as vector population size and distribution (see Gagnon, Smoyer-Tomic & Bush, 2002 ; Brown, Medlock & Murray, 2014 ), but to our knowledge, no study has reported on the effects of drought on infection complexity. While previous studies on human malaria have shown changes in COI during wet and dry seasons in Africa, these studies did not specifically measure for drought conditions (for example: Gnagne et al, 2019 ; Collins et al, 2022 ). Infection complexity, although often correlated with disease prevalence ( Wanji et al, 2012 ; Tusting et al, 2014 ; Gatei et al, 2015 ; Fola et al, 2017 ), can be high despite overall low prevalence and vice versa ( e.g ., Barry et al, 2013 ; Gunawardena et al, 2014 ; Fola et al, 2017 ; Koepfli & Mueller, 2017 ).…”

Genetic Diversity and Complexity of Plasmodium Falciparum Infections in the Microenvironment Among Siblings of the Same Household in North-central Nigeria

“…Notable amongst these markers are the genes encoding surface antigens found at the developmental stages of the parasite life cycle, particularly the blood-stage antigens Merozoite surface protein 1 (MSP-1) and 2 (MSP-2), which are known to be highly polymorphic. Several studies have utilized PCR typing of the MSP-2 locus alone or together with the MSP-1 locus to assess genetic diversity and complexity of P. falciparum infections in different communities with varying transmission intensities and among infected individuals with different clinical presentations of malaria [21][22][23][24][25][26][27][28][29]. However, little is known about the diversity of P. falciparum infections at the level of the microenvironment, among members of the same household.…”