Plasmodium species occurrence, temporal distribution and interaction in a child-aged population in rural Burkina Faso

Abstract

BackgroundMalaria can be caused by five Plasmodium species. Due to their higher prevalence, much of the research concentrates on Plasmodium falciparum and Plasmodium vivax. In Burkina Faso, where P. falciparum co-exists with Plasmodium malariae and Plasmodium ovale, there is not much data about the prevalence of the latter two species across human population. Moreover, interactions between co-infecting Plasmodium species are not documented. The aim of the current research is to determine species-specific prevalence and temporal distribution. The potential interactions between co-infecting Plasmodium species amongst the child-aged population in Burkina Faso are also discussed.MethodsThe study took place in the Sudanese savannah zone in Burkina Faso in a rural village, Laye. Surveys were conducted during the wet season across four years, 2007 to 2010. Volunteers aged three to 15 years with parental signed consent were enrolled. Ten children per week were screened for any history of pain, fever. Parasitological data were obtained by blood slide processing.ResultsThree sympatric Plasmodium species were recorded during this study with an average prevalence of 70.7%. Species temporal distribution showed an increase of P. malariae parasite prevalence from 0.9% in 2007 to 13.2% in 2010. Within a season, P. falciparum occurred in the overall study period while P. malariae and P. ovale were highly prevalent after the rainy part of this period. Species-specific infection analysis showed that in a comparison of mono-infections, P. malariae gametocyte prevalence and median density were higher than those of P. falciparum (88.9% vs 34.5% and 124.0 vs 40.0 gametocytes/μl, respectively). Likewise, in P. falciparum co-infections with P. malariae or P. ovale, gametocyte prevalence was also higher than in P. falciparum mono-infection. However, in P. falciparum mixed infection with P. malariae, P. falciparum gametocyte prevalence and median density as well as asexual form density decreased compared to P. falciparum mono-infection while for P. malariae mono-infection, only asexual form density significantly vary.ConclusionThese data revealed high gametocyte prevalence in other Plasmodium species than P. falciparum with a significant variation of P. malariae gametocyte carriers and gametocyte density across years. Molecular tools and entomological studies are needed to highly assess species-specific contribution to malaria transmission.

High and Heterogeneous Prevalence of Asymptomatic and Sub-microscopic Malaria Infections on Islands in Lake Victoria, Kenya

“…Indeed, gametocytes are the currency of transmission from human to mosquito for maintaining the malaria cycle. The presence and infectiousness of gametocytes in circulation determines the success of transmission from humans to mosquitoes33.…”

Equivalent susceptibility of Anopheles gambiae M and S molecular forms and Anopheles arabiensis to Plasmodium falciparum infection in Burkina Faso

“…Laye was used because it is part of the Demographic Surveillance System (DSS) used by the Centre National de Recherche et de Formation sur le Paludisme (CNRFP), the national malaria research centre for epidemiological studies. Epidemiological characteristics of the study site were recently described [29]. There is little geographic population structure of P. falciparum in Africa [30] and populations from Burkina Faso and Mali were not genetically distinct [31], so the small distance between Laye and Goundry should have no effect.…”

“…The screening took place the same day as the experimental infection of mosquitoes. Carriers were chosen based on two criteria, as described and used previously [29]: i) infection with only a single species of malaria parasite, P. falciparum, and ii) presence of mature gametocytes. For carriers meeting these criteria, 5 ml of venous blood was drawn into heparinized tubes for experimental feedings.…”

Egress and invasion machinery of malaria: an in-depth look into the structural and functional features of the flap dynamics of plasmepsin IX and X

“…7 P. falciparum, predominating in Africa, is considered to be the most virulent species being responsible for 85% of human death. 8 The complex life cycle of P. falciparum embodies multiple cycles of invasion, multiplication and egress in the human red blood cells. 9,10 Evidently, targeting the egress/invasion machinery, at its most vulnerable stage of the life cycle of the parasite may not only reduce the severity of the malarial disease, but may jointly eradicate disease transmission.…”