Assessment of exposure to Plasmodium falciparum transmission in a low endemicity area by using multiplex fluorescent microsphere-based serological assays

Compared to other antigens, a high percentage of seropositivity and specific antibody levels were detected with Glurp, Salsa1, Lsa3NR2, and Lsa1J antigens. The seropositivity increased with age for all tested antigens. Specific IgG levels to Glurp, Salsa1, Lsa3NR2, and Lsa1J were significantly higher in P. falciparum infected children compared to non-infected and this increase is significantly correlated with parasite density.The multiplex assay represents a useful technology for a serological assessment of rapid variations in malaria transmission intensity, especially in a context of low parasite rates. The use of such combined serological markers (i.e. Glurp, Lsa1, Lsa3, and Salsa) could offer the opportunity to examine these variations over time, and to evaluate the efficacy of integrated malaria control strategies.Plasmodium falciparum malaria is a major cause of human morbidity and mortality in sub-Saharan Africa, and its transmission varies greatly in endemicity across the continent [1]. The expanding utilization of combined malaria control strategies including insecticide impregnated bednets and artemisinin combination therapies, has contributed to greatly reduce malaria transmission in several sub-Saharan African areas [2,3]. Consequently, the current methods for evaluating malaria transmission intensity (MTI), such as entomological inoculation rate and Plasmodium parasitemia in human populations, present substantial limitations, e.g. reproducibility and can be time-consuming. In addition, both entomological and parasitological measures are affected by the seasonality and require a precise follow-up during longitudinal studies [4]. For this purpose, there is an increased need for developing new tools for the monitoring of MTI in more frequent contexts of low malaria transmission. In this respect, the sero-epidemiological approach offers a theoretical advantage over parasite prevalence for assessing MTI or changes in prevalence following the implementation of