First attempt to validate the gSG6-P1 salivary peptide as an immuno-epidemiological tool for evaluating human exposure to Anopheles funestus bites

Abstract

The development of a biomarker of exposure based on the evaluation of the human antibody response specific to Anopheles salivary proteins seems promising in improving malaria control. The IgG response specific to the gSG6-P1 peptide has already been validated as a biomarker of An. gambiae exposure. This study represents a first attempt to validate the gSG6-P1 peptide as an epidemiological tool evaluating exposure to An. funestus bites, the second main malaria vector in sub-Saharan Africa. A multi-disciplinary survey was performed in a Senegalese village where An. funestus represents the principal anopheline species. The IgG antibody level specific to gSG6-P1 was evaluated and compared in the same children before, at the peak and after the rainy season. Two-thirds of the children developed a specific IgG response to gSG6-P1 during the study period and--more interestingly--before the rainy season, when An. funestus was the only anopheline species reported. The specific IgG response increased during the An. funestus exposure season, and a positive association between the IgG level and the level of exposure to An. funestus bites was observed. The results suggest that the evaluation of the IgG response specific to gSG6-P1 in children could also represent a biomarker of exposure to An. funestus bites. The availability of such a biomarker evaluating the exposure to both main Plasmodium falciparum vectors in Africa could be particularly relevant as a direct criterion for the evaluation of the efficacy of vector control strategies.