Specific antibodies to Anopheles gSG6-P1 salivary peptide to assess early childhood exposure to malaria vector bites

Papa Drame (1, 2) , Anne Poinsignon (1) , Célia Dechavanne (3) , Gilles Cottrell (3) , Manon Farce (1) , Rodolphe Ladekpo , Achille Massougbodji , Sylvie Cornélie (1) , David Courtin (3) , Florence Migot-Nabias (3) , André Garcia (3) , Franck Remoue (1)

1 MIVEGEC - Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle
2 CREC - Centre de Recherche Entomologique de Cotonou
3 MERIT - UMR_D 261 - Mère et enfant en milieu tropical : pathogènes, système de santé et transition épidémiologique

Background: The estimates of risk of malaria in early childhood are imprecise given the current entomologic and parasitological tools. Thus, the utility of anti-Anopheles salivary gSG6-P1 peptide antibody responses in measuring exposure to Anopheles bites during early infancy has been assessed. Methods: Anti-gSG6-P1 IgG and IgM levels were evaluated in 133 infants (in Benin) at three (M3), six (M6), nine (M9) and 12 (M12) months of age. Specific IgG levels were also assessed in their respective umbilical cord blood (IUCB) and maternal blood (MPB). Results: At M3, 93.98 and 41.35% of infants had anti-gSG6-P1 IgG and IgM Ab, respectively. Specific median IgG and IgM levels gradually increased between M3 and M6 (p < 0.0001 and p < 0.001), M6–M9 (p < 0.0001 and p = 0.085) and M9–M12 (p = 0.002 and p = 0.03). These levels were positively associated with the Plasmodium falciparum infection intensity (p = 0.006 and 0.003), and inversely with the use of insecticide-treated bed nets (p = 0.003 and 0.3). Levels of specific IgG in the MPB were positively correlated to those in the IUCB (R = 0.73; p < 0.0001) and those at M3 (R = 0.34; p < 0.0001). Conclusion: The exposure level to Anopheles bites, and then the risk of malaria infection, can be evaluated in young infants by assessing anti-gSG6-P1 IgM and IgG responses before and after 6-months of age, respectively. This tool can be useful in epidemiological evaluation and surveillance of malaria risk during the first year of life.

Mots clés: Malaria; Salivary proteins; Biomarker of exposure; Anopheles bites; Maternal IgG transfer; Infants; Africa

Domaines: Maladies infectieuses; Pédiatrie; Santé publique et épidémiologie

Papa Drame, Anne Poinsignon, Célia Dechavanne, Gilles Cottrell, Manon Farce, et al.. Specific antibodies to Anopheles gSG6-P1 salivary peptide to assess early childhood exposure to malaria vector bites. Malaria Journal, 2015, 14, pp.285. ⟨10.1186/s12936-015-0800-6⟩. ⟨hal-02991240⟩