title: gSG6-P1 salivary biomarker discriminates micro-geographical heterogeneity of human exposure to Anopheles bites in low and seasonal malaria areas.
abstract: BACKGROUND
  Over the past decade, a sharp decline of malaria burden has been observed in several countries. Consequently, the conventional entomological methods have become insufficiently sensitive and probably under-estimate micro-geographical heterogeneity of exposure and subsequent risk of malaria transmission. In this study, we investigated whether the human antibody (Ab) response to Anopheles salivary gSG6-P1 peptide, known as a biomarker of Anopheles exposure, could be a sensitive and reliable tool for discriminating human exposure to Anopheles bites in area of low and seasonal malaria transmission.
  
  
  METHODS
  A multi-disciplinary survey was performed in Northern Senegal where An. gambiae s.l. is the main malaria vector. Human IgG Ab response to gSG6-P1 salivary peptide was compared according to the season and villages in children from five villages in the middle Senegal River valley, known as a low malaria transmission area.
  
  
  RESULTS
  IgG levels to gSG6-P1 varied considerably according to the villages, discriminating the heterogeneity of Anopheles exposure between villages. Significant increase of IgG levels to gSG6-P1 was observed during the peak of exposure to Anopheles bites, and decreased immediately after the end of the exposure season. In addition, differences in the season-dependent specific IgG levels between villages were observed after the implementation of Long-Lasting Insecticidal Nets by The National Malaria Control Program in this area.
  
  
  CONCLUSIONS
  The gSG6-P1 salivary peptide seems to be a reliable tool to discriminate the micro-geographical heterogeneity of human exposure to Anopheles bites in areas of very low and seasonal malaria transmission. A biomarker such as this could also be used to monitor and evaluate the possible heterogeneous effectiveness of operational vector control programs in low-exposure areas.
authors.affiliation: Centre de Recherche Biomédicale (CRB) Espoir Pour La Santé, 269 Route de la corniche, Sor - BP: 226, Saint-Louis, Sénégal. andre.sagna@espoir-sante.org
authors.forename: André Barembaye
authors.initials: AB
authors.lastname: Sagna
authors.forename: Jean Biram
authors.initials: JB
authors.lastname: Sarr
authors.forename: Lobna
authors.initials: L
authors.lastname: Gaayeb
authors.forename: Papa Makhtar
authors.initials: PM
authors.lastname: Drame
authors.forename: Mamadou Ousmane
authors.initials: MO
authors.lastname: Ndiath
authors.forename: Simon
authors.initials: S
authors.lastname: Senghor
authors.forename: Cheikh Saya
authors.initials: CS
authors.lastname: Sow
authors.forename: Anne
authors.initials: A
authors.lastname: Poinsignon
authors.forename: Modou
authors.initials: M
authors.lastname: Seck
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Hermann
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Schacht
authors.forename: Ngor
authors.initials: N
authors.lastname: Faye
authors.forename: Cheikh
authors.initials: C
authors.lastname: Sokhna
authors.forename: Franck
authors.initials: F
authors.lastname: Remoue
authors.forename: Gilles
authors.initials: G
authors.lastname: Riveau
mesh_terms: D000328:Adult; D000818:Animals; D000852:Anopheles / Q000472:pathogenicity*; D015415:Biomarkers / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006805:Human Experimentation; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D007299:Insect Bites and Stings; D019476:Insect Proteins / Q000276:immunology*; D008137:Longitudinal Studies; D008288:Malaria / Q000635:transmission*; D008297:Male; D012424:Rural Population; D012471:Salivary Proteins and Peptides / Q000276:immunology*; D012621:Seasons; D012675:Senegal; D019371:Topography, Medical
chemical_list: D015415:Biomarkers; D007074:Immunoglobulin G; D019476:Insect Proteins; D012471:Salivary Proteins and Peptides