Anopheles Salivary Biomarker to Assess Malaria Transmission Risk Along the Thailand-Myanmar Border

Author(s): Ya-Umphan, Phubeth; Cerqueira, Dominique; Parker, Daniel M; Cottrell, Gilles; Poinsignon, Anne; Remoue, Franck; Brengues, Cecile; Chareonviriyaphap, Theeraphap; Nosten, Francois; Corbel, Vincent | Abstract: BackgroundThe modalities of malaria transmission along the Thailand-Myanmar border are poorly understood. Here we address the relevance of using a specific Anopheles salivary biomarker to measure the risk among humans of exposure to Anopheles bites.MethodsSerologic surveys were conducted from May 2013 to December 2014 in 4 sentinel villages. More than 9400 blood specimens were collected in filter papers from all inhabitants at baseline and then every 3 months thereafter, for up to 18 months, for analysis by enzyme-linked immunosorbent assay. The relationship between the intensity of the human antibody response and entomological indicators of transmission (human biting rates and entomological inoculation rates [EIRs]) was studied using a multivariate 3-level mixed model analysis. Heat maps for human immunoglobulin G (IgG) responses for each village and survey time point were created using QGIS 2.4.ResultsThe levels of IgG response among participants varied significantly according to village, season, and age (Pl.001) and were positively associated with the abundance of total Anopheles species and primary malaria vectors and the EIR (Pl.001). Spatial clusters of high-IgG responders were identified across space and time within study villages.ConclusionsThe gSG6-P1 biomarker has great potential to address the risk of transmission along the Thailand-Myanmar border and represents a promising tool to guide malaria interventions.