Spatial Assessment of Contact Between Humans and Anopheles and Aedes Mosquitoes in a Medium-Sized African Urban Setting, Using Salivary Antibody–Based Biomarkers

Abstract

Background Anarchic and poorly controlled urbanization led to an increased risk of mosquito-borne diseases (MBD) in many African cities. Here, we evaluate the spatial heterogeneity of human exposure to malaria and arboviral disease vectors in an urban area of northern Senegal, using antibody-based biomarkers of exposure to Anopheles and Aedes mosquito bites. Methods A cross-sectional study was undertaken during the rainy season of 2014 in 4 neighborhoods of Saint-Louis, a city in northern Senegal. Among children aged 6–59 months in each neighborhood, the dried blood spot technique was used to evaluate immunoglobulin G (IgG) responses to both gSG6-P1 (Anopheles) and Nterm–34-kDa (Aedes) salivary peptides as validated biomarkers of respective mosquito bite exposure. Results IgG response levels to gSG6-P1 and Nterm–34-kDa salivary peptides varied significantly between the 4 neighborhoods (P < .0001). The level of exposure to Aedes bites also varied according to household access to sanitation services (P = .027), whereas that of exposure to Anopheles bites varied according to insecticide-treated bed net use (P = .006). In addition, spatial clusters of high contact between humans and mosquitoes were identified inside 3 neighborhoods. Conclusions Antibody-based biomarkers of exposure to Anopheles and Aedes mosquito bites could be helpful tools for evaluating the heterogeneity of exposure to malaria and arboviral disease vectors by national control programs.

Sterile Insect Technique (SIT) against Aedes Species Mosquitoes: A Roadmap and Good Practice Framework for Designing, Implementing and Evaluating Pilot Field Trials

“…In these cases, nuisance and biting rates may be useful indicators. Salivary antibody-based biomarkers can also be used as secondary indicators of a reduction in biting [136].…”

Serological biomarker for assessing human exposure to Aedes mosquito bites during a randomized vector control intervention trial in northeastern Thailand

“…aegypti infestation indices in Benin [ 42 ] and Laos [ 43 ]. More recently, the Nterm-34 kDa salivary peptide successfully investigated the spatial heterogeneity of Aedes exposure in several urban districts of Senegal [ 44 ]. However, most of these Aedes serological studies estimated vector infestation through “indirect” (relative) indicators such as immature ‘ Stegomyia ’ ( Aedes ) indices and climatic factors, thus were unlikely to represent more accurate adult infestation that which is directly associated with virus transmission potential.…”

Influence of Host-Related Factors and Exposure to Mosquito Bites on the Dynamics of Antibody Response to Plasmodium falciparum Antigens

“…During the last decade, these serological biomarkers were developed and aimed at evaluating the level of exposure to mosquito bites [ 37 , 38 ]. Specific human IgG against salivary peptides from Anopheles (gSG6-P1) and Aedes (Nterm–34 kDa) represents a proxy of human exposure to Anopheles and Aedes bites and is a reliable tool for assessing the spatial and temporal heterogeneity of exposure at the individual level [ 39 , 40 ].…”