Human IgG antibody response to Aedes aegypti Nterm-34 kDa salivary peptide as an indicator to identify areas at high risk for dengue transmission: a retrospective study in urban settings of Vientiane city, Lao PDR Emmanuel Elanga Ndille 1,2 , Audrey Dubot-P er es 3,4,5 , Souleymane Doucoure 6 , Franc ßois Mouchet 6 , Sylvie Cornelie 1,2 , Bounpone Sidavong 7 , Florence Fournet 8 and Franck Remoue 1,2 1 Institut de recherche pour le d eveloppement (IRD), UMR Maladies Infectieuses et Vecteurs, Ecologie, G en etique, Evolution et Con- tr^ ole, UMR IRD 224 - CNRS 5290 – Universities of Montpellier 1 and 2, Cotonou, B enin 2 Centre de Recherche Entomologique de Cotonou, Minist ere de la Sant e Publique, Cotonou, B enin 3 Institut de recherche pour le d eveloppement (IRD), UMR 190 “Emergence des Pathologies Virales”,  Ecole des Hautes  Etudes en Sant e Publique (EHESP), Aix-Marseille University, Marseille, France 4 Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao 5 Centre for Tropical Medicine, University of Oxford, Churchill Hospital, Oxford, UK 6 Institut de recherche pour le d eveloppement (IRD), UMR MIVEGEC Maladies Infectieuses et Vecteurs : Ecologie, G en etique, Evolu- tion et Contr^ ole, UMR IRD 224 – CNRS 5290 – Universit es Montpellier 1 and 2, Montpellier, France 7 Center of Malaria, Parasitology, Entomology, Ministry of Health, Vientiane, Lao 8 Institut de recherche pour le d eveloppement (IRD), UMR MIVEGEC : Maladies Infectieuses et Vecteurs, Ecologie, G en etique, Evo- lution et Contr^ ole, UMR IRD 224 – CNRS 5290 – Universities of Montpellier 1 and 2, Bobo-Dioulasso, Burkina-Faso Abstract objective Using human IgG antibody response to the Aedes Nterm-34 kDa salivary peptide as an indicator of human exposure to Aedes bites in surveying exposed populations from areas at risk of dengue virus (DENV) transmission in urban settings of Vientiane city, Lao PDR. methods Enzyme-linked immunosorbent assay tests were performed to measure the IgG response to Nterm-34 kDa peptide in blood samples collected within a flavivirus seroprevalence survey carried out in 2006 including 3558 randomly selected individuals. The level of IgG response to the Nterm- 34 kDa peptide in individuals was analysed in relation to the level of urbanisation of the individual’s residence, areas that presented significant differences in the prevalence of recent DENV infection. results No differences were observed in the anti-Nterm-34 kDa IgG level between DENV-positive and DENV-negative individuals. However, the level of specific IgG response was higher among individuals living in slightly urbanised neighbourhoods than among those in more highly urbanised areas (P < 0.0001). Interestingly, a similar pattern had already been observed concerning the prevalence of recent DENV infection in the same populations. conclusion The results of this retrospective study indicate that the evaluation of human IgG response to the Aedes Nterm-34 kDa salivary peptide could be a useful indicator to identify places with risk of dengue virus transmission in urban endemic areas. keywords salivary biomarker, Aedes bites, dengue risk, spatial distribution, residential neighbourhoods, Vientiane Introduction Dengue fever (DF) has become the most rapidly expand- ing arthropod-borne disease worldwide. Almost half of the world’s population is now at risk of infection, espe- cially in urban areas of developing countries (Guzman et al. 2010). Dengue fever presents a real risk of emerg- ing in developed countries where many cases have now been reported. One example confirming this threat is the autochthonous sporadic outbreak reported in 2010 in southeastern France (Gould et al. 2010). Adequate strategies must be urgently developed to control this dis- ease. Dengue virus (DENV) is transmitted by the bite of infected Aedes mosquitoes, mainly of two species: Aedes aegypti and Aedes albopictus. As no drugs and vaccines are available, the reduction and/or interruption of © 2014 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd. 1 This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Tropical Medicine and International Health doi:10.1111/tmi.12280 volume 00 no 00