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

ObjectiveUsing human IgG antibody response to the Aedes Nterm-34kDa 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. MethodsEnzyme-linked immunosorbent assay tests were performed to measure the IgG response to Nterm-34kDa 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-34kDa 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. ResultsNo differences were observed in the anti-Nterm-34kDa 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. ConclusionThe results of this retrospective study indicate that the evaluation of human IgG response to the Aedes Nterm-34kDa salivary peptide could be a useful indicator to identify places with risk of dengue virus transmission in urban endemic areas. ObjectifUtiliser la reponse de l'anticorps IgG humaine au peptide salivaire Nterm-34kDa de l'Aedes comme un indicateur de l'exposition humaine aux piqures de l'Aedes dans la surveillance des populations exposees dans les zones a risque de transmission du virus de la dengue (DENV) en milieu urbain de la ville de Vientiane, au Laos. MethodesDes tests ELISA ont ete effectues pour mesurer la reponse IgG au peptide Nterm-34kDa dans des echantillons de sang preleves dans une etude de seroprevalence du flavivirus realisee en 2006, sur 3558 personnes choisies aleatoirement. Le niveau de reponse IgG contre le peptide Nterm-34kDa chez les individus a ete analyse en relation avec le niveau d'urbanisation du lieu de residence des individus, les zones qui presentaient des differences significatives dans la prevalence de l'infection DENV recente. ResultatsAucune difference n'a ete observee dans le niveau d'IgG anti-Nterm-34kDa entre les individus positifs et negatifs pour le DENV. Cependant, le niveau de la reponse IgG specifique etait plus eleve chez les personnes vivant dans des quartiers un peu urbanises que chez ceux vivant dans des zones plus fortement urbanisees (P