Browsing by Autor "Z. Barja Simon"

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Genetic structure and phylogeography of Aedes aegypti, the dengue and yellow-fever mosquito vector in Bolivia
(Elsevier BV, 2012) Christophe Paupy; Gilbert Le Goff; Cécile Brengues; Mabel Guerra; Jimmy Revollo; Z. Barja Simon; Jean-Pierre Hervé; Didier Fontenille
Human Antibody Response to Aedes aegypti Saliva in an Urban Population in Bolivia: A New Biomarker of Exposure to Dengue Vector Bites
(American Society of Tropical Medicine and Hygiene, 2012) Souleymane Doucouré; François Mouchet; Amandine Cournil; Gilbert Le Goff; Sylvie Cornélie; Yelin Roca; Mabel Guerra Giraldez; Z. Barja Simon; Roxana Loayza; Dorothée Missé
Aedes mosquitoes are important vectors of re-emerging diseases in developing countries, and increasing exposure to Aedes in the developed world is currently a source of concern. Given the limitations of current entomologic methods, there is a need for a new effective way for evaluating Aedes exposure. Our objective was to evaluate specific antibody responses to Aedes aegypti saliva as a biomarker for vector exposure in a dengue-endemic urban area. IgG responses to saliva were strong in young children and steadily waned with age. Specific IgG levels were significantly higher in persons living in sites with higher Ae. aegypti density, as measured by using entomologic parameters. Logistic regression showed a significant correlation between IgG to saliva and exposure level, independently of either age or sex. These results suggest that antibody responses to saliva could be used to monitor human exposure to Aedes bites.
Natural vertical transmission of dengue viruses by<i>Aedes aegypti</i>in Bolivia
(EDP Sciences, 2011) Gilbert Le Goff; Jane Yen Revollo; Maria Madalena Pessoa Guerra; M. Cruz; Z. Barja Simon; Yelin Roca; Jorge Vargas Flores; Jean-Pierre Hervé
The natural transmission of dengue virus from an infected female mosquito to its progeny, namely the vertical transmission, was researched in wild caught Aedes aegypti during an important outbreak in the town of Santa Cruz de la Sierra, Bolivia. Mosquitoes were collected at the preimaginal stages (eggs, larvae and pupae) then reared up to adult stage for viral detection using molecular methods. Dengue virus serotypes 1 and 3 were found to be co-circulating with significant higher prevalence in male than in female mosquitoes. Of the 97 pools of Ae. aegypti (n = 635 male and 748 female specimens) screened, 14 pools, collected in February-May in 2007, were found positive for dengue virus infection: five DEN-1 and nine DEN-3. The average true infection rate (TIR) and minimum infection rate (MIR) were respectively 1.08% and 1.01%. These observations suggest that vertical transmission of dengue virus may be detected in vectors at the peak of an outbreak as well as several months before an epidemic occurs in human population.