congresos y reuniones científicas
Life table characteristics and vector competence of field populations of Aedes aegypti for Chikungunya virus in Argentina
MICIELI, MARIA VICTORIA; CHIN, PAM; BALSALOBRE, AGUSTIN; MUTTIS, EVANGELINA; GAUTO, NERIS; MANGUDO CAROLINA; KRAMER, LAURA
Workshop; Gaps and Opportunities in Chikungunya Research: Expert Consultation on Chikungunya Disease in the Americas; 2015
Chikungunya virus (Togaviridae; Alphavirus) wasintroduced into the Caribbean in October 2013 and subsequently expanded itsrange to Central and South America as well as the United States. Endemictransmission of the virus has not yet been detected in Argentina, althoughthere have been imported cases and the virus is indigenous now in neighboringBrazil. The predominant vector implicated in CHIKV transmission in the westernhemisphere is Aedes aegypti. Thisspecies is found predominantly from the northeastern province of Misiones southto Buenos Aires. We conducted a comprehensive study in 2014 on Ae. aegypti in Argentina over the extentof this geographic range. The project focuses on how local cycling temperaturesand genetic variation in natural populations of Ae. aegypti impact lifehistory traits of this mosquito, as well as its ability to transmit Chikungunya(and Dengue viruses). Ae. aegypti is known to have considerable genetic,behavioral, and ecological variation that is often spatially and/or temporallyheterogeneous. The genetic variation observed in Argentina is most likely aconsequence of multiple introductions leading to heterogeneity in a largenumber of traits: morphology, ecology, genetics, behavior, and ability totransmit arboviruses. We collected Ae. aegypti from reported geneticallydistinct populations in Argentina, from containers around homes, tires,cemeteries, and other temporary sources in four locations ranging from subtropicalIguazu and Posadas in the north to temperate Buenos Aires in the south, andSalta in the northwest. The mosquitoes were reared to the first generation ofadults in the laboratory, then blood fed for F1- F2 eggs, which were hatched todetermine life table characteristics and vector competence at the naturalcycling temperatures recorded in each of the study sites. The genetic analysesused nine microsatellite loci and two mitochondrial DNA regions (COI and ND4),as were successfully used to determine phylogeny of Bolivian Ae.aegypti. Life table studies included developmenttime, survivorship, fecundity at the 4 sets of cycling temperatures. The experimentshave been completed and the results are currently being analyzed.