Vector competence of Argentine mosquitoes (Diptera: Culicidae) for West Nile virus (Flaviviridae: Flavivirus).

MICIELI, M. V.; MATACCHIERO, A.C.; MUTTIS, E.; FONSECA, D.M.; ALIOTA,M.T.; KRAMER, L.D.

JOURNAL OF MEDICAL ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Lugar: Lanham; Año: 2012

0022-2585

The objective of the present study was to determine the ability of Culex pipiens L. complex mosquitos from Argentina to serve as competent vectors for the flavivirus West Nile virus  in order to determine their potential importance in WNV transmission risk in Argentina. Field populations of Culex spp. were collected as egg rafts from different breeding sites (man-made drainage ditches) located at suburban areas of La Plata city, Buenos Aires province, Argentina during February 2012. Eggs collected from emerged females were shipped to the Arbovirus Laboratories, Wadsworth Center, New York State, USA. The mosquitoes were identified by morphological and molecular methods as Culex quinquefasciatus Say,Culex pipiens form molestus and hybrids between Cx. pipiens f.molestus and Cx. quinquefasciatus. Progeny from F3-F4 of Cx. quinquefasciatus and Cx. pipiens f. molestus from these populations were used for vector competence studies using NY99 and WN02 genotype strains of WNV from New York State, U.S. For the experiments, mosquito species from U.S. colonies were employed as controls. Cx. quinquefasciatus and Cx. pipiens f. molestus from temperate Argentina are competent but only moderately efficient vectors for WNV.  They are less susceptible to this virus compared to the same U.S. mosquito species. Studies of vertical transmission of NY99 virus to Cx. pipiens f. molestus from Argentina were conducted. The minimal filial infection rate (MFIR) for Cx. pipiens f. molestus was 1.19 infected/1000 specimens tested from females feeding during their second and later blood meals.