Mosquito Species for Rift Valley Fever Virus

Ahstract. Selected North American mosquito species were evaluated as potential vectors I of Rift Valley fever virus. Field Populations of .1edes canadensis Ae. camawr, A(. everu' tans. .,ie. so[iitans, .e. tae'tlorh Iteh,. .ic. trseratus. .1 ntophwk' hradleti-crucians, ( u/c. alinariis. (vtursais. and (V. erritanS perorally exposed to 10"'-10-plaque forming units of Rift ValLv fever virus rcd.Jilv became infected. Infection rates ranged from 51% (65 o27) f r ('v. salinarius to 96% (64 67) for ..e. canaden.sis. Disseminated infection rates ,%wre generally greater at 14 days than at 7 days after the infectious bloodmeal, and. with the exception of.-In. hrad/eyi-crumcan5, the\' were not significantly different than the pooled rate of 59% fbr each species tested. Only 5 55 (9%) of the An. hradh'it-cructn, developed a disseminated infection. For most of the species. about half of the mosquitoes with a disseminated infection transmitted an infectious dose of virus to hamsters. While all species. with the exception of..Ip. hrad/ei*'i-crutca.s, transmitted virus. .ie. canadenve.Ac.1c. ta(,ilorblvn-hus, and Cv. tarsalis had the highest vector potential of the species tested. Following inoculation of approximately 101 " plaque forming units of virus. 10110% of the mosquitoes of each species became infected. For most species, transmission rates were similar for inoculated individuals and those that developed a disseminated infection following peroral infection. Viral titers of transmitting and nontransmitting-disseminated individuals were similar for all species tested-These data suggest that. if Rift Valle% fever virus was introduced into North America, several mosquito species would be capable of transmitting it.