Potential for evolution of California serogroup bunyaviruses by genome reassortment in Aedes albopictus

Aedes albopictus was introduced into the United States in used tires in 198 5. Its successful colonization of the upper Midwest has potential to alter the current epidemiology of bunyaviruses that circulate in the region. It i s permissive for the replication of several arboviruses, including La Cross e (LACV) and Jamestown Canyon (JCV) bunyaviruses. In this study, we demonst rate the ability of LACV and JCV to coinfect Ae. albopictus mosquitoes and to form all six possible reassortant genotypes. All reassortant viruses inf ect Ae. albopictus orally and can be transmitted to suckling mice. All reas sortants are neurovirulent in mice. However, reassortant viruses carrying t he LACV M segment in the foreign genetic background of JCV are more neuroin vasive than JCV, or any other reassortant genotype. In addition, these reas sortants can replicate in gerbils and infect Ae. triseriatus, characteristi cs of LACV, but not JCV. Because Ae. albopictus is spreading into new geogr aphic areas and feeds on a variety of mammals, including humans, it has the potential to transmit new, emerging bunyaviruses in nature.