Studies on selection of LaCrosse virus variants by natural vertebrate hosts and vector mosquitoes.

The effect of passage in natural hosts on LaCrosse virus plaque size, mouse neurovirulence, and plaquing efficiency was studied. Seven field strains, as previously unpassaged naturally infected Aedes triseriatus suspensions, were inoculated into chipmunks Tamias striatus and thence into colonized Ae. triseriatus. The prototype strain, with seven prior laboratory passages, was also passed through the same natural host species. The field strains …