| | | | | Vertebrate (species and organ) and arthropod | No. isolations/No. tested | No. with antibody/No. tested Test used | Country and region |
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| | In addition to the original isolate from the brain tissues of the fatal case of 1960, isolates have also been obtained from insects and the blood of sentinel rabbits caged in forested sites. | | Of eight isolates of LAC obtained from mosquitoes in Wisconsin during 1964 through 1968, five were from 1,985 Aedes triseriatus, and one each from 35,865 Ae communis, 36,800 Ae trivittatus, and 1,818 Culex pipiens (7). Fourteen more isolates were obtained from Ae triseriatus collected in hardwood deciduous forest study areas during 1969-1970. Fifty-nine other isolates reported from or obtained by the CDC from other states, are from various species, but again, highest infection rates were in Ae triseriatus (8). | | Neutralizing antibodies are present in sera of small forest-dwelling mammals in Wisconsin; in 62/117 (53%) of chipmunk, Tamias striatus; 68/176 (39%) of tree squirrels, Sciurus carolinensis and niger; 2/13 (15%) of cottontail, Sylviagus floridans; 2/40 (5%) of flying squirrels, Glaucomys volans; and 0/23 Peromyscus leucopus (9). | | Although antibodies neutralizing CAL group viruses are commonly found in rural outdoor workers (10), antibodies which neutralize LAC virus in higher titers than with other CAL group viruses from the state (JC, TVT, and SSH) are usually related to those with exposure to the hardwood deciduous forests common to southwestern Wisconsin and portions of other midwestern states. Convalescent serums from cases of California encephalitis consistently neutralize LAC virus in highest titer (14). | | Tamias striatus (eastern chipmunk; blood) | 7 | | Wisconsin, USA (21) | | Sentinel gray squirrels (Sciurus carolienis; blood) | 6 | | Wisconsin, USA (22) | | Man (brain) | 1 | | Wisconsin, USA (24) | | | | | |
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