Connecticut Virus: A New Sawgrass Group Virus from Ixodes Dentatus (Acari: Ixodidae)1

A new member of the Sawgrass serogroup, Connecticut virus, was isolated from a pool of 21 nymphal Ixodes dentatus removed from 2 nonviremic Eastern Cottontails ( Sylvilagus floridanus ) trapped on 22 August 1978 in Lyme (New London Co.), Connecticut, USA. This strain (Ar-1152-78) killed suckling but not weanling mice by intracerebral inoculation; neither suckling nor weanling mice were killed by intraperitoneal or subcutaneous inoculation. The only evidence of infection in adult female laboratory rabbits and guinea pigs inoculated subcutaneously was neutralizing antibody in the guinea pigs. Plaques were first observed in Vero and BHK-21 cell cultures on 6 and 8 days, respectively, after inoculation. Neutralizing antibody was detected in 3 of 14 (21.4%) Eastern Cottontails from south-central Connecticut, suggesting an I. dentatus –rabbit maintenance cycle.