Evaluation of Aedes albopictus tissue culture for use in association with arbovirus isolation

The susceptibility and sensitivity of Aedes albopictus cell cultures to five different primary and four different low-passage arboviruses were tested. Yellow fever, West Nile, Ilesha, eastern equine encephalitis, and Flanders viruses replicated in A albopictus tissue cultures. Replication was determined by the ability of selected tissue culture fluids to infect suckling mice, and by recovery from tissue culture fluid of progressively increasing amounts of complement-fixing (CF) antigen with time. Virus persistence was demonstrated with Nodamura, western equine encephalitis, and Mayaro viruses, but multiplication was not proven; neither persistence nor multiplication was demonstrated with a Kemerovo group virus. When yellow fever and Ilesha viruses were simultaneously inoculated into A albopictus culture, CF antigen for each was consistently detected. In a more detailed comparative study of field specimens, 12 unpassaged strains of yellow fever virus were tested for infectivity in A albopictus tissue culture, Vero cells, and baby mice. Higher titers of virus were detected (0.8--2.3 log ID50 per ml) in Vero cell culture than in A albopictus tissue culture or baby mouse systems. These results suggest the feasibility of using A albopictus cells in association with the primary isolation of arboviruses.