Abstract
Comparative neutralization tests on 24 sera from residents of Indonesia carried out both in adult mice and in hamster kidney cell cultures gave essentially identical results. Comparative isolation attempts using field collected mosquitoes, early mouse passages from field isolates and human brain tested in hamster kidney cell cultures and suckling mice showed the in vitro indicator system to be as sensitive and possibly more sensitive to the presence of minimal amounts of virus. The implications of these findings were discussed for immediate application in public health laboratories.