ISOLATION OF JAPANESE TYPE B ENCEPHALITIS VIRUS FROM MOSQUITOES IN SHANGHAI

1.A total of 281 separate lots of mosquitoes were collected in Shanghai between April andOctober in 1954,and the isolation for virus by intracerebral inoculation on mice,failed to yieldpositive result. 2.From May to September in 1955,further experiments were made,and a total of 35separate lots of mosquitoes were examined.During July two strains of virus were isolated fromtwo lots of Culex pipiens var.pallens collected from a same cow-shed and three strains of viruswere isolated from three lots of Culex tritaeniorhynchus collected from another cow-shed. 3.These five virus strains were all identified as Japanese B encephalitis virus by test foranimal host range,complement fixation and neutralization tests. 4.It was concluded,that repeated collection of mosquitoes from some animal sheds,in whichmany mosquitoes may easily be found,in the epidemic district just before or during the earlypart of the epidemic,may yield better results for the isolation of Japanese type B encephalitisvirus in its insect vectors.