[Studies on the susceptibility of two northern Taiwan strains of Aedes albopictus mosquitoes to Japanese encephalitis virus].

Aedes albopictus is a dominant mosquito species in northern Taiwan. In laboratory, the vector competence of 2 geographical strains of Aedes albopictus mosquitoes to NT 113 strain of Japanese encephalitis virus was examined. The mosquito infection dose50 (MI-D50) of Sanhsia (SH) strain by intrathoracic (i.t.) inoculation was shown to be -1.1 log WMICLD50 (weanling mice intracerebrum lethal dose), while that of Yungho (YH) strain was -2.0 log WMICLD50. The infection dose for 50% mosquitoes transmission (MTID50) by i.t. inoculation was 3.5 log with SH strain but no transmission occurred with YH strain. By feeding sweetened blood-virus mixture, the MID50 with SH strain was 2.7 log though YH strain did not attain 50% infection rate. By viremic mouse blood feeding, the highest infection rate for both strains was about 30%. No evidence of virus transmission was demonstrated by oral infection.