Objective: To study the viremia formation in guinea-pigs infected with wild type and attenuated Japanese encephalitis virus (JEV).
Methods: Guniea pigs were inoculated intraperitoneally with different wild JEV strains and the attenuated vaccine strain and its parent virulent strain. Viremia was detected on different days following virus inoculation.
Results: All the guinea-pigs inoculated with the wild JEV strains induced different levels of viremia (1.00-3.40 Lg pfu) on the 1st and 3rd day post inoculation. Using a virus titer of 10(4) pfu for inoculation, the animals inoculated with the SA14 parent strain induced relatively high viremia (10(2.4)-10(3.4) pfu), however no viremia coulds be detected on any tested days.
Conclusion: The degree of viremia in guinea pigs can be used as a new method to evaluate the attenuation of JEV.