Results of Inoculating Okinawan Horses with the Virus of Japanese B Encephalitis

Summary

It has been demonstrated that an Okinawan horse was susceptible to infection by the virus of Japanese B encephalitis and that the virus was present in the circulating blood 3 and 6 days after inoculation. It could not be demonstrated 16 hours after inoculation, nor after 9 days, at which time a small amount of neutralizing antibody had appeared. In 3 other horses which possessed high titers of neutralizing antibodies prior to the injection, virus could not be demonstrated in the blood stream following inoculation. These results, when considered in conjunction with the previously demonstrated presence of high titers of antibodies in the sera of many Okinawan horses,1 constitute further evidence that this species of animal may play a role in the epidemiology of Japanese B encephalitis.