ENCEPHALITIS IN NORTH CHINA. RESULTS OBTAINED WITH NEUTRALIZATION TESTS

Abstract

Two cases of epidemic encephalitis and one case of possible vaccine encephalitis observed in Peiping, China, are described, Both cases of epidemic encephalitis occurred in American women: one contracted the disease in China, the other in Japan. The cases of epidemic encephalitis were severe and followed by clear-cut se-, quelae. The case of possible vaccine encephalitis occurred in a Chinese girl 8 years of age, following a successful revaccination. Symptoms developed 9 days after vaccination. The child was critically ill for 4 days and then recovered rapidly and completely. Neutralization tests were done in mice with the sera of these patients against Japanese encephalitis virus (Hashimoto) and the St. Louis encephalitis virus (Webster). The serum of the first patient with epidemic encephalitis obtained 11/2 yrs. after discharge, protected mice both against the Hashimoto virus and the St. Louis virus. The serum of the 2d patient with epidemic encephalitis obtained during convalescence at the hospital, failed to protect mice against the Japanese encephalitis virus. It was not tested against the St. Louis virus. The serum of the child thought to have vaccine encephalitis obtained 5 months after discharge, failed to neutralize either the Japanese virus or the St. Louis virus.