[Japanese encephalitis in citizens of Russia who travel abroad]

Typical and atypical forms of Japanese encephalitis (JE) in the Russians visiting Asian countries endemic for JE are described. A patient who contracted the disease in China developed 5 months after returning to Russia acute meningoencephalitis with mental disorders and a lethal outcome on day 5 with bulbar symptoms. JE virus (strain SP-69) was isolated from his brain. By antigenic and genetic properties this strain occupies an intermediate position between Jagar-01 and Nakayama serotypes. A pregnant woman (6 months gestation) who lived in Birma for 3 years suffered from encephalitis running a protracted (more than 6 months) course; mildly manifest pyramidal signs were detected in her one-year-old infant with a normal mental status. Serologic studies showed that the disease was caused by infection with Jagar-01 serotype of JE virus. A patient contracting the disease 1 month after arrival in Japan developed a recurrent pattern of the illness: the diagnosis of JE was confirmed by repeated detection of virus-neutralizing anti-bodies in the blood and liquor. None of the patients was vaccinated against JE. Indications to prophylactic vaccination of subjects leaving for countries endemic for JE are discussed.