Virological and epidemiological studies on an outbreak of aseptic meningitis caused by echovirus 4 in northern Japan in 1964

During the summer and autumn of 1964, echovirus 4 was found widely distributed in northern Japan; this virus was associated with localized outbreaks of iaseptic meningitis in many regions. The evidence that the echovirus was aetio-logically related to aseptic meningitis was shown by the virus isolation from cerebrospinal fluids and faeces and the serodiagnosis of paired sera in many patients: Age-specific sero-immunity and morbidity rate suggested that echovirus 4 had spread extensively in about 1954. The strains of echovirus 4 isolated in the 1964; epidemic were similar to the prototype strain, Pesascek, in biological characteristics.

Isolation and characterization of the measles virus strains with low hemagglutination activity

Six measles virus strains were isolated from clinical specimens. They differed from a prototype strain in being incapable to grow in cell lines derived from monkey kidney and having a slower electrophoretic mobility of the hemagglutinin protein and a very low hemagglutination activity.