摘要：Influenza C virus (C/Osaka C/1/90) was isolated from the throat swab of an infant who also had fever and gastrointestinal symptoms in an established line of Madin-Durby canine kidney (MDCK) cells in Dec. 1990 in Osaka. Near the patient's home were living many other persons who had contracted at the same time the common cold and in whom adenovirus, echovirus and Coxsackie viruses were detected. Antigenic variation between C/Osaka C/1/90 and C/Ann Arbor/JJ/50 viruses was recognized but slight difference was found over a period of 40 years. The rates of fluorescent antibody positive sera against the C virus in human age bracket gradually increased with age: 32% positive in teen-agers, 45% in persons 20 years of age and 100% in persons over 70. Studies on antibody prevalence indicated infection with influenza C virus to possibly be common and occur repeatedly in persons.
