Aseptic meningitis due to Frater type virus in Ontario.

During the summer and fall of 1959 and 1960 a virus was isolated on 14 occasions from the stool or cerebrospinal fluid or both of 12 patients with a clinical picture of non-paralytic poliomyelitis or aseptic meningitis. The patients were from eight different localities in Ontario. The isolated virus was not neutralized by antisera to any of the known enteroviruses, reoviruses or adenoviruses, nor did antiserum to the isolate neutralize any of these viruses. Antiserum to Frater virus, however, did neutralize this isolate and in turn was itself neutralized by antiserum to this virus. Frater virus was isolated in Scotland from cases of aseptic meningitis during the same period in 1959 and 1960. In Ontario this virus was not encountered before 1959. Isolation of the virus from cerebrospinal fluid and demonstration of immunological response in the patients establish its etiological significance. Biological characteristics indicate that it belongs to the Echo group.