Abstract
Within the past two years, since the autumun of 1950, scattered outbreaks of unknown etiologic polyradiculoneuritis, “Landry-Guillain-Barré's syndrome” occurred in these parts bordering the Inland Sea of Japan.
During these time 15 (23%) of 65 patients who were admitted to our children's clinic hospital died with bulbar paralysis.
During the summer and autumn of 1952, we discovered the virus pathogenic for suckling mice in feces obtained, during the acute stage of illness, from 2 children out of 12 patients, with the methods of Beeman et al. (1952) for the isolation of Coxsackie viruses.
The first strain was isolated from patient S. Dohi, a 5-year-old boy (Dohi strain) and the second was isolated from H. Okumoto, a 4-year-old girl (Okumoto strain), (See page 32-39.)
The properties of our two strains of virus and the results of neutralization tests were as follows.
1. The oldest mice susceptible to Dohi strain were 14 days old, and the oldest susceptible to Okumoto strain were 16 days old.
2. The LD50 titre, log of dilution, of the infected mouse muscle of Dohi strain was 6.00, and that of Okumoto strain was 7.00. The LD50 titre of the infected mouse brain of Dohi strain was 4.00, and that of Okumoto strain was 6.00.
3. The neutralization index log of patient S. Dohi serum collected on 27th day after the onset of illness was 5.50 for Dohi strain, and on the 191st day it was decreased 50 fold.
The neutralization index log of the patient H. Okumoto serum collected on the 3rd day was 1.23 for the Okumoto strain, Unfortunately, because H. Okumoto died on the next day, the convalescent serum could not be tested.
