1958 年 8 巻 2 号 p. 110-117
It was already presumed on the basis of epidemiological survey on poliomyelitis as well as immune state of inhabitan's against polimyelitis that Japan might be under so poor sanitary conditions that any new born could be infected with poliomyelitis virus during the childhood (Paul, Kitaoka and others). In order to give positive evidence for such a conception attempt was made to isolate poliomyelitis virus from stools of healthy looking infants, The stool samples were collected for poliomyelitis virus isolation by using skin muscle of human embryo from 306 healthy children aged one day to 3 years old in the 4 Infant Homes, 2 located in Tokyo Prefecture and each one in Yamagata and Aomori Prefectures respectively, and 58 children of nonpoliomyelitis in the Aomori Prefectural Hospital As a result 6 (7.8%) out of 77 children in the Setagaya Infant Home, Tokyo Prefecture, were proven to be poliomyelitis virus positive. All of them were identified as type II virus. These positive samples were collected during the period from August to September 1955 but not during the other seaon. In 1955, no case was recognized among the infants at the same Infant Home. The youngest positive child was 2 months 28 days old and the other positive were under 2 years old. Five of 6 new isolates produced the poliomyelits syndrome in mice following intracerebral inoculation but not the other one which gave rise to paralysis after intraspinal inoculation. In other words they were not proven to be avirulent for mice. The neutralizing antibodies ranging from 1:16 to 1:64 of titer were found against type II poliomyelitis virus in the serum collected two months later after the date of stool collection from each poliomyelitis positive child.
During the poliomeylitis virus isolation procedure 16 nonpoliomyelitis viruses were encountered which gave rise to cytopathogenic effect on human embryo tissue.
Compared with the cytopathogenic effect of the new isolates including poliomyelitis and nonpoliomeylitis viruses on mokey kidney, cells, human embryo skin muscle, HeLa and human amnion cells it was reconfirmed that the monkey kidney cells would be the most suitable for isolation of poliomyelitis virus.