부산대학교 도서관

During the period from late summer till early fall of 1953, an acute febrile illness characterized by headache, moderate pyrexia and paroxysmal pain at the costal margin, sporadically occured in Nanyo Town, Yamaguchi, Japan.Two patients were admitted to the Nanyo Hospital. Case 1 was H. Yoshimitsu, 20yrs. female and Case 2 was F. Nakai, 37yrs. female.The intraperitoneal inoculation to one-day-old mice with fecal suspension collected from these patients, resulted in getting the isolation of one strain (Yoshimitsu strain) of virus from Case 1.The mice during the first 3 days of life are completely susceptible by intraperitoneal inoculation of 10% infected mouse muscle suspension (Table I) and such mice die in three or five days showing tremor, ataxia, marked dystrophy, sometimes spastic paralysis or convulsion (Fig. I).The ID50 of a pool of mouse muscle material from the first passage was 10-7.4 and that of brain was 10-6.8 by intraperitoneal route.Histological examination of such animals as infected with peritoneal routes, showed focal myositis, acute necrotic pancreatitis and steatites, but lesions of the cerebrum were not observed.These findings indicate that the virus belongs to Group B Coxsackie virus.Then the cross-neutralisation tests were made to infant mice with 100 ID50 of three strains of Coxsackie viruses (Yoshimitsu, Dalldorf's Group B Type 1 and 2 viruses) and its specific antisera. The results of the tests are illustrated in Table II, which shows Yoshimitsu strain is identical with Group B Type 1 (Conn.-5) virus.Furthermore neutralisation tests were performed with the patient's paired sera and the strain of Coxsackie virus referred to above (Table III). These two patient's acute phase sera were obtained on October 4, 1953 and convalescent sera were drawn on January 22, 1954, about 4 months after an attack of their illnesses.In case 1, neutralisation index of the acute phase sample was 100, and the convalescent one was larger than 1000. In second case, we failed to isolate virus from her stool, and could not demonstrate neutralizing antibody in acute phase serum, but a specimen of serum obtained on January 22, 1954, gave neutralisation index larger than 1000.A rise in the titer of neutralizing antibodies in the patient's sera shows that this virus is of human origin and played an etiological role in their illnesses.