During the period from May to August, 1978, an epidemic of hand, foot and mouth disease (HFMD) occurred in Gifu prefecture. Epidemiological, virological and serological investigations were performed. Cases involved ranged from 0 to 31 years of age, and 80.2% of them were under 5 years of age. The incidence of HFMD with neurological complication (3.7%) was lower than that in 1973. Enterovirus 71 (EV71) was isolated from 83 of 108 cases (75.9%) and a significant rise in the neutralization antibody titer against the isolate was found in 14 of 25 cases (56%) . Thus, it was confirmed that the causative agent of the epidemic of HFMD in Gifu prefecture in 1978 was enterovirus 71.
