Abstract
A total of 49 adenovirus type 3 (Ad3) strains from patients with epidemic keratoconjunctivitis at an eye clinic in Sapporo, Japan, from 1983 to 1986 were classified into either genome type Ad3f (26 strains) or Ad3g (23 strains). By the use of Hinf1 and TaqI restriction endonucleases, they were classified into 11 and 3 subgenome types, respectively. During this observation period, two epidemics of Ad3 infection relating to epidemic keratoconjunctivitis occurred. The prevalent Ad3g strains isolated during the epidemic in 1983 belonged to a single subgenome type. However, in the course of the Ad3f epidemic in 1986, alteration of one subgenome type of the prevalent strain to a different subgenome type which was presumed to be a derivative of the former was observed. In the years in which only a few Ad3 strains were isolated, such Ad3f strains were classified into different subgenome types. However, all Ad3g strains except two belonged to the same subgenome type.