6-YEAR LONGITUDINAL ANALYSIS OF ADENOVIRUS TYPE-3 GENOME TYPES ISOLATED IN YAMAGATA, JAPAN

Five hundred eighty-seven adenovirus type 3 (Ad3) isolates were establ ished from children with acute respiratory infections (ARI) from 1986 to 1991, in Yamagata, Japan, Ad3 could be found in almost all the mont hs during the 6 years when two epidemics occurred, in 1987 and 1989. A molecular epidemiological study was done on 346 of the 587 isolates, using restriction endonucleases; BamHI, HindIII, SmaI, and BgIII were used. The Ad3 isolates were classified into seven genome types. The ge netic differences among the seven genome types were < 0.9%, and their phylogenetic tree, estimated by the neighbor-joining method, correlate d highly with their monthly distribution. One genome type predominated for 56 months, while the other six related genome types cocirculated for a short period. These results suggested that the predominant genom e type of Ad3 might have been endemically perpetuated in the Yamagata area with minor genomic variations. Furthermore, the outbreaks of Ad3 may have been due not to the appearance of a new genome type but rathe r to the endemic genome type. (C) 1994 Wiley-Liss, Inc.