Molecular epidemiology of adenovirus type 3 detected from 1994 to 2006 in Hyogo Prefecture, Japan.

The molecular epidemiology of 126 adenovirus type 3 (AdV3) isolates obtained in Hyogo Prefecture (population: 5.5 million) from 1994 to 2006 was studied. The hexon-coding region, including 7 hypervariable regions (HVRs) (1,419 bp), was sequenced. We found 5 nonsynonymous nucleotide substitutions in the HVRs. The results are strongly suggestive of positive Darwinian selection. We classified the AdV3 strains analyzed here into 3 genome types: AdV3x (n=44), AdV3y (n=46), and AdV3z (n=36). AdV3x first appeared in 2001 in Hyogo Prefecture, and was detected predominantly during a large outbreak of AdV3 in 2003-2005. AdV3x was identical to a Korean strain responsible for a large outbreak of AdV3 in Korea in 1998-1999. We conclude that at least 3 genome types of AdV3 have circulated in Hyogo Prefecture, Japan, during the past 13 years (1994-2006). The findings also suggest that AdV3x was imported from Korea to Hyogo Prefecture in 2001.