High evolutionary rate of human astrovirus.

Human astrovirus is one of the etiological agents of acute gastroenteritis in humans, mostly in young children and elderly people. Complete genome sequencing of four human astrovirus strains isolated in Novosibirsk, Russia was performed. Analysis of these sequences and the sequences available in GenBank database has detected numerous potential recombination breakpoints. For the first time the rate of human astrovirus evolution was estimated based on the genome fragments without recombination breakpoints; the determined rate is typical of the RNA viruses with high evolutionary rate, amounting to approximately 3.7 × 10(-3) nucleotide substitutions per site per year, and for the synonymous changes, 2.8 × 10(-3) nucleotide substitutions per site per year.