Prevalence of HA mutations characteristic of H5 sublineages A, BI and BII viruses in virus isolates from Egypt and Asia.

aPercent of H5N1 viruses that have mutation characteristic of sublineages A, BI and BII for each geographic region, host and year.bSequence information from the National Center for Biotechnology Information database in addition to sequences analyzed for this study.- denotes no sequence information available.