Active Surveillance for Avian Influenza Virus, Egypt, 2010–2012
Figure 5. . . Phylogenetic tree of the hemagglutinin gene of influenza A(H9N2) viruses from Egypt, 2010–2012. Squares and red text indicate viruses that were isolated and sequenced as part of the study. Black text indicates sequences available on GenBank from previous years or other groups. Circles indicate co-infection with influenza virus subtypes H5N1 and H9N2. Scale bar indicates phylogenetic distance (1 base substitution/100 positions).