TABLE 2

Prevalences of HA2 mutations among all avian influenza virus subtypes

SubtypeNo. of sequencesHA2 mutation at position [no. (%) of sequences]:
436450536
ATOther (only H)QLOthersKROthers
H1 avian45001 (0.2)449 (99.8)450 (100)000S 449 (99.8)
H1 human18,71304 (0.02)18,694 (99.9)18,702 (99.9)000S 18,680 (99.8)
H2 avian37600376 (100)376 (100)000S 375 (99.7)
H2 human930093 (100)93 (100)000S 91 (99.9)
H3 avian1,1867 (0.6)1,179 (99.4)1,184 (99.8)01 (0.1)0Q 1,183 (99.9)
H3 human15,2163 (0.03)15,207 (99.9)15,211 (99.97)4 (0.03)00Q 15,208 (99.9)
H41,069001,064 (99.5)00A 1,069 (100)1 (0.1)0Q 1,068 (99.9)
H54,244004,242 (99.95)4,238 (99.86)2 (0.05)00S 4,228 (99.6)
H61,196001,196 (100)1,189 (99.4)7 (0.6)00S 1,186 (99.2)
H71,5061,421 (94.4)85 (5.6)a1,505 (99.9)01,503 (99.9)2 (0.1)0
H8910091 (100)1 (1.1)0R 90 (98.9)00Q 90 (98.9)
H91,428001,426 (99.86)00A 1,401 (98.1)00S 1,426 (99.86)
H10499457 (91.6)41 (8.2)b0499 (100)0491 (98.4)8 (1.6)
H11, H13, H1649301 (0.2)492 (99.8)0493 (100)00S 459 (93.1)
H1211900119 (100)0119 (100)00Q 119 (100)
H1417017 (100)0017 (100)10 (58.8)0Q 7 (41.2)
H151313 (100)00013 (100)13 (100)0
Total46,7091,901 (4.1)16,535 (35.4)043,448 (93.0)655 (1.4)2,019 (4.3)10 (0.01)
  • a A total of 85 non-Italian H7N1 viruses possessed the virulence marker T436: 24 equine H7N7 viruses from 1956 to 1977 harboring anomalous CS as a result of recombination in the HA PENSTHKQLTHHMRKKR*GLF, PENSIHKQLTHHMRKKR*GLF, or PEAPAHKQLTHHMRKKR*GLF”; 15 strains from the United States in 2004 to 2010 (12 H7N2 and 1 H7N3), Singapore in 1994 (1 H7N1), and Korea in 2010 (1 H7N7) carrying monobasic CS; 42 LPAI H7N2 viruses from New York in 2004 to 2006 carrying PEKPKKRGLF; and only 4 viruses containing mCS (2 H7N7 [Germany, 1979, and Australia, 1985], 1 H7N2 [Tasmania/Australia, 2007], and 1 H7N6 [Australia, 2007]).

  • b H10 viruses of wild-bird origin from the United States in 2009.