TABLE 2.
Yr of isolation | No. of viruses with PB1-F2 protein of indicated putative length (aa) |
Total no. of viruses | % carrying truncated protein | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Truncated protein (≤78 aa) |
Nontruncated protein (≥79 aa) |
||||||||||||||
0 | 8 | 11 | 24 | 25 | 34 | 57 | 63 | 79 | 81 | 87 | 90 | 101 | |||
1996 | 1 | 1 | 0 | ||||||||||||
1997 | 2 | 17 | 19 | 10.5 | |||||||||||
1998 | 2 | 2 | 0.0 | ||||||||||||
1999 | 11 | 11 | 0.0 | ||||||||||||
2000 | 11 | 11 | 0.0 | ||||||||||||
2001 | 39 | 39 | 0.0 | ||||||||||||
2002 | 3 | 31 | 34 | 0.0 | |||||||||||
2003 | 61 | 1 | 62 | 0.0 | |||||||||||
2004 | 2 | 136 | 1 | 139 | 0.0 | ||||||||||
2005 | 1 | 242 | 243 | 0.4 | |||||||||||
2006 | 1 | 2 | 1 | 1 | 1 | 316 | 322 | 1.6 | |||||||
2007 | 3 | 1 | 2 | 1 | 2 | 1 | 2 | 1 | 323 | 336 | 3.0 | ||||
2008 | 2 | 1 | 2 | 4 | 2 | 3 | 167 | 1 | 182 | 4.9 | |||||
2009 | 4 | 16 | 106 | 2 | 128 | 15.6 | |||||||||
2010 | 1 | 12 | 7 | 1 | 1 | 2 | 129 | 153 | 13.7 | ||||||
2011 | 1 | 2 | 3 | 11 | 12 | 1 | 164 | 194 | 14.9 | ||||||
2012 | 2 | 3 | 7 | 2 | 52 | 1 | 67 | 17.9 | |||||||
2013 | 14 | 9 | 23 | 60.9 | |||||||||||
Totals | 10 | 7 | 4 | 16 | 41 | 1 | 43 | 1 | 6 | 5 | 9 | 1,817 | 6 | 1,966 | |
123 | 1,843 | 1,966 | 6.7 |
PB1 sequences from highly pathogenic H5N1 influenza viruses were retrieved from the NCBI, GISAID, and CDC databases. Sequences were aligned using MAFFT, and PB1-F2 sequence lengths were inferred from the sequences. Sequences were sorted by year of isolation and PB1-F2 protein length. The sequences expressing a protein of 78 aa or smaller were annotated as truncated.