TABLE 1

Mutations in HA2 of the Italian LP and HP H7N1 viruses

PositionAmino acidNo. of sequences with mutationa
LP (n = 66)HP (n = 83)Total
398I303b
V6383146
423H000
L6583148c
436A66066
T08383
450Q668d74
L07575
536K66066
R08383
  • a The total was 149 sequences, excluding the Lp and Hp viruses used in this study.

  • b Three Lp viruses with I398 were isolated from August to October 2000, about 8 months after emergence of the HP.

  • c One low-pathogenic virus contained F423.

  • d Eight HPAI viruses carrying Q450 were isolated during the very early outbreak from 12 October 1999 and still circulated for a limited time, to 2 July 2000. Thereafter, all the viruses contained the three mutations.