XK and susceptibility to pneumonia measurement: The co-occurring mutations H122Q, A127T, P144L, N150K, G181E, S194D, and K200R in HA and D53N, N59S, and G233E in NA were detected in 78.0% (32/41) of the isolates, including 18 from the pneumonia group and 14 from the non-pneumonia group.