Table 2.
Frequency of amino acid substitutions in NAs, submitted to GISAID and NCBI sequence databases, known to occur clinically and cause clinical resistance.a
| Type/subtype | NA amino acid substitutionb | No. of sequences containing the substitution (%)c | Home country patient (n) | Included in phenotypic analysisd |
|---|---|---|---|---|
| A(N1) | ||||
| H275Y + I223R | 1 (0.1%) | Japan (1) | Yes (HRI to oseltamivir and peramivir; RI to zanamivir and peramivir) | |
| H275Y | 148 (11%) | Australia (1) | Yes (HRI to oseltamivir and peramivir) | |
| China (1) | Yes (HRI to oseltamivir and peramivir) | |||
| China (1) | Yes (HRI to oseltamivir) | |||
| China (4) | No | |||
| Dominican Republic (1) | Yes (HRI to oseltamivir and peramivir) | |||
| Haiti (1) | Yes (HRI to oseltamivir and peramivir) | |||
| Japan (86) | Yes (HRI to oseltamivir and peramivir) | |||
| Japan (1) | No | |||
| Mexico (1) | Yes (HRI to oseltamivir and peramivir) | |||
| New Caledonia (1) | Yes (HRI to oseltamivir and peramivir) | |||
| Spain (1) | Yes (HRI to oseltamivir) | |||
| United States (48) | Yes (HRI to oseltamivir and peramivir) | |||
| United States (1) | No | |||
| H275Y/H | 16 (1%) | Brazil (1) | Yes (HRI to oseltamivir and peramivir) | |
| China (1) | Yes (HRI to oseltamivir) | |||
| Japan (2) | Yes (HRI to oseltamivir and peramivir) | |||
| Japan (2) | Yes (HRI to oseltamivir and RI to peramivir) | |||
| Japan (2) | Yes (RI to oseltamivir and HRI to peramivir) | |||
| Japan (2) | Yes (RI to oseltamivir and peramivir) | |||
| Japan (1) | Yes (RI to oseltamivir) | |||
| Japan (1) | Yes (RI to peramivir) | |||
| Japan (1) | No | |||
| Paraguay (1) | Yes (RI to oseltamivir) | |||
| United States (2) | Yes (NI) |
a
As listed in the table on the WHO website, available at: http://www.who.int/influenza/gisrs_laboratory/antiviral_susceptibility/nai_overview/en/; accessed 15 January 2015.
b
Amino acid position numbering is N1 specific.
c
Percentage based on the number of sequences in the final data set after curation – see Supplementary Table 2.
d
Yes indicates that the virus was analysed by a WHO CC. HRI = highly reduced inhibition, RI = reduced inhibition, NI = normal inhibition, assessed by in vitro assay for the neuraminidase inhibitors indicate.