Volume 16, Number 1—January 2010
Letter
Oseltamivir- and Amantadine-Resistant Influenza Virus A (H1N1)
Table
Prevalence of oseltamivir-resistant and amantadine- and oseltamivir-resistant influenza A virus (H1N1) detected in Hong Kong, with clade designations, July 2008–June 2009
Date detected | No. isolates tested | No. (%) isolates oseltamivir resistant | No. (%) isolates oseltamivir and amantadine resistant | Predominating influenza A virus (H1N1) clade, no. identified/total no. sequenced (%) |
---|---|---|---|---|
2008 Jul | 462 | 78 (16.9) | 4 (5.1) | Clade 2C, 104/182 (57.1) |
2008 Aug | 313 | 45 (14.4) | 1 (2.2) | Clade 2C, 51/95 (53.7) |
2008 Sep | 61 | 21 (34.4) | 1 (4.8) | Clade 2B, 20/39 (51.3) |
2008 Oct | 19 | 13 (68.4) | 0 | Clade 2B, 13/16 (81.3) |
2008 Nov | 16 | 15 (93.8) | 0 | Clade 2B, 16/16 (100) |
2008 Dec | 45 | 44 (97.8) | 0 | Clade 2B, 41/41 (100) |
2009 Jan | 327 | 313 (95.7) | 0 | Clade 2B, 90/104 (86.5) |
2009 Feb | 769 | 755 (98.2) | 0 | Clade 2B, 138/153 (90.2) |
2009 Mar | 279 | 279 (100) | 0 | Clade 2B, 61/61 (100) |
2009 Apr | 63 | 63 (100) | 2 (3.2) | Clade 2B, 18/18 (100) |
2009 May | 22 | 22 (100) | 2 (9.1) | Clade 2B, 7/7 (100) |
2009 Jun | 77 | 77 (100) | 46 (59.7) | Clade 2B, 55/55 (100) |