Table 2. Clade descriptions with isolation period, source, and geographic location*.
| Clade | Year | Geographic location | Isolation source | Description and strain name |
|---|---|---|---|---|
| 0 |
1996–2002 |
PRC, Hong Kong |
Avian/human |
Early progenitors of H5N1; HK/PRC 1997 avian influenza outbreak
Gs/Guangdong/1/96 |
| 3 |
2000–2001 |
PRC, Hong Kong, Vietnam |
Avian |
Ck/Hong Kong/YU562/2001
|
| 4 | 2002/2003 | PRC, Hong Kong | Avian | Gs/Guiyang/337/2006 |
|
|
2005/2006 |
Guiyang, PRC |
Avian |
Described as Guiyang 1 (5) |
| 5 | 2000–2003 | PRC, Vietnam | Avian | Gs/Guangxi/914/2004 |
|
|
2004 |
Guangxi, PRC |
Avian |
|
| 6 |
2002/2004 |
PRC |
Avian |
Ck/Hunan/01/2004
|
| 7 | 2002/2004 | PRC | Avian/human | Human case from Beijing in 2003 |
|
|
2005/2006 |
Yunnan, Hubei, and Shanxi, PRC |
Avian |
Described as Yunnan 2 (5)
Ck/Shanxi/2/2006 |
| 8 |
2001–2004 |
Hong Kong, PRC |
Avian |
Ck/Hong Kong/YU777/2002
|
| 9 |
2003–2005 |
PRC |
Avian |
Dk/Guangxi/2775/2005
|
| 1 | 2002/2003 | Hong Kong, PRC | Avian/human | Described as Guangdong (3) |
|
|
|
Vietnam, Cambodia,
Thailand, Laos, Malaysia |
Avian/human |
Spread of H5N1 to southeast Asia;
described as Vietnam/Thailand/Malaysia (3)
Vietnam/1203/2004 |
| 2.1.1 |
2003–2005 |
Eastern Indonesia |
Avian |
Described as Indonesia (ref 3)
Ck/Indonesia/BL/2003 |
| 2.1.2 |
2005–2006 |
Western Indonesia |
Avian/human |
Primarily avian with human cluster from Medan; described as Indonesia (3)
Indonesia/538H/2006 |
| 2.1.3 |
2004–2007 |
Eastern and western
Indonesia |
Avian/human |
Described as Indonesia (3)
Indonesia/5/2005 |
| 2.2 | 2005 | Qinghai Lake, Jiangxi, PRC | Avian | Progenitors from Qinghai Lake outbreak; described as Qinghai-like (5) |
|
|
2005–2007 |
Mongolia, Europe,
Middle East, Africa |
Avian/human |
Long-distance spread of H5N1; described as EMA clade (4)
BHGs/Qinghai/1A/2005 |
| 2.3.1 |
2003–2005 |
Hunan and Guangdong, PRC |
Avian |
Described as Hunan (3)
Dk/Hunan/303/2004 |
| 2.3.2 | 2004–2006 | Hong Kong, southern PRC | Avian | Described as Mixed/Vietnam 2 (3,5) |
|
|
2005 |
Vietnam |
Avian |
Described as Mixed/Vietnam 2 (3,5)
Ck/Guangxi/2461/2004 |
| 2.3.3 | 2004 | Hunan, PRC | Avian | Ck/Guiyang/3055/2005 |
|
|
2005 |
Guiyang, PRC |
Avian |
Described as Guiyang 2 (5) |
| 2.3.4 |
2005–2006 |
Hong Kong, PRC, Thailand, Laos, Malaysia |
Avian/human |
Described as Fujian-like (5)
Dk/Fujian/1734/2005 |
| 2.4 |
2002–2005 |
PRC (predominantly
Yunnan and Guangxi) |
Avian |
Described as Yunnan (3)
Ck/Yunnan/115/2004 |
| 2.5 | 2003/2004 | PRC, Korea, Japan | Avian | Spread of H5N1 to east Asian countries |
| 2006 | Shantou, PRC | Avian | Described as Guangdong/2006 (5) Ck/Korea/ES/2003 |
*PRC, People’s Republic of China; BHGs, bar-headed goose; Ck, chicken; Dk, duck; Gs, goose. Strain name in boldface represents the prototype virus for that clade.