Lu X, Cho D, Hall H, Rowe T, Sung H, Kim W, Kang C, Mo I, Cox N, Klimov A, Katz J
Influenza Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
J Med Virol. 2003 Apr;69(4):553-9. doi: 10.1002/jmv.10344.
Avian influenza A viruses are the ancestral origin of all human influenza viruses. The outbreak of highly pathogenic (HP) avian H5N1 in Hong Kong in 1997 highlighted the potential of these viruses to infect and cause severe disease in humans. Since 1999, HP H5N1 viruses were isolated several times from domestic poultry in Asia. In 2001, a HP H5N1 virus, A/Duck/Anyang/AVL-1/2001 (Dk/Anyang), was isolated from imported frozen duck meat in Korea. Because of this novel source of HP H5N1 virus isolation, concerns were raised about the potential for human exposure and infection; we therefore compared the Dk/Anyang virus with HP H5N1 viruses isolated from humans in 1997 in terms of antigenicity and pathogenicity for mammals. At high doses, Dk/Anyang virus caused up to 50% mortality in BALB/c mice, was isolated from the brains and lymphoid organs of mice, and caused lymphopenia. Overall Dk/Anyang virus was substantially less pathogenic for mice than the H5N1 virus isolated from a fatal human case in 1997. Likewise, Dk/Anyang virus was apathogenic for ferrets. Dk/Anyang virus was antigenically distinguishable by hemagglutination-inhibition (HI) assay from human H5N1 viruses isolated in 1997 and avian H5N1 viruses isolated in 2001 in Hong Kong. Nevertheless, prior infection with Dk/Anyang virus protected mice from death after secondary infection with HP human H5N1 viruses. These results indicate that compared with HP human H5N1 viruses, Dk/Anyang virus is substantially less pathogenic for mammalian species. Nevertheless, the novel source of isolation of this avian H5N1 virus must be considered when evaluating the potential risk to public health.
甲型禽流感病毒是所有人类流感病毒的祖先起源。1997年香港高致病性（HP）H5N1禽流感的爆发凸显了这些病毒感染人类并导致严重疾病的可能性。自1999年以来，多次从亚洲的家禽中分离出高致病性H5N1病毒。2001年，在韩国从进口冷冻鸭肉中分离出一种高致病性H5N1病毒，A/鸭/安阳/AVL-1/2001（鸭/安阳）。由于这种高致病性H5N1病毒分离的新来源，人们对人类接触和感染的可能性提出了担忧；因此，我们在抗原性和对哺乳动物的致病性方面，将鸭/安阳病毒与1997年从人类分离出的高致病性H5N1病毒进行了比较。高剂量时，鸭/安阳病毒在BALB/c小鼠中导致高达50%的死亡率，从小鼠的脑和淋巴器官中分离到该病毒，并导致淋巴细胞减少。总体而言，鸭/安阳病毒对小鼠的致病性远低于1997年从一例致命人类病例中分离出的H5N1病毒。同样，鸭/安阳病毒对雪貂无致病性。通过血凝抑制（HI）试验，鸭/安阳病毒在抗原性上与1997年分离的人类H5N1病毒以及2001年在香港分离的禽H5N1病毒不同。然而，用鸭/安阳病毒预先感染可保护小鼠在再次感染高致病性人类H5N1病毒后免于死亡。这些结果表明，与高致病性人类H5N1病毒相比，鸭/安阳病毒对哺乳动物的致病性要低得多。然而，在评估对公共卫生的潜在风险时，必须考虑这种禽H5N1病毒的新分离来源。
