感染人類的禽流感（H5N1, H7N9及H10N8）：過去與現在

Human Avian Influenza: Past and Present (H5N1, H7N9, and H10N8)

1997年，人類對禽流感既是陌生又是恐懼，爾後每年擔心的便是禽流感何時又會出現，根據多年來的觀察，禽流感病毒感染人類已經不是會不會出現的問題，而是會不會又有新興的禽流感病毒株產生，進而造成人類生命健康的威脅。目前對於禽流感病毒感染人類，能使用的武器無論是使用疫苗來預防或是抗病毒的藥物治療，皆有相當不足的地方。比較重要的是當病人併發嚴重肺炎或急性呼吸窘迫症候群時的加護病房照顧及隔離措施的落實，避免散播，這也是未來醫界努力的方向。所以，面對日新月異的禽流感病毒的威脅，便必須在感染管制措施多加著墨，包括禽鳥疫情監控、人類疫情監控、加強邊境檢疫措施、適當的感染管制措施、衛教民眾養成良好衛生習慣等，才能使禽流感病毒的衝擊減至最低。

In 1878, avian influenza was first described as a fowl plague in Italy, indicating a contagious disease in poultry associated with high mortality rates. The first human case infected by a low pathogenic avian influenza virus (H7N7) resulting in conjunctivitis was reported in the United Kingdom in 1996. Transmission of H5N1, a highly pathogenic avian influenza A virus, from poultry to humans was confirmed, causing respiratory illness and mortality. Subsequently, there have been several outbreaks in humans infected with avian influenza viruses. The two avian influenza viruses to most recently break the species barrier into humans are H7N9 and H10N8. The fatality rates associated with three viral infections in humans are high (H5N1, 59%; H7N9, 39%; and H10N8, 66.7%). Vaccination is the best preventive method against avian influenza infection. However, licensed vaccines only exist globally for H5N1; there are no licensed vaccines for H7N9 or H10N8. Neuraminidase inhibitors, such as oseltamivir, zanamivir, and peramivir, remain the primary treatment for humans infected with avian influenza. Unfortunately, resistance to neuraminidase inhibitors has been reported. Therefore, prevention and control of infection is the most important strategy to reduce damage from avian influenza infection.