英文摘要 |
Infection with influenza viruses can cause severe morbidity and mortality in the elderly and children. In April 2009, a novel H1N1 (pandemic H1N1) influenza virus was first discovered in North America and then spread worldwide rapidly. It also resulted in many severe cases and fatalities which cause global panic. New influenza viral strains may originate from mutations and reassortment of viral genes with unpredictable degrees of pathogenicity, transmissibility, and pandemic potential. Investigations of virulence determinants of influenza A virus may provide the clues of pathogenicity as well as understanding of the factors that cause pandemics. In addition, monitoring the risk markers in avian species as well as swine can help us in early detection of threatening strains which may assist prevention and control of future pandemics. In this review, epidemiology, genomic variations and virulence factors of influenza viruses are discussed. |