世卫组织：全球流感活动增加 主要由甲流病毒引起

Core Insights - The World Health Organization (WHO) reported an increase in global influenza activity since October, with most detected viruses being of the influenza A type [1] - The proportion of the H3N2 subtype of influenza A virus has been rising in multiple countries and regions [1] - Genetic sequencing indicates a significant evolution of the H3N2 virus since August, although current epidemiological data does not show an increase in disease severity [1] Summary by Categories Influenza Activity - Global influenza activity has increased since October, with a notable rise in influenza A viruses detected [1] - Some countries in the Northern Hemisphere have reported an early onset of the flu season, while others are seeing increased activity that has not yet reached epidemic levels [1] Virus Evolution - The number of K sub-branch H3N2 viruses detected has increased since August, indicating significant evolution of the virus [1] - Despite genetic differences between the circulating strains and those covered by the flu vaccine, the vaccine is still expected to provide protection and prevent severe cases [1] Public Health Implications - The WHO emphasizes that vaccination remains one of the most effective public health measures, especially as respiratory infections from flu and other common viruses are expected to rise with the onset of winter in the Northern Hemisphere [1] - In the Southern Hemisphere, some countries have experienced an unusually prolonged flu season, with virus activity remaining above historical levels [1]