流感病毒进化能力变强了吗？张文宏团队发声

Core Insights - The ongoing flu season in China is experiencing a rise in cases, but the evolution capability of the flu virus is not necessarily stronger than before [1][2] - The H3N2 subtype of the flu virus is currently dominant, accounting for over 95% of cases [1] - The flu activity level this season has slightly exceeded last year's peak, with a notable increase in positive cases among children and adolescents [2] Group 1 - The flu virus undergoes antigenic drift, which causes seasonal outbreaks, but this does not indicate an increase in its evolutionary strength [1] - Recent monitoring suggests that flu cases may peak in mid-December, with 17 provinces experiencing high levels of flu activity [1] - The overall number of flu cases remains within seasonal limits, with the positivity rate for flu tests rising, particularly among younger patients [1][2] Group 2 - The flu-like illness cases reported in hospitals accounted for 9.6% of total emergency visits, with a positivity rate of 51.1% among these cases [2] - The monitoring of flu cases is based on symptoms such as fever, cough, and sore throat, with a focus on the proportion of flu virus detected in sampled cases [2] - The current flu season is noted to be earlier than previous seasons, with comparisons made to the severe flu season of late 2017 to early 2018 [2]