Group 1 - The core viewpoint of the articles highlights the rising trend of influenza activity in China, with a significant increase in school outbreaks and a notably higher positive detection rate among children aged 5-14 compared to other age groups [1][3][4] Group 2 - The H3N2 strain is prevalent among current influenza cases, characterized by rapid mutation, strong pathogenicity, and severe symptoms, particularly affecting vulnerable populations such as the elderly and children [3][4] - Vaccination remains the most effective preventive measure against H3N2, with this year's flu vaccine containing components that provide targeted protection [4][5] - The typical duration of influenza in children is acute and self-limiting, with fever usually subsiding within 2-5 days, although cough may persist longer [6][17] Group 3 - The "golden 48 hours" for treatment emphasizes the importance of early antiviral medication to reduce symptoms and complications, as the virus replicates rapidly during this period [7][15] - Antiviral medications like Oseltamivir and Baloxavir are effective in shortening the duration of symptoms but should not be used indiscriminately for all fevers [8][10] - Parents are advised to avoid common misconceptions in home care, such as using multiple antipyretics simultaneously, which can increase the risk of adverse effects [11][12][13]

Core Insights - The flu virus is becoming more active as temperatures drop across China, with a significant rise in flu activity reported in southern provinces and low levels in northern provinces [1][6] - The dominant strain of the flu virus is the H3N2 subtype, accounting for over 90% of flu cases, contrasting with last year's prevalence of the H1N1 strain [1][10] - H3N2 infections present more severe symptoms and longer duration compared to common colds, with a strong recommendation for vaccination, especially for vulnerable groups [1][15] Summary by Category Flu Activity - The flu virus is rising rapidly among respiratory pathogens, with a positivity rate of 12.8% for flu cases in emergency departments during the 43rd week of 2025 [3][6] - The monitoring period for this data is from October 20 to October 26, 2025 [3][6] Virus Strains - The H3N2 strain is the primary subtype detected, with 96.7% in southern provinces and 99.1% in northern provinces [10] - Other respiratory pathogens like rhinovirus and enterovirus are also present, but flu is increasing at a faster rate [6][9] Symptoms and Prevention - H3N2 flu symptoms include high fever (39°C to 40°C), severe body aches, and prolonged illness, distinguishing it from common colds which have milder symptoms [12][13] - Vaccination is emphasized as the most effective prevention method, particularly for the elderly, pregnant women, and children [15]