Group 1 - The flu season in Shanghai has started earlier this year, entering the peak period from late November to early January, with the dominant strain being H3N2 [1] - The so-called "K strain" circulating online is a variant of the H3N2 strain, not a new virus, as confirmed by health officials [1] - The current flu virus activity is at a high level, with multiple respiratory diseases posing risks due to fluctuating temperatures [1] Group 2 - Community health service centers in Shanghai are operating seven days a week to optimize testing and early identification of flu cases [2] - Medical institutions are enhancing their capacity for flu treatment, ensuring that fever clinics in secondary hospitals are fully operational and equipped [2] - The city is improving the medical process, including pre-examination and triage, and utilizing "Internet + healthcare" for online consultations [2] Group 3 - It is recommended to get the flu vaccine before the season starts, ideally in October, as it takes 2 to 4 weeks to develop antibodies [3] - The flu vaccine can provide 70%-80% protection against severe illness, even if administered during the peak season [3] - Antiviral medications are categorized into two types: neuraminidase inhibitors and RNA polymerase inhibitors, with the best effect when taken within 48 hours of infection [3]

Core Insights - The prevalence of influenza among children aged 5 to 14 is significantly higher compared to other age groups, with an annual infection rate of approximately 20% to 30%, and in peak seasons, it can reach up to 50% [1][2] Group 1: Influenza Impact on Children - Children are identified as a high-risk group for influenza, with a higher likelihood of developing severe cases due to their immature immune systems [1][2] - Specific high-risk children include those under 5 years old, especially those under 2, premature infants, and those with underlying health conditions such as neurological, respiratory, cardiovascular diseases, and immunodeficiencies [1][2] Group 2: Complications and Transmission - Common complications from influenza in children include pneumonia, neurological issues (e.g., encephalitis), and musculoskeletal damage, with a high mortality rate for severe neurological complications [2] - Children can shed the virus for longer periods, with infants potentially shedding for 1 to 3 weeks, making them significant sources of transmission in families and communities [2] Group 3: Treatment and Guidelines - The National Health Commission's guidelines emphasize the need for timely detection and antiviral treatment for high-risk groups, including children under 5 and the elderly [3] - Antiviral medications used in pediatric care include Oseltamivir, Baloxavir, and Peramivir, with specific recommendations based on age and weight [3]