1. Definition of Influenza A in Children Influenza A is an acute respiratory infectious disease caused by influenza A virus and is usually prevalent in winter and spring. Children are one of the high-risk groups for influenza A because their immunity is not fully developed and they are susceptible to infection. This article explains the symptoms and treatment of influenza A in children. 2. Symptoms of influenza A in children 1. Fever The most common symptom of influenza A in children is high fever, usually over 38°C. This high fever may last for several days and be difficult to treat. 2. Fatigue and physical discomfort Children may experience fatigue, dizziness and physical discomfort.