I. Clinical manifestations 1. Incubation period: about a few hours to 1 or 2 days. 2. Symptoms: When children suffer from influenza, their clinical symptoms often vary according to their age. According to age, it is roughly divided into the following categories: older children from 7 years old to 18 years old. Symptoms are similar to those of adults, mostly manifested as common flu symptoms, the onset of acute, high fever, chills, head, back, limbs and other aches and pains, fatigue and other symptoms, and soon appeared sore throat, dry cough, runny nose, conjunctival congestion, tearing, and localized lymph node enlargement, the lungs can be heard in the coarse rhonchi accompanied by diarrhea, abdominal distension and other digestive system performance. Preschoolers: Children between the ages of 3 and 7. Symptoms are similar to other respiratory viral colds. It is not easy to distinguish between the inflammation spread to the upper and lower respiratory tracts, larynx, trachea, lungs, the disease is more serious, children often have a high fever, runny nose, often accompanied by vomiting, diarrhea, body temperature of 38 ℃ -40 ℃, there can be high fever convulsions. Infants and young children may have severe inflammation of the larynx, trachea and bronchus, accompanied by sticky sputum, and even respiratory obstruction occurs. The total number of white blood cells decreases, and when complicated with pneumonia, the total number of white blood cells decreases more. 3.Complications: older children and preschool children will have complications such as rhinitis, otitis media, pharyngitis, bronchitis, myocarditis, encephalitis, mumps and so on. Infants and young children may develop pneumonia. Second, prevention 1, influenza virus is mainly spread through the air and contact. Babies should avoid contact with respiratory patients with influenza symptoms (fever, cough, runny nose, etc.) or pneumonia; avoid going to crowded places, and if you do need to take your baby in and out of these places, it’s best to put a mask on your baby. Try not to have physical contact, including shaking hands, kissing and sharing meals. This can play a role in preventing contact with H1N1 sources of disease. 2, pay attention to the baby’s personal hygiene, should often use disinfectant and water to wash hands; baby should maintain adequate sleep, more exercise, pay attention to indoor ventilation, cultivate the baby’s good personal hygiene habits. 3, this year has not been vaccinated against influenza baby, to be vaccinated as soon as possible, although the flu vaccine can not prevent H1N1 influenza, but can improve the baby’s immunity to influenza. 4, eat cooked and boiled food, eat less or not eat raw, half raw shellfish, unclean food. Vegetables and fruits should be thoroughly cleaned, and it is best to sterilize or peel them if possible. 5, the closest contact with the child’s parents may become a source of infection of the child. Therefore, parents should pay attention to at home: immediately after returning home, wash hands and face with soap; often open the windows to ventilate the daily household items and children’s toys to clean and disinfect; parents once the symptoms of the flu, to have a sense of crisis, immediately isolated from the child.