We are entering the peak season of influenza incidence in winter and spring. During the flu type change, children and the elderly have weaker resistance and are most likely to be hit, especially when the weather changes from cold to hot. How to recognize influenza? Question 1: What is influenza and is it the same as the flu? It is not the same. Influenza (often referred to as “flu”) is a highly contagious, acute illness caused by the influenza virus. The influenza A and B viruses are the most clinically relevant. Influenza A viruses are the most widespread and are associated with the most severe outbreaks of influenza. There is often a clear seasonal epidemiological component as well as a population exposure component. Influenza viruses act on the upper and lower respiratory tracts, spreading outward through droplets when an infected person coughs or sneezes. Systemic symptoms are evident, such as fever, sore throat, cough, and malaise, and serious complications often arise in immunocompromised people. In contrast, cold is a mild upper respiratory tract viral infection, which is less contagious, manifesting as runny nose, cough, nasal congestion, etc., with mild systemic symptoms, and will generally get better naturally in 5-7 days. Simply put, cold is an individual epidemic with mild symptoms, while flu is a group epidemic with heavy symptoms. The types of viruses infecting the two are also different. Question 2: How did my baby get infected? Influenza viruses are spread through droplets of respiratory secretions and can also be spread through contact. Often your baby will have a history of contact with other influenza patients before infection, such as other children in the kindergarten school class with fever, your baby coming into contact with other sick children in the hospital for a medical check-up, or parents and grandparents at home with symptoms of fever. The common incubation period for children is 1 to 4 d (average 2 d), so the illness often starts soon after exposure. Because influenza patients are contagious from the end of the incubation period to the acute phase of the disease. Viral detoxification increases significantly from 0.5 to 1d after infection and peaks within 24h after onset, so that the time frame for easy transmission of the virus is wider, thus enhancing its transmissibility. Also, parents should be aware that younger children have the same amount of viral discharge as adults at the onset of the disease and have a longer duration of viral discharge, so they are more likely to transmit the flu virus to family members or as a source of infection to schools and communities. Contagiousness. Parents should also be aware that younger children are more likely to pass the flu virus to family members or as a source of infection in schools and communities because they have the same amount of viruses as adults and take longer to get sick. Don’t think that if your child is sick, it is not easy to pass on to adults, and try to keep your child out of crowded places during this time. Question 3: How does the flu in babies behave? What kind of tests will the doctor ask for when I go to the hospital? The main symptoms are fever, body temperature can be 39~40℃, chills and chills, accompanied by headache, general muscle pain, extreme weakness, loss of appetite and other general symptoms, often cough, sore throat, runny nose or nasal congestion, and in some cases, nausea, vomiting and diarrhea, and more digestive symptoms in children than in adults. Clinical symptoms of influenza in infants and children are often atypical. In children, acute laryngitis, acute otitis media, tracheitis, bronchitis, capillary bronchitis, and pneumonia caused by influenza viruses are more common than in adults. Most children with uncomplicated influenza have symptoms that resolve after 3-7 days, but coughing and physical recovery often take 1 to 2 weeks, so children often have poor spirits and poor appetite a week after getting sick, and mothers and fathers do not need to be overly anxious as this is a normal disease process. Severely ill children develop rapidly, with pneumonia appearing in 5~7d, body temperature often remaining above 39℃, respiratory distress, and intractable hypoxemia. When parents bring their babies to the hospital, the pediatrician will often ask the child to have a routine blood test, which is characterized by a normal or decreased total white blood cell count, an increased lymphocyte count and ratio, a normal or mildly increased C-reactive protein (CPR), and an increased total white blood cell and neutrophil count when combined with a bacterial infection. If the child has a fever for more than three days with a significant cough and shortness of breath, then a chest X-ray is needed. Question 4: What should I do if my baby has the flu and is there any specific medication? The doctor will assess the general condition of the baby, the severity of the disease, the onset of symptoms, and the local influenza epidemic to determine the treatment plan. Anti-influenza medication should be started as soon as possible within 48 hours of the onset of the disease, and symptomatic medications (antipyretic, cough suppressant, etc.) should be used appropriately to avoid blind or inappropriate use of antibiotics. The most effective anti-influenza drug for influenza is oseltamivir, which has been approved by the FDA for treatment and prophylaxis in children aged 1 year and older, and only for treatment in newborns aged >14d. The best time to administer oseltamivir is within 48 hours of the onset of influenza symptoms, and it is also effective when given after 96 hours of symptom onset.