The causes of viral infections in children include respiratory transmission, food intake, and close contact. 1. Respiratory transmission: If the child often goes to a closed, poorly ventilated and crowded environment such as a supermarket or market, viruses may be present in the air and the child’s immunity is low, making him or her susceptible to viral invasion and respiratory viral infections. 2. Eating: When children eat food contaminated by norovirus, rotavirus, etc., children may have gastrointestinal infections. Infection may also occur if the child does not pay attention to personal hygiene, such as washing hands before meals. 3. Close contact: If a child plays with an infected child or plays with toys that other infected children have played with, this may lead to the child being infected with the virus. Children with viral infections can go to the hospital in time, and follow the doctor’s instructions for reasonable treatment.