上呼吸道感染是小儿最常见疾病。12岁以内儿童平均每人每年可患4次呼吸道疾病,3岁内平均每人每年可患7次,我们将每年患上感10次以上者称为反复上感儿。上感的影响因素很多,如机体的的免疫功能,季节,气候,年龄,喂养,居住条件等等。本文采用病例—对照研究,讨论微量元素对反复上感儿发病的影响作用。 Upper respiratory tract infection is the most common disease in children. Children under the age of 12 may suffer from respiratory diseases by an average of 4 times per person per year, with an average of 7 times per person per year for 3 years of age. We will refer to those who feel more than 10 times a year as repeatedly feeling children. There are many influencing factors, such as the body’s immune function, season, climate, age, feeding, living conditions and so on. This article uses a case-control study to discuss the effect of trace elements on the incidence of recurrent upper respiratory tract infection.