To analyze the clinical characteristics of Mycoplasma pneumoniae (MP) infection in children of different ages based on simultaneous amplification and testing (SAT).

The clinical data of 285 children with community-acquired pneumonia (CAP) diagnosed as MP infection by SAT from May 2018 to July 2019 in our hospital were analyzed retrospectively. All the children with MP infection were classified into three groups according to their ages as follows: infant group(≤3 years old), preschool children group(>3-6 years old)and school-aged children group(>6 years old). The differences in children with MP infection of different ages in terms of clinical symptoms, pulmonary signs, laboratory indexes, chest X-rays and extrapulmonary complications were compared.

The clinical manifestations of the three groups were statistically significant (P<0.05). In the infant group, the main clinical manifestations of wheezing was relatively obvious, the average fever duration was short, and the extrapulmonary manifestations were mainly digestive system symptoms; The fever was more common in the school-aged children group, and the average fever duration was longer than that in the infant group, the extrapulmonary complications were more common, and the blood, cardiovascular system damage were the main cause. The symptoms of the preschool children group were in between. There was no significant difference in cough symptoms and pulmonary signs among the three groups (P>0.05); The children with MP infection had multiple presentations of chest X-rays. The lobular parenchymal infiltration and interstitial infiltration in the infant group and preschool children group were significantly higher than those in the school-aged children group, and more segmental parenchymtous infiltration of chest X-ray could be found in the school-aged children group than that in the infant group and preschool children group(P<0.01); The LDH level in the infant group was higher than that in the school-aged children group, and the CRP level in the school-aged children group was higher than that in the infant group (P<0.01), the preschool children group is somewhere in between.

There are differences in clinical symptoms, pulmonary signs, laboratory indexes, chest X-rays and extrapulmonary complications in children with MP infection of different ages, attention should be paid to in clinical work.