Epidemiology and clinical characteristics of Mycoplasma pneumoniae pneumonia in hospitalized children younger than three year-old / 中国小儿急救医学

ABSTRACT

Objective To summarize the epidemiology and evaluate possible age-related differences in the presenting clinical features in three year-old children with Mycoplasma pneumoniae pneumonia(MPP)during 2009 to 2014.Methods The medical records of 17855 children with community-acquired pneumonia enrolled by Children′s Hospital of Soochow University during 2009 to 2014.Totally 1145 younger than three year-old children with MPP were enrolled,and they were classified into three groups of 1 month to 1 year-old group (n=512),1 to 2 year-old group (n=393) and 2 to 3 year-old group (n=240).The epidemiology and possible age-related differences in the presenting clinical features,main laboratory and imaging results in three year-old children with MPP were summarized.Results (1) The highest infection rate of different reasons in Suzhou was in autumn(10.46%),and the lowest was in spring(6.95%),The highest infection rate of different ages was 2 to 3 year-old group(11.61%),and the difference was statistically significant (P<0.05).(2) Compared with 1 month to 1 year-old group(n=512,4.31%) and 1 to 2 year-old group (n=39,10.09%),2 to 3 year-old group (n=240,11.61%) had higher infection rate,more patients with fever(53.9% vs. 77.1% vs. 85.4%) and high fever(16.8% vs. 30.5% vs. 41.4%),longer time to normalization of temperature(3d vs. 5d vs. 6d),but less patients with wheezing(61.3% vs. 52.4% vs. 42.9%) and dyspnea(7.6% vs. 4.6% vs. 3.8%).(3) The differences were statistically significant in the percentage of neutrophils,lymphocytes,CRP and platelet count between different ages(P<0.001).(4) The incidences of large area of lesions in chest X-ray examination among different ages had significant differences(P<0.001).Conclusions MP is one of the important pathogens of respiratory tract infection in younger than 3 year-old children.It can occur in every season,and the highest infection rate of MP is in autumn and spring.In younger than 3 year-old,older patients are more vulnerable to infection of MP,the number of fever and high fever are more,fever duration is longer,but younger patients are more vulnerable to virus infection and prone to dyspnea.Chest X-ray examination shows small patchy shadow in most cases,the younger children are more easily to have large area of lesions and pleural effusion.