A Study On Epidemiology Of Mycoplasma Pneumoniae Pneumonia Of Children From 2007 To 2009 Year

Objective:Respiratory infections are the most common diseases in children, and pneumonia is the main reason leading to hospitalization of many children. Mycoplasma (Mycoplasma pneumoniae, MP) is one of the important pathogens of respiratory tract infections in children, especially in the lower respiratory tract infections such as pneumonia. Mycoplasma pneumoniae can cause diseases throughout the year. Its clinical manifestations of respiratory symptoms include fever, cough, asthma, etc., but it also can cause a lot of extra-pulmonary complications such as encephalitis, myocarditis, skin lesions, urinary system and digestive system damages and other symptoms. Some complications of them are severe, if the effective treatment is not given in time, the prognosis is poor, and life will be threatened. This study investigated the epidemiological characteristics of MP infection during 2007-2009, in order to provide information for clinical early diagnosis and rational treatment.Methods:Patients who were diagnosed as "pneumonia" in hospitalized children from 2007 to 2009 were enrolled. Venous blood were collected in 12701 cases to detect Mycoplasma pneumoniae-specific antibody IgM by quantitative ELISA, and sputum were collected in 17,514 cases to detect Mycoplasma pneumoniae DNA by PCR.Results:(1) From 2007 to 2009, mycoplasma pneumonia IgM antibody positive rate were 13.04%,16.77%,5.3%, respectively, and the average rate was 11.09%. In general, the incidence of 2008 was significantly higher than other years, the incidence difference was statistically significant (p<0.05). However, the detection rate of Mycoplasma pneumoniae DNA from 2007 to 2009 are 13.70%,21.37%,24.47%, the average rate was 19.83%. According to PCR results, the incidence of 2009 was significantly higher than other years, the difference was statistically significant.(2) The distribution of ages, IgM antibody positive rate:2007≤1y 11.42%,～3y 12.07%,～7y 16.30%,>7y 20.00%; 2008≤1y 15.05%,～3y 15.51%,～7y 22.82%,>7y 20.18%; 2009≤1y 1.78%,～3y 5.88%,～7y 8.92%,>7y 11.45%; PCR positive rate:2007≤1y 8.69%,～3y 12.21%,～7y 28.78%, >7y 45.58%; 2008≤1y 12.86%,～3y 23.63%,～7y 45.69%,>7y 59.74%; 2009≤1y 8.66%,～3y 26.55%,～7y 49.40%,>7y 61.49%. Both ELISA and PCR detection show that the older the child, the higher the MP positive rate. (3) The distribution of seasons: from spring to winter, Mycoplasma pneumoniae IgM positive rates are 10.72%,13.45 %,11.46%,9.64%; and DNA positive rates are as follows:19.41%,30.40%,25.03%, 11.81%. It shows the two seasons, summer and autumn, have higher positive rates, the difference was statistically significant.Conclusions:1, Mycoplasmal pneumonia occurs mostly in children of school age, but the prevalence in infants and young children are also not low.2, The incidence of MP infection is closely related to the season with the higher rates in summer and autumn.