Variation Tendency Of Clinical Characteristics Of Mycoplasma Pneumoniae Pneumonia In Children With Different Ages During 2000～2006

Background:Mycoplasma pneumoniae is a kind of procaryon microorganism without cell wall.15 kinds of mycoplasma have been isolated from human body.Mycoplasma pneumoniae(MP)is the one which can causes respiratory tract diseases.MP was isolated firstly from sputum of a patient with acute pneumonia in 1944,but it was not affirmed formally until 1963.MP is an intracyst infective pathogen,spread mainly by respiratory tract. Children and youth are vulnerable.It has no region differences,and outbreak in autumn mainly.Every two to six years it spread globally.The incidence rate was high in crowded place such as school.MP can easily spread among family member. The threat MP brings to people can not be ignored.Acute low respiratory tract infection remains the most frequent and common disease in children in our country,accounting for 24.5%～65.2%pediatric hospitalization.Pneumonia accounted for global 19%child mortality rate under 5 ages.MP pneumonia is the manifestation of MP infection,in all kinds of pneumonia, 8.5%～27.9%are MP pneumonia.Since MP pneumonia has been increasing in recent years,infant infection is receiving much more attention.In recent years, doctors found MP pneumonia more refractory and severe.When treated by erythromycin and azithromycin,these patients have persistent fever and no improvement of cough and pulmonary inflammation,even deteriorating to pulmonary necrosis.But uptill now,research about variation tendency of clinical feature of MP pneumonia in children is still lacking,so we decided to investigate variation tendency of clinical characteristics of MP pneumonia in children with different ages during the years 2000～2006.Objectives:1.To investigate clinical characteristics of MP pneumonia in children with different ages.2.To investigate variation tendency of clinical characteristics of MP pneumonia in children in different years.Methods:Four hundred and ninety children(male 259,female 231,1 month-14years)with MP pneumonia in our hospital from 2000 to 2006 were investigated.1.To compare manifestation,laboratory results,chest X-ray and prognosis in children with MP pneumonia in different ages2.To compare the tendency of manifestation,laboratory results,chest X-ray and prognosis in children with MP pneumonia in different ages in different years (2000～2002,2003～2004,2005～2006).Results:1.Variation of fever and fever duration:450 cases(91.8%)got fever to different extent.Among the total,43 cases are 1m～1y,126 cases～3y,281 cases～14y. There is significant difference among the three groups(65.2%,92.7%,97.6%, P＜0.01).1m～1y group have more low-grade fever and the other two groups have more high fever(9.1%,50.7%,66.0%),the difference is significant(x~2=112.36, P＜0.01).The difference of fever duration among the three groups is significant (3.48±2.27d,7.45±4.81d and 8.80±4.69d,F=34.95,P＜0.001).Fever duration of～3y and～14y patients in 2005～2006 and 2000～2002 has significant difference (8.15±4.32 d vs 7.16±4.51d;10.54±5.06d vs8.08±4.42 d,F=4.81,P＜0.05;F=8.89, P＜0.01).2.Symptom of respiratory tract:1m～1y manifested cough and wheezing mainly,～3y cough,dyspnea and shiver mainly,and～14y cough,chest pain and shiver mainly.Respiratory tract symptoms in three groups show difference year by year(P＜0.05).3.Extrapulmonary damage:18 cases(27.3%)of 1m～1y had extrapulmonary damage who had gently symptoms and recoverd quickly,28 cases(20.6%)of～3y had extrapulmonary damage,86 cases(29.9%)of～14y had extrapulmonary damage who had serious and extensive symptoms.The extrapulmonary damage increased year by year and reached 48.3%of total cases of～14y group in the year 2005～2006(x~2=6.87,P＜0.05).4.Chest X-ray:1 m～1 y and～3y patients mainly manifested patching shadow. But～3y patients manifested increased rate of large lamellar shadow in three duration(9.1%,14.9%,29.4%),and intra-lung complications,also increased yearly reaching significant differences(x~2=9.98,P＜0.01).～14y group manifested macrolamellar shadow in 48.3%,many lesions being in right lower field of lung,and 29.9%of all cases accompanied by pleural effusion and pulmonary atelectasis in the year 2005～2006,with significant difference between different years(x~2=18.32, P＜0.01).5.Laboratory results:there is no significant difference of WBC and CRP in different age groups(x~2=0.06,x~2=0.04.P＞0.05),but ESR has significant difference (x~2=4.55,P＜0.05).The differences of laboratory result between different age group in different year have no statistical difference(P＞0.05).6.Therapy and prognosis:Erythromycin and azithromycin have the same therapeutic efficacy in all age groups(x~2=1.12,P＞0.05).However,cure rate decline yearly.The cure rates of 1m～1y patients in three duration were 100.0%,90.9%, 80.0%respectively,the cure rates of～3y patients in three duration were 96.4%, 85.1%,70.6%,and of～14y were 87.0%,74.3%,65.5%.3 cases(3.5%)have ineffective therapeutic efficacy in the year 2005～2006.Therapeutic efficacy in different age groups and different years has significant difference(x~2=4.11,5.13 and 4.07 respectivelly,All P＜0.05).Conclusions:1.Children of different ages with MP pneumonia have different clinical manifestation,chest X-ray and extrapulmonary complications.Erythromycin and azithromycin have satisfied therapeutic efficacy.2.Recent years,children with MP pneumonia have prolonged fever duration, refractory wheezing,dyspnea,chest pain,shiver,and increasing extrapulmonary damage.They are usually accompanied by pleural effusion,pulmonary atelectasis and become serious and refractory.