A Study On Etiology And Clinical Epidemiology Of Respiratory Tract Infection In Children In Kunming Area

ObjectTo realize the infection rate of the main pathogenes, mixed infection and their epidemiological and clinical characters of children's respiratory tract infection in Kunming Area, it could give more evidence for diagnosis and treatment.Method388 NPAs specimen were collected from children's nasal pharynx secretion and cast-off cells at the first or the second day of hospital, and all of these children meet the inclusion creteria, in the second affiliated hospital of Kunming Medical College, the first affiliated hospital of Kunming Medical College, Yan'an hospital in Kunming, the first People's Hospital in Yunnan Province, the first People's Hospital in Kunming, Maternal and Child Care Service Centre in Kunming from September 2009 to September 2010, and detected by mutiplex Polymerase Chain Reaction. There are 15 viruses, including respiratory syncytial virus A,B,adenovirus A/B/C/D/E, influenza A virus, influenza B virus, parainfluenza virus 1,2,3,4, rhinovirus A/B/C, coronavirus 229E/NL63, coronavirus OC43/HKU1, human bocavirus 1/2/3/4, metapneumovirus, enterovirus; and 4 bacterials, including streptococcus pneumoniae. haemophilus influenza, legionella pneumophila, bordetella pertussis.and mycoplasma pneumonia, chlamydia pneumoniae.Results 1. Among all of these children, there are 236 boys (60.82%), and 152 girls (39.18%), and the gender ratio is 1.55:1; and the children of the month age≤6m have 101 (26.03%),～12m have 83 (21.39%),-24m have 63 (16.24%),-36m have 67 (17.27%),-60m have 74 (19.07%).2. In the 388 NPAs specimen, the cases of total etiolgy detection were 304, the rate was 78.35%; The detection of only one etiology was 175 (57.57%), among which the cases only include viruse/viruses were 164, and only include bacteria were 10; the mixed infection of virus and bacteria were41. The ratio of children having mixed infection was 42.43%, in which two pathogene was 67.44%, three pathogene was 27.13%, four pathogene was 4.65%, six pathogene was 0.78%.3. The detection ratio from high to low in 21 pathogenes:respiratory syncytial virus B was 28.4%, rhinovirus was 16.5%, parainfluenza virus 3 was 13.7%, respiratory syncytial virus A was 11.9%, influenza A virus was 10.3%, parainfluenza virus 1 was 9.0%, streptococcus pneumoniae was 7.0%, haemophilus influenza was 5.4%, metapneumovirus was 5.2%, human bocavirus was 3.1%,parainfluenza virus 2 was 2.3%, adenovirus was 2.1%, coronavirus 229E/NL63 was 1.8%, bordetella pertussis was 1.5%, parainfluenza virus 4 was 1.3%, mycoplasma pneumonia was 1.3%, influenza B virus was 0.8%, enterovirus was 0.8%, legionella pneumophila was 0.3%,and caronavirus OC43/HKU1 and chlamydia pneumoniae were 0%. The detection ratio of virus is 74.23%, the ratio of bacteria is 13.14%, the ratio of mycoplasma is 1.3%, the ratio of chlamydia is 0%.4. In the 304 positive specimen, boys were 187(61.51%), girls were 117(38.49%), the raito is 1.6:1.5. In different stage of ages, the month age of≤6m was 87(86.1%),～12m was 72(86.7%),-24m was 47(72.3%),-36m was 52(77.6%),-60m was 46(62.2%).6. All of these specimen, the detection ratio in different season separately was spring 80%, summer 64.7%, autum 78.5%, winter 77.2%.7. Among the clinical diagnosis in the ward, acute upper respiratory tract infection was 2.6%, acute bronchitis was 10.8%, acute bronchopneumonia was 78.1%, wheezing bronchitis was 3.6%, capillary bronchitis was 2.6%, bronchial asthma was 2.3%.8. When there were only bacteria, the change of the number of white blood cell, neutrophil ratio and lymphocyte ratio has not statistically significant.But when there were only virus or virus and bacteria mixed with each other, the number of white blood cell is normal, neutrphil ratio decreases and lymphocyte ratio increases.9. After being hospital, all of the children took antibiotic, one kind of injection antibiotic were 131, two was 197, three was 46, four was 6, five was 3, six was 2, seven was 3; no oral antibiotic was 153, one kind of oral antibiotic was 193, two was 36, three was 6; at the same time, usage both of oral and injetion antibiotic was 235; antivirus was 243, nebuliaztion of glucocorticoid was 274, injection of glucocorticoid was 212.10. Among the 388 children.the average day in hospital is 8.66, the average of hospitalization expenses was 3332.12.Conclusions1. To detect the etiology of 388 children's NPA's specimen,who were under 5 years old, and had acute respiratory tract infection disease, there was 304 positive spcimen.2. Among four kinds of etiology, including virus, bacteria, mycoplasma pneumonia, chlamydia pneumoniae, the detection ratio of virus is 81.58%, bacteria is 3.29%, virus mixed with bacteria is 13.49%, mycoplasma is 1.64%, chlamydia is 0.3. The detection ratio from high to low in 21 pathogenes:respiratory syncytial virus B, rhinovirus, parainfluenza virus 3, respiratory syncytial virus A, influenza A virus, parainfluenza virus 1, streptococcus pneumoniae,haemophilus influenza, metapneumovirus, human bocavirus, parainfluenza virus 2, adenovirus, coronavirus 229E/NL63, bordetella pertussis, parainfluenza virus 4, mycoplasma pneumonia, influenza B virus, enterovirus, legionella pneumophila.and none of caronavirus OC43/HKU1 and chlamydia pneumoniae had detected.4. The ratio of mixed infection in children's acute respiratory tract infection is 42.43%, among which parainfluenza virus, influenza A virus, respiratory syncytial virus, rhinovirus, streptococcus pneumoniae are common.5. In the 388 spceimen and 304 positive spceimen, there is difference between male and female in both of them. And rhinovirus, metapneumovirus, human bocavirus, streptococcus pneumoniae also have the same conclusion.6. Among the 388 cases, the most of positive ratio is the age of under 1 year old, and 2 years old and 3 years old are similar with each other, while after 4 years old, the ratio will decrease. Parainfluenza virus 1, rhinovirus, influenza A virus, respiratory syncytial virus B, metapneumovirus. human bocavirus. haemophilus influenza are common in children of under 1 year old.7. In the children's acute respiratory tract infection, virus infection is common in season of autum and winter, but bacteria and mycoplasma are not.8. In the clinical symtoms, it is common for cough, sputum, fever; in the wheezing, respiratory syncytial virus, parainfluenza virus, influenza virus, metapneumovirus, human bocavrirus, rhinovirus are common; and adenovirus always have difficult breathing.9. When the number of white blood cell was normal, the neutrophil ratio decreased and lymphocyte ratio increased, it point out that there is virus; but it has not tell the virus infection from virus mixed with bacteria infection.10. In the cases of reasearch, the usage of antibiotic has reached to 100% in the clinical treatment, and at the same time, there are several antibiotics are used and altered. That could affect the change of the number of white blood cell when there is only infection of bacteria.