Etiology And Clinical Characteristic Of Spastic Cough In Hunan' Children

ObjectiveBy detecting a variety of respiratory pathogens, including pertussis,to analyze the Etiology and clinical characteristics of spasmodic cough children with respiratory tract infection in Hunan and lay the foundation for the prevention and treatment of respiratory tract infection in the local area.Method:1.Establishing a real-time fluorescent quantitative PCR assay method for detection of Bordetella pertussis,and evaluating the sensitivity and specificity of this method.2.Nasopharyngeal swab and Nasopharyngeaaspirates samples(NPA)were collected from 280 spasmodic cough children with respiratory infection in Hunan from January 2015 to December 2015.3.The detection of nasopharyngeal swab for respiratory syncytial virus(RSV), human rhinovirus( HRV), Influenza virus A( IFVA),Influenza virus B(IFVB),parainfluenza virus( PIV1-3),Bordetella pertussis(BP), Mycoplasma(MP), Chlamydia pneumoniae(CP), adenovirus(ADV), human coronary virus HCOV-229E(HCOV-229E), human coronary virus HCOV-OC43(HCOV-OC43),human Boca virus(HBo V) by Real-time fluorescence polymerase chain reaction(RT-PCR), and the detection of NPAs for others bacteria by Bacterial culture method.4.Analysis of pathogens and clinical characteristics in Hunan's Children with spastic cough.Results:1.The established real-time PCR method for detecting Bordetella pertussis has a good liner relationship in the concentration range of 2 ×102-109copies/ml,the linear correlation coefficient is 0.997.2.The limit detection of the real-time PCR method is 200copies/ml.3.Used the real-time PCR method to detecte the other 36 kinds of common pathogens,the results had no crossreaction,confirmed the high specificity.4.The low and high concentration of standard preparation were repeatedly detected with the real-time PCR method.The results are as follows:the low concentration intra-assay variation coefficients were0.4%, the high concentration intra-assay variation coefficients were 0.3%.5.The six different concentrations of Bordetella pertussis standard strains and two clinical suspected pertussis nasopharyngeal swab specimens were detected positive,Sequences the Amplified fragment and reference sequences obtained from Gen Bank were determined and analyzed using the Dnastar software package. The real-time PCR method detected.6.Among the 280 Nasopharyngeal swab and NPA, pathogen were detected in 280 sample(78.2%),among which BP(47.9%)was the most common pathogen,followed by RSV(10.4%)?MP(8.6%)?HPIV3(8.2%)and Adv(7.1%); there were 141 samples of simple infection, 78 samples in mix infection, the proportion were 64.4% and 35.6%,respectively, suggesting that a single pathogen infection is mainly caused in Hunan's Children with spastic cough; Of the 78 Mixed infection samples, BP mixed infection accounted for 59 cases, detection rate of75.6%, other pathogen mixed infection accounted for 19 cases, the detection rate of 24.4%, BP mixed infection was the main cause of the mixed infection of the spastic cough. ADV is a common pathogen ofmixed infection in BP, the detection rate of 4.98%, ranking first, followed by BP+RSV 2.71%, BP+flu A2.26%, BP+MP, BP+ influenza virus,BP+RHV 1.81%.7.A retrospective analysis of 75 children with pertussis infection about Clinical features. The result: Children with pertussis are distributed in all ages, but most in 2-4 months infants, And infants is generally not vaccination while age ? 12 months, most in Ages of 3-6 months, up to54.8%; pertussis incidence in four seasons, the highest incidence season was fall 40%(30/75), followed by summer26.7%(20/75) and spring22.7%(17/75), but the lowest incidence rate was in winter of 10.7%(8/75); The clinical features of children with pertussis infection were varied, but typical pertussis remains visible, such as spastic cough with crow like roar, face red, cyanosis, vomiting,and so on. Facial congestion is the most common manifestation of cough, accounting for 76%; Cough mainly at night, accounted for 69.3%; Their were nonspecific in Accompanying symptoms,including fever, wheezing and a runny nose.Peripheral blood often showed white cells and lymphocyte increased,there were accounted for 73.3%(55/75) when the white blood cell count was equal to or more than 10 x 109 / L, and also accounted for 73.3%when the the lymphocyte percentage was more than 60%;Bronchitis and normal pulmonary structures were the most common change in the pulmonary imaging of pertussis, accounted for 70.7%;There were 9 cases of children with pertussis have cough patients contact history within 21 days before symptom onset, the contact rate was only 12%, and the contact members were family members who was in close contact with Children; The use rate of macrolides was 82.7%,but spasmodic cough rate was still 81.3% when at the time of discharge.8.Divided 141 samples of simple infection into pertussis and no-pertussis groups.compare the clinical characteristic of two groups.The overall positive rate of pathogen detection showed no significant differences between males and females(P>0.05); the positive rate of pathogen detection showed significant differences in the age section less than 12 months old(P <0.05),and the highest positive rate was noted in the age section of 2 months to 4 months old; The overall positive rate of pathogen detection showed no significant differences in term of seasonal distribution, Total course of disease, vaccination rate and Utilization rate of macrolides; The overall positive rate of pathogen detection showed significant differences in fever, coughs followed by a vigorous inspiratory and whoop, Hyperaemia of face, cyanosis, leucocyte count,Lymphocyte percentage and spastic cough after leaving from hospital.Pertussis group, its age often less than 12 month, coughs followed by a vigorous inspiratory and whoop is more common, and have more leucocyte count > 15 × 109/L,Lymphocyte percentage in 60-80%,bronchitis image change and spastic cough after leaving fromhospital,but less fever, leucocyte count ? 10 × 109/L and Pneumonia image change than the non pertussis group.Conclusions1.The real-time PCR method for detection of Bordetella pertussis had established. and this method provides a new rapid assay for clinical of Bordetella pertussis.2.BP predominate in the etiology of spasmodic cough children with respiratory tract infection in Hunan,and RSV, MP, HPIV3 and Adv is the main pathogens, compared to other pathogen.3.There is a certain characteristic in age, season, clinical manifestation and so on for Children with pertussis infection. Pertussis patients usually not vaccinated not on schedule.4.The Caused by Bordetella pertussis(BP) was more prone to coughs followed by a vigorous inspiratory effort, Hyperaemia of face, cyanosis,leucocyte count more than 15×109/L, Lymphocyte percentage in 60-80%,bronchitis image change and spastic cough after leaving from hospital,but less fever,pulmonary rale,leucocyte count ?10×109/L and Pneumonia image change than the non pertussis group.These features are helpful in guiding the selection of clinical antibiotics.