Objective To study the epidemiological and clinical features of human parainfluenza virus (HPIV) infection in children in Suzhou,and to provide the evidence-based foundation for early warning,diagnosis and treatment of respiratory infection in children.Methods The sputum specimens and medical history were obtained from children with acute respiratory tract infection hospitalized at the Childen's Hospital Affiliated to Soochow University from January 2006 to December 2015.Seven kinds of common respiratory viruses including respiratory syncytial virus,influenza virus A,influenza virus B,HPIV Ⅰ,HPIV Ⅱ,HPⅣV Ⅲ and adenovirus were detected by using the direct im-munofluorescence.Mycoplasma pneumoniae(MP),chlamydia pneumoniae,human bocavirns (hBoV) were detected by using fluorescence quantitative PCR.Rhinovirus and human metapneumovirus were detected by using reverse transcription-PCR.Sputum was cultured for bacteria.Results In 21 769 cases,the detection rate of HPIV positive was 3.21％ (829 cases),among which,HPIV Ⅰ,HPIV Ⅱ,HPIV Ⅲ were respectively detected in 113 cases (0.52％),16 cases (0.07 ％) and 700 cases (3.21％),respectively.There were 378 cases of simple infection and 428 cases of mixed infection,and the mixed infection was very common in Streptococcus pneumoniae,Haemophilus influenza,MP and hBoV.There was a difference in HPIV infection among genders,and the detection rate of the boys was higher than that of girls[4.14％ (563/13 591 cases) vs.3.25％ (266/8 178 cases),x2 =11.036,P =0.001].In the 28 d-1 year old and ＞ 1-3 year old group,the detection rate of HPIV was higher[4.71％ (494/10 476 cases) and 4.21％ (244/5 793 cases),respectively].In spring and summer,there was a higher detection rate of HPIV infection.The clinical manifestations with simple infection of HPIV Ⅰ and HPIV Ⅲ were cough,fever and wheezing.The rate of fever and shortness of breath in those of HPIV Ⅰ was 71.74％ (33/46 cases),10.87％ (5/46 cases),and that in HPIV Ⅲ was 40.12％ (134/334 cases),2.10％ (7/334 cases),HPIV Ⅰ infection was more likely to cause fever and shortness of breath than those of HPIV Ⅲ,there were significant differences (x2 =16.410,P ＜ 0.001;x2 =10.177,P =0.001).Pneumonia had the highest detection rate of viral infection.Conclusions HPIV Ⅲ is the leading pathogen among the types of HPIV in the hospitalized children in Suzhou area.Among the subtypes of HPIV,the peak of HPIV infection occurs in spring and summer.The children less than 3 years old are the most susceptible to parainfluenza virus,and the HPIV detection rate is gradually declines with age.

Objective To analyze the clinical features of infants infected by respiratory syncytial virus (RSV) or human rhinovirus (HRV) in lower respiratory tract in Suzhou area based on the month age and the month of the year.Methods From January 2013 to December 2015,2 206 nasopharyngeal aspirates specimens were collected from the infants with lower respiratory tract infection.Direct immunofluorescence assay was performed to test RSV.Reverse transcription-polymerase chain reaction(RT-PCR) method was used to test HRV.The medical history was collected and pulmonary function tests were performed in some infants who were infected with RSV and HRV.Results In 2 206 cases,total RSV positive rate was 19.90％ (439/2 206 cases) and simple RSV infection positive was detected in 399 cases.Total HRV positive rate was 14.14％ (312/2 206 cases),in which simple HRV infection positive was detected in 250 cases and the detection rate of RSV was significantly higher than that of HRV(x2 =25.88,P ＜0.05).The incidence rate of wheezing in simple RSV infection was 68.17％ (272/399 cases),which was significantly higher than that of simple HRV infection (42.80％,107/250 cases) (x2 =11.174,P ＜ 0.05).RSV infection was frequent from November to February of the next year in which the detection rate in December was highest with the proportion of 50.00％ (99/198 cases) while the rate in June was only 0.57％ (1/175 cases).The detection rate of HRV was 22.86％ (40/175 cases),20.47％ (35/171 cases) and 20.33％ (25/123 cases) in June,July and September respectively.The detection rate of HRV was lower during December to February of the next year.In January,the detection rate was only 4.68％ (11/235 cases),which was the lowest in the whole year.The detection rates of RSV were 33.33％ (4/12 cases),25.21％ (118/468 cases),23.46％ (84/358 cases) and 23.81％ (60/252 cases) in the age group of 28 d-1 month,＞ 1-2 month,＞ 2-3 month and ＞ 3-4 months respectively.Up to the age of 4 months old,the detection rate decreased gradually,and with the increase of age and the detection rate in ＞ 7-8 month group was only 10.96％ (16/146 cases).The detection rate of HRV was 0 (0/12)and 9.40％ (44/468 cases) in the age group of 28 d1 month,＞ 1-2 month,respectively.After 2 months age old,the detection rate fluctuation ranged from 13.22％ to 16.67％.The incidence rate of severe RSV infection was 12.30％ (54/439 cases) and the incidence rate of severe HRV infection was 5.13％ (16/312 cases).Increased respiratory rate was more common in patients with severe RSV infection while severe HRV infection in infants were accompanied by multiple lobar involvement.After RSV infection,the incidence rate of pulmonary function damage was 89.03％ (276/310 cases).After HRV infection,89.27％ (183/205 cases)of the infants suffered from pulmonary function damage.Both RSV and HRV infection might cause pulmonary function damage.Conclusions RSV and HRV are the major pathogens in infants of Suzhou areas.The incidence of RSV-induced wheezing is significantly higher than that of HRV.RSV is detected positive mainly in winter and early spring and the infants within 4-month old are susceptible population.HRV is detected positive mainly in June,July and September and the infants older than 2 months are susceptible population.The incidence of severe RSV infection is significantly higher than that of HRV.Severe RSV infection may cause increased respiratory rate and severe HRV infection mainly cause multiple lobar involvement.RSV and HRV infection may cause pulmonary function damage.

Objective To study the epidemiological and clinical features of viral pathogen of acute respiratory tract infection(ARTI)in children in Suzhou. To provide the evidence-based medicine for early warning,diagnosis and treatment of respiratory tract infection in children. Methods The study population comprised of all the children ranging from 28 days to 15 years old with ARTI admitted to Department of Respiration,the Childrenˊs Hospital Affiliated to Soo-chow University,between January 2006 and December 2015. The study cases were divided into 4 age groups based on ages(28 days to <1 year old,1- <3 years old,3- <5 years old and ≥5 years old). The nasopharyngeal aspirates and medical history were obtained by qualified medical personnel. Seven kinds of common respiratory virus were detec-ted by using the direct immunofluorescence. Mycoplasma pneumonia(MP),chlamydia pneumonia(CP)and human bo-cavirus(hBoV)were detected by adopting fluorescence quantitative PCR. Human rhinovirus(HRV)and human metap-neumovirus(hMPV)were detected by means of reverse transcriptionpolymerase chain reaction( RT -PCR). Sputum was cultured for bacteria. Results In 21 624 cases,17 618 cases were detected,and the positive detection rate of virus was 30. 74%(5 416 cases). The highest detection rate of virus was 44. 25%(881/1 991 cases)in 2011 in the 10 years. There were 3 317 cases of single virus pathogen infection,accounting for 18. 83%. Among them,respiratory syn-cytial virus(RSV)was the first with 9. 42%(1 660/17 618 cases),followed by HRV(5. 17%,278/5 372 cases), hBoV(3. 12%,351/11 263 cases),Pinf 3(2. 17%,383/17 618 cases),and the lowest rate was Pinf 2 with 0. 05%(8/17 618 cases). There were 2 099 cases of overlap infection,accounting for 11. 91%. The virus combined with bacte-rial infection accounted for 7. 86%(1 384/17 618 cases),which had the most positive cases. With the increase of age, the single virus pathogen infection rate gradually dropped. The highest detection rate was 22. 82%(1 976/8 656 cases) in the group between 28 days and <1 year old,and the lowest detection rate was 7. 81%(159/2 035 cases)of children over 5 years of age. The virus positive rate of the four seasons was 18. 28%(833/4 556 cases),13. 86%(625/4 508 cases),5. 91%(684/4 298 cases),27. 68%(1 178/4 256 cases),respectively,and detection rate in winter was the highest,and the least in summer. In the single virus infection,bronchiolitis had the highest percentage(36. 32%,25/69 cases),and the least rate was 5. 83%(63/1 080 cases)of lobar pneumonia. Conclusions Monitored for 10 years of the virus respiratory infection in Suzhou area,RSV,HRV and hBoV turned out to play an important role in respiratory tract infection in children. The children less than 3 years old are the most susceptible to virus infection. The epidemic season of each virus is different and characteristic.