The effects of influenza-like illness definitions on influenza surveillance in hospitalized children / 中华疾病控制杂志

Objective To evaluate clinical factors associated with laboratory-confirmed influenza infection and probe into the effects of different influenza-like illness(ILI) definitions on influenza surveillance in hospitalized children. Methods The influenza surveillance on the hospitalized children with acute respiratory infection was carried out in Soochow university affiliated children’s hospital from October 2017 to May 2018. The definition of influenza-like illness(ILI), which proposed by world health organization (WHO), the European center for disease prevention and control (ECDC) and ministry of public health of China, was analyzed to determine the area under receiver operating characteristic curve (ROC), sensibility, specificity, and the positive and negative predictive values of the ILI definition using the laboratory evidence of influenza virus infection as golden criteria. Logistic regression model was employed to explore the risk factors of the laboratory confirmed influenza infection among the hospitalized children. Results Of the enrolled 1 459 hospitalized children, 204(14.0%) were lab-confirmed influenza cases. The ECDC definition had the highest sensitivity (91.7%, 95% CI: 87.9%-95.5%) but the lowest specificity (44.6%, 95% CI: 41.9%-47.4%). The WHO definition had the lowest specificity (70.6%, 95% CI: 64.3%-76.8%). China’s definition was the most discriminant definition with relatively high sensitivity (91.2%, 95% CI: 87.3%-95.1%) and specificity (51.5%, 95% CI: 48.8%-54.3%), and its positive area under curve value (71.2%, 95% CI: 67.9%-74.5%) was the highest. Multivariate analysis model showed that the detection rate of influenza virus in children with fever (≥38 ℃) was higher than that in children without fever (OR=7.03, 95% CI:3.89-12.70). Conclusions It is suggested to adopt China’s ILI definition to get better output during influenza surveillance among hospitalized children.

Study on lung function and inflammatory indicators among infants with high_risk asthma / 中华实用儿科临床杂志

Objective To analyze the changes in lung function and inflammatory indicators such as eosino-phils(EOS),Creola bodies and exhaled nitric oxide(FeNO),and to explore their value in early diagnosing asthma. Methods One hundred and thirty-five infants with high-risk asthma were selected as an observation group who were admitted to Department of Respiratory,Childrenˊs Hospital of Soochow University from April 2016 to August 2017 due to asthmatic bronchitis and asthmatic bronchopneumonia,and a total of 200 non -asthmatic and non -allergic healthy children who were screened and followed up at the Department of Cardiology in the same period were selected as a healthy control group for the measurement of moist respiratory lung function and FeNO. In the observation group,the bronchial dilation test(BDT),EOS and Creola bodies were performed simultaneously. Classification of lung function:23%≤time to peak ratio(TPTEF/Te)<28% had mild obstruction,15%≤TPTEF/Te<23% had moderate obstruc-tion,and TPTEF/Te<15% showed severe obstruction. Results The TPTEF/Te[17. 20%(8. 10%)],volume to peak ratio(VPEF/Ve)[21. 20%(6. 20%)],tidal volume per kilogram of body weight(VT/kg)[7. 80(3. 70)]and ratio of tidal expiratory flow 25% to peak tidal expiratory flow(25/PF)[0. 54(0. 20)]in the observation group were signifi-cantly lower than those in the healthy control group[22. 30%(9. 22%),27. 15%(7. 10%),8. 90(3. 17),0. 60 (0. 18)],and the differences were statistically significant(Z＝ -6. 81,-9. 35,-3. 16,-3. 52,all P<0. 05). BDT positive rate in the mild obstruction group was 20. 00%(3/15 cases),BDT positive rate in the moderate obstruction group was 26. 56%(17/64 cases),and BDT positive rate in the severe obstruction group was 48. 72%(19/39 cases). The higher the degree of obstruction,the higher the value of BDT positive diagnosis(F＝6. 353,P<0. 05). BDT of VPEF/Ve,25/PF and TPTEF/Te were consistent and statistically significant(Kappa＝0. 78,0. 49,all P<0. 001). Ti-dal expiratory flow 50% -remaining(TEF50% -r)[(117. 86 ± 42. 16)mL/s],tidal expiratory flow 25% -remai- ning(TEF25% -r)[(82. 82 ± 35. 44)mL/s]in the second wheezing group were higher than those in the first whee-zing group[(92. 81 ± 28. 40)mL/s,(65. 22 ± 24. 93)mL/s],and the differences were statistically significant( t＝3. 34,2. 77,all P <0. 05). There was no statistically significant difference in sputum EOS,FeNO and Creola body scores among wheezing children between the first and second groups(all P>0. 05). FeNO in the observation group [3. 80(5. 43)μg/L]was significantly lower than that in the healthy control group[9. 60(11. 3)μg/L],and the diffe-rence was statistically significant(Z＝14. 56,P<0. 05). Sputum EOS had a positive correlation with blood EOS and Creola bodies(r＝0. 20,0. 21,all P<0. 05);there was no correlation between lung function parameters and inflamma-tory indices(all P>0. 05). Conclusions In the acute phase of infant asthma attack,the pulmonary function presents different degrees of obstructive ventilation dysfunction,the higher the degree of obstruction,the higher the diagnostic value of BDT. The value of single FeNO measurement is limited,and continuous dynamic monitoring may be more mea-ningful in predicting the occurrence of asthma. Detection of Creola bodies may be helpful in predicting asthma.

Detection of viral pathogens and allergens in infants and young children at high risk of asthma during a wheezing episode / 中国当代儿科杂志

OBJECTIVE@#To investigate the viral etiology and allergen distribution in infants and young children at high risk of asthma during a wheezing episode.@*METHODS@#A total of 135 infants and young children at high risk of asthma were enrolled who were admitted due to asthmatic bronchitis or asthmatic bronchopneumonia between April 2016 and August 2017. Fluorescent probe PCR was used to measure influenza A (Flu A), respiratory syncytium virus (RSV), adenovirus (ADV), parainfluenza virus (PinF), human rhinovirus (HRV), human partial lung virus (hMPV) and human bocavirus (HBoV) in nasopharyngeal aspirates. ImmunoCAP was used to measure inhaled allergens, food allergens, and total IgE concentration.@*RESULTS@#Among the 135 patients, the overall virus detection rate of nasopharyngeal aspirates was 49.6%, and HRV had the highest detection rate of 25.2%, followed by HBoV (9.6%), RSV (8.1%), PinF (5.9%), Flu-A (3.7%), ADV (1.5%) and hMPV (0.7%). The 1-3 years group had a significantly higher detection rate of HRV than the <1 year group (P<0.05). The positive rate of allergen screening was 59.3%, with 44% for inhaled allergens and 89% for food allergens. Among the inhaled allergens, dust mites had the highest positive rate of 77%, followed by mould (37%), pollen (26%) and animal dander (9%). Among the food allergens, egg white had a positive rate of 73% and milk had a positive rate of 68%. The <1 year group had a significantly higher positive rate of inhaled allergens than the 1-3 years group (P<0.05). The 1-3 years age group had a significantly higher level of T-IgE than the <1 year group (P<0.05). The positive virus group had a significantly higher positive rate of inhaled allergens than the non-virus group (P<0.05). The children with the second wheezing episode had significantly higher positive rates of inhaled allergens and food allergens and level of T-IgE than those with the first wheezing episode (P<0.05). The children with the second wheezing episode also had significantly higher positive rates of dust mites and mould than those with the first wheezing episode (P<0.05).@*CONCLUSIONS@#Early HRV infection and inhaled allergen sensitization are closely associated with the development of wheezing in infants and young children at high risk of asthma.

Epidemiological analysis of 440 cases of respiratory adenovirus infections in children from the Suzhou area between 2006 and 2015 / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the epidemiological characteristics of respiratory adenovirus (ADV) infections in children from the Suzhou area, China.</p><p><b>METHODS</b>The clinical data of ADV-positive children out of 35 529 children with respiratory tract infections who were hospitalized in the Children's Hospital of Soochow University between January 2006 and December 2015 were retrospectively studied.</p><p><b>RESULTS</b>Of the 35 529 children with respiratory tract infections, 440 (1.24%) were ADV-positive. There was no significant difference in the rate of ADV infections between boys and girls (1.18% vs 1.34%). The ADV infection rates of children at the age of <1 year old, 1-3 years old, 3-7 years old and 7-14 years old were 0.39% (71/18 002), 1.12% (103/9 191), 3.14% (201/6 398), and 3.35%( 65/1 938) respectively and the rate increased with age (P<0.01). The ADV infection rates in spring [1.85%(60/8 658)] and summer [2.20%(189/8 606)] were significantly higher than in autumn [0.30%(27/8 952)] and winter [0.69%(64/9 313)] (P<0.01).</p><p><b>CONCLUSIONS</b>The ADV infection rate is increased with age in the children from the Suzhou area, but it is not associated with gender. ADV infections are more common in spring and summer.</p>

Bacterial pathogenic characteristics of respiratory tract infection in children in Suzhou, China: an analysis of 14,994 cases / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the bacterial pathogenic characteristics of respiratory tract infection in children.</p><p><b>METHODS</b>The medical data from 14,994 children with respiratory tract infection who were hospitalized in Children's Hospital Affiliated to Soochow University between November 2005 and October 2014 were retrospectively reviewed.</p><p><b>RESULTS</b>Among the 14,994 sputum samples from the children with respiratory tract infection, 3,947 (26.32%) had a positive bacterial culture. The most common bacterial pathogen was Streptococcus pneumonia (12.79%), followed by Haemophilus influenzae (5.02%) and Moraxella catarrhalis (2.91%). The bacterial detection rates differed significantly in different years and seasons and children of different ages (P<0.01). The children who had not taken antibacterial agents before admission had a significantly higher positive bacterial culture rate than those who had taken antibacterial agents (P<0.01). There were significant differences in the bacterial detection rate among the children with different course of disease (<1 month, 1-3 months and >3 months) (P<0.05). The detection rates of Streptococcus pneumonia, Moraxella catarrhalis and Acinetobacter baumannii showed an increased trend with a prolonged disease course (P<0.05).</p><p><b>CONCLUSIONS</b>Streptococcus pneumonia is the most common bacterial pathogen causing respiratory tract infection in children, followed by Haemophilus influenzae and Moraxella catarrhalis. The detection rate of bacterial pathogens varies in different years and seasons and children of different ages. The course of the disease and application of antibacterial agents outside hospital can affect the detection rate of bacterial pathogens in children with respiratory tract infection.</p>

Association of T lymphocyte subsets and allergens with Mycoplasma pneumoniae infection complicated by wheezing in infants and young children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the percentage of T lymphocyte subsets and allergen screening results in infants and young children with Mycoplasma pneumoniae (MP) infection complicated by wheezing.</p><p><b>METHODS</b>Flow cytometry was used to measure the percentage of peripheral blood T cell subsets in 354 infants and young children with MP infection complicated by wheezing (MP wheezing group), 336 infants and young children with MP infection but without wheezing (MP non-wheezing group), and 277 children with recurrent wheezing (recurrent wheezing group). Allergen screening was also performed for these children.</p><p><b>RESULTS</b>Both the MP wheezing group and recurrent wheezing group had significantly lower percentages of CD3and CD3CD8lymphocytes than the MP non-wheezing group (p<0.05). The MP groups with or without wheezing had a significantly higher percentage of CD3CD4lymphocytes than the recurrent wheezing group (p<0.05). Both the MP wheezing group and recurrent wheezing group had significantly higher percentages of CD3CD19and CD19CD23lymphocytes than the MP non-wheezing group (p<0.05), and the recurrent wheezing group had the highest percentages (p<0.05). The overall positive rate of food allergens was significantly higher than that of inhaled allergens (30.3% vs 14.7%; p<0.05). The positive rates of food and inhaled allergens in the recurrent wheezing group and MP wheezing group were significantly higher than in the MP non-wheezing group (p<0.05), and the recurrent wheezing group had the highest rates.</p><p><b>CONCLUSIONS</b>Imbalance of T lymphocyte subsets and allergic constitution play important roles in the pathogenesis of MP infection complicated by wheezing in infants and young children.</p>

An epidemiological study on human rhinovirus C in hospitalized children with respiratory tract infections / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the detection rates, epidemical characteristics, and clinical features of human rhinovirus C (HRV-C) in hospitalized children with respiratory tract infections (RTIs) in Suzhou, China.</p><p><b>METHODS</b>A total of 1 702 hospitalized children with RTIs from January to December, 2014 were enrolled, and 1 702 nasopharyngeal aspirate samples were collected from all children. RT-PCR was used to measure HRV mRNA, and quantitative real-time PCR combined with high-resolution melting curve was used to measure HRV-C.</p><p><b>RESULTS</b>Of all children, 244 (14.34%) were detected to have HRV infection, among whom 69 (69/244, 28.3%) had HRV-C infection. The rate of mixed infection of HRV-C with other viruses and bacteria was 61% (42/69). HRV-C was detected in each month of the year, and the detection rate of HRV-C in autumn was significantly higher than that in spring, summer, and winter (P<0.05). The children aged 2-5 years had a significantly higher detection rate of HRV-C than those in the other age groups (P<0.05). Compared with HRV-A/B infection, HRV-C infection led to significantly higher proportions of patients with lobar pneumonia and acute exacerbation of asthma (P<0.05), as well as patients with increased neutrophil count and CRP level (P<0.05). There were no significant differences in sex distribution or other clinical manifestations (P>0.05).</p><p><b>CONCLUSIONS</b>HRV-C infection accounts for about 1/3 of HRV infection, with a high incidence rate in autumn. The rate of mixed infection of HRV-C with other viruses and bacteria is high, and children aged 2-5 years have the highest detection rate of HRV-C. Children with HRV-C infection have similar clinical manifestations as those with HRV-A/B infection.</p>

Clinical significance of MP-DNA from endotracheal aspirates in diagnosis of Mycoplasma pneumoniae pneumonia in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To compare the detection rates of Mycoplasma pneumoniae (MP) from nasopharyngeal aspirates (NPA) and bronchoalveolar lavage fluid (BALF) in children with pneumonia.</p><p><b>METHODS</b>A total of 164 hospitalized children with pneumonia were enrolled. NPA and BALF of these children were collected within 24 hours of admission, and MP-DNA was detected by fluorescence quantitative PCR. Venous blood samples of all these children were collected within 24 hours of admission and on days 7-10 of treatment, and serum MP-IgM was detected using ELISA.</p><p><b>RESULTS</b>The positive rate of MP-DNA in NAP of the 164 cases was 51.8% , which was lower than 63.4% as the detection rate of MP-IgM in serum (P=0.044), and the two detection rates were moderately consistent with each other (Kappa=0.618, P<0.01). The positive rate of MP in BALF was 71.3%, which was not significantly different with that of MP-IgM in serum (P>0.05), and the detection rates were well consistent (Kappa=0.793, P<0.01). The detection rate of MP in NPA was lower than that in BALF (P<0.01), with moderate consistency between two of them (Kappa=0.529, P<0.01). The median MP copy number in BALF was significantly higher than that in NPA (P<0.01). The MP detection rates in NPA and BALF were significantly different among different courses of disease (P<0.05). As the course of disease extended, the MP detection rates in both NPA and BALF showed a declining trend; children with MP pneumonia of 1-2 weeks' duration and 2-4 weeks' duration had a higher MP-DNA detection rate in BALF than in NPA (P<0.05).</p><p><b>CONCLUSIONS</b>MP-DNA in BALF has a high sensitivity, with a great significance for early diagnosis of MP pneumonia, while NPA MP-DNA tests may lead to a missed diagnosis.</p>

Etiology of acute respiratory tract infection in hospitalized children in Suzhou from 2005 to 2011 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To elucidate the etiology of acute respiratory tract infection (ARI) in hospitalized children in Suzhou from 2005 to 2011.</p><p><b>METHODS</b>A total of 10 243 hospitalized children with ARI in Children's Hospital Affiliated to Soochow University from September 2005 to October 2011 were enrolled in the study. The clinical information was collected; and the nasopharyngeal aspiration fluid and serum samples were sent for multi-pathogen detection. Respiratory syncytial virus (RSV), influenza virus type A and B (IV-A, IV-B), parainfluenza virus type 1-3 (PIV-1-PIV-3) and adenovirus (ADV) were detected by direct immunofluorescence assay. Human bocavirus (HBoV), mycoplasma pneumoniae (MP) and chlamydia pneumoniae (CP) were detected by fluorescent quantitative PCR while human metapneumovirus (hMPV) was detected by reverse transcription PCR (RT-PCR). Sputum culture was applied to detect bacterial infection and quantitative ELISA was adopted to detect the specific antibodies of MP and CP. The results of the above detections were analyzed, and thereby to explore the prevalent pathogens among different aging children and the seasonal distribution and characteristics of the disease.</p><p><b>RESULTS</b>At least one type of pathogen was detected in 5871 out of 10 243 hospitalized children and the overall positive rate was 57.32%; including 3326 virus samples with positive rate at 32.47% (3326/10 243), 2870 bacteria samples with positive rate at 28.02% (2870/10 243) and 2759 atypical pathogen samples,with positive rate at 26.94% (2759/10 243). MP was the most common pathogen,whose detected rate was 25.74% (2637/10 243). The median age of children with RSV (6 months) or PIV-3(8 months) infection was younger than the median age of all hospitalized children (12 months) (χ(2) = 380.992, 34.826, P < 0.05). While the median age of children with ADV (42 months), HBoV (14 months) or IV-A (24 months) infection was older than it of all hospitalized children (χ(2) = 83.583, 13.169, 18.012, P < 0.05). The median age of children with MP (30 months),streptococcus pneumoniae (17 months) or haemophilus parainfluenzae (21 months) infection was older than it of all hospitalized children (χ(2) = 728.299, 60.463, 8.803, P < 0.05). The detected rate of RSV in the groups of children aging less than 6 months, 7-12 months, 2-3 years, 4-5 years and over 6 years was separately 25.59% (840/3283), 17.05% (333/1953), 11.85% (310/2615), 6.68% (90/1347), and 2.87% (30/1045); which decreased while the age grew (χ(2) = 178.46, P < 0.01). Conversely, the positive rate of MP increased with the age growing (χ(2) = 379.21, P < 0.01). The rate in the above groups was 8.25% (271/3283), 19.46% (380/1953), 33.00% (863/2615), 41.43% (558/1347), 54.07% (565/1045), respectively. RSV and IV-A were prevalent in winter, whose detected rates were 35.73% (941/2634) and 4.44% (117/2634) respectively.hMPV infection was common in spring, with the detected rate at 10.55% (278/2634); while HBoV infection was common in summer and autumn, with the positive rate at 9.99% (149/1491) and 9.71% (98/1009). MP and CP were frequently detected in summer, up to 31.27% (819/2619) and 10.07% (43/427) respectively. RSV was the most common pathogen in bronchiolitis (33.27% (866/2603)) and MP was the most common pathogen in bronchopneumonia (26.05% (1152/4422)) and lober pneumonia (52.25% (267/511)).</p><p><b>CONCLUSION</b>MP and RSV were the most common pathogens in respiratory tract infection in hospitalized children. The novel virus included hMPV and HBoV, which also played an important role in ARI. Different pathogens were prevalent in different ages; with respective seasonal distribution and characteristics.</p>

Characteristics of human metapneumovirus respiratory tract infection in children and the relationship between the infection and meteorological conditions / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the epidemiology of human metapneumovirus (hMPV) infection in children and its relations with meteorological conditions in Suzhou.</p><p><b>METHOD</b>Samples obtained from 6655 children hospitalized with acute respiratory tract infections (ARIs) during the period from 2006 to 2009, were tested for virus pathogens. Nasopharyngeal aspirates were obtained from the children according to a standard protocol and were tested for respiratory syncytial virus (RSV), influenza viruses (IFV) A and B, parainfluenza virus (PIV) types 1, 2, and 3 and adenovirus (ADV) with direct immunofluorescence assay. Samples were tested for hMPV with reverse transcription polymerase chain reaction (RT-PCR). Meteorological conditions including mean temperature, relative humidity, rainfall amount, sum of sunshine and mean wind velocity were collected monthly. The relationship between activity of the virus and meteorological conditions was analyzed by linear regression and stepwise regression analysis.</p><p><b>RESULT</b>Viral pathogens were identified in 32.2% of 6655 specimens. The positive rate of hMPV was 8.9%, RSV was 15.7%, IFV, PIV and ADV detection rates were less than that of hMPV. The annual positive rate of hMPV from 2006 to 2009 was 8.2%, 8.1%, 12.7%, 7.4% respectively (χ(2) = 33.23, P < 0.05). The hMPV positive rate of the four seasons was 11.6%, 7.6%, 4.7% and 11.7%, respectively, detection rate in winter and spring was significantly higher than those in summer and autumn (χ(2) = 74.67, P < 0.001). The positive rate of hMPV and the monthly mean temperature was moderately correlated (r = -0.43), and the monthly average rainfall (r = -0.29), monthly mean relative humidity (r = -0.27), monthly average sunshine duration (r = -0.11), the monthly average wind speed (r = -0.13) had low correlations.</p><p><b>CONCLUSION</b>hMPV was the second most common viral pathogen of acute respiratory tract infection in children in Suzhou, which prevailed predominantly in the winter and spring. Climatic factors, especially temperature and rainfall may affect the prevalence of hMPV.</p>

Characteristics and the prevalence of respiratory viruses and the correlation with climatic factors of hospitalized children in Suzhou children's hospital / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the epidemiological characteristics of respiratory virus infection and its relations to climatic factors in Suzhou.</p><p><b>METHODS</b>From 2006 to 2009, viral etiology surveillance was conducted among 6655 children hospitalized with acute respiratory tract infections (ARIs). Direct immunofluorescence method was used to test respiratory secretion samples for respiratory syncytial virus (RSV), influenza viruses A and B (Inf-A, Inf-B), parainfluenza virus types I, II, and III (Pinf-I, Pinf-II, Pinf-III) and adenovirus. Samples were tested for human metapneumovirus (hMPV) with reverse transcription polymerase chain reaction (RT-PCR). Samples from Jan 2006 to Dec 2009 were also tested for human bocavirus (HBoV). Climatic factors, including mean temperature, relative humidity, rainfall amount, sum of sunshine and mean wind velocity were collected monthly. The relationship between activity of each virus and climatic factors were analyzed by linear regression and stepwise regression analysis.</p><p><b>RESULTS</b>From 2006 to 2009, in the total virus detection rate was 32.2% (2142/6655) in Suzhou. RSV was the most common virus and the average detection rate was 15.7% (1048/6655), followed by hMPV 8.9% (596/6655), HBoV 7.8% (148/1883), Pinf-III 2.7% (183/6655), Inf-A 2.4% (161/6655), ADV 1.3% (89/6655), Pinf-I 0.4% (29/6655), Inf-B 0.37% (25/6655) and Pinf-II 0.16% (11/6655). The positive rates of RSV, hMPV and ADV were significantly different in four years (χ(2) = 17.71, 33.23, 8.42, all P values < 0.05). Different virus has different epidemiological characteristics and distinct seasonality. The detection rate of RSV, hMPV, Inf-A were higher in Winter as 37.2%, 13.2%, 4.4%, respectively. ADV and Pinf-III were higher in summer as 2.3% and 4.6% respectively. The peak of HBoV existed in Autumn as 3.3%. The total virus detection rate showed significant inverse correlation with month average temperature (r = -0.732, P < 0.001) and a weak inverse correlation with average wind velocity was also found (r = -0.36, 0.01 < P < 0.05). The highest month total virus detection rate was from 47.6% to 84.4% when average temperature was from 3.2°C to 9.4°C and mean wind velocity was from 1.2 - 1.9 m/s. The associations of average temperature, sum of sunshine and wind velocity with RSV activity were statistical significant (r = -0.88, P < 0.001; r = -0.43, P < 0.01; r = -0.47, P < 0.01). The highest rate was from 24.3% to 58.2%, when mean temperature was from 5.3°C to 19.9°C, mean wind velocity was from 1.3 - 2.4 m/s and sum of sunshine was 61.0 to 153.4 hours. hMPV detection rate was inversely correlated with mean temperature and rain account (r = -0.43, P < 0.01; r = -0.29, P < 0.05). The rate was highest from 11.7% to 31.6% when mean temperature was from 5.3°C to 21.9°C and rain account was from 27.5 millimeter to 150.9 millimeter. Only mean temperature was positively correlated with Pinf-III (r = 0.53, P < 0.001). The rate was from 2.8% to 7.2% when mean temperature was between 11.9°C and 30.4°C. ADV detection rate was positively correlated with mean temperature and sum of sunshine, but negatively correlated with wind velocity (r = 0.35, P < 0.05; r = 0.30, P < 0.05; r = -0.32, P < 0.05). The rate was from 2.2% to 6.6% when mean temperature was between 15.9°C and 30.4°C, and sum of sunshine between 93 hours to 240.7 hours and mean wind velocity was from 1.1 - 2.8 m/s. Average temperature and relative humidity showed interactions on the detection rate of ADV (r = 0.36, P = 0.0093; r = -0.34, P = 0.016), but temperature showed higher effect on ADV detection rate. ADV detection rate was high at higher temperature (15.9 - 30.4°C) and low humidity (56% - 71%).</p><p><b>CONCLUSION</b>RSV was one of the most common viruses among hospitalized children in Suzhou, and hMPV and HBoV also played an important role in respiratory tract infection of children. Different virus has different cycle and seasonality. Climatic factors, especially mean temperature, was the main factor affecting the virus prevalence.</p>

Epidemiological study on respiratory syncytial virus and its bronchopneumonia among children in Suzhou / 中华预防医学杂志

<p><b>OBJECTIVE</b>To probe the epidemiological trend of respiratory syncytial virus (RSV) and cellular immunological change of RSV bronchopneumonia among children in Suzhou in the past five years.</p><p><b>METHODS</b>10,205 children with acute respiratory tract infection from January 2001 to December 2005 were enrolled into the study. Nasopharyngeal aspirates were obtained from the respiratory tract by aseptic vacuum aspiration. Direct immuno-fluorescence assay was employed to detect seven kinds of virus antigens including RSV antigen. CD3, CD4, CD8, CD19, CD16 and CD56 in peripheral blood mononuclear cells of 30 patients with RSV bronchopneumonia (1.5-24.0 months old group) were analyzed by flow cytometry analysis, and 15 normal infants (1.5-24.0 months old group) were enrolled as control group.</p><p><b>RESULTS</b>The annual positive rate of RSV was 24.94%, 25.83%, 24.05%, 25.39% and 27.30% respectively from 2001 to 2005. It also found that the peak season for RSV infection was spring or winter (January to March or November to December). The positive rate of RSV was significantly higher in 1-12 months old group than that in > 12 months old group (chi2 = 97.320, P < 0.01), as well as the groups between 1-12 months old (chi2 = 7.804, P < 0.05, the highest positive rate was occurred at 3-6 months old group). The positive rate of RSV was significantly higher in boys than that in girls (chi2 = 9.693, P < 0.01). The percentages of CD3+, CD4+, CD8+ and NK (CD16 + 56)+ cells were significantly lower in RSV bronchopneumonia than those in control group (t = 3.199, P < 0.01; t = 2.215, P < 0.05; t = 2.619, P < 0.05 and t = 5.240, P < 0.01, respectively). While the percentage of CD19+ cells was significantly elevated in RSV bronchopneumonia than that in control group (t = 2.875, P < 0.01).</p><p><b>CONCLUSION</b>RSV infection is of obvious seasonal changes. The younger the patient, the higher positive rates of RSV infection is, while and the cellular immunity function is lower. The effective measures for preventing RSV infection are important, especially for the infants. Further investigation is necessary to understand the causes of the variations for RSV infections between boys and girls.</p>