Viral etiology of medically attended influenza-like illnesses in children less than five years old in Suzhou, China, 2011-2014.

Limited information is available on the non-influenza etiology and epidemiology of influenza-like illness (ILI) in China. From April 2011 to March 2014, we collected oropharyngeal swabs from children less than 5 years of age with symptoms of ILI who presented to the outpatient departments of Suzhou University Affiliated Children's Hospital (SCH). We used reverse transcription polymerase chain reaction (rt-PCR) or PCR to detect 11 respiratory viruses. Among 3,662 enrolled ILI patients, 1,292 (35.3%) tested positive for at least one virus. Influenza virus (16.9%) was detected most frequently (influenza A 7.4%, influenza B 9.5%), followed by respiratory syncytial virus (RSV) (5.6%), parainfluenza virus (PIV) types 1-4 (4.8%), human bocavirus (HBoV) (3.8%), human metapneumovirus (HMPV) (3.5%), and adenovirus (ADV) (3.0%). Co-infections were identified in 108 (2.9%) patients. Influenza virus predominantly circulated in January-March and June-July. The 2013-2014 winter peaks of RSV and influenza overlapped. Compared with other virus positive cases, influenza positive cases were more likely to present with febrile seizure, and RSV positive cases were more likely to present with cough and wheezing, and were most frequently diagnosed with pneumonia. These data provide a better understanding of the viral etiology of ILI among children less than 5 years of age in Suzhou, China. Influenza is not only the most frequently identified pathogen but it is also the only vaccine preventable illness among the 11 pathogens tested. Such findings suggest the potential value of exploring value of influenza vaccination among this influenza vaccination target group. J. Med. Virol. 88:1334-1340, 2016. © 2016 Wiley Periodicals, Inc.

Influenza-associated outpatient visits among children less than 5 years of age in eastern China, 2011-2014.

BACKGROUND: The disease burden of influenza in China has not been well described, especially among young children. The aim of this study was to estimate the incidence of outpatient visits associated with influenza in young children in Suzhou, a city of more than 11 million residents in Jiangsu Province in eastern China. METHODS: Influenza-like illness (ILI) was defined as the presence of fever (axillary temperature ≥38 °C) and cough or sore throat. We collected throat swabs for children less than 5 years of age with ILI who visited Suzhou University Affiliated Children's Hospital (SCH) outpatient clinic or emergency room between April 2011 and March 2014. Suzhou CDC, a national influenza surveillance network laboratory, tested for influenza viruses by real-time reverse transcription-polymerase chain reaction assay (rRT-PCR). Influenza-associated ILI was defined as ILI with laboratory-confirmed influenza by rRT-PCR. To calculate the incidence of influenza-associated outpatient visits, we conducted community-based healthcare utilization surveys to determine the proportion of hospital catchment area residents who sought care at SCH. RESULTS: The estimated incidence of influenza-associated ILI outpatient visits among children aged <5 years in the catchment area of Suzhou was, per 100 population, 17.4 (95 % CI 11.0-25.3) during April 2011-March 2012, 14.6 (95 % CI 5.2-26.2) during April 2012-March 2013 and 21.4 (95 % CI: 10.9-33.5) during April 2013-March 2014. The age-specific outpatient visit rates of influenza-associated ILI were 4.9, 21.1 and 21.2 per 100 children aged 0- <6 months, 6- <24 months and 24- <60 months, respectively. CONCLUSION: Influenza virus infection causes a substantial burden of outpatient visits among young children in Suzhou, China. Targeted influenza prevention and control strategies for young children in Suzhou are needed to reduce influenza-associated outpatient visits in this age group.

Seasonal distribution and epidemiological characteristics of human metapneumovirus infections in pediatric inpatients in Southeast China.

Human metapneumovirus (hMPV) is an important respiratory pathogen in young children whose seasonal activity varies substantially from year to year among different populations. This study was conducted to investigate if there was a seasonal variation in the incidence of hMPV infection in young children and possible associations between hMPV infection and local meteorological parameters in Suzhou, China. A total of 6,655 children with acute respiratory tract infection (ARTI) admitted to the Children's Hospital affiliated to Soochow University, Suzhou, were tested from January 2006 to December 2009 for the presence of hMPV using reverse-transcription polymerase chain reaction. The relationship between the presence of the virus and regional meteorological conditions was analyzed by linear and multivariate regression analysis. The overall hMPV infection incidence over the four-year study was 8.2 %, 8.1 %, 12.7 % and 7.4 % per year, respectively. Four hundred eighty-eight hMPV-positive children (78.2 %) were younger than 3 years of age. hMPV infections appear to have a seasonal distribution in Suzhou. In 2006, 2007 and 2009, the peak seasons were in December to January, while in 2008, the peak of hMPV activity occurred in May. The incidence of hMPV infection was negatively correlated with the average monthly temperature and rainfall. hMPV was one of the most common viral pathogens after respiratory syncytial virus that was associated with acute respiratory tract infection in children in Suzhou. hMPV infection occurred throughout the year with peaks during late winter and early spring. Climatic factors, especially monthly average temperature, may affect the prevalence of hMPV in Suzhou.

[Comparison of clinical features and co-infection between pneumonia caused by influenza virus A and pneumonia caused by influenza virus B among children].

OBJECTIVE: To compare the clinical features and co-infection between pneumonia caused by influenza virus A (IVA) and pneumonia caused by influenza virus B (IVB) among children. METHODS: A total of 165 children with pneumonia caused by influenza virus (IV) were included in the study. These subjects were divided into IVA(n=71) and IVB pneumonia groups (n=94) according to the subtypes of IV. The IVA pneumonia group was further divided into simple infection (n=14) and co-infection subgroups (n=57), and the IVB pneumonia group was also further divided into simple infection (n=27) and co-infection subgroups (n=67). Co-infection rate and pathogen spectrum were analysed in children with IV pneumonia. RESULTS: The IVB pneumonia group had significantly increased mean age of onset and significantly prolonged mean duration of fever compared with the IVA pneumonia group (P<0.05). Co-infection rate among children with IV pneumonia was 75.2%, who were co-infected with bacteria (44.2%), Mycoplasma pneumoniae (MP, 21.8%) and other viruses (45.5%). Respiratory syncytial virus (RSV) was most common in children co-infected viruses (89% ). The rate of co-infection with RSV was significantly higher in the IVA pneumonia group than in the IVB pneumonia group. There were no significant differences in age, length of hospital stay, duration of fever, percentage of neutrophils, prealbumin, C-reactive protein, alanine aminotransferase, and creatine kinase-MB between the simple infection and co-infection subgroups of each group. CONCLUSIONS: Children with IVB pneumonia have prolonged duration of fever and increased age of onset compared with those with IVA pneumonia. Co-infection rate is high among children with IV pneumonia, who may be co-infected with bacteria, viruses and MP. Co-infection with RSV is more common in children with IVA pneumonia. It is difficult to identify the presense of co-infection using clinical indices.

Digital tool assessment for the community management of patients with pulmonary tuberculosis in Yiwu city, China: evidence from real world data in 2020.

Background: High-quality medication compliance is critical for the cure of pulmonary tuberculosis (PTB); however, the implementation of directly observed treatment (DOT) under direct interview still faces huge difficulties. Assessment of the effect of digital tool during community management has not been performed in eastern China. Methods: All drug-sensitive PTB cases notified in Yiwu city from June to December 2020 were divided into the routine group and digital tool group based on patients' willingness. The variables influencing the on-time completion level of home visits, medication adherence and treatment outcomes were estimated. Results: A total of 599 eligible patients were enrolled, with 268 participating in the routine group and 331 using a digital tool. Most participants were men (n = 357, 59.6%), and nearly all were new cases (n = 563, 94.0%). Participants' mean age was 44.22 ± 20.32 years. There were significant differences in age, diagnostic type, and source of patients between the two groups. During the study period, the digital tool group had a higher on-time completion rate of home visits (91.5% vs. 82.5%) and medication adherence rate (94.3% vs. 89.6%) than the routine group, whereas there was no significant difference in the treatment success rate between the two groups (91.2% vs. 86.8%). Multivariate logistic regression analysis demonstrated that the digital tool group showed a more positive function in the on-time completion status of home visits, with an adjusted odds ratio of 0.41 (95% confidence interval: 0.25-0.70). Conclusion: Digital tools can be employed to improve the on-time completion rate of home visits in Yiwu city. Further large-scale studies that use digital tools for community management are warranted.

[Monitoring of influenza virus B and clinical features of pediatric pneumonia caused by influenza virus B only].

OBJECTIVE: To investigate the epidemiological features of influenza virus B (IVB) in the winter and the clinical features of pediatric pneumonia caused by IVB only. METHODS: A retrospective study was performed on the clinical data of children with respiratory infection who received pathogen testing and therapy at Soochow University Affiliated Children's Hospital during the winters of 2008, 2009, 2010 and 2011. RESULTS: The positive rates of influenza viruses A and B in the winters of 2008, 2009, and 2010 were 0.89%, 5.49%, and 6.24% respectively; the positive rate of influenza viruses A and B in the winter of 2011 was 8.72%, significantly higher than those in 2008-2010. The positive rates of IVB in the winters of 2008, 2009, and 2010 were 0%, 0%, and 0.21% respectively; the positive rate of IVB in the winter of 2011 was 5.36%, which was significantly higher than in the years 2008 to 2010. Pneumonia caused by IVB was confirmed in 94 children during the winter of 2011, including 27 cases of pneumonia caused by IVB only. Most of children with pneumonia caused by IVB only were aged over 6 months. The common symptoms in the 27 children caused by IVB only were fever (85%), runny nose (89%), and cough (100%). Wheezing (26%) and dyspnea (7%) were also seen in some cases. Among the 27 children, 19% showed abnormal white blood cell count, 30% showed increased C-reactive protein, 70% showed decreased prealbumin, and none showed visible organ dysfunction. No specific imaging findings were seen in the children with pneumonia caused by IVB only. However, many abnormal humoral and cellular immunological parameters were found in the majority of these children. The average length of hospital stay was approximately one week, there were no critical patients and the prognosis was good. CONCLUSIONS: Influenza viruses were at a peak level in inpatient children in the winter of 2011. IVB infection rate was gradually increasing. In children with pneumonia caused by IVB only, there are few critical patients, the symptoms are nonspecific and the prognosis is good.

[Comparative studies on the composition and antibiotic-resistance of pathogenic bacteria between children with community-acquired and hospital-acquired pneumonia].

OBJECTIVE: This research was to explore the difference between children with community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) in the composition and antibiotic-resistance of pathogenic bacteria. METHODS: 241 CAP and 116 HAP with positive sputum culture who were hospitalized from January to December in 2008 in Children's Hospital Affiliated to Suzhou University were selected in this study. The bacteria were identified by traditionally manual method and antibiotic sensitivity tests were performed by K-B method. The chi-square or Fisher's exact test were used for statistical test. RESULTS: In 241 CAP, Streptococcus pneumoniae and haemophilus influenza accounted for (42.2%, 106/251) and (12.4%, 31/251) infection, respectively; however in 116 HAP, Enterobacteriaceae and Non-fermenters accounted for (88.2%, 127/144). In addition, methicillin-resistant Staphylococcus aureus weren't isolated, however, its detection rate was 66.7% in HAP. The drug resistance was 1.5 times higher in HAP than that in CAP for several types of antibiotics, such as ceftazidime (37.5% (6/16) vs 75.6% (31/41)), cefepime (37.5% (6/16) vs 78.0% (32/41)), aztreonam (50.0% (8/16) vs 90.2% (37/41)), cefoperazone/sulbactam (12.5% (2/16) vs 51.2% (21/41)) and piperacillin/tazobactam (12.5% (2/16) vs 56.0% (23/41)). Klebsiella pneumoniae isolated from HAP had higher drug resistance than that isolated from CAP against some antibiotics, for example, gentamicin (0 vs 63.6% (7/11)), SMZ + TMP (20.0% (1/5) vs 63.6% (7/11)) and cefoperazone/sulbactam (0 vs 54.5% (6/11)). We also found Enterobacter cloacae isolated from HAP showed high drug resistance than that isolated from CAP against imipenem (0 vs 46.7% (7/15)), aztreonam (9.1% (1/11) vs 60.0% (9/15)) and cefoperazone (18.2% (2/11) vs 80.0% (12/15)) and Pseudomonas aeruginosa from HAP had higher resistance than that from CAP against gentamicin (0 vs 50.0% (9/18)), amikacin (0 vs 38.9% (7/18)), ceftazidime (0 vs 55.6% (10/18)), cefepime (0 vs 50.0% (9/18)) and cefoperazone (33.3% (2/6) vs 94.4% (17/18)). The detection rates of ESBLs for Escherichia coli were 84.6% (11/13) and 93.3% (14/15) in CAP and HAP, respectively (χ(2) = 0.553, P > 0.05); while for Klebsiella pneumoniae, they were 81.3% (13/16) and 95.1% (39/41), respectively (χ(2) = 2.767, P > 0.05). CONCLUSION: CAP was mainly comprised of Streptococcus pneumoniae and haemophilus influenza; while HAP was mainly comprised of Enterobacteriaceae and Non-fermenters. The drug resistance of gram-negative bacilli was higher in HAP than that in CAP.

[Characteristics and the prevalence of respiratory viruses and the correlation with climatic factors of hospitalized children in Suzhou children's hospital].

OBJECTIVE: To study the epidemiological characteristics of respiratory virus infection and its relations to climatic factors in Suzhou. METHODS: 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. RESULTS: 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%). CONCLUSION: 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.

The epidemiology of hospitalized influenza in children, a two year population-based study in the People's Republic of China.

BACKGROUND: The epidemiology and disease burden of annual influenza in children in mainland People's Republic of China have not been reported in detail. To understand the incidence and epidemiology of laboratory-proven influenza hospitalization in children in China, a review of available laboratory and hospital admission data was undertaken. METHODS: We conducted a retrospective population-based study in Suzhou and the surrounding area of Jiangsu province, China for hospitalized cases of respiratory illness at Suzhou Children's Hospital. Cases of pneumonia or respiratory illness were identified from hospital computer data bases. Routine virological testing by fluorescent monoclonal antibody assay of all hospitalized children identified influenza and other viruses. We calculated incidence rates using census population denominators. RESULTS: Of 7,789 specimens obtained during 2007 and 2008, 85 were positive for influenza A and 25 for influenza B. There were 282 specimens with parainfluenza virus and 1392 with RSV. Influenza occurred throughout the year, with peaks in the winter, and in August/September. Overall estimated annual incidence of laboratory-proven influenza hospitalization was 23-27/100,000 children 0-4 years old, and 60/100,000 in infants 0-6 months, with an average hospitalization of 9 days. CONCLUSIONS: Influenza disease in young children in this part of China is a relatively common cause of hospitalization, and occurs throughout the year. The use of influenza vaccine in Chinese children has the potential to reduce the effect of influenza in the children, as well as in their communities. Studies are needed to further assess the burden of influenza, and to develop and refine effective strategies of immunization of young children in China.

[Viral pathogens of acute respiratory infection in hospitalized children from Suzhou].

OBJECTIVE: To investigate the viral pathogens of acute respiratory infection (ARI) in hospitalized children from Suzhou of China. METHODS: The nasopharyngeal aspirate samples were obtained from 1,668 hospitalized children with ARI. Common respiratory viruses, including respiratory syncytial virus (RSV), influenza virus A and B, parainfluenza viruses 1, 2 and 3 and adenovirus, were detected using direct immunofluorescence. Human metapneumovirus (hMPV) gene fragments were detected by RT-PCR. RESULTS: Viral agents were identified in 597 cases (35.8%). RSV was the most frequent (17.6%). RSV infection is more common in children less than 1 year old. A highest detection rate of RSV was found during winter and spring. hMPV was detected in 10.6% of the cases, with a peak detection rate between March and May. Single viral infection was found in 561 cases (33.6%) and mixed viral infection in 36 cases (including 27 cases at age of less than 1 year). RSV and hMPV co-infection was common (n=22). CONCLUSIONS: RSV is common pathogen of ARI in children from Suzhou. RSV viral activity peaks during winter and spring. The children at age of less than 1 year are susceptible to RSV. hMPV is also an important pathogen of ARI, with a peak detection rate between March and May. Mixed viral infection is common in children less than 1 year old.

Influenza-associated Hospitalization in Children Younger Than 5 Years of Age in Suzhou, China, 2011-2016.

BACKGROUND: Studying the burden and risk factors associated with severe illness from influenza infection in young children in eastern China will contribute to future cost-effectiveness analyses of local influenza vaccine programs. METHODS: We conducted prospective, severe acute respiratory infection (SARI) surveillance at Suzhou University-Affiliated Children's Hospital to estimate influenza-associated hospitalizations in Suzhou University-Affiliated Children's Hospital by month in children younger than 5 years of age from October 2011 to September 2016. SARI was defined as fever (measured axillary temperature ≥ 38°C) and cough or sore throat or inflamed/red pharynx in the 7 days preceding hospitalization. We combined SARI surveillance data with healthcare utilization survey data to estimate and characterize the burden of influenza-associated SARI hospitalizations in Suzhou within this age group in the 5-year period. RESULTS: Of the 36,313 SARI cases identified, 2,297 from respiratory wards were systematically sampled; of these, 259 (11%) were influenza positive. Estimated annual influenza-associated SARI hospitalization rates per 1,000 children younger than 5 years of age ranged from 4 (95% confidence interval [CI], 2-5) in the 2012-2013 season to 16 (95% CI, 14-19) in the 2011-2012 season. The predominant viruses were A/H3N2 (59%) in 2011-12, both A/H1N1pdm09 (42%) and B (46%) in 2012-13, A/H3N2 (71%) in 2013-14, A/H3N2 (55%) in 2014-15 and both A/H1N1pdm09 (50%) and B (50%) in 2015-16. The age-specific influenza-associated SARI hospitalization rates for the 5-year period were 11 (95% CI, 8-15) per 1,000 children 0-5 months of age; 8 (95% CI, 7-10) per 1,000 children 6-23 months of age and 5 (95% CI, 4-5) per 1,000 children 24-59 months of age, respectively. CONCLUSIONS: From 2011 to 2016, influenza-associated SARI hospitalization rates in children aged younger than 5 years of age in Suzhou, China, were high, particularly among children 0-5 months of age. Higher hospitalization rates were observed in years where the predominant circulating virus was influenza A/H3N2. Immunization for children > 6 months, and maternal and caregiver immunization for those < 6 months, could reduce influenza-associated hospitalizations in young children in Suzhou.

[Etiology of pneumonia in hospitalized patients less than 3 years of age].

OBJECTIVE: To understand the etiology of pneumonia in hospitalized patients less than 3 years of age. METHODS: A total of 316 children with pneumonia admitted to the Children's Hospital of Suzhou University in Jiangsu Province from March, 2006 to January, 2007 were enrolled in this study. Sputum samples were obtained by deep nasotracheal aspiration technique for bacterial and viral cultures. RESULTS: Of the 316 samples, specific microbial etiology was obtained in 192 cases (60.8%). Bacterial infection was found in 162 cases (51.3 %), viral infection in 19 cases (6.3%)and compound infection with virus and bacteria in 11 cases (3.5 %). Haemophilus influenzae was the most common agent (46 cases; 14.6%) in bacterial infection, followed by Streptococcus pneumoniae (32 cases; 10.1%). Respiratory syncycial virus (RSV) was the most common agent (12 cases; 4.0%) in viral infection, followed by adenovirus (11 cases; 3.6%). CONCLUSIONS: Bacterial infection was a leading cause of pneumonia in children less than 3 years of age in Suzhou area. Haemophilus influenzae was the most common agent, followed by Streptococcus pneumoniae.

[Epidemiological study on respiratory syncytial virus and its bronchopneumonia among children in Suzhou].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Characteristics of pediatric invasive pneumococcal diseases and the pneumococcal isolates in Suzhou, China before introduction of PCV13.

BACKGROUND: Data on characteristics of invasive pneumococcal diseases (IPD) is limited in China. We aimed to understand the clinical features and explore the molecular characteristics of the pneumococcal isolates in China. METHODS: Since 2010, we prospectively collected the pneumococcal isolates and the IPD patients' demographic and clinical information in Suzhou University Affiliated Children's Hospital (SCH). The antibiotic susceptibility, serotypes, genotypes of Streptococcus pneumoniae strains were identified by E-test, quellung reaction and/or multiplex PCR, and multi-locus sequence typing, respectively. RESULTS: During the period from January 2010 to December 2015, a total of 80 IPD patients were identified. They were diagnosed as meningitis (31.3%), septicemia (27.5%), pneumonia (21.3%) and others (20.0%). About half of them required vancomycin treatment, 42.5% were admitted to ICUs, 36.2% had complications and 6.2% were hospitalized for over 1year. The most common serotypes of the pneumococcal isolates were serotypes 6B and 14, the coverage of PCV13 was 92.5%, and CC236s and CC199s were the most common clone complexes. CONCLUSIONS: Pediatric IPD patients had severe clinical symptoms, demanded intensive treatment, suffered poor prognosis and substantial burden. The pneumococcal isolates' serotype coverage of PCV13 vaccine was high, which leads to implication of PCV vaccine usage among children in China.

Seasonal influenza vaccine effectiveness against medically attended influenza illness among children aged 6-59 months, October 2011-September 2012: A matched test-negative case-control study in Suzhou, China.

BACKGROUND: Seasonal influenza infections among young children in China lead to substantial numbers of hospitalizations and financial burden. This study assessed the seasonal influenza vaccine effectiveness (VE) against laboratory confirmed medically attended influenza illness among children in Suzhou, China, from October 2011-September 2012. METHODS: We conducted a test-negative case-control study among children aged 6-59 months who sought care at Soochow University Affiliated Children's Hospital (SCH) from October 2011-September 2012. A case was defined as a child with influenza-like illness (ILI) or severe acute respiratory infection (SARI) with an influenza-positive nasopharyngeal swab by rRT-PCR. Controls were selected from children presenting with ILI or SARI without laboratory confirmed influenza. We conducted 1:1 matching by age and admission date. Vaccination status was verified from the citywide immunization system database. VE was calculated with conditional logistic regression: (1-OR)×100%. RESULT: During the study period, 2634 children aged 6-59 months presented to SCH with ILI (1975) or SARI (659) and were tested for influenza. The vaccination records were available for 69% (1829; ILI: 1354, SARI: 475). Among those, 23% (427) tested positive for influenza, and were included as cases. Among influenza positive cases, the vaccination rates were 3.2% for SARI and 4.5% for ILI. Among controls, the vaccination rates were 13% for SARI, and 11% for ILI. The overall VE against lab-confirmed medically attended influenza virus infection was 67% (95% CI: 41-82). The VE for SARI was 75% (95% CI: 11-93) and for ILI was 64% (95% CI: 31-82). CONCLUSIONS: The seasonal influenza vaccine was effective against medically attended lab-confirmed influenza infection in children aged 6-59 months in Suzhou, China in the 2011-12 influenza season. Increasing seasonal influenza vaccination among young children in Suzhou may decrease medically attended influenza-associated ILI and SARI cases in this population.

Etiology and epidemiology of children with acute otitis media and spontaneous otorrhea in Suzhou, China.

BACKGROUND: There are scare data about bacterial etiology and the antibiotic susceptibility, serotype distribution and molecular characteristics of pneumococci in children with acute otitis media (AOM) in China. METHODS: A prospective study was conducted in Suzhou University Affiliated Children's Hospital. All children under 18 years of age diagnosed as AOM and with spontaneous otorrhea were offered enrollment, and collection of middle ear fluid was then cultured for bacterial pathogens. The antibiotic susceptibility, serotypes, macrolide resistance genes and sequence types of Streptococcus pneumoniae strains were identified. RESULTS: From January 2011 to December 2013, a total of 229 cases of AOM with spontaneous otorrhea were identified; of these, 159 (69.4%) middle ear fluid specimens were tested positive for bacterial pathogens. The leading cause was S. pneumoniae (47.2%), followed by Staphylococcus aureus (18.8%) and Haemophilus influenzae (7.4%). The antibiotic resistance rates of S. pneumoniae isolates to erythromycin were 99.1%, and the nonsusceptible rate to penicillin was 54.6%. The most common serotypes identified were 19A (45.1%) and 19F (35.4%). The coverage against PCV7 serotypes for this outcome was 56.1% and of PCV13 was 97.6%. The macrolide resistance was mainly mediated by both ermB and mefA/E genes (88.6%). The CC271 was the major clonal complex identified. CONCLUSIONS: S. pneumoniae was a leading cause for AOM in children in Suzhou, China. Antibiotics resistance rates of S. pneumoniae were high and mainly due to the spread of CC271 clonal complex.

Molecular characterization and antimicrobial susceptibility of Streptococcus pneumoniae isolated from children hospitalized with respiratory infections in Suzhou, China.

BACKGROUND: Dissemination of antibiotic resistant clones is recognized as an important factor in the emergence and prevalence of resistance in pneumococcus. This study was undertaken to survey the antimicrobial susceptibility and serotypes distribution of pneumococci and to explore the circulating clones in hospitalized children in Suzhou, China. METHODS: The pneumococci were isolated from the nasopharyngeal aspirates of children less than 5 years of age admitted to Soochow-University-Affiliated-Children's-Hospital with respiratory infections. The capsular serotypes were identified by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility was tested by E-test. The presence of ermB, mefA/E genes were detected by PCR and the genotypes were explored by Multilocus sequence typing (MLST). RESULTS: From July 2012 to July 2013, a total of 175 pneumococcal isolates were collected and all strains were resistant to erythromycin and clindamycin, about 39.4% strains were non-susceptible to penicillin G. Overall, 174 (99.4%) isolates were resistant to ≥ 3 types of antibiotics. Serotypes 19F (28.1%), 6B (19.7%), 19A (18.0%), and 23F (17.4%) were the most common serotypes in all identified strains. The serotypes coverage of PCV7 and PCV13 were 71.9% and 89.9%, respectively. Four international antibiotic-resistant clones, including Taiwan19F-14 (n = 79), Spain23F-1(n = 25), Taiwan23F-15(n = 7) and Spain6B-2(n = 7), were identified. The Taiwan19F-14 clones have a higher non-susceptibility rate in ß-lactams than other clones and non-clone isolates (p<0.001). In addition, 98.7% Taiwan19F-14 clones were positive of both ermB and mefA/E genes, compare to 33.3% in other clones and non-clone strains. CONCLUSIONS: The spread of international antibiotic-resistant clones, especially Taiwan19F-14 clones, played a predominant role in the dissemination of antimicrobial resistant isolates in Suzhou, China. Considering the high prevalence of PCV7 serotypes and serotype 19A, the introduction of PCV13 may be a promising preventive strategy to control the increasing trend of clonal spread in China.

Clinical characteristics and direct medical cost of respiratory syncytial virus infection in children hospitalized in Suzhou, China.

BACKGROUND: There have been few studies on children hospitalized with respiratory syncytial virus (RSV) published from mainland China. We performed a retrospective review of medical charts to describe the epidemiology, clinical features and direct medical cost of laboratory-proven RSV children hospitalized in Suzhou, China. METHODS: Testing is routine for RSV for children admitted to the respiratory ward at Suzhou University Children's Hospital. We performed a retrospective study on children with documented RSV infection hospitalized at Suzhou University Children Hospital during 2005-2009 using a structured chart review instrument. RESULTS: A total of 2721 hospitalized children (15.0% of those tested) were positive by immunofluorescent assay for RSV during 2005-2009, and 64.0% of them were male. Eighty-seven percentage of the RSV-infected children were 2 years old and younger, and 56.6% were ≤ 6 months of age. The median length of hospital stay was 8 days. Of the RSV-infected children, 92.5% developed pneumonia and 21.8% experienced wheezing. In total, 49 (5.1%) of RSV-positive children were transferred to the ICU. Children ≤ 6 months old and who had congenital heart disease had higher risk of severe RSV disease. The mean cost of each RSV-related hospitalization was US$571.8 (US$909.6 for children referred to ICU and US$565.4 for those cared for on the wards). Multivariable logistic regression showed that compared with the ≤ 6 months children, those aged >6 months old had higher hospitalization cost; children with respiratory distress or with chronic lung diseases tended to have higher hospitalization costs than others. CONCLUSIONS: RSV infections and severe RSV diseases mostly occurred in early infancy. The direct medical cost was high relative to family income. Effective strategies of RSV immunization of young children in China may be beneficial in addressing this disease burden.

Socio-economic burden of influenza among children younger than 5 years in the outpatient setting in Suzhou, China.

BACKGROUND: The disease burden of children with laboratory-confirmed influenza in China has not been well described. The aim of this study was to understand the epidemiology and socio-economic burden of influenza in children younger than 5 years in outpatient and emergency department settings. METHODS: A prospective study of laboratory-confirmed influenza among children presenting to the outpatient settings in Soochow University Affiliated Children's Hospital with symptoms of influenza-like illness (ILI) was performed from March 2011 to February 2012. Throat swabs were collected for detection of influenza virus by reverse transcription polymerase chain reaction assay. Data were collected using a researcher administered questionnaire, concerning demographics, clinical characteristics, direct and indirect costs, day care absence, parental work loss and similar respiratory illness development in the family. RESULTS: Among a total of 6,901 children who sought care at internal outpatient settings, 1,726 (25%) fulfilled the criteria of ILI and 1,537 were enrolled. Influenza was documented in 365 (24%) of enrolled 1,537 ILI cases. Among positive patients, 52 (14%) were type A and 313 (86%) were type B. About 52% of influenza outpatients had over-the-counter medications before physician visit and 41% visited hospitals two or more times. Children who attended daycare missed an average of 1.9 days. For each child with influenza-confirmed disease, the parents missed a mean of 1.8 work days. Similar respiratory symptoms were reported in 43% of family contacts of influenza positive children after onset of the child's illness. The mean direct and indirect costs per episode of influenza were $123.4 for outpatient clinics and $134.6 for emergency departments, and $125.9 for influenza A and $127.5 for influenza B. CONCLUSIONS: Influenza is a common cause of influenza-like illness among children and has substantial socio-economic impact on children and their families regarding healthcare seeking and day care/work absence. The direct and indirect costs of childhood influenza impose a heavy financial burden on families. Prevention measures such as influenza vaccine could reduce the occurrence of influenza in children and the economic burden on families.