BackgroundThis study was designed to explore the epidemiological and clinical profiles of respiratory syncytial virus (RSV) infection in neonates from the Suzhou area of China, taking into consideration how climate factors influence disease.MethodsFrom 2010 to 2014, nasopharyngeal aspirates (NPA) collected from hospitalized neonates with lower respiratory tract infections (LRIs) were screened for seven common respiratory viruses including RSV by direct immunofluorescence assay. Human bocavirus, human metapneumovirus, and mycoplasma pneumoniae were detected by polymerase chain reaction.ResultsOf the 1803 hospitalized neonates analyzed, 20.74 % were found to be infected with RSV. Interestingly, 30 subjects were identified as being coinfected with other viruses. The rate of RSV infection was highestduring thewinter and early spring seasons; however, infection was negatively associated with monthly mean temperature (rs = −0.821, P < 0.0001), total rainfall (rs = −0.406, P = 0.002), and sum of sunshine (rs = −0.386, P = 0.001). Monthly mean temperature was the only independent factor associated with RSV activity, as determined using multivariate regression analysis. Compared with non-RSV neonates, neonates with RSV infection presented more frequently with tachypnea,moist rales, and abnormal chest X-rays requiring supplemental oxygen and extended hospitalization postpartum. Neonatal admittance into the NICU was determined based on prematurity and coinfection with other viruses; two independent risk factors for RSV disease, as determined by multivariate logistic analysis.ConclusionsImportant as a major cause of LRIs in hospitalized neonate, we found that the subtropical climate of the Suzhou area was associated with RSV activity. The identified risk factors ofsevere disease in neonates with RSV infection should be taken into consideration when implementing disease health interventions.

Mycoplasmas are atypical bacteria that disrupt the immune response to promote respiratory tract infections and secondary complications. However, not every immunologic response that protects or damages the host during mycoplasma infection is known. Interleukin-17A (IL-17A) is elevated in individuals infected with mycoplasmas, but how IL-17A and its cellular sources dictate disease outcome remains unclear. Here, IL-17A is hypothesized to worsen disease in individuals susceptible to mycoplasma infection. Thus, monoclonal anti-IL-17A antibodies were given to disease-susceptible BALB/c mice and disease-resistant C57BL/6 mice infected with Neutralizing the function of IL-17A using anti-IL-17A antibodies reduced disease severity during infection in BALB/c, but not C57BL/6, mice. Neutralizing IL-17A also reduced the incidence of neutrophilic lung lesions during infection in BALB/c mice. Reduced pathology occurred without impacting the bacterial burden, demonstrating that IL-17A is not required for mycoplasma clearance. The main source of IL-17A throughout infection in BALB/c mice was CD4 T cells, and neutralizing IL-17A after infiltration of the lungs by T cells reduced disease severity, identifying the Th17 response as a herald of late mycoplasma pathology in susceptible mice. Neutralizing IL-17A did not further reduce disease during infection in BALB/c mice depleted of neutrophils, suggesting that IL-17A requires the presence of pulmonary neutrophils to worsen respiratory pathology. IL-17A is a pathological element of murine respiratory mycoplasma infection. Using monoclonal antibodies to neutralize IL-17A could reduce disease severity during mycoplasma infection in humans and domesticated animals.

Lower respiratory tract infection is a major cause of morbidity and mortality in children. Human bocavirus (HBoV) is confirmed to have an association with pediatric lower respiratory tract infection. Seasonal and meteorological factors may play a key role in the epidemiology of HBoV. The purpose of this study was to ascertain the frequency, season, and clinical characteristics of hospitalized children with HBoV infection. In addition, an evaluation of the effects of meteorological factors on the incidence of HBoV in a subtropical area in China will be conducted. Children were <14 years in age and hospitalized for lower respiratory tract infection between January 1, 2009 and December 31, 2012 in the Respiratory Disease Department at the Children's Hospital affiliated to Soochow University. Multi-pathogens were detected in nasopharyngeal aspirate samples. The association between HBoV activity and regional meteorological conditions was analyzed. The average incidence of HBoV infection was 6.6% (502/7,626). Of the 502 HBoV positive children, the median age was 13 months (range 1-156 months). The HBoV infection rate was highest among the 7-12 months groups (12.9%, 163/1,267). Seasonal distribution of HBoV was noted during June to November, especially during the summer season (June to August). HBoV activity was associated with temperature and humidity although the lag effect between temperature and HBoV activity observed. HBoV is one of the most common viral pathogens in children with lower respiratory tract infection. HBoV infection occurs throughout the year with a peak during the summer. Temperature and humidity may affect the incidence of HBoV.

The purpose of this study was to examine the epidemiological profiles of hand, foot, and mouth disease (HFMD) activity in Suzhou, China, and the relationship between meteorological factors and enterovirus71 (EV71) and coxsackievirus A16 (CoxA16) infection. Children < 14 years old with probable HFMD at Soochow University Affiliated Children's Hospital were enrolled during January 2008 to December 2013. Samples from hospitalized children with HFMD were collected and tested using real-time reverse transcription PCR. Correlations between probable HFMD, laboratory-confirmed HFMD, and meteorological factors were analyzed using bivariate correlation, stepwise regression and time series analysis. A total of 29,530 probable cases were diagnosed with HFMD, and 1090 hospitalized cases were confirmed in the laboratory. The median age of individuals with HFMD was 28.6 months (interquartile range, 18-46.9 months), and the incidence was highest in children aged 12-36 months. Children infected with other enteroviruses were younger than those infected with EV71 and CoxA16. Mean temperature and total rainfall were strongly correlated with probable HFMD. In terms of the specific pathogen, only EV71 cases were associated with mean temperature during the study period of 2012-2013. Based on a simple seasonal model with a good fit, a seasonal pattern of HFMD activity could be predicted. This study provides quantitative evidence that probable HFMD was associated with mean temperature and total rainfall. Furthermore, a seasonal model could be used as an early and reliable monitoring system to predict seasonal pattern of HFMD in Suzhou, China.