Lower respiratory tract infection caused by influenza virus A and influenza virus B in Wenzhou, China: a clinical analysis of 366 children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To compare the epidemiological and clinical features of lower respiratory tract infection (LRTI) caused by influenza virus A (IVA) and influenza virus B (IVB) in children.</p><p><b>METHODS</b>The clinical data of 366 children with LRTI caused by influenza virus (IV), who were hospitalized in Yuying Children′s Hospital of Wenzhou Medical University between 2010 and 2014, were analyzed retrospectively, and there were 272 cases caused by IVA and 94 cases caused by IVB.</p><p><b>RESULTS</b>IV was mainly prevalent from December to March of the next year, with the predominance of IVA. There were small peaks of IVA prevalence in July or September every other year, and IVB was prevalent from December to March of the next year every other year. The children with LRTI caused by IVA alone had a significantly higher white blood cell (WBC) count and significantly higher percentages of children with increased WBC, abnormal serum sodium, and abnormal serum potassium than those caused by IVB alone (P<0.05). However, there were no significant differences in age, sex, underlying diseases, clinical manifestations, and co-infection rate with bacteria or atypical pathogens between the two groups (P>0.05). The rate of co-infection with respiratory syncytial virus (RSV) was significantly higher in the IVB group than in the IVA group (P<0.01).</p><p><b>CONCLUSIONS</b>IVA is prevalent in winter and spring every year and has small peaks in summer every other year, while IVB is prevalent in winter and spring every other year. Compared with IVB, IVA causes more cases of increased WBC and electrolyte disturbance. The children infected with IVB are more likely to be co-infected with RSV. The children with LRTI caused by IVA and IVB have similar clinical manifestations.</p>

Viral etiology of acute respiratory infection in children from Wenzhou between 2007 and 2008 / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the viral etiology of acute respiratory infection (ARI)in children from Wenzhou, Zhejiang between 2007 and 2008.</p><p><b>METHODS</b>The nasopharyngeal aspirate samples were obtained from 5 097 hospitalized children with ARI. Seven 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.</p><p><b>RESULTS</b>Viral agents were identified in 2 209 cases (43.3%).Of the 2 209, RSV was the most frequent (78.1%), followed by parainfluenza 3 (12.4%), influenza virus A (3.0%), adenovirus (2.8%), parainfluenza 1 (1.7%), influenza B (0.5%) and parainfluenza 2 (0.3%). The infants at ages of <3 months and <6 months had higher detection rate of viruses (53.6% and 49.2%, respectively). A highest detection rate of viruses was found in winter.</p><p><b>CONCLUSIONS</b>RSV is the leading pathogen of ARI in children from Wenzhou, Zhejiang between 2007 and 2008. The children at age of less than 6 months are susceptible to respiratory viruses. The viral activity peaks in winter.</p>