重庆单中心2009至2011年急性呼吸道感染住院患儿2种甲型流感病毒检出情况及临床特征分析

Comparative analysis of epidemiological and clinical features in hospitalized children with acute respiratory infection caused by novel swine-origin influenza virus and seasonal influenza virus A in Chongqing from 2009 to 2011

目的了解重庆地区急性呼吸道感染住院患儿新型甲型H1N1流感病毒(S-OIVs)与季节性甲型流感病毒(IVA)检出情况及临床特征。方法收集2009年6月至2011年5月重庆医科大学附属儿童医院呼吸科急性呼吸道感染住院患儿鼻咽抽吸物(NPA),采用荧光定量PCR技术检测S-OIVs和季节性IVA基因组RNA,分析流行特点和临床特征,并采用Logistic回归分析急性呼吸道感染进展为重症肺炎的危险因素。结果共收集NPA标本1 074份,经PCR检测IVA阳性105份(9.8%),其中1.4%(15/1 074)为S-OIVs,8.4%(90/1 074)为季节性IVA。2种病毒阳性病例男女比例、年龄分布和平均住院天数差异均无统计学意义(P>0.05)。①S-OIVs在2009年夏季高发(11/15,73.3%),季节性IVA在2009年夏季(26/95,27.4%)、2010年夏季(22/95,23.2%)和2011年春季(25/95,26.3%)检出率明显高于其他各季节。②2种病毒阳性患儿临床症状、外周血WBC计数、CRP水平相当,S-OIVs阳性患儿重症毛细支气管炎1例(6.7%),季节性IVA阳性患儿重症肺炎14例(15.6%)。③15份S-OIVs阳性标本中,单纯S-OIVs感染3份,合并其他病毒感染9份,痰培养阳性7份。90份季节性IVA阳性标本中,单纯季节性IVA感染21份,合并其他病毒感染42份,痰培养阳性10份。④心脏基础疾病(OR=13.60)、发生喘息(OR=6.82)和合并腺病毒感染(OR=6.21)为季节性IVA感染患儿进展为重症肺炎的危险因素。结论重庆单中心急性呼吸道感染住院患儿S-OIVs检出率低于季节性IVA。S-OIVs和季节性IVA感染患儿均以下呼吸道感染为主。心脏基础疾病、喘息症状和合并腺病毒感染有可能是季节性IVA感染患儿进展为重症肺炎的危险因素。

Objective To describe the epidemiological and clinical features in hospitalized children with acute respiratory infection caused by novel swine-origin influenza virus and seasonal influenza virus A in Chongqing. Methods A total of 1 074 nasopharyngeal aspirates were collected in hospitalized children with acute respiratory tract infection enrolled in the department of respiratory medicine in Children's Hospital of Chongqing Medical University from June 2009 to May 2011. The RNA of S-OIVs /seasonal IVA in the sample was examined using real time PCR. Clinical data were recorded and analyzed. Results The presence of IVA was detected in 105(9. 8%)samples of 1 074 cases,including S-OIVs in 15(1. 4%)samples and seasonal IVA in the rest of samples(8. 4%). No differences in gender,age and average inpatient hospital stay were found between patients with S-OIVs infection and seasonal IVA infection. ①The prevalence of S-OIVs was 73. 3%(11/15)in summer of 2009,and the incidence of seasonal IVA infection was higher in the summer of 2009(26/95,27. 4%),summer of 2010(22/95,23. 2%)and spring of 2011 (25/95,26. 3%). The incidence of both two viruses infection was lower in autumn and winter of 2009-2010. ②The rate of severe pneumonia in patients with S-OIVs and seasonal IVA infection was 1/15(6. 7%)and 14/90(15. 6%). There were no significant differences in clinical manifestation,white cell counts,CRP level between S-OIVs and seasonal IVA positive cases. 14 of 90 seasonal IVA positive cases were with severe pneumonia and 1 of 15 S-OIVs positive cases was with severe bronchiolitis. ③Five samples were found with single S-OIVs infection among 15 S-OIVs positive cases,other respiratory viruses were detected in 9 samples. Twenty one samples were found to be single seasonal IVA postive among 90 seasonal IVA positive cases,other respiratory viruses were detected in 42 samples. ④Multivariate logistic regression analysis showed that underling heart medical condition (OR=13. 60),wheezing(OR=6. 82)and co-infection with adenovirus(OR=6. 21)were the risk factors of developing severe pneumonia in patients with seasonal IVA infection. Conclusion The study indicated that the detection rate of S-OIVs infection and seasonal IVA was 1. 4% and 8. 4% respectively,in hospitalized children with acute airway respiratory infection in Chongqing. Children younger than 2 years old appeared to be susceptible to both virus infections. Diagnosis of non-severe respiratory tract infection was mainly presented in hospitalized patients with S-OIVs and IVA infection in the respiratory medicine division of our hospital. Underling heart medical condition,symptom of wheezing,and co-infection with adenovirus increase the risk of developing severe pneumonia in patients with seasonal IVA infection.