长沙地区住院儿童人冠状病毒NL63的感染状况及临床特征

Prevalence and clinical characteristics of Coronavirus NL63 infection in children hospitalized for acute lower respiratory tract infections in Changsha

目的了解HCOV—NL63在长沙地区急性下呼吸道感染住院儿童中的流行状况以及临床特征。方法采集长沙地区2008年9月至2010年10月因急性下呼吸道感染住院儿童NPA样本1185份，用RT—PCR方法检测HCOV—NL63N基因，阳性扩增产物经测序确认，统计分析临床资料。结果1185份NPA样本中，HCOV—NL63检出阳性10份，检出率为0．8％，其中春季检出1例、夏季检出6例、秋季检出2例、冬季检出1例；阳性检出病例患儿年龄最大2岁半，最小2个月，平均月龄12．5个月；男童7例，女童3例；临床诊断为支气管肺炎6例、毛细支气管炎3例、急性喉气管支气管炎1例；10例中有4例病情危重；4例有基础疾病；7例合并其他病毒混合感染；阳性扩增产物经测序分析与HCOV．NL63参考株同源性为97％～100％。结论本资料HCOV—NL63阳性检出患儿年龄均在3岁以下；夏季检出率高；男童感染为主；单一基因型在长沙地区流行；HCOV—NL63可能也是我国儿童急性下呼吸道感染中的一种病原。

Objective The main objective of this study was to explore the prevalence and clinical characteristics of human coronavirus NL63 infection in hospitalized children with acute lower respiratory tract infection （ALRTI） in Changsha. Methods Nasopharyngeal aspirates （NPA） samples were collected from 1185 hospitalized children with ALRTI at the People＇s Hospital of Hunan province, between September 2008 and October 2010. Reverse transcriptase polymerase chain reaction （RT-PCR） was employed to screen for coronavirus NL63, which is a 255 bp fragment of a part of N gene. All positive amplification products were confirmed by sequencing and compared with those in GenBank. Results The overall frequency of coronavirus NL63 infection was 0. 8% ,6 （60%） out of the coronavirus NL63 positive patients were detected in summer,2 in autumn,1 in spring and winter, respectively. The patients were from 2 months to two and a half years old. The clinical diagnosis was bronchopneumonia （60%）, bronchiolitis （30%）, and acute laryngotracheal bronchitis（ 10% ）. Four of the 10 cases had critical illness, 4 cases had underlying diseases, and 7 cases had mixed infection with other viruses. The homogeneity of coronavirus NL63 with those published in the GenBank at nucleotide levels was 97%-100%. Conclusion Coronavirus NL63 infection exists in hospitalized children with acute lower respiratory tract infection in Changsha. Coronavirus NL63 infections are common in children under 3 years of age. There is significant difference in the infection rate between the boys and the girls： the boys had higher rate than the girls. The peak of prevalence of the coronavirus NL63 was in summer. A single genetic lineage of coronavirus NL63 was revealed in human subjects in Changsha. Coronavirus NL63 may also be one of the lower respiratory pathogen in China.