住院呼吸道感染患儿博卡病毒检测分析

Detection and analysis of bocavirus in hospitalized children with respiratory infection

目的了解人博卡病毒（HBoV）在天津地区急性呼吸道感染患儿中的检测情况和基因的遗传进化特征。方法收集2012年1~12月确诊为急性呼吸道感染患儿的鼻咽抽吸物标本1259份,提取病毒核酸,采用实时荧光定量PCR法检测HBoV,并采用PCR法扩增阳性标本HBoV核衣壳蛋白基因片段;随机选取部分产物进行测序确证,将所获得的序列与已知的HBoV基因序列进行比对并进行系统进化分析;同时对所有标本进行其他多种呼吸道相关病毒检测。结果 1259份标本中HBoV阳性检出率为4.53%（57/1259）,其中75%（43/57）发生在6~36月龄的患儿;检出高峰主要集中在夏季（6~8月）;存在与其他病毒的混合感染情况。对其中36份阳性标本的PCR产物进行序列分析,证实检测结果确为HBoV,且与已知HBoV的基因序列同源性较高。结论天津地区部分儿童的急性呼吸道感染可能与HBoV感染相关,且HBoV感染在6~36月龄的婴幼儿中更为常见,夏季为流行高峰;系统进化分析显示与已知HBoV的基因序列同源性高,基因序列变异较小。

Objective To detect human bocavirus（HBoV） and investigate its genetic and evolutionary characteristics in children with acute respiratory infection in Tianjin, China. Methods A total of 1 259 samples of nasopharyngeal aspirates were collected from children with a confirmed diagnosis of acute respiratory infection between January and December, 2012. Viral nucleic acid was extracted, HBoV was detected by real-time quantitative PCR, and the gene segments of nucleocapsid protein of HBoV in positive samples were amplified by PCR. Several products were randomly selected and sequenced.The sequence obtained was compared with the known sequence of HBoV, and a phylogenetic analysis was performed. All the samples were examined to detect for other common respiratory tract viruses. Results Among the 1259 samples, the positive rate of HBoV was 4.53%（57/1 259）, and among the 57 samples with positive HBoV, 75%（43/57） were positive in children with an age of 6-36 months. The positive rate of HBoV in children peaked in summer（from June to August）, and there was a mixed infection with other viruses. Sequence analysis was performed for the PCR products from 36 positive samples, and the presence of HBoV was confirmed, with a higher homology to the known sequence of HBoV. Conclusions In Tianjin, acute respiratory infection in some children may be associated with HBoV infection, which is commonly seen in infants with an age of 6-36 months. The peak of HBoV infection occurs in summer. The phylogenetic analysis shows a high homology to the known sequence of HBoV, with few gene sequence variations.