自2005年人博卡病毒首次发现以来，其流行性已在世界各地广泛报道。由中科院上海巴斯德研究所杜文圣研究员（Vincent Deubel）领导的新生病毒研究组通过各种实验手段，深入研究博卡病毒在病毒学及免疫学上的特性，发现了人博卡病毒感染与体液免疫反应的关系，以及在患有急性呼吸道感染的儿童中，博卡病毒与其他呼吸道病毒的高共感染性。这引起我们对该病毒适应宿主和协助其他病毒感染的可能性的警惕。该研究成果发表在2009年12月16日的临床病毒学杂志上（Journal of Clinical Virology）。
博卡病毒是一种新发现的细小病毒。2005年，瑞典实验室从下呼吸道感染的儿童体内发现了人博卡病毒。自此以后，世界各地纷纷在呼吸道，血液，粪便，尿液等处发现博卡病毒。有呼吸道病症的患者感染博卡病毒的几率明显比正常人高，但同时，博卡病毒阳性患者常常发现有其他病毒共感染现象。因此，人博卡病毒是否会引起呼吸道疾病还有争议。
经过两年时间，研究组从上海南翔医院共获得817例样本，并做了12例回访病例研究。研究发现，人博卡病毒在该群患儿中阳性率高达11.8%，仅次于流感病毒以及呼吸道合胞病毒；小于2岁的患儿，博卡病毒的检出率大大高于年长患儿；然而，抗博卡病毒IgG阳性率却随着患儿年龄增加而逐步上升。这证明了博卡病毒可能在幼儿期有很高的感染率。
研究发现，博卡病毒与其他呼吸道病毒的共感染率可高达51%，且更多地出现在那些只有低拷贝博卡病毒的患儿样品中。博卡病毒可以以低拷贝数长期存在于呼吸道，血液以及尿液中达一个月之久。而共感染现象在这些长期感染博卡病毒的病人中十分普遍。
本研究提出了急性博卡病毒感染可以导致系统性感染，引起免疫反应，并最终表现为患儿的呼吸道疾病。
此项工作得到了中科院外国专家特聘研究员计划，以及国家科技重大专项“呼吸系统与中枢神经系统病毒感染病原和免疫应答检测技术平台的建立”，李嘉诚基金会（RESPARI项目），法国发展署资助的“东南亚流行病检测调查”等支持。
原始出处：
Journal of Clinical Virology doi:10.1016/j.jcv.2009.11.015
Correlation between bocavirus infection and humoral response, and co-infection with other respiratory viruses in children with acute respiratory infection
Kai Wanga, Wei Wanga, Huajie Yanb, Peijun Rena, Jing Zhanga, Jun Shenb and Vincent Deubela, ,
a Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai Institute of Biological Sciences, Unit of Emerging Viruses, Shanghai, PR China
b Shanghai Nanxiang Hospital, Pediatric Department, Shanghai, PR China
Background
Human bocavirus (HBoV), a recently discovered virus, is prevalent among children with respiratory tract infection throughout the world. Co-infection was frequently found in HBoV-positive patients. Thus, whether HBoV is responsible for the respiratory disease is still arguable.
Objectives
A comprehensive study was carried out to integrate clinical and virological prevalence in HBoV-positive outpatient children, and to determine genetic and serologic characteristics of HBoV in Shanghai, China.
Study design
Nasal/throat swabs and sera were obtained over a 2-year period from 817 children with respiratory tract infection to examine the presence of HBoV and its co-infection. The seroepidemiology of HBoV was studied by ELISA and Western blot against the capsid protein VP2-based fragment. Persistence of HBoV was also analyzed in 12 pairs of return-visit cases.
Results
HBoV was identified in 96 samples (11.8%). The co-infection rate with other respiratory viruses was 51%. IgM was detected in 55.7% of HBoV RT-PCR-positive patients, and in 72.7% of those who had high viral genome load. In addition, persistent viral DNA positivity was detected in 10 of 12 HBoV-positive cases tested, an average of 14 days later, and one child was still HBoV-positive after 31 days.
Conclusion
HBoV was found frequently in children with respiratory tract symptoms associated with other respiratory viruses, and persisted in the respiratory tract and in serum and urine. The presence of IgM was significantly more prevalent in viremic patients and those diagnosed with high load of HBoV DNA in nasal/throat swabs.
