2007-2008年北京地区儿童手足口病的病原学分析

目的 通过病毒分离和鉴定了解2007-2008年春夏北京地区手足口病的病原学特征,为手足口病防治工作提供科学依据.方法 分别于2007年4-8月及2008年5-9月收集256例手足口病患儿的咽拭子和疱疹液标本共356份,其中咽拭子255份(包括10份重症患儿标本),疱疹液标本101份.将所有标本接种Vero细胞进行病毒分离,分离阳性的毒株用RT-PCR进行鉴定;对10份重症患儿标本除病毒分离外,还直接进行RT-PCR检测病毒核酸.结果 256例被检测患儿中188例为肠道病毒阳性,阳性率为73.4%.356份标本中共分离到239株肠道病毒,总阳性率为67.1%.其中疱疹液标本分离阳性率为75.2%(76/101),咽拭子标本分离阳性率63.9%(163/255),但两种标本接种细胞后出现病变的速度没有差别.重症患儿标本病毒分离阳性率50%(5/10).2007年的45例病毒分离株经肠道病毒通用引物PCR检测均为阳性,分型PCR显示,其中CA16占95.6%(43/45),EV71占4.4%(2/45);而2008年的143例病毒分离株经肠道病毒通用引物PCR检测142例为阳性,PCR分型显示,EV71占82.4%(117/142),CA16占16.8%(24/142).10份重症患儿标本直接分型检测结果均为EV71.结论 北京儿童手足口病病原体以EV71和CAV16为主,2007年与2008年流行的优势型别不同,2007年主要为CA16,而2008年主要为EV71.本组重症手足口病患儿的病原均为EV71.

Etiology study on hand, foot and mouth disease in children in Beijing during 2007 to 2008

Objective To investigate the etiological agents of hand, foot and mouth disease (HFMD) in children in spring and summer from 2007 to 2008 in Beijing and the characteristics of the disease by virus isolation and to provide the scientific evidence for prevention and treatment for HFMD. Methods During April to August, 2007 and May to September, 2008, 356 clinical specimens including 255 throat swabs and 101 vesicle fluids were collected from 256 patients with HFMD who visited the Children's Hospital Affiliated to Capital Institute of Pediatrics and children with severe HFMD with neural system complications from Ditan Hospital and Youan Hospital All of the specimens were inoculated into Vero cells for virus isolation. After the cell pathogenic effects (CPE) appeared, the isolates were identified by RT-PCR with the universal primers within 5'untranslated region of enterovirus and typed by specific primers for VP1 gene of EV71 and CA16, respectively. The throat swabs from all of 10 severe HFMD were tested for enterovirus by RT-PCR addition to virus isolation. Results Out of 256 patients, 188 were positive for enterovirus by virus isolation, with the overall positive rate of 73.4%. Among the 356 clinical specimens collected from these 256 patients, 239 enterovirus strains were isolated with the overall positive rate of 67.1%. The positive rate for virus isolation from vesicle fluid samples was 75.2% which was higher than the positive rate of isolation from throat swabs (63.9%), but the time for CPE appearing in cell culture showed no significant difference. The positive rate of virus isolation from throat swabs from children with severe HFMD was 50% (5/10) which was lower than overall positive rate (73.4%) from regular HFMD. The RT-PCR typing for virus isolates revealed that among 45 enterevirus strains isolated from the specimens collected in 2007 by the universal primer pairs, 43 were CAI6 (95.6%, 43/45) and 2 were EV71 (4.4%, 2/45), whereas for the specimens collected in 2008, out of 143 enterovirus isolates by PCR with universal primers, 117 were EV71 (82.4%, 117/142) and 24 were CA16 (16.8%, 24/142). All of 10 severe cases were positive for EV71 by RT-PCR directly from clinical specimens. Conclusion CA16 and EVT1 were the etiological pathogens of HFMD in Beijing during 2007 to 2008 HFMD seasons. The dominant type of enterovirus was different between 2007 and 2008. Enterovirus type CA16 was predominant in 2007, whereas EV71 was predominant in 2008. All of severe cases of HFMD in children in this study were caused by EV71.