2013至2014年北京手足口病流行季相关肠道病毒型别变化和分析

Analysis on the change of genotype of enteroviruses associated hand, foot and mouth disease in Beijing during 2013 to 2014

目的分析北京2013至2014年手足口病流行期间肠道病毒的型别、流行趋势和临床特点，为手足口病的防治提供科学依据。方法2013年4至9月和2014年3至10月，首都儿科研究所附属儿童医院感染门诊就诊患儿的咽拭子标本共977份，其中2013年初步诊断手足口病患儿标本147份；2014年初步诊断手足口病患儿标本343例，不典型手足口病患儿标本201份，疱疹性咽峡炎患儿标本83份，发热伴抽搐患儿标本25份，发热伴出疹患儿标本64份，皮疹待查患儿标本114份。采用实时荧光逆转录聚合酶链反应方法检测肠道病毒（EV）通用型，肠道病毒71型（EV71）和柯萨奇病毒A组16型（CA16）；采用巢式PCR方法对EV通用型阳性而非EV71和CA16的标本核酸进行VP1片段的扩增和测序分析以鉴定型别。分别比较不同年龄组、不同年份间肠道病毒的检出情况，分析其在两个年份的流行趋势。结果977份标本总阳性率为80．1％（783／977），其中CA16为25．6％（250／977），EV71为18．9％（185／977），CA6为20．0％（195／977），CA10为5．0％（49／977），CA4为1．5％（15／977），其他EV为9．1％（89／977），阴性19．9％（194／977）。2013年和2014年检出的各型别地方株同型间均具有较高的同源性，CA6的同源性为94．3％～100％，CA10的同源性为93．8％～99．1％，CA4的同源性为92．7％～99．8％。≤1岁年龄患儿肠道病毒总阳性率为71．1％（106／149），低于其他年龄组（P均〈0．05），但与〉5岁组相近（χ2=1．181，P=0．277）。2013年147例手足口病患儿标本中肠道病毒阳性率为85．7％（126／147），CA6为优势型别占54．8％（69／126），其次是CA16和EV71，分别为20．6％（26／126）和11．9％（15／126）。2014年343例手足口病患儿标本中肠道病毒阳性率为85．4％（293／343），CA16和EV71成为主要型别，分别占42．7％（125／293）和38．2％（112／293），而CA6仅占11．3％（33／293）。2014年不典型手足口病、疱疹性咽峡炎、发热伴抽搐、发热伴出疹和皮疹待查患儿标本的肠道病毒阳性率分别为83．6％（168／201），80．7％（67／83），76．0％（19／25），64．1％（41／64）和60．5％（69／114）。各型肠道病毒的流行高峰主要集中在5至8月份，而每年各型肠道病毒的流行趋势却没有明显的规律。结论北京地区引发儿童手足VI病的肠道病毒，2013年CA6占据第一，2014年CA16和EV71再次成为主要型别；CA6、CA10和CA4等型别肠道病毒引发的临床症状与EV71和CA16引发的临床症状可能存在差异；除EV71和CA16外，也需要重视对CA6、CA10和CA4等其他型别肠道病毒的监测和研究。

Objective To analyze the genotype, epidemic pattern and the characteristics of the disease of enteroviruses during the epidemic season of hand, foot and mouth disease （ HMFD ） in childrenfrom 2013 to 2014 in Beijing to provide the scientific evidence for prevention and treatment of HFMD. Method During April to September in 2013 and March to October in 2014, a total of 977 throat swabs were collected from children who visited the Children＇s Hospital Affiliated to Capital Institute of Pediatrics, including 147 from patients with HFMD in 2013, 343 with HFMD, 201 with atypical HFMD, 83 with herpangina, 25 with fever with convulsions, 64 fever with rash and 114 with rash in 2014. Enterovirnses universal type （EV） , Enteroviruses type 71 （EV71） and Coxsackievirus group A 16 （CAI6） were detected by real-time RT-PCR respectively. The nucleic acid of specimens which were identified with non-EV71, non-CA16 was tested by nested PCR and analyzed by VP1 sequencing. The detection rate and epidemic pattern of different genotypes of enterovirns were analyzed among different age groups and between 2013 and 2014. Result Of 977 throat swabs, 80. 1% samples were detected positive for enterovirnses. The positive rates of CA16, EV71, CA6, CA10, CA4 and other EVs were 25.6% （250/977）, 18.9% （185/977） , 20. 0% （ 195/977）, 5.0% （49/977）, 1.5% （15/977） and 9. 1% （89/977）, respectively. Twenty six of the 89 other EVs included CA2, CA5, CA8, CA9, CA12, CA14, CB2, CB5, E6, E9 and E25, each genotype of which was no more than 3. The nucleotide homologies shared among CA6, CA10 and CA4 strains between 2013 and 2014 were 94. 3% - 100%, 93. 8% - 99. 1% and 92. 7% - 99.8%, respectively. The positive rates of ≤1 year group were 71.1% （106/149）, which was lower than that of other age groups （ all P 〈 0. 05 ）, but similar to that of 〉 5 year group （ χ2 = 1.181, P = 0. 277 ）. In 2013, the positive rate of EV was 85.7% （126/147） and the predominant genotype was CA6 54. 8% （69/126）, followed by CA16 20. 6% （26/126） and EV71 11.9% （15/126）. In 2014, the positive rate of EV was 85.4% （293/343） in the 343 children with HFMD, the predominant genotypes were CAI6 with the positive rate of 42.7% （125/293）, EV71 with 38.2% （112/293） and CA6 with only 11.3% （33/293）. In 2014, the positive rates of EV in 201 atypical HFMD, 83 herpangina, 25 fever with convulsions, 64 fever with rash and 114 rash were 83.6% （ 168/201 ）, 80. 7% （ 67/83 ）, 76. 0% （ 19/25 ）, 64. 1% （41/64） and 60. 5% （69/114）, respectively. All genotypes of enterovirnses peaked mainly during May to August every year, but there were no obvious epidemiological pattern about each genotype. Conclusion CA6 became the main causative agent of HFMD in 2013, however, CA16 and EV71 predominated again in 2014 in Beijing. The clinical manifestations caused by CA6, CAI0, CA4 and other genotype of enterovirnses differed from EVT1 and CA16. Besides EV71 and CA16, more attention should be paid to CA6, CA10, CA4 and other type of enteroviruses.