目的:分析5月份广东省某市一起急性出血性结膜炎(acute hemorrhagic conjunctivitis，AHC)疫情中病原体的进化特征及变异情况，为制定新一轮AHC流行防控措施提供科学依据。方法:采集20份AHC患者眼结膜拭子，采用实时荧光定量PCR(real-time quantitative PCR，qPCR)方法，对其进行肠道病毒(enterovirus，EV)、EV70(human enterovirus 70, HEV70)和CVA24v(coxsackievirus A24 variant，CVA24v)核酸检测，并对CVA24v阳性样本的VP1区和3Cpro区进行序列测定，分析其与国内外流行的CVA24v基因进化关系。结果:20份眼拭子标本中，肠道病毒全部显示EV阳性，CVA24v全部阳性，阳性率100%，EV70全部阴性。其中5份样本的CVA24v的VP1和7份样本的CVA24v的3Cpro区基因组成功测序，基于VP1和3Cpro区的分子特征分析发现，本次疫情流行的CVA24v与2014年泰国和2015年法属留尼群岛流行的CVA24v具有最大的核苷酸相似性。3Cpro区和VP1区的系统发育进化树显示本次疫情CVA24v与2014年泰国和2015年法属留尼群岛流行的CVA24v聚为一簇，具有较高亲缘关系。与2010年广东、2014年泰国和2015年法属留尼群岛流行的CVA24v相比，本次疫情流行的CVA24v在3Cpro区4个氨基酸位点发生替换，在VP1区有1个氨基酸位点发生替换。结论:引起本次疫情病原体为肠道病毒CVA24v，且与2014年泰国和2015年法属留尼群岛流行的CVA24v具有最高相似性，3Cpro区和VP1区序列均出现新的的氨基酸突变。

目的 为鉴定2023年深圳市宝安区某学校一起急性出血性结膜炎(acute hemorrhagic conjunctivitis,AHC)聚集性疫情的病原并进行病原学特点分析,为快速追溯传染源以及处置此类疫情提供了参考和依据.方法 对深圳市宝安区2023年某学校一起AHC聚集性疫情采集22份眼拭子标本进行分析.采用实时荧光定量聚合酶链式反应(poly-merase chain reaction,PCR)方法对采集自患者的眼拭子标本进行肠道病毒70型(Enterovirus 70,EV70)和柯萨奇病毒A组24型(Coxsackievirus A24,CVA24)基因检测,然后测定阳性样本中病毒基因(VP1)核苷酸的全序列,测定的序列与不同时期、不同地区CVA24的序列比对,分析同源性并构建系统进化树,同时将核苷酸序列翻译成氨基酸序列,分析氨基酸位点突变情况.结果 采集的22份眼拭子标本中,经荧光定量PCR检测,有16份CVA24病毒阳性,阳性率为72.73%,而EV70病毒均为阴性.其中16份标本用VP1引物进行扩增,并对扩增产物测序,成功扩增并测序出14份标本的VP1全长序列.分析和比对核苷酸序列,鉴定结果均为CVA24v GⅣ基因型.基因进化分析显示这14株CVA24v核苷酸同源性为100.00%,与CVA24v的原型株EH24/70的核苷酸同源性为85.14%,与CVA24的原型株Joseph的核苷酸同源性为77.27%.系统进化树显示,它们与同时期广东省中山市流行的CVA24v毒株处于同一进化分支上,其亲缘关系最近.与2023年以前流行的参考序列的氨基酸序列比较,本次流行株的VP1区氨基酸序列在16位点形成一个新的突变,由亮氨酸(L)替换为异亮氨酸(I).结论 本次急性出血性结膜炎聚集性疫情的病原体是柯萨奇A24型变异株,其氨基酸序列出现一个新的变异位点,根据系统进化树结果,推测毒株可能来源于同时期广东省流行的株型.

目的 了解中山市急性出血性结膜炎的致病病原体及其基因分型,分析急性出血性结膜炎病原体流行规律及其分子流行特征.方法 采集临床急性结膜炎病例眼拭子标本,荧光定量PCR法检测肠道病毒70型(EV70)、柯萨奇A24病毒变种(CVA24V)和腺病毒(Adv)核酸,用PCR法扩增腺病毒六邻体(Hexon)片段基因和基因测序,在Genbank上进行序列比对分型.结果 从2017年3月-2018年12月,共检测中山市哨点医院眼科医院门诊急性结膜炎病例眼拭子标本384份.核酸检测结果EV70和CVA24v均为阴性,152份标本Adv阳性,阳性率为39.58％.腺病毒六邻体片段基因测序成功的124份样本中,检测到Adv3、4、7、8、37、53、64等基因型,主要型别为Adv3型(26.61％,33/124)、Adv64型(20.16％,25/124)和Adv8型(20.16％,25/124).结论 腺病毒是引起中山市2017-2018年急性结膜炎的主要病原体,且基因型别以3型、64型以及8型为主.

Enteroviruses (EVs) belong to the family Picornaviridae and are divided into 15 species:enterovirus A–L and rhinovirus A–C (http://www. picornaviridae.com). EV-C consists of 23 serotypes, including poliovirus 1-3, CVA1, CVA11, CVA13, CVA17, CVA19, CVA20, CVA21, CVA22, CVA24, EV-C95, EV-C96, EV-C99, EV-C102, EV-C104, EV-C105, EV-C109, EV-C113, EV-C116, EV-C117, and EV-C118, which can cause diseases as herpangina, hand, foot and mouth disease, acute hemorrhagic conjunctivitis (AHC), aseptic meningitis, and acute flaccid paralysis (AFP)[1-3]. CVA1 is only rarely detected during EVs monitoring, so the data of this virus is very limited. Up to now, only six strains of CVA1 with whole genome or polyprotein gene sequence have been published. The prototype strain Tompkins was identified from the fecal sample of a patient with paralytic disease in the Coxsackie, USA in 1947 which was pathogenic for lactating mice and hamsters but not for rhesus monkeys. It caused significant damage to the skeletal muscle of experimental animals, but not to the central nervous system[4]; HT-THLH02F/XJ/CHN/2011 strain and KS-ZPH01F/XJ/CHN/2011 strain were isolated from two healthy children's fecal samples in the Xinjiang Uygur autonomous region of China, in 2011. they could elicit cytopathic effects (CPE) in a human rhabdomyosarcoma (RD) cell line[5]; BBD34 strain was identified from a patient with gastrointestinal disease in Bangladesh in 2009[6]; V18A strain was isolated from fecal sample in Venezuela in 2015;ETH_P8/A1_2016 strain was isolated from the excrement of children who participated in a clean water intervention experiment in Ethiopian, in 2016[7].

Coxsackievirus A24 variant(CVA24v)is a major pathogen that causes continued outbreaks and pandemics of acute hemorrhagic conjunctivitis(AHC).In China,the first confirmed outbreak of CVA24v-related AHC occurred in Beijing in 1988,followed by another two significant outbreaks respectively in 1994 and 2007,which coincides with the three-stage dynamic distribution of AHC in the world after 1970s.To illustrate the genetic characteristics of CVA24v in different periods,a total of 23 strains were isolated from those three outbreaks and the whole genome of those isolations were sequenced and analyzed.Compared with the prototype strain,the 23 strains shared four nucleotide deletions in the 5'UTR except the 0744 strain isolated in 2007.And at the 98th site,one nucleotide insertion was found in all the strains collected from 2007.From 1994 to 2007,amino acid polarity in the VP1 region at the 25th and the 32nd site were changed.Both the 3C and VP1 phylogenetic tree indicated that isolates from 1988 and 1994 belonged to Genotype Ⅲ(GⅢ),and 2007 strains to Genotype Ⅳ(GⅣ).According to the Bayesian analysis based on complete genome sequence,the most recent common ancestors for the isolates in 1988,1994 and 2007 were respectively estimated around October 1987,February 1993 and December 2004.The evolutionary rate of the CVA24v was estimated to be 7.45×10-3 substitutions/site/year.Our study indicated that the early epidemic of CVA24v in Chinese mainland was the GⅢ.Point mutations and amino acid changes in different genotypes of CVA24v may generate intensity differences of the AHC outbreak.CVA24v has been evolving constantly with a relatively rapid rate.