Clinical features of severe cases of hand,foot and mouth disease with EV71 virus infection in China

Introduction

Hand, foot and mouth disease (HFMD) caused by EV71 infection has become one of the major public health issues in China, which deeply affects children''s health. The prevention and control of EV71 is a challenge currently because there is no safe and effective vaccine or antiviral medications available.

Material and methods

A case control study was conducted in a designated hospital to compare severe and mild cases of patients infected with the EV71 virus. Demographic information along with clinical features of HFMD was collected through a standardized questionnaire. Multi-factorial logistic regression was used to analyze independent associations between potential risk factors and severe HFMD.

Results

There were 120 cases (60 cases and 60 controls) collected. The male-to-female ratio was 1.3: 1 in the case group and 1.7: 1 in the control group. Multi-factorial logistic regression revealed that the main risk factors for severe cases were highest body temperature being ≥ 38.5°C (OR = 9.45, 95% CI: 2.07–43.11, p < 0.05), first visited a village level clinic (OR = 4.72, 95% CI: 1.15–19.45, p < 0.05), etc.

Conclusions

Close surveillance combined with laboratory testing should be in place during the epidemic period of HFMD. Grass root level medical facilities and training of clinical and laboratory staff should be reinforced so that the diagnostic and treatment capacity can be improved.     

Association of polymorphisms in the vitamin D receptor gene with severity of hand,foot, and mouth disease caused by enterovirus 71

Severe hand, foot, and mouth disease (HFMD) is sometimes associated with critical complications that can cause substantial child mortality. Activity of the vitamin D receptor (VDR) may influence the outcomes of enterovirus 71 (EV71) infection. This case-control study aimed to assess the association of single-nucleotide polymorphisms (SNPs) in the gene encoding the VDR with the severity of EV71-associated HFMD. We selected four VDR SNPs based on linkage disequilibrium and functional prediction, and we tested them using the SNPscan multiple SNP typing method for potential association with severity of EV71-associated HFMD. We found a significant association in the case of rs11574129 (G vs A: odds ratio (OR), 0.3439; 95% confidence intervals (CI), 0.1778-0.6653) and rs739837 (T vs G: OR, 0.5580; 95%CI, 0.3352-0.9291). Our results suggest that these two SNPs may influence the severity of EV71-associated HFMD.     

深圳市某街道2009-2010年手足口病病原体监测分析

目的对2009-2010年深圳市某街道手足口病进行病原学监测分析。方法收集5440份手足口病患者的病原学监测资料,对资料进行描述性分析和χ2检验。结果总肠道病毒（EV71和CoxA16）阳性率为43.3%,其中EV71阳性率为19.4%,CoxA16阳性率为23.9%,二者差异无统计学意义（χ2=0.396,P=0.529）。男性总肠道病毒阳性率为44.7%,女性阳性率为41.4%,不同性别间肠道病毒阳性率差异无统计学意义（χ2=0.076,P=0.783）。各年龄段肠道病毒阳性率差异有统计学意义（χ2=4.241,P=0.039）。12名重症患者中,EV71阳性率75.0%。结论深圳市某街道2009-2010年手足口病流行的病原体为EV71和CoxA16,不同性别的阳性率无差别,各年龄段肠道病毒阳性率差异有统计学意义。     

2008年广东省肠道病毒71型分离株全基因组核苷酸序列分析

目的 了解2008年广东省流行的肠道病毒(EV)71型基因特征.方法 选择2008年广东省分离的1株EV71毒株(GDFS-3),进行全基因组序列测定和基因进化特性的分析.结果 GDFS-3株与其他EV71型毒株相比,在编码区没有核苷酸的缺失和插入,其5'UTR和3'UTR的长度和序列有一定的差异.核苷酸同源性比较结果 表明,GDFS-3株与中国台湾流行株(TW984)的同源性最高(为96.0%),与新加坡流行株SIN5865及标准株MS、BrCr的同源性则在81.0%左右.氨基酸同源性比较结果 表明,GDFS-3株与TW984同源件最高(99.0%).根据VP1基因序列构建亲缘性关系树,GDFS-3株与C4亚型(subgenogroup)聚为一簇,与C4亚型代表株的核苷酸序列同源性为91.0%～95.0%.结论 遗传进化分析表明,GDFS-3株和中国台湾2004年流行的EV71毒株的亲缘关系最为密切,属于C4亚型,而与标准株BrCr和MS的亲缘关系较远.5'UTR的突变对于EV71毒力增强可能有重要作用.上述结果 有助于EV71型的基础研究和中国对于EV71所致疾病的预防.     

Enterovirus spectrum from the active surveillance of hand foot and mouth disease patients under the clinical trial of inactivated Enterovirus A71 vaccine in Jiangsu,China, 2012‐2013

Epidemiological data from active surveillance on human enterovirus, which could cause hand, foot, and mouth disease, were limited. An active surveillance system was used to investigate the enterovirus spectrum and the incidence of different enteroviruses in infants aged 6–35 months in Jiangsu Province from 2012 to 2013. Fifty‐nine infants were randomly selected from 522 non‐EV‐A71/CV‐A16 HFMD patients. We collected 173 throat swabs and 174 rectal swabs from these infants. RT‐PCR was used to amplify 5'‐UTR and VP1 regions of enteroviruses and the serotypes were determined by the sequence comparison using BLAST. Twenty‐one non‐EV‐A71/CA16 enterovirus serotypes were detected in those infants. E16, E18 were firstly reported in HFMD patients. The four top common non‐EV‐A71/CV‐A enteroviruses among infants were CV‐B3, CV‐A10, CV‐A6, and E9 with the HFMD incidence rates at 1.4%, 0.84%, 0.56%, and 0.47%, respectively. Over 20.8% patients were co‐infected with multiple enteroviruses. Neither the course of sickness nor clinical symptoms of the co‐infected patients was more severe than those infected with single enterovirus. Two patients were infected different enterovirus successively within 2 months. Several new enterovirus serotypes and multiple models of infection associated with HFMD were discovered through the active surveillance system. These data provide a better understanding of the viral etiology of HFMD. J. Med. Virol. 87:2009–2017, 2015. © 2015 Wiley Periodicals, Inc.

     

肠道病毒71型手足口病的疫苗筛选和观察

目的 筛选安全有效新型EV71候选疫苗,为将来EV71疫苗开发应用奠定基础.方法 以重组蛋白VP1为疫苗设计靶点,不同候选疫苗包括灭活疫苗、DNA疫苗、VP1蛋白疫苗在0、2周、4周分别按照不同剂量和肌内注射途径免疫BALB/c雌性小鼠,在0、2周、4周、6周、8周、10周、16周分别采集小鼠尾静脉血,16周处死小鼠,收集小鼠脾脏细胞,检测小鼠体液免疫和细胞免疫功能,筛选评价候选疫苗的疗效和安全性.结果 灭活病毒疫苗、VP1 DNA质粒疫苗、VP1蛋白疫苗免疫小鼠2周后IgG抗体滴度即开始升高,4周后明显升高,8周后达高峰,至少维持16周以上;IgG亚类以IgG2a和IgG1为主.三种疫苗能诱导以γ-IFN和IL-4为主的细胞免疫反应.灭活疫苗疗效优于其他候选疫苗,未发现疫苗相关不良反应.结论 灭活病毒疫苗、VP1 DNA质粒疫苗、VP1蛋白疫苗均能诱导持久的特异性细胞免疫和中和抗体反应,以灭活病毒疫苗疗效较好,需要将来攻毒实验可进一步验证其免疫力.     

Ongoing change of severe hand,foot, and mouth disease pathogens in Yunnan,China, 2012 to 2016

Hand, foot, and mouth disease (HFMD) is a common infectious disease caused by enteroviruses (EVs). In this study, a total of 341 children with serious HFMD were admitted to a pediatric hospital in Yunnan, China in 2012 to 2016. EVs were detected in 283 specimens (83.0%) and were assigned to 17 EV types. Enterovirus A71 (EV-A71) was predominant, accounting for 41.6%, and was followed by coxsackievirus A16 (CV-A16; 18.8%), CV-A6 (9.1%), CV-A10 and E-9 (2.9%), CV-B5 (1.8%), CV-A9 (1.2%), E-30 (0.9%), E-18, CV-A4, C-B3, and CV-A2 (0.6%) and other EV types such as CV-A8, CV-A14, E-14, E-11, and CV-B4 (0.3%). All of the EV-A71 isolates belonged to C4a; the CV-A16 belonged to B1b or B1a, although the B1b strains were predominant; and CV-A6 belonged to D3. In 2012 to 2014, E-9 was the third most frequent serotype (8.2%, 5.0%, and 6.5%, respectively). E-9 was not detected in 2015 and 2016. CV-A6 was not detected in 2012 but was the second most frequent serotype (25.3%) in 2015. Active etiological surveillance of HFMD makes it necessary to be aware of these emerging pathogens.     

柯萨奇病毒A组6型与肠道病毒71型感染所致手足口病临床特征比较

目的 了解柯萨奇病毒A组6型、肠道病毒71型手足口病临床特点,为指导临床诊断,调整手足口病防控策略提供科学依据.方法 采用前瞻性调查的方法,收集2013至2014年在北京市西城区手足口病临床确诊病例信息,将手足口病原核酸检测阳性的病例分为CA6、EV71组,分析比较2组的临床特点、流行特征、预后等.结果 CA6组130例,EV71组121例.2组的年龄、性别分布差异无统计学意义.CA6组发热比例高达82.3％,明显高于EV71组(34.7％,P＜0.05),其中大于等于38℃占85.0％.CA6组出现大疱疹(7.4％)、恢复期脱皮(16.9％)、脱甲(10.0％)的比例高于EV71组(P＜0.05).不同年份流行主要毒株不同.结论 与EV71感染相比,CA6感染引起的高热比例较高,部分病例可表现为大疱疹、脱皮、脱甲,整体预后较好.CA6和EV71感染所致的HFMD发病高峰季节不一致.     

Understanding the epidemiological characteristics of EV71 and CVA16 infection to aid the diagnosis and treatment of hand,foot, and mouth disease

Hand, foot, and mouth disease (HFMD) have been recognized over the past several years as a highly infectious disease in children. Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) are the two major causative agents. The objective of this study was to determine the optimal time and method of HFMD detection, explore the seroconversion of IgM and IgG antibodies, and examine the response of neutralizing antibody (NtAb) to EV71 or CVA16. Between January 2016 and December 2017, a total of 460 patients, diagnosed with HFMD based on clinical symptoms and hospitalized in the First Hospital of Jilin University, were recruited for the study. At approximately 72 hours post illness onset, we observed that the positive rate of both IgM and real-time polymerase chain reaction detection of EV71 or CVA16 was the highest, this could be considered as the optimal detection time for clinical diagnosis. During the initial 0 -96 hours, the relative highest IgM and the relative lowest IgG antibody levels were observed. The NtAb titers to EV71 and CVA16 also gradually increased with time, showing a positive correlation with age, and being the predominant factor during the hospitalized days. Thus, our study provides important information for the clinical diagnosis and treatment of HFMD.     

Hand,foot and mouth disease in Guangdong,China, in 2013: new trends in the continuing epidemic

Millions of incidents of hand, foot and mouth disease occur annually in China, with EVA71 and CVA16 as two major causative pathogens. A provincial surveillance system has been implemented in Guangdong for almost 5 years to analyze the aetiological spectrum and epidemic changes. An unusual enterovirus type, CVA6, was identified as the predominant serotype associated with an HFMD epidemic from late 2012 to 2013. In contrast to virus strains isolated before, all CVA6/CHN/2012–2013 strains segregated into one major genetic cluster. This study suggested that one cluster of circulating CVA6 strain had emerged as a new and major cause during a continuing HFMD epidemic in Guangdong, China.     

Outbreak of hand,foot and mouth disease/herpangina associated with coxsackievirus A6 and A10 infections in 2010, France: a large citywide,prospective observational study

Hand, foot and mouth disease (HFMD) and herpangina (HA) are frequently caused by several distinct serotypes belonging to the human enterovirus A species (HEVA). Enterovirus 71 is considered as a significant public health threat because of rare but fatal neurological complications. A sentinel surveillance system involving paediatricians from Clermont-Ferrand (France) was set up to determine the clinical and epidemiological characteristics of HFMD/HA associated with enterovirus infections. A standardized report form was used to collect demographic and clinical data. Throat or buccal specimens were obtained prospectively and tested for the presence of enteroviruses. The frequency of HEVA serotypes was determined by genotyping. Phylogenetic relationships were analysed to identify potential new virus variants. From 1 April to 31 December 2010, a total of 222 children were enrolled. The predominant clinical presentation was HA (63.8%) and this was frequently associated with clinical signs of HFMD (48%). An enterovirus infection was diagnosed in 143 (64.4%) patients and serotype identification was achieved in 141/143 (98.6%). The predominant serotypes were coxsackievirus A10 (39.9%) and A6 (28%), followed by coxsackievirus A16 (17.5%) and enterovirus 71 (6.3%). Fever was observed in 115 (80.4%) children. No patient had neurological complications. Coxsackievirus A10 and A6 strains involved in the outbreak were consistently genetically related with those detected earlier in Finland and constituted distinct European lineages. Although several enterovirus serotypes have been involved in HFMD/HA cases, the outbreak described in this population survey was caused by coxsackievirus A6 and coxsackievirus A10, the third dual outbreak in Europe in the last 3 years.     

Molecular epidemiology analysis of enterovirus 71 strains isolated in Dak Lak,Vietnam, 2011-2016

Human enterovirus 71 (EV71) is the major etiologic agent of hand, foot, and mouth disease (HFMD). EV71 outbreaks have been reported in Dak Lak in recent years, however, the genotypes/subgenotypes information and phylogeny of circulating EV71 strains are limited. The objectives of this study were to determine the genotypes/subgenotypes and investigate the phylogeny of EV71 isolates in Dak Lak over a 6-year period. Viruses were isolated from clinical samples from patients with HFMD. In total, 43 EV71 isolates circulated in Dak Lak during 2011-2016 were used for the phylogenetic analysis using complete VP1 gene. The phylogenetic analysis of the VP1 gene revealed that two major genotypes, B and C, were found. Among the 43 EV71 strains, 29 belonged to subgenotype C4, 2 belonged to subgenotype C5, and 12 belonged to subgenotype B5. Of these, the subgenotype C4 was predominant in 2011-2013 and this was later replaced by the subgenotype B5 in 2014. The subgenotype B5 was dominant between 2014 and 2015, and then C4 recirculated in 2016. Our study also indicated that the subgenotypes C4 and B5 emerged into Dak Lak were closely related to variants causing epidemics of HFMD in the southern and central region of Vietnam and Thailand. Sequence analysis showed that nine amino acid mutations were detected in the VP1 region. Our results identified two significant amino acid substitutions (D31N and E145G/Q) associated with enhancing EV71 virulence.