Genetic diversity of coxsackievirus A16 associated with hand, foot, and mouth disease epidemics in Japan from 1983 to 2003

To clarify the chronologic genetic diversity of coxsackievirus A16 (CV-A16) strains associated with hand, foot, and mouth disease (HFMD) epidemics in a restricted area and their genetic relation with those isolated in other areas, we investigated the genetic diversity of the 129 CV-A16 strains associated with HFMD epidemics in Fukushima, Japan, from 1983 to 2003, and compared their genetic relation to 49 CV-A16 strains isolated in other areas of Japan and in China by using phylogenetic analysis based on the VP4 sequences. Phylogenetic reconstruction of the CV-A16 strains isolated in Fukushima from 1983 to 2003 demonstrated three distinct genetically divergent clusters related to HFMD epidemics that occurred from 1984 to 1994 (including the 1985 and 1991 outbreaks), HFMD epidemics from 1987 to 1998 (including the 1988 and 1998 outbreaks), and HFMD epidemics from 1995 to 2003 (including the 1995 and 2002 outbreaks). CV-A16 strains isolated during each period in Fukushima formed a single cluster with those isolated during essentially the same time period in other areas of Japan and in China. Our results demonstrated that prevalent CV-A16 strains causing HFMD in Fukushima, Japan, genetically changed twice during 21 epidemics, and changes were also observed in the CV-A16 strains causing HFMD epidemics in other areas. We concluded that repeated outbreaks of CV-A16-related HFMD in Japan were caused, in part, by the introduction of genetically changed CV-A16 strains, which might be transmitted overseas.     

Molecular epidemiology of enterovirus 71, coxsackievirus A16 and A6 associated with hand,foot and mouth disease in Spain

Hand, foot and mouth disease (HFMD) is a childhood illness frequently caused by genotypes belonging to the enterovirus A species, including coxsackievirus (CV)-A16 and enterovirus (EV)-71. Between 2010 and 2012, several outbreaks and sporadic cases of HFMD occurred in different regions of Spain. The objective of the present study was to describe the enterovirus epidemiology associated with HFMD in the country. A total of 80 patients with HFMD or atypical rash were included. Detection and typing of the enteroviruses were performed directly in clinical samples using molecular methods. Enteroviruses were detected in 53 of the patients (66%). CV-A6 was the most frequent genotype, followed by CV-A16 and EV-71, but other minority types were also identified. Interestingly, during almost all of 2010, CV-A16 was the only causative agent of HFMD but by the end of the year and during 2011, CV-A6 became predominant, while CV-A16 was not detected. In 2012, however, both CV-A6 and CV-A16 circulated. EV-71 was associated with HFMD symptoms only in three cases during 2012. All Spanish CV-A6 sequences segregated into one major genetic cluster together with other European and Asian strains isolated between 2008 and 2011, most forming a particular clade. Spanish EV-71 strains belonged to subgenogroup C2, as did most of the European sequences circulated. In conclusion, the recent increase of HFMD cases in Spain and other European countries has been due to a larger incidence of circulating species A enteroviruses, mainly CV-A6 and CV-A16, and the emergence of new genetic variants of these viruses.     

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.     

Epididymitis Caused by Coxsackievirus A6 in Association with Hand,Foot, and Mouth Disease

Coxsackievirus A6 (CV-A6) caused hand, foot, and mouth disease (HFMD) with a unique manifestation of epididymitis. The patient underwent operation due to suspicion of testicular torsion. Epididymitis was diagnosed by ultrasound examination. Enterovirus was detected from epididymal fluid by PCR and typed by partial sequencing of viral protein 1 as CV-A6.     

2010—2018年乐清地区肠道病毒感染疾病的病原特征分析

目的分析乐清地区2010—2018年引起儿童肠道病毒(EV)相关疾病的病原谱变化及其各型别的流行趋势,为肠道病毒引起手足口病防控工作提供科学依据。方法从乐清市疾病监测信息报告管理系统导出2010—2018年肠道病毒感染引起手足口病病例资料,采用描述性流行病学方法分析手足口病病例发病的季节、年龄、性别、区域分布及病原体的分布特点。结果2010—2018年乐清市手足口病病例共计53178例。全年各月均有发病,发病高峰在4—7月,重症75例,死亡6例,5岁以下的散居儿童和托幼儿童发病为主,男性高于女性。2010—2018乐清地区儿童中感染的病原谱发生了明显变化,2010—2014年均以EV71型为主,2013年之后EV71检出比例逐年降低,近几年来非EV71非柯萨奇病毒A16型的其他肠道病毒比例明显升高。结论乐清地区肠道病毒引起手足口病具有明显的季节性、人群性,应加强病原学检测,在4—7月,对重点对象采取综合防控措施,防止引起手足口病暴发流行。     

Enterovirus infections in hospitals of Ile de France region over 2013

BackgroundThe monitoring and genotyping of Enterovirus (EV) infections can help to associate particular or severe clinical manifestations with specific EV types and to identify the aetiology of infectious outbreaks.ObjectivesTo describe the epidemiological features of EV infections diagnosed during the year 2013 in the Greater Paris area (Ile de France).Study designDuring 2013, 2497 samples taken from 470 patients in 33 hospitals of Ile-de France were tested for EV genome by RT-PCR. EV genotyping was performed by the National Reference Centre (NRC) laboratories. EV infections were retrospectively reviewed by retrieving clinical and genotyping data from the NRC database.ResultsOf the 2497 samples, 490 (19.6%) was positive for EV genome detection. These EV infections represented 88.7% and 24.1%, respectively, of all reported regional and national infections. Twenty-seven different genotypes were identified. Echovirus 30 (E-30) accounted for 54.1% of all characterized strains and caused a large outbreak. Four severe neonatal infections were reported, of which two were caused by EV-A71. Respiratory infections involving EV-D68 were observed in two adults. One fatal case of Coxsackievirus A2-associated myocarditis was reported.ConclusionMonitoring EV infections in combination with EV genotyping via the French EV network characterized the epidemiology of EV infections in the Ile de France region in 2013 and documented severe EV infections associated with EV-A71 or CV-A2.     

Outbreak of acute hemorrhagic conjunctivitis in French Guiana and West Indies caused by coxsackievirus A24 variant: phylogenetic analysis reveals Asian import

An outbreak of acute hemorrhagic conjunctivitis occurred in French Guiana between April and July 2003, with approximately 6,000 cases in the two major cities Kourou and Cayenne. Since acute hemorrhagic conjunctivitis is not a notifiable disease in France, there was no registration of the number of cases. Therefore, these were estimated by comparing the consumption of antibiotic eye drops and ophthalmic ointments during 2002 and 2003. The outbreak rapidly spread into the Caribbean Islands, causing an outbreak in Guadeloupe in October. Viral isolates from conjunctival swabs of 16 patients were confirmed to be enterovirus by PCR directed to the 5' UTR of the genome. The isolates could not be neutralized by the Melnick intersecting pools, but were shown to be CV-A24 variant by limited sequencing within the VP1 and 3C regions of 12 strains. Phylogenetic analysis revealed that they were similar to the genotype III strains causing outbreaks in Korea 2002 and Malaysia 2003. The previous outbreak of conjunctivitis caused by CV-A24 in the Caribbean in the 1980s was also introduced from Asia, and disappeared after 3 years. This new introduction from Asia and its rapid spread into the Caribbean, where the infection disappeared after a few months, indicates that the CV-A24 variant has a different epidemiological pattern in this region compared to South East Asia, since it has not established an endemic infection. It had to be reintroduced from Asia, where it has been circulating since the 1970s.     

Risk factors for severe hand,foot, and mouth disease infected with Coxsackievirus A6: A hospital-based case-control study

Coxsackievirus 6 (CV-A6) has been emerging as another predominant serotype for severe hand, foot, and mouth disease (HFMD) in China, after the introduction of enterovirus 71 inactivated vaccine (EV71 vaccine) for 3 years. Data on the risk factors for severe HFMD infected with CV-A6 are limited. We interviewed the caregivers to collected data on HFMD patients who sought medical care in the People's Hospital of Baoan district, Shenzhen, from 2015 to 2017. Totally, 131 severe patients were frequency-matched by age and gender with 174 mild patients infected with CV-A6. Univariable and multivariable logistic regression analyses were conducted to analyze the risk factors for severe CV-A6 HFMD. The average age was 20.62 ± 14.18 months and 20.52 ± 12.76 months for severe and mild patients, respectively. Multivariate analyses indicated complications at birth (odds ratio [OR], 4.18; 95% confidence interval [CI]: 1.64-10.63), peak body temperature over 39°C (OR, 4.04; 95% CI: 2.29-7.10) and first-born child (OR, 2.17; 95% CI: 1.27-3.70) increased the risk of severe HFMD infected with CV-A6. Breastfeeding (OR, 0.52; 95% CI: 0.32-0.87), and washing hands after playing frequently (OR, 0.58; 95% CI: 0.34-0.97) were negatively associated with severe illness. Compared with HFMD with infection of EV-A71, complications at birth and first-born child were newly found to be associated with severe illness in HFMD patients infected with CV-A6.     

Genetic diversity of enterovirus 71 isolated from cases of hand,foot and mouth disease in Yokohama City between 1982 and 2000

Summary.  Enterovirus 71 (EV71) is known as one of the major causative agents of hand, foot and mouse disease (HFMD) and is also associated with neurological manifestations such as aseptic meningitis, polio-like paralysis and encephalitis. Recently, large HFMD outbreaks, involving severe neurological complications, have been experienced in Malaysia, Taiwan and some other countries in the Western-Pacific region. To investigate the genetic diversity of EV71 isolates in a single community in Japan, nucleotide sequences of the VP4 region of 52 EV71 isolates in Yokohama City from 1982 to 2000 were determined and the phylogenetic relationship was compared with other referential EV71 strains in Japan and in the world. There were two major genotypes of EV71 in Yokohama City through the 1980’s and 1990’s. Six EV71 isolates in the early 1980’s in Yokohama City were closely related to those from HFMD outbreaks in Japan and from outbreaks of polio-like paralysis in Europe in the 1970’s. During recent HFMD outbreaks in 1997 and 2000, two distinct genotypes of EV71 were co-circulating in Yokohama City as in HFMD outbreaks in Malaysia and Taiwan. However, the genetic diversity of EV71 in Yokohama City was not directly correlated with the severity of HFMD. The results confirmed the circulation of two distinct genotypes of EV71 over the past 20 years in Japan. Received June 25, 2002; accepted September 16, 2002     

Changing epidemiology of human enteroviruses (HEV) in a hand,foot and mouth disease outbreak in Vellore,south India

PurposeHand Foot and mouth disease (HFMD) is a major childhood exanthematous disease causing outbreaks that have become a major public health threat in recent years. In Vellore district of Tamil Nadu, south India, occasional outbreaks are common among the paediatric age group, most commonly in those under 5years of age (U5s). CoxsackieA6, A4, A5, A9, A10, B2 and B5 are the common serotypes causing outbreaks. This study aimed to identify the molecular serotype of the causative agent, co-circulating in this region.MethodsAdapting the WHO case definition, cases during an HFMD outbreak between October and December 2017, were identified by a clinical criterion of fever, mouth ulcers and rash in the extremities. Vesicle fluid from these lesions were collected in viral transport medium and transported cold to the Clinical Virology laboratory of a tertiary care hospital in Vellore. Identification of the causative agent was undertaken by two real time PCRs (EV1 and EV2) followed by sequencing the VP1–2C region and constructing a phylogenetic tree.ResultsAmong the 31 HFMD patients included in this study, 23 (74.2%) were U5s, 3 (9.7%) were between 6 and 15 years and the remaining 5 (16.1%) were adolescents (>15 ?yrs). The outbreak ran a mild clinical course, with 22(71%) patients having fever as a prodromal symptom. Papulovesicular lesions characteristic of HFMD were present on all 31 (100%) patients’ palms and soles, buttocks of 19 (61.3%), oral mucosa of 12 (38.7%), and all over the body in 4 (12.9%) patients. Coxsackie A6(75%) and Coxsackie A16(25%) were the pathogens associated with this outbreak.ConclusionsChanging epidemiology of HFMD was seen in this outbreak since; other serotypes apart from the classical Coxsackievirus serotypes causing HFMD outbreak were also found co-circulating. EV1 PCR was a better screening assay than EV2 PCR in this region. Continued surveillance and molecular serotyping are necessary for HFMD outbreaks in any region.     

Chikungunya virus of Asian and Central/East African genotypes in Malaysia

BackgroundChikungunya virus (CHIKV) of the Central/East African genotype has caused large outbreaks worldwide in recent years. In Malaysia, limited CHIKV outbreaks of the endemic Asian and imported Central/East African genotypes were reported in 1998 and 2006. Since April 2008, an unprecedented nationwide outbreak has affected Malaysia.ObjectiveTo study the molecular epidemiology of the current Malaysian CHIKV outbreak, and to evaluate cross-neutralisation activity of serum from infected patients against isolates of Asian and Central/East African genotypes.Study designSerum samples were collected from 83 patients presenting in 2008, and tested with PCR for the E1 gene, virus isolation, and for IgM. Phylogenetic analysis was performed on partial E1 gene sequences of 837 bp length. Convalescent serum from the current outbreak and Bagan Panchor outbreak (Asian genotype, 2006) were tested for cross-neutralising activity against representative strains from each outbreak.ResultsCHIKV was confirmed in 34 patients (41.0%). The current outbreak strain has the A226V mutation in the E1 structural protein, and grouped with Central/East African isolates from recent global outbreaks. Serum cross-neutralisation activity against both Central/East African and Asian genotypes was observed at titres from 40 to 1280.ConclusionsThe CHIKV strain causing the largest Malaysian outbreak is of the Central/East African genotype. The presence of the A226V mutation, which enhances transmissibility of CHIKV by Aedes albopictus, may explain the extensive spread especially in rural areas. Serum cross-neutralisation of different genotypes may aid potential vaccines and limit the effect of future outbreaks.     

Online-Only Abstract: Population-based burden of bloodstream infections in Finland

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.     

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.     

2008-2009年广东手足口病非CA16非EV71肠道病毒株的鉴定及其VP1基因分型研究

目的 探讨2008-2009年广东省手足口病非CAI6非EV71肠道病毒株的流行情况以及毒株型别.方法 从2008-2009年广东省手足口病粪便样本中采用RD细胞和HEp-2细胞分离病毒毒株,待出现细胞病变后收集上清采用RT-PCR进行鉴定.非CA16非EV71毒株再进行VP1测序分析,序列通过BLAST程序鉴定型别,用MEGA4.0软件进行基因进化分析.结果 共分离到22株非CA16非EV71毒株,通过BLAST程序鉴定犁别.2008年9株非CA16、非EV71的毒株有CA2型、CA4、CB3型;2009年13株有EV80、E13、E30、CB5、E24、PV1、CA10、CA6和CA2.各毒株间同源性低,各毒株分别归属CoxA、CoxB、埃可肠道病毒、新型肠道病毒和脊灰病毒组.结论 广东省2008-2009年两年来,手足口病除了CA16和EV71占主导地位外,并不存在其他的优势株,其他型肠道病毒分布比较广,既有CoxA组病毒、CoxB组,也有E13、E24、E30、新型病毒EV80和脊髓灰质炎病毒PV1,儿组病毒伴随流行.     

东莞市2008-2009年手足口病流行病学特征分析

目的分析东莞市2008-2009年手足口病流行病学特征,为制定有效防控措施提供科学依据。方法描述性分析东莞市2008-2009年网络直报的手足口病资料。结果东莞市2008-2009年共报告手足口病病例12687例,年均发病率为87.21/10万,其中2008年发病率为46.26/10万,2009年发病率为128.16/10万,不同年份间发病率的差异具有统计学意义（P〈0.01）;发病主要集中在4-7月,占总病例数的56.59%;我市各镇（街）均有病例报告,发病率最高为大朗镇（364.64/10万）,最低为长安镇（34.05/10万）,不同地区间发病率差异具有统计学意义（P〈0.01）;发病主要集中在5岁以下儿童,占总病例数的91.09%;以散居儿童为主,占总病例数的76.81%;男性发病率高于女性;两年间共报告暴发疫情22起,罹患率为0.48%～14.58%,时间集中在4-6月份。结论手足口病是东莞市重点防控的传染病之一,应加强疫情监测和控制,防止其暴发流行。     

Simultaneous detection of human enterovirus 71 and coxsackievirus A16 in clinical specimens by multiplex real-time PCR with an internal amplification control

The recent and continuing HFMD outbreak caused by EV71 in several provinces of China since March 2008 has affected thousands of children and resulted in nearly 50 deaths. In this study, a sensitive and specific multiplex real-time RT-PCR assay has been developed for the rapid detection of EV71 and CV-A16. By using an internal amplification control, the real-time assay achieves detection of samples containing inhibitors and avoids false negatives. It should prove useful for clinical diagnosis of EV71 or CV-A16 infections.     

Genetic diversity of epidemic enterovirus 71 strains recovered from clinical and environmental samples in Taiwan

Most enteroviruses excreted in human feces and urine are present in environmental water. In order to clarify the infection route of enterovirus, the detection of viruses in both clinical and environmental samples may contribute to understanding the mode of transmission of strains responsible for human infection. Thus, 21 epidemic enterovirus 71 strains from environmental water or stool samples were collected from HFMD children during 2005. Enterovirus genomic RNA was first amplified directly from clinical and environmental samples and then characterized by DNA sequencing and phylogenetic analysis. Results showed that these clinical strains share similar sequence identity (86.4-86.8%) to prototype BrCr based on the 5'-nontranslated region (NTR). However, environmental strains, except HME 77, share similar sequence identity (86.2-87.2%) to prototype BrCr. HME 77 showed higher sequence identity (90.1%). Results from phylogenetic analysis revealed that five environmental isolates were clustered as genogroup 3, which was closely related to a Taiwan outbreak in 1998 (AY055133). HME 77 was more closely related to a China epidemic isolate (AY895144), which belonged to genogroup 4. In contrast, all strains from clinical samples tested belonged to genogroup 3, which clustered with AY055133. In conclusion, there are two major epidemic clones (genogroups 3 and 4) prevalent in Taiwan since 2004 either in water or clinical patients.     

某高中一起柯萨奇病毒A组6型手足口病暴发疫情的流行病学调查

目的 了解某高中一起手足口病暴发疫情的流行病学特征,寻找导致该暴发发生的危险因素,同时了解柯萨奇病毒A组6型(CVA6)手足口病的临床表现.方法 按照病例定义开展病例搜索.采用统一设计的调查表调查患者一般情况和临床表现,采用病例对照研究分析暴发危险因素.结果 该学校从8月17日-9月10日出现28名病例(24例学生,4例家长),其中23例临床诊断病例,5例实验室确诊病例(检出病原体CVA 6).患者中82.1％ (23/28)的病例出现发热症状,64.3％ (18/28)的病例体温≥38.5℃;21.4％(6/28)的病例出现皮疹部位疼痛症状;46.4％(13/28)的病例恢复期出现脱皮症状;17.9％(5/28)的病例出现脱甲症状.发病前1周与手足口病患者接触、饭前不洗手是手足口病发病的危险因素.结论 患者未及时隔离、与患者密切接触和饭前不洗手是造成疾病蔓延的主要原因.CVA6导致的手足口病患者常出现高热、脱甲、脱皮等非典型手足口病临床症状.     

Rapid detection of enterovirus 71 by real-time TaqMan RT-PCR.

BACKGROUND: Enterovirus 71 (EV71) is the main etiological agent of Hand, Foot and Mouth Disease (HFMD) and has been associated with neurological complications which resulted in fatalities during recent outbreaks in Asia Pacific region. OBJECTIVE: Develop a real-time TaqMan RT-PCR for rapid detection of EV71. STUDY DESIGN: Specific primers and probe were designed based on highly conserved VP1 region of EV71. The sensitivity of the real-time RT-PCR was evaluated with 67 clinical specimens collected from pediatric patients with suspected HFMD. RESULTS: Our real-time TaqMan RT-PCR showed 100% specificity in detecting EV71 and showed an analytical sensitivity of 5 viral copies. High sensitivity was also achieved in detecting EV71 directly from clinical specimens. CONCLUSIONS: Real-time TaqMan RT-PCR offers a rapid and sensitive method to detect EV71 from clinical specimens, and will allow quarantine measures to be taken more effectively during outbreaks.