Virulence of enterovirus-A71 fluctuates depending on the phylogenetic clade formed in the epidemic year and epidemic region

2021 ◽  
Author(s):  
Kyousuke Kobayashi ◽  
Hidekazu Nishimura ◽  
Katsumi Mizuta ◽  
Tomoha Nishizawa ◽  
Son T. Chu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Foot And Mouth Disease ◽  
Virus Genome ◽  
Mouth Disease ◽  
Asia Pacific ◽  
Enterovirus A71 ◽  
Viral Virulence ◽  
Foot And Mouth ◽  
Potential Risks ◽  
A Minor

Although epidemics of hand, foot, and mouth disease (HFMD) caused by enterovirus A71 (EV-A71) have occurred worldwide, the Asia-Pacific region has seen large sporadic outbreaks with many severe neurological cases. This suggests that the virulence of the circulating viruses fluctuates in each epidemic and that HFMD outbreaks with many severe cases occur when highly virulent viruses are circulating predominantly, which has not been experimentally verified. Here, we analyzed 32 clinically isolated strains obtained in Japan from 2002 to 2013, along with 27 Vietnamese strains obtained from 2015 to 2016 that we characterized previously using human SCARB2 transgenic mice. Phylogenetic analysis of the P1 region classified them into five clades belonging to subgenogroup B5 (B5-I to B5-V) and five clades belonging to subgenogroup C4 (C4-I to C4-V) according to the epidemic year and region. Interestingly, the clade B5-I and B5-II were very virulent, while clades B5-III, B5-IV, and B5-V were less virulent. Clades C4-II, C4-III, C4-IV, and C4-V were virulent, while clade C4-I was not. The result experimentally showed for the first time that several clades with different virulence levels emerged one after another. The experimental virulence evaluation of circulating viruses using SCARB2 transgenic mice is helpful to assess potential risks of circulating viruses. These results also suggest that a minor nucleotide or amino acid substitution in the EV-A71 genome during circulation may cause fluctuations in virulence. The data presented herein may increase our understanding of the dynamics of viral virulence during epidemics. IMPORTANCE Outbreaks of hand, foot, and mouth disease (HFMD) with severe enterovirus A71 (EV-A71) cases have occurred repeatedly, mainly in Asia. In severe cases, central nervous system complications can lead to death, making it an infectious disease of importance to public health. An unanswered question about this disease is why outbreaks of HFMD with many severe cases sometimes occur. Here, we collected EV-A71 strains that were prevalent in Japan and Vietnam over the past 20 years and evaluated their virulence in a mouse model of EV-A71 infection. This method clearly revealed that viruses belonging to different clades have different virulence, indicating that the method is powerful to assess the potential risks of the circulating viruses. The results also suggested that factors in the virus genome may potentially cause an outbreak with many severe cases and that further studies may facilitate the prediction of large epidemics of EV-A71 in the future.

scholarly journals Meteorological factors and its association with hand, foot and mouth disease in Southeast and East Asia areas: a meta-analysis

2018 ◽  
Vol 147 ◽  
Author(s):  
Chunxiao Duan ◽  
Xuefeng Zhang ◽  
Hui Jin ◽  
Xiaoqing Cheng ◽  
Donglei Wang ◽  
...  
Keyword(s):  
East Asia ◽  
Meteorological Factors ◽  
Global Climate ◽  
Meta Analysis ◽  
Foot And Mouth Disease ◽  
Correlation Coefficients ◽  
Mouth Disease ◽  
Asia Pacific ◽  
China National Knowledge Infrastructure ◽  
Foot And Mouth

AbstractSince the late 1990s, hand, foot and mouth disease (HFMD) has become a common health problem that mostly affects children and infants in Southeast and East Asia. Global climate change is considered to be one of the major risk factors for HFMD. This study aimed to assess the correlation between meteorological factors and HFMD in the Asia-Pacific region. PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Data and Weipu Database were searched to identify relevant articles published before May 2018. Data were collected and analysed using R software. We searched 2397 articles and identified 51 eligible papers in this study. The present study included eight meteorological factors; mean temperature, mean highest temperature, mean lowest temperature, rainfall, relative humidity and hours of sunshine were positively correlated with HFMD, with correlation coefficients (CORs) of 0.52 (95% confidence interval (CI) 0.42–0.60), 0.43 (95% CI 0.23–0.59), 0.43 (95% CI 0.23–0.60), 0.27 (95% CI 0.19–0.35), 0.19 (95% CI 0.02–0.35) and 0.19 (95% CI 0.11–0.27), respectively. There were sufficient data to support a negative correlation between mean pressure and HFMD (COR = −0.51, 95% CI −0.63 to −0.36). There was no notable correlation with wind speed (COR = 0.10, 95% CI −0.03 to 0.23). Our findings suggest that meteorological factors affect the incidence of HFMD to a certain extent.

scholarly journals Early Evidence of Inactivated Enterovirus 71 Vaccine Impact Against Hand, Foot, and Mouth Disease in a Major Center of Ongoing Transmission in China, 2011–2018: A Longitudinal Surveillance Study

2019 ◽  
Author(s):  
Jennifer R Head ◽  
Philip A Collender ◽  
Joseph A Lewnard ◽  
Nicholas K Skaff ◽  
Ling Li ◽  
...  
Keyword(s):  
Time Series ◽  
Incidence Rate ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Asia Pacific ◽  
Full Time ◽  
Study Region ◽  
Foot And Mouth ◽  
Vaccine Impact

Abstract Background Enterovirus 71 (EV71) is a major causative agent of hand, foot, and mouth disease (HFMD), associated with severe manifestations of the disease. Pediatric immunization with inactivated EV71 vaccine was initiated in 2016 in the Asia-Pacific region, including China. We analyzed a time series of HFMD cases attributable to EV71, coxsackievirus A16 (CA16), and other enteroviruses in Chengdu, a major transmission center in China, to assess early impacts of immunization. Methods Reported HFMD cases were obtained from China’s notifiable disease surveillance system. We compared observed postvaccination incidence rates during 2017–2018 with counterfactual predictions made from a negative binomial regression and a random forest model fitted to prevaccine years (2011–2015). We fit a change point model to the full time series to evaluate whether the trend of EV71 HFMD changed following vaccination. Results Between 2011 and 2018, 279 352 HFMD cases were reported in the study region. The average incidence rate of EV71 HFMD in 2017–2018 was 60% (95% prediction interval [PI], 41%–72%) lower than predicted in the absence of immunization, corresponding to an estimated 6911 (95% PI, 3246–11 542) EV71 cases averted over 2 years. There were 52% (95% PI, 42%–60%) fewer severe HFMD cases than predicted. However, the incidence rate of non-CA16 and non-EV71 HFMD was elevated in 2018. We identified a significant decline in the trend of EV71 HFMD 4 months into the postvaccine period. Conclusions We provide the first real-world evidence that programmatic vaccination against EV71 is effective against childhood HFMD and present an approach to detect early vaccine impact or intended consequences from surveillance data.

scholarly journals Epidemiological study on hand, foot and mouth disease in Tongzhou District, Beijing, 2013–2017

2019 ◽  
Vol 47 (6) ◽  
pp. 2615-2625 ◽  
Author(s):  
Xiao-Feng Liu ◽  
Xiu-Mei Sun ◽  
Xiao-Wei Sun ◽  
Yu-Qing Yang ◽  
Cong-Hui Huang ◽  
...  
Keyword(s):  
Incidence Rate ◽  
Local Population ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Migrant Population ◽  
Enterovirus A71 ◽  
Tongzhou District ◽  
Foot And Mouth ◽  
Polymerase Chain ◽  
Epidemiological Characteristics

Objective To study the epidemiological characteristics of hand, foot and mouth disease (HFMD) in Tongzhou District, Beijing between 2013 and 2017. Methods Data on HFMD infections from 1 January 2013 to 31 December 2017 were collected from the Notifiable Infectious Diseases Reporting Information System and analysed. Serotyping of enteroviruses from samples from patients with HFMD was undertaken using reverse transcription–polymerase chain reaction. Results A total of 15 341 patients with HFMD were reported and 32 patients (0.2%) were classified as having severe HFMD. The annual mean incidence rate of HFMD was 219.3/100 000 of the general population. The incidence and case-severity rates of HFMD generally decreased between 2013 and 2017. In the floating migrant population, the incidence and cases-severity rates of HFMD were significantly higher than in the local population. The peak incidence and severity-case rates were at 2 years of age and > 90% of patients were ≤5 years. Enterovirus A71 and Coxsackievirus A16 were the predominant pathogens in 2013–2017. Conclusions During the 5-year period 2013–2017, the incidence rate and case-severity rate of HFMD generally decreased in Tongzhou District, Beijing. The floating migrant population and children ≤5 years of age were at the highest risk of HFMD.

scholarly journals Synthetic RNAs Mimicking Structural Domains in the Foot-and-Mouth Disease Virus Genome Elicit a Broad Innate Immune Response in Porcine Cells Triggered by RIG-I and TLR Activation

Viruses ◽  
2015 ◽  
Vol 7 (7) ◽  
pp. 3954-3973 ◽  
Author(s):  
Belén Borrego ◽  
Miguel Rodríguez-Pulido ◽  
Concepción Revilla ◽  
Belén Álvarez ◽  
Francisco Sobrino ◽  
...  
Keyword(s):  
Immune Response ◽  
Disease Virus ◽  
Innate Immune Response ◽  
Foot And Mouth Disease ◽  
Virus Genome ◽  
Mouth Disease ◽  
Innate Immune ◽  
Structural Domains ◽  
Mouth Disease Virus ◽  
Foot And Mouth

scholarly journals Cyclical Patterns of Hand, Foot and Mouth Disease Caused by Enterovirus A71 in Malaysia

2016 ◽  
Vol 10 (3) ◽  
pp. e0004562 ◽  
Author(s):  
NMN NikNadia ◽  
I-Ching Sam ◽  
Sanjay Rampal ◽  
WMZ WanNorAmalina ◽  
Ghazali NurAtifah ◽  
...  
Keyword(s):  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Enterovirus A71 ◽  
Foot And Mouth

scholarly journals RSAD2 and AIM2 Modulate Coxsackievirus A16 and Enterovirus A71 Replication in Neuronal Cells in Different Ways That May Be Associated with Their 5′ Nontranslated Regions

2017 ◽  
Vol 92 (6) ◽  
Author(s):  
Thinesshwary Yogarajah ◽  
Kien Chai Ong ◽  
David Perera ◽  
Kum Thong Wong
Keyword(s):  
Viral Replication ◽  
Neuronal Cells ◽  
Neuroblastoma Cells ◽  
Foot And Mouth Disease ◽  
Neurological Complications ◽  
Mouth Disease ◽  
Host Responses ◽  
Coxsackievirus A16 ◽  
Enterovirus A71 ◽  
Foot And Mouth

ABSTRACT Coxsackievirus A16 (CV-A16) and enterovirus A71 (EV-A71) are closely related enteroviruses that cause the same hand, foot, and mouth disease (HFMD), but neurological complications occur only very rarely in CV-A16 compared to EV-A71 infections. To elucidate host responses that may be able to explain these differences, we performed transcriptomic analysis and real-time quantitative PCR (RT-qPCR) in CV-A16-infected neuroblastoma cells (SK-N-SH), and the results showed that the radical S -adenosylmethionine domain containing 2 (RSAD2) was the highest upregulated gene in the antimicrobial pathway. Increased RSAD2 expression was correlated with reduced viral replication, while RSAD2 knockdown cells were correlated with increased replication. EV-A71 replication showed no apparent correlation to RSAD2 expressions. Absent in melanoma 2 (AIM2), which is associated with pyroptotic cell death, was upregulated in EV-A71-infected neurons but not in CV-A16 infection, suggesting that the AIM2 inflammasome played a significant role in suppressing EV-A71 replication. Chimeric viruses derived from CV-A16 and EV-A71 but containing swapped 5′ nontranslated regions (5′ NTRs) showed that RSAD2 expression/viral replication and AIM2 expression/viral replication patterns may be linked to the 5′ NTRs of parental viruses. Differences in secondary structure of internal ribosomal entry sites within the 5′ NTR may be responsible for these findings. Overall, our results suggest that CV-A16 and EV-A71 elicit different host responses to infection, which may help explain the apparent lower incidence of CV-A16-associated neurovirulence in HFMD outbreaks compared to EV-A71 infection. IMPORTANCE Although coxsackievirus A16 (CV-A16) and enterovirus A17 (EV-A71) both cause hand, foot, and mouth disease, EV-A71 has emerged as a leading cause of nonpolio, enteroviral fatal encephalomyelitis among young children. The significance of our research is in the identification of the possible differing and novel mechanisms of CV-A16 and EV-A71 inhibition in neuronal cells that may impact viral neuropathogenesis. We further showed that viral 5′ NTRs may play significant roles in eliciting different host response mechanisms.

scholarly journals Immunodominant IgM and IgG Epitopes Recognized by Antibodies Induced in Enterovirus A71-Associated Hand, Foot and Mouth Disease Patients

PLoS ONE ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. e0165659 ◽  
Author(s):  
Kam Leng Aw-Yong ◽  
I-Ching Sam ◽  
Mia Tuang Koh ◽  
Yoke Fun Chan
Keyword(s):  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Enterovirus A71 ◽  
Foot And Mouth

scholarly journals Structure, Immunogenicity, and Protective Mechanism of an Engineered Enterovirus 71-Like Particle Vaccine Mimicking 80S Empty Capsid

2017 ◽  
Vol 92 (1) ◽  
Author(s):  
Xiaoli Wang ◽  
Zhiqiang Ku ◽  
Xiang Zhang ◽  
Xiaohua Ye ◽  
Jinhuan Chen ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Asia Pacific ◽  
Protective Mechanism ◽  
Particle Assembly ◽  
Virus Like Particle ◽  
Empty Capsid ◽  
Foot And Mouth

ABSTRACTEnterovirus 71 (EV71) is the major causative agent of severe hand, foot, and mouth disease, which affects millions of young children in the Asia-Pacific region annually. In this study, we engineered a novel EV71 virus-like particle (VLP) that lacks VP4 (therefore designated VLPΔVP4) and investigated its structure, antigenicity, and vaccine potential. The cryo-electron microscopy (cryo-EM) structure of VLPΔVP4was reconstructed to 3.71-Å resolution. Results from structural and biochemical analyses revealed that VLPΔVP4resembles the end product of the viral uncoating process, the 80S empty capsid. VLPΔVP4is able to elicit high-titer neutralizing antibodies and to fully protect mice against lethal viral challenge. Mechanistic studies showed that, at the cellular level, the anti-VLPΔVP4sera exert neutralization effects at both pre- and postattachment stages by inhibiting both virus attachment and internalization, and at the molecular level, the antisera can block multiple interactions between EV71 and its key receptors. Our study gives a better understanding of EV71 capsid assembly and provides important information for the design and development of new-generation vaccines for EV71, and perhaps for other enteroviruses, as well.IMPORTANCEEnterovirus 71 (EV71) infection may lead to severe hand, foot, and mouth disease, with significant morbidity and mortality. Knowledge regarding EV71 particle assembly remains limited. Here, we report the generation and characterization of a novel EV71 virus-like particle that lacks the VP4 capsid subunit protein. This particle, termed VLPΔVP4, structurally mimics the 80S empty capsid, which is the end stage of EV71 uncoating. We further show that VLPΔVP4exhibits desirable immunogenicity and protective efficacy in proof-of-concept studies. In addition, the inhibitory mechanisms of the VLPΔVP4-induced antibodies are unraveled at both the cellular and molecular levels. Our work provides the first evidence of picornaviral particle assembly in the complete absence of VP4 and identifies VLPΔVP4as an improved EV71 vaccine candidate with desirable traits. These findings not only enhance our understanding of particle assembly and uncoating of picornaviruses, but also provide important information for structure-guided vaccine design for EV71 and other enteroviruses.

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