Mouth Disease Patients Research Articles

Arginine depletion-induced autophagy and metabolic dysregulation are involved in the disease severity of hand, foot, and mouth disease

ABSTRACT Amino acid metabolism provides significant insight into the development and prevention of many viral diseases. Therefore, the present study aimed to compare the amino acid profiles of hand, foot, and mouth disease (HFMD) patients with those of healthy individuals and to further reveal the molecular mechanisms of HFMD severity. Using UPLC-MS/MS, we determined the plasma amino acid expression profiles of pediatric patients with HFMD (mild, n = 42; severe, n = 43) and healthy controls (n = 25). Brain tissues from CVA6-infected mice were examined using untargeted metabolomics. Several amino acids were significantly different between the three groups. Pathway analysis revealed that arginine, proline, and tryptophan metabolism are implicated in the pathogenesis of HFMD. A similar arginine depletion was observed in the brain tissues of CVA6-infected mice. Importantly, L-arginine supplementation improved the survival rate of CVA6-infected mice, inhibited virus multiplication, and reduced pathological autophagy associated with mTOR-autophagy pathway in the brain. Collectively, arginine, as the hub amino acid metabolite of the mammalian target of rapamycin (mTOR) signaling pathway affecting autophagy, plays an important role in the pathogenesis of severe HFMD. L-arginine supplementation may serve as a potential therapeutic option for critical patients with HFMD.

Whole-genome sequencing and phylogenetic analysis of coxsackievirus-A16 strains causing hand, foot and mouth disease (HFMD) in India.

Hand, foot and mouth disease (HFMD) is a common childhood infectious disease, caused by enteroviruses (EVs), which can present with typical or atypical lesions. The illness is self-limiting, but it can also have serious complications. Since 1997, HFMD infections have become endemic and have increased to epidemic proportions across the Asia Pacific region, including India. Coxsackievirus-A16 (CV-A16) outbreaks occurred in India from 2005 onwards, although the clinical symptoms were noticeably different during this period. Understanding the population dynamics of enteroviruses that cause HFMD is crucial in the post-polio era because one of the circulating strain may replace another as the dominant strain. The aim of this study is to describe the genetic features of the CV-A16 strains isolated from hand, foot and mouth disease (HFMD) patients in India. Reverse transcription PCR (RT-PCR) and cell-culture-based isolation of CV-A16 was done from the 55 clinical samples. The entire genome of the CV-A16 isolate was performed from the seven isolates. After the sequences were analysed, a phylogenetic tree was created using bioinformatics tools. The total genomic length obtained was 7411 base pairs (bp). Nucleotide similarity across various regions, including 5'UTR, P1, P2 and 3'UTR, ranged from 87.0-97.9 %, 77.0-95.4 %, 80.3-96.9 %, and 77.9-96.2 %, respectively. Correspondingly, similarities in the VP1 region's nucleotide and amino acid sequences were 91.4-96.4 % and 99.3-99.7 %, respectively. Phylogenetic analysis highlighted that CV-A16 strains identified in Pune, Maharashtra, were grouped within the same cluster. The analysed CV-A16 isolates in this study aligned with subgenotype B1c. These findings have far-reaching implications for the surveillance, prevention and management of HFMD and CV-A16. Monitoring the dynamics of CV-A16 strains, informed by the genetic characteristics identified here, will significantly impact strategies aimed at tackling HFMD and its associated public health challenges.

Antibody signatures in hospitalized hand, foot and mouth disease patients with acute enterovirus A71 infection.

Enterovirus A71 (EV-A71) infection is a major cause of severe hand, foot and mouth disease (HFMD) in young children. The characteristics of EV-A71 neutralizing antibodies in HFMD patients are not well understood. In this study, we identified and cloned EV-A71-neutralizing antibodies by single cell RNA and B cell receptor sequencing of peripheral blood mononuclear cells. From 145 plasmablasts, we identified two IgG1 monoclonal antibodies (mAbs) and six IgM mAbs that neutralized EV-A71. Four of the IgM mAbs harbor germline variable sequences and neutralize EV-A71 potently. Two genetically similar IgM antibodies from two patients have recurrent heavy chain variable domain gene usage and similar complementarity-determining region 3 sequences. We mapped the residues of EV-A71 critical for neutralization through selection of virus variants resistant to antibody neutralization in the presence of neutralizing mAbs. The residues critical for neutralization are conserved among EV-A71 genotypes. Epitopes for the two genetically similar antibodies overlap with the SCARB2 binding site of EV-A71. We used escape variants to measure the epitope-specific antibody response in acute phase serum samples from EV-A71 infected HFMD patients. We found that these epitopes are immunogenic and contributed to the neutralizing antibody response against the virus. Our findings advance understanding of antibody response to EV-A71 infection in young children and have translational potential: the IgM mAbs could potentially be used for prevention or treatment of EV-A71 infections.

Genomic Epidemiology and Transmission Dynamics of Global Coxsackievirus B4.

The aim of this study was to determine the global genetic diversity and transmission dynamics of coxsackievirus B4 (CVB4) and to propose future directions for disease surveillance. Next-generation sequencing was performed to obtain the complete genome sequence of CVB4, and the genetic diversity and transmission dynamics of CVB4 worldwide were analyzed using bioinformatics methods such as phylogenetic analysis, evolutionary dynamics, and phylogeographic analysis. Forty complete genomes of CVB4 were identified from asymptomatic infected individuals and hand, foot, and mouth disease (HFMD) patients. Frequent recombination between CVB4 and EV-B multiple serotypes in the 3Dpol region was found and formed 12 recombinant patterns (A-L). Among these, the CVB4 isolated from asymptomatic infected persons and HFMD patients belonged to lineages H and I, respectively. Transmission dynamics analysis based on the VP1 region revealed that CVB4 epidemics in countries outside China were dominated by the D genotype, whereas the E genotype was dominant in China, and both genotypes evolved at a rate of > 6.50 × 10-3 substitutions/site/year. CVB4 spreads through the population unseen, with the risk of disease outbreaks persisting as susceptible individuals accumulate. Our findings add to publicly available CVB4 genomic sequence data and deepen our understanding of CVB4 molecular epidemiology.

Dynamic changes of viral load and the duration of viral shedding in patients with hand, foot and mouth disease: a protocol for longitudinal study

BackgroundThe duration of virus shedding is necessary for determining the infectious period. But there were few quantitative studies on the changes of viral load and the law of the viral shedding in hand foot and mouth disease (HFMD) patients has not yet been clarified.MethodsThis study will prospectively recruit coxsackievirus A10 (CV-A10), coxsackievirus A16 (CV-A16) and coxsackievirus A6 (CV-A6) infected inpatients from January 2022 to December 2022. A series of samples and questionnaire information will be collected regularly to establish the dynamic function relationship between time and viral load changes and a Bayesian multilevel model will be constructed to clarify the evolvement rules which reflect the dynamic changes of viral load and the duration of viral shedding in patients with HFMD.DiscussionThe results of this study is expected to further clarify the evolvement rules which reflect the dynamic changes of viral load and the duration of viral shedding in HFMD patients under the influence of related factors. It can also provide important evidence for the scientific definition of the infectious period and isolation period of HFMD in China.

Multiple molecular characteristics of circulating enterovirus types among pediatric hand, foot and mouth disease patients after EV71 vaccination campaign in Wuxi, China.

Abstract The molecular properties of the circulating causative agents of hand, foot and mouth disease (HFMD) in Wuxi remain unclear, posing diagnostic and prevention challenges. Additionally, in several regions of mainland China, the EV71 immunisation drastically reduced related cases and altered the HFMD pathogen spectrum, while the precise situation in Wuxi remained unknown. To address these issues, paediatric HFMD cases diagnosed in the clinic were enrolled and anal swabs were acquired in the spring of 2019. The 5′-UTR and VP1 genes were interpreted using RT-nPCR with degenerate primers to confirm their genotypes. Following that, the entire genome sequences of each viral type were recovered, allowing for the interpretation of several molecular properties. A total of 249 clinically confirmed HFMD cases had their anal swabs taken for viral identification, from which the genome sequences of seven genotypes were recovered. Coxsackievirus A16 is the most prevalent type, followed by Coxsackievirus A6, A10, A2, A4, A5 and Echovirus 11, all of which were genetically determined for the first time in Wuxi. Phylogenetic and recombination analyses were used to evaluate their evolutionary relationships with other strains found in other regions. Noticeably, a CVA16 subtype, responsible for a large proportion of the observed cases, phylogenetically clustered within clade B1a along with some strains from other countries, was the first one to be reported in China. Furthermore, some recombination events were inferred from strains detected in sporadic cases, particularly the recombination between CVA2 and CVA5 strains. Our investigation elucidated the multiple molecular characteristics of the HFMD causal enterovirus strains in Wuxi, underlining the potential hazards associated with these circulating viral types in the population and aiding in future surveillance and prevention of this disease.

Association of Clinical Severity With Family Affluence-Based Socioeconomic Status Among Hospitalized Pediatric Hand, Foot, and Mouth Disease Patients in Henan, China: A Single Hospital-Based Case Series Study.

BackgroundThe association between the clinical severity of hand, foot, and mouth disease (HFMD) inpatients and socioeconomic status (SES) is important for quantifying SES inequality in HFMD disease burden and informing decision-makers regarding medical subsidy and reimbursement policies. Here, this association was investigated using a quantitative SES measurement.MethodsLaboratory-confirmed HFMD cases hospitalized at Henan Children’s Hospital from February 15, 2017, to February 15, 2018, were invited. We utilized the revised Family Affluence Scale for family affluence–based SES measurement. Clinical severity was diagnosed based on central nervous system (CNS) complications, treatments, and length of stay. We applied logistic regression for association analyses and multiple imputation for missing data.ResultsA total of 1229 laboratory-confirmed HFMD inpatients responded. Adjusted by age, sex, rural residence, EV-A71 infection, and health-seeking behavior, CNS complications (odds ratio [OR], 2.72; 95% CI, 1.41–5.31), intensive care unit (ICU) admission (OR, 7.30; 95% CI, 2.21–25.97), and prolonged hospitalization (OR, 4.28; 95% CI, 2.44–7.58) were significantly associated with lower family affluence–based SES. These associations increased as the SES category descended. For EV-A71-infected inpatients, severe HFMD was significantly associated with low and intermediate SES. For non-EV-A71-infected inpatients, only the association of prolonged hospitalization with low SES increased significantly. Also, severe HFMD inpatients, especially those admitted to the ICU, incurred high hospitalization costs.ConclusionsThe clinical severity of HMFD inpatients was significantly associated with family affluence–based SES. Severe HFMD inpatients were more likely to have lower SES than nonsevere inpatients and suffered a heavy economic burden. Therefore, medical subsidy and reimbursement policies should offer sufficient monetary support to severe HFMD inpatients to alleviate economic burden in low-SES populations and reduce potential SES inequality.

The Upregulation of a Novel Long Noncoding RNA AK097647 Promotes Enterovirus 71 Replication and Decreases IFN-λ1 Secretion

Background: Enterovirus 71 (EV71) infects millions of children every year in China and has become a challenge to public health. However, there is no effective treatment for EV71 infection. Long noncoding RNAs (lncRNAs) have been found to play various roles in virus replication and infection. Objective: We aimed to explore the role of a novel long noncoding RNA AK097647 (lncRNA-AK097647) during EV71 infection. Methods: To assess the role of lncRNA-AK097647 during EV71 infection, siRNAs were used to silence lncRNA-K097647 expression. RT-qPCR assay and Western blotting were applied to measure the mRNA and protein levels of EV71 VP1 and the phosphorylation of NF-κB. ELISA was used to detect the level of IFN-λ1 expression. Results: The novel lncRNA-AK097647 was upregulated in human rhabdomyosarcoma cells and the blood of hand, foot, and mouth disease patients infected with EV71, as demonstrated by RT-qPCR. Interestingly, RNAi-mediated knockdown of lncRNA-AK097647 dramatically increased the level of IFN-λ1 expression, resulting in the suppression of EV71 replication. In contrast, overexpression of lncRNA-AK097647 decreased the level of IFN-λ1 expression and resulted in increased EV71 replication. In addition, we found that lncRNA-AK097647 could inhibit the phosphorylation of NF-κB. Conclusion: These results suggest a novel mechanism by which EV71 evades the IFN-mediated host antiviral response by increasing lncRNA-AK097647 expression.

Incidence, aetiology, and serotype spectrum analysis of adult hand, foot, and mouth disease patients: A retrospective observational cohort study in northern Zhejiang, China

BackgroundHand, foot, and mouth disease (HFMD) in adults has rarely been reported in the literature, although its clinical significance is underestimated. This study was performed to systematically elucidate the epidemiological characteristics of adult HFMD. MethodsA total of 266 adult patients with HFMD were recruited. The control group comprised 40 healthy adults. Swabs and serum samples were collected. Enterovirus strains were tested by RT-PCR, and cytokine expression was examined using commercial kits. Socio-demographic data were collected through follow-up telephone calls. Daily meteorological data were obtained from the China Meteorological Data Sharing Service System. Socio-economic data were collected from the statistical bureau. ResultsThis study identified several unique spatiotemporal patterns in adult HFMD. Having a child recently diagnosed with HFMD was a risk factor for HFMD, whereas keeping pets was a protective factor against HFMD. The results of this study indicate the existence of subclinical carriers or misdiagnosed patients who might be the latent infectious source of HFMD. Further, this study also indicated that adults may act as the main infectious source of trans-regional spread of HFMD. ConclusionsThis study revealed the potential hazards of adult HFMD and is a reminder of the vital clinical significance of further research into adult HFMD.

Evolution of VP1 gene of coxsackievirus A16 in hand, foot, and mouth disease

Objective To investigate the genetic evolution of VP1 gene of pathogenic coxsackievirus A16 (CV-A16) strain isolated from clinical hand, foot, and mouth disease (HFMD) patients. Methods A total of 160 HFMD cases with CV-A16-positive results were collected from hospitals in Kunming during January 2015 to June 2017. Fecal samples were collected. Real-time polymerase chain reaction (PCR) was used to detect the CV-A16 virus nucleic acid. The VP1 genes of CV-A16-positive samples were amplified by reverse transcription-PCR. The amplified positive products were sequenced and aligned. The homologies were identified and their subgenotypes were determined. The phylogenetic tree was constructed and homology modeling was conducted. Results All the 160 CV-A16 isolates were B2 subtypes. The genetic distance between detected strains of CV-A16 and the strains in Fujian, Beijing, Nanjing was 0.76. The genetic distance to the strains in Malaysia was 0.78, and to the strains in Australia was 1.86. Homologous modeling revealed that the amino acid sequence of the VP1 gene of the strain had a G227R mutation. Conclusions There is no major genetic variation in the CV-A16 strains during 3 years. CV-A16 isolates are close to those of epidemic strains in Beijing, Fujian and Malaysia, but are far fram the strains from Australia. Key words: Hand, foot and mouth disease; Coxsackievirus A16; VP1 gene; Phylogenetic tree; Homology modeling

Longitudinal study on enterovirus A71 and coxsackievirus A16 genotype/subgenotype replacements in hand, foot and mouth disease patients in Thailand, 2000–2017

BackgroundEnterovirus A71 (EV-A71) and coxsackievirus A16 (CV-A16) are the major causative agents of hand, foot and mouth disease (HFMD) worldwide, particularly in the Asia-Pacific region. Several strains have emerged, circulated, and faded out over time in recent decades. This study investigated the EV-A71 and CV-A16 circulating strains and replacement of genotypes/subgenotypes in Thailand during the years 2000–2017. MethodsThe complete VP1 regions of 92 enteroviruses obtained from 90 HFMD patients, one asymptomatic adult contact case, and one encephalitic case were sequenced and investigated for serotypes, genotypes, and subgenotypes using a phylogenetic analysis. ResultsThe 92 enterovirus isolates were identified as 67 (72.8%) EV-A71 strains comprising subgenotypes B4, B5, C1, C2, C4a, C4b and C5, and 25 (27.2%) CV-A16 strains comprising subgenotypes B1a and B1b. Genotypic/subgenotypic replacements were evidenced during the study period. EV-A71 B5 and C4a have been the major circulating strains in Thailand for more than a decade, and CV-A16 B1a has been circulating for almost two decades. ConclusionsThis study provides chronological data on the molecular epidemiology of EV-A71 and CV-A16 subgenotypes in Thailand. Subgenotypic replacement frequently occurred with EV-A71, but not CV-A16. Monitoring for viral genetic and subgenotypic changes is important for molecular diagnosis, vaccine selection, and vaccine development.

The gut microbiota of hand, foot and mouth disease patients demonstrates down-regulated butyrate-producing bacteria and up-regulated inflammation-inducing bacteria.

This study explored the gut microbiota of children with hand, foot and mouth disease (HFMD). We enrolled 15 cases with HFMD admitted to the West China Second Hospital, Sichuan University, China, from July to September 2016 at a median age of three years. The controls were 15 healthy children of a similar age who underwent routine health examinations at the hospital during the same period. Gut microbiota was analysed using high throughput 16S ribosomal deoxyribonucleic acidsequencing. The gut microbiota in the HFMD patients was distinct from the controls. Compared with the controls, the composition of gut microbiota in the HFMD cases represented a reduction of two butyrate-producing bacteria, Ruminococcus (0.73±1.28 versus 7.78±20.01, p=0.026) and Roseburia (0.67±1.69 versus 1.61±3.27, p=0.024) and an up-regulation of Escherichia (5.26±10.50 versus 1.59±5.90,p<0.01) and Enterococcus (4.12±12.49 versus 0.12±0.41, p=0.015). The dysbiosis of gut microbiota of the HFMD cases included a reduction of butyrate-producing bacteria and an up-regulation of inflammation-inducing bacteria. These may have impaired the intestinal biological mucosal barrier and host immune functions, promoting the invasion of the enterovirus.

Long non-coding RNA expression profiles in different severity EV71-infected hand foot and mouth disease patients

Enterovirus 71 (EV71) is associated with the severe hand foot and mouth disease (HFMD) outcomes, however the host-virus interaction mechanism and the pathogenesis remain poorly understood. Long non-coding RNAs (lncRNAs) are involved in variety physiological and pathological processes, but the functions of lncRNAs in EV71 infection remain elusive. Here we profiled the expression of lncRNAs in peripheral blood mononuclear cells (PBMCs) from EV71-infected mild patients, severe patients as well as the healthy controls, and identified 8541 lncRNAs were differentially expressed. Focused on the dynamic changed lncRNAs, we performed systematic bioinformatics analysis with Series Test of Cluster (STC) algorithm, Gene Ontology (GO) analysis, pathway analysis and lncRNA-mRNA co-expression network analysis, and revealed the potential functions and related pathways of these lncRNAs were associated with immunity and inflammation during the clinical process of EV71-infected HFMD. Among the significant dynamic changed lncRNAs, ten lncRNAs were screened whose expression were further validated in EV71-infected mild patients, severe patients and healthy control. These results shed light on the potential roles of lncRNAs in EV71-infected HFMD, especially in distinguishing the mild and severe cases for early diagnose and treatment, moreover, provide deeper insight into the mechanism of EV71-induced immune and inflammatory responses, as well as the pathogenesis of the imbalanced inflammation in severe EV71 infection.

Economic costs and health-related quality of life for hand, foot and mouth disease (HFMD) patients in China.

BackgroundHand, foot and mouth disease (HFMD) is a common illness in China that mainly affects infants and children. The objective of this study is to assess the economic cost and health-related quality of life associated with HFMD in China.MethodA telephone survey of caregivers were conducted in 31 provinces across China. Caregivers of laboratory-confirmed HFMD patients who were registered in the national HFMD enhanced surveillance database during 2012–2013 were invited to participate in the survey. Total costs included direct medical costs (outpatient care, inpatient care and self-medication), direct non-medical costs (transportation, nutrition, accommodation and nursery), and indirect costs for lost income associated with caregiving. Health utility weights elicited using EuroQol EQ-5D-3L and EQ-Visual Analogue Scale (VAS) were used to calculate associated loss in quality adjusted life years (QALYs).ResultsThe subjects comprised 1136 mild outpatients, 1124 mild inpatients, 1170 severe cases and 61 fatal cases. The mean total costs for mild outpatients, mild inpatients, severe cases and fatal cases were $201 (95%CI $187, $215), $1072 (95%CI $999, $1144), $3051 (95%CI $2905, $3197) and $2819 (95%CI $2068, $3571) respectively. The mean QALY losses per HFMD episode for mild outpatients, mild inpatients and severe cases were 3.6 (95%CI 3.4, 3,9), 6.9 (95%CI 6.4, 7.4) and 13.7 (95%CI 12.9, 14.5) per 1000 persons. Cases who were diagnosed with EV-A71 infection and had longer duration of illness were associated with higher total cost and QALY loss.ConclusionHFMD poses a high economic and health burden in China. Our results provide economic and health utility data for cost-effectiveness analysis for HFMD vaccination in China.

Development of a pseudovirus based assay for measuring neutralizing antibodies against coxsackievirus B5

Coxsackievirus B5 (CV-B5), an important Coxsackie B virus from genus Enteroviruse within the family Picornaviridae, has also been isolated from Hand, Foot, and Mouth Disease (HFMD) patients, and often associated with neurological manifestations. In this study, we found out that Coxsackievirus B3 (CV-B3) replicon RNA could be encapsidated with CV-B5 capsid to assemble infectious CV-B5 pseudovirus. We then utilized this single round infection system of CV-B5 to develop a neutralizing antibody quantification assay. This pseudovirus neutralization assay showed superiority in biosafety, sensibility, quantitativity, efficiency and high throughput, and would facilitate the epidemiological studies and vaccine development of CV-B5.

Health related quality of life on severe hand, foot and mouth disease patients

Objective: To evaluate the health related quality of life (HRQoL) for severe hand, foot and mouth disease (HFMD) patients with different complications. Methods: A national telephone interview under the EQ-5D proxy2 questionnaire (EQ-SD and EQ-VAS), was conducted to obtain the HRQoL of lab-confirmed severe HFMD patients, aged between six months and five-year-olds from the national communicable disease surveillance system from January 1, 2012 to December 31, 2013. Results: A total of 685 severe HFMD cases were included in the study. A total of 456 (66.6%) of them were males with 75.8% of them younger than three years old. A total of 337 (49.2%) and 407 (59.4%) of the participants reported that they had problems in mobility or daily activities. A total of 569 (83.1%) and 616 (89.9%) of the cases reported having problems in pain/discomfort or anxiety/depression. The average EQ-5D and EQ-VAS scores were 0.58±0.23 and 53.6±25.7, both were positively associated with the duration of illness. Mean quality adjusted life years loss during the HFMD episode for the severe patients was (15.45±13.75) years/1 000 persons. The QALY losses for severe patients with each of below complication were: respiratory diseases (11.17±8.83) years/1 000 persons, aseptic meningitis (13.56±11.99) years/1 000 persons, encephalitis/brainstem encephalitis/acute flaccid paralysis (AFP) (15.31±12.63) years/1 000 persons, Myocarditis (17.28±18.16) years/1 000 persons, pulmonary hemorrhage/pulmonary edema (17.34±14.98) years/1 000 persons, cardiopulmonary failure (25.47±20.53) years/1 000 persons. Among patients with lab confirmed Entero virus A71 (EV71) (16.51±14.48) years/1 000 persons, the QALY loss was seen higher than Coxsackie virus A16 (Cox A16) (13.02±11.45) years/1 000 persons and other Enter virus (14.74±14.22) years/1 000 persons (Z=11.83, P=0.003). Conclusion: The HRQoL loss for severe HFMD patients substantially increased under complications exacerbation and related to the duration of illness.

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

Enterovirus A71 (EV-A71) is one of the main causative agents of hand, foot and mouth disease (HFMD). Unlike other enteroviruses that cause HFMD, EV-A71 is more frequently associated with severe neurological complications and fatality. To date, no effective licensed antivirals are available to combat EV-A71 infection. Little is known about the immunogenicity of viral non-structural proteins in humans. Previous studies have mainly focused on characterization of epitopes of EV-A71 structural proteins by using immunized animal antisera. In this study, we have characterized human antibody responses against the structural and non-structural proteins of EV-A71. Each viral protein was cloned and expressed in either bacterial or mammalian systems, and tested with antisera by western blot. Results revealed that all structural proteins (VP1-4), and non-structural proteins 2A, 3C and 3D were targets of EV-A71 IgM, whereas EV-A71 IgG recognized all the structural and non-structural proteins. Sixty three synthetic peptides predicted to be immunogenic in silico were synthesized and used for the characterization of EV-A71 linear B-cell epitopes. In total, we identified 22 IgM and four IgG dominant epitopes. Synthetic peptide PEP27, corresponding to residues 142–156 of VP1, was identified as the EV-A71 IgM-specific immunodominant epitope. PEP23, mapped to VP1 41–55, was recognized as the EV-A71 IgG cross-reactive immunodominant epitope. The structural protein VP1 is the major immunodominant site targeted by anti-EV-A71 IgM and IgG antibodies, but epitopes against non-structural proteins were also detected. These data provide new understanding of the immune response to EV-A71 infection, which benefits the development of diagnostic tools, potential therapeutics and subunit vaccine candidates.

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.

Circadian rhythm disruption was observed in hand, foot, and mouth disease patients.

Hand, foot, and mouth disease (HFMD) with central nerve system complications may rapidly progress to fulminated cardiorespiratory failure, with higher mortality and worse prognosis. It has been reported that circadian rhythms of heart rate (HR) and respiratory rate are useful in predicting prognosis of severe cardiovascular and neurological diseases. The present study aims to investigate the characteristics of the circadian rhythms of HR, respiratory rate, and temperature in HFMD patients with neurological complications.Hospitalized HFMD patients including 33 common cases (common group), 61 severe cases (severe group), and 9 critical cases (critical group) were contrasted retrospectively. Their HR, respiratory rate, and temperatures were measured every 4 hours during the first 48-hour in the hospital. Data were analyzed with the least-squares fit of a 24-hour cosine function by the single cosinor and population-mean cosinor method.Results of population-mean cosinor analysis demonstrated that the circadian rhythm of HR, respiratory rate, and temperature was present in the common and severe group, but absent in the critical group. The midline-estimating statistic of rhythm (MESOR) (P = 0.016) and acrophase (P < 0.01) of temperature and respiratory rate were significantly different among 3 groups. But no statistical difference of amplitude in temperature and respiratory rate was observed among the 3 groups (P = 0.14). MESOR value of HR (P < 0.001) was significantly different in 3 groups. However, amplitude and acrophase revealed no statistical difference in circadian characteristics of HR among 3 groups. Compared with the common group, the MESOR of temperature and respiratory rate was significantly higher, and acrophase of temperature and respiratory rate was 2 hours ahead in the severe group, critical HFMD patients lost their population-circadian rhythm of temperature, HR, and respiratory rate. The high values of temperature and respiratory rate for the common group were concentrated between 3 and 9 pm, whereas those for the severe group were more dispersive. And the high values for the critical group were equally distributed in 24 hours of the day.Circadian rhythm of patients’ temperature in the common group was the same as the normal rhythm of human body temperature. Circadian rhythm of patients’ temperature, HR and respiratory rate in 3 groups were significantly different.

Prevalence and genetic characteristics of Saffold cardiovirus in China from 2009 to 2012.

The epidemiology and clinical features of the Saffold cardiovirus (SAFV) remain ambiguous. The present study was designed to systematically and intensively investigate the epidemiological features of SAFV in pediatric patients in China. Three cohorts of pediatric patients were recruited from 2009 to 2012. Cohort 1 comprised patients with acute respiratory tract infections. Cohort 2 comprised patients with diarrhea. Cohort 3 comprised hand, foot, and mouth disease (HFMD) patients. A total of 115 patients (1.6%) among 6052 (17/1647, 12/2013, and 86/2392 in cohorts 1, 2, and 3, respectively) were SAFV-positive. The samples from 82 SAFV-positive patients were successfully sequenced, and four genotypes were identified: 8 SAFV-1, 41 SAFV-2, 29 SAFV-3, and 4 SAFV-6. A significantly higher detection rate was found in the HFMD patients than in other two cohorts (both P <0.001). A higher frequency of severe clinical outcome and nervous system manifestation were also observed in the SAFV-positive HFMD patients. Additionally, 6 (3.5%) cerebrospinal fluid and 7 (2.2%) serum samples from the HFMD-associated encephalitis patients were SAFV-positive. Based on the VP1 sequences, all four genotypes displayed distinct geographical clustering. SAFV infection might be associated with a wide clinical spectrum and contribute to HFMD.