Pathogenicity and landscape of differential gene expression in mice orally infected with clinical coxsackievirus A6 (CA6).

Hand, foot, and mouth disease (HFMD) is caused by more than 20 pathogenic enteroviruses belonging to the Picornaviridae family and Enterovirus genus. Since the introduction of the enterovirus-71 (EV71) vaccine in 2016, the number of HFMD cases caused by EV71 has decreased. However, cases of infections caused by other enteroviruses, such as coxsackievirus A6 (CA6) and coxsackievirus A10, have been increasing accordingly. In this study, we used a clinical isolate of CA6 to establish an intragastric infection mouse model using 7-day-old mice to mimic the natural transmission route, by which we investigated the differential gene expression profiles associated with virus infection and pathogenicity. After intragastric infection, mice exhibited hind limb paralysis symptoms and weight loss, similar to those reported for EV71 infection in mice. The skeletal muscle was identified as the main site of virus replication, with a peak viral load reaching 2.31 × 107 copies/mg at 5 dpi and increased infiltration of inflammatory cells. RNA sequencing analysis identified differentially expressed genes (DEGs) after CA6 infection. DEGs in the blood, muscle, brain, spleen, and thymus were predominantly enriched in immune system responses, including pathways such as Toll-like receptor signaling and PI3K-Akt signaling. Our study has unveiled the genes involved in the host immune response during CA6 infection, thereby enhancing our comprehension of the pathological mechanism of HFMD.IMPORTANCEThis study holds great significance for the field of hand, foot, and mouth disease (HFMD). It not only delves into the disease's etiology, transmission pathways, and severe complications but also establishes a novel mouse model that mimics the natural coxsackievirus A6 infection process, providing a pivotal platform to delve deeper into virus replication and pathogenic mechanisms. Additionally, utilizing RNA-seq technology, it unveils the dynamic gene expression changes during infection, offering valuable leads for identifying novel therapeutic drug targets. This research has the potential to enhance our understanding of HFMD, offering fresh perspectives for disease prevention and treatment and positively impacting children's health worldwide.

Enterovirus-A71 exploits RAB11 to recruit chaperones for virus morphogenesis.

BACKGROUND: Enterovirus 71 (EV-A71) causes Hand, Foot and Mouth Disease (HFMD) in children and has been associated with neurological complications. The molecular mechanisms involved in EV-A71 pathogenesis have remained elusive. METHODS: A siRNA screen in EV-A71 infected-motor neurons was performed targeting 112 genes involved in intracellular membrane trafficking, followed by validation of the top four hits using deconvoluted siRNA. Downstream approaches including viral entry by-pass, intracellular viral genome quantification by qPCR, Western blot analyses, and Luciferase reporter assays allowed determine the stage of the infection cycle the top candidate, RAB11A was involved in. Proximity ligation assay, co-immunoprecipitation and multiplex confocal imaging were employed to study interactions between viral components and RAB11A. Dominant negative and constitutively active RAB11A constructs were used to determine the importance of the protein's GTPase activity during EV-A71 infection. Mass spectrometry and protein interaction analyses were employed for the identification of RAB11A's host interacting partners during infection. RESULTS: Small GTPase RAB11A was identified as a novel pro-viral host factor during EV-A71 infection. RAB11A and RAB11B isoforms were interchangeably exploited by strains from major EV-A71 genogroups and by Coxsackievirus A16, another major causative agent of HFMD. We showed that RAB11A was not involved in viral entry, IRES-mediated protein translation, viral genome replication, and virus exit. RAB11A co-localized with replication organelles where it interacted with structural and non-structural viral components. Over-expression of dominant negative (S25N; GDP-bound) and constitutively active (Q70L; GTP-bound) RAB11A mutants had no effect on EV-A71 infection outcome, ruling out RAB11A's involvement in intracellular trafficking of viral or host components. Instead, decreased ratio of intracellular mature viral particles to viral RNA copies and increased VP0:VP2 ratio in siRAB11-treated cells supported a role in provirion maturation hallmarked by VP0 cleavage into VP2 and VP4. Finally, chaperones, not trafficking and transporter proteins, were found to be RAB11A's top interacting partners during EV-A71 infection. Among which, CCT8 subunit from the chaperone complex TRiC/CCT was further validated and shown to interact with viral structural proteins specifically, representing yet another novel pro-viral host factor during EV-A71 infection. CONCLUSIONS: This study describes a novel, unconventional role for RAB11A during viral infection where it participates in the complex process of virus morphogenesis by recruiting essential chaperone proteins.

MST1/2 exerts a pivotal role in inducing neuroinflammation and Coxsackievirus-A10 replication by interacting with innate immunity.

Coxsackievirus-A10 (CV-A10), responsible for the hand, foot and mouth disease (HFMD) pandemic, could cause serious central nervous system (CNS) complications. The underlying molecular basis of CV-A10 and host interactions inducing neuropathogenesis is still unclear. The Hippo signaling pathway, historically known for a dominator of organ development and homeostasis, has recently been implicated as an immune regulator. However, its role in host defense against CV-A10 has not been investigated. Herein, it was found that CV-A10 proliferated in HMC3 cells and promoted the release of inflammatory cytokines. Moreover, pattern recognition receptors (PRRs)-mediated pathways, including TLR3-TRIF-TRAF3-TBK1-NF-κB axis, RIG-I/MDA5-MAVS-TRAF3-TBK1-NF-κB axis and TLR7-MyD88-IRAK1/IRAK4-TRAF6-TAK1-NF-κB axis, were examined to be elevated under CV-A10 infection. Meanwhile, it was further uncovered that Hippo signaling pathway was inhibited in HMC3 cells with CV-A10 infection. Previous studies have been reported that there exist complex relations between innate immune and Hippo signaling pathway. Then, plasmids of knockdown and overexpression of MST1/2 were transfected into HMC3 cells. Our results showed that MST1/2 suppressed the levels of inflammatory cytokines via interacting with TBK1 and IRAK1, and also enhanced virus production via restricting IRF3 and IFN-ß expressions. Overall, these data obviously pointed out that CV-A10 accelerated the formation of neuroinflammation by the effect of the Hippo pathway on the PRRs-mediated pathway, which delineates a negative immunoregulatory role for MST1/2 in CV-A10 infection and the potential for this pathway to be pharmacologically targeted to treat CV-A10.

Recent Progress in Innate Immune Responses to Enterovirus A71 and Viral Evasion Strategies.

Enterovirus A71 (EV-A71) is a major pathogen causing hand, foot, and mouth disease (HFMD) in children worldwide. It can lead to severe gastrointestinal, pulmonary, and neurological complications. The innate immune system, which rapidly detects pathogens via pathogen-associated molecular patterns or pathogen-encoded effectors, serves as the first defensive line against EV-A71 infection. Concurrently, the virus has developed various sophisticated strategies to evade host antiviral responses and establish productive infection. Thus, the virus-host interactions and conflicts, as well as the ability to govern biological events at this first line of defense, contribute significantly to the pathogenesis and outcomes of EV-A71 infection. In this review, we update recent progress on host innate immune responses to EV-A71 infection. In addition, we discuss the underlying strategies employed by EV-A71 to escape host innate immune responses. A better understanding of the interplay between EV-A71 and host innate immunity may unravel potential antiviral targets, as well as strategies that can improve patient outcomes.

A review on current diagnostic tools and potential optical absorption spectroscopy for HFMD detection.

Hand, Foot, and Mouth Disease (HFMD) is an outbreak infectious disease that can easily spread among children under the age of five. The most common causative agents of HFMD are enterovirus 71 (EV71) and coxsackievirus A16 (CVA16), but infection caused by EV71 is more associated with fatalities due to severe neurological disorders. The present diagnosis methods rely on physical examinations by the doctors and further confirmation by laboratories detection methods such as viral culture and polymerase chain reaction. Clinical signs of HFMD infection and other childhood diseases such as chicken pox, and allergies are similar, yet the genetics and pathogenicity of the viruses are substantially different. Thus, there is an urgent need for an early screening of HFMD using an inexpensive and user-friendly device that can directly detect the causative agents of the disease. This paper reviews current HFMD diagnostic methods based on various target types, such as nucleic acid, protein, and whole virus. This was followed by a thorough discussion on the emerging sensing technologies for HFMD detection, including surface plasmon resonance, electrochemical sensor, and surface enhanced Raman spectroscopy. Lastly, optical absorption spectroscopic method was critically discussed and proposed as a promising technology for HFMD screening and detection.

Distinct expression and clinical value of aquaporin 4 in children with hand, foot and mouth disease caused by enterovirus 71.

Brain dysfunction is a prerequisite for critical complications in children with hand, foot, and mouth disease (HFMD). Aquaporin 4 (AQP-4) may be involved in the pathological process of cerebral oedema and injury in children with severe and critical HFMD. This study aimed to assess the association of AQP-4 with the severity of enterovirus 71 (EV71)-associated HFMD. Children with EV71-infected HFMD were divided into a common group (clinical stage 1), a severe group (clinical stage 2), and a critical group (clinical stage 3) according to Chinese guidelines. The levels of AQP-4, interleukin-6 (IL-6), norepinephrine (NE), and neuron-specific enolase (NSE) before and after treatment were tested. Serum AQP-4, IL-6, NE, and NSE levels showed significant differences among the critical, severe, and common groups before and after treatment (P < 0.01). No significant differences in AQP-4 levels in cerebrospinal fluid (CSF) were observed between the critical and severe groups before and after treatment, but the CSF AQP-4 levels in these two groups were higher than those in the common group before treatment (P < 0.01). Serum AQP-4 levels, but not CSF AQP-4 levels, closely correlated with serum IL-6, NE, and NSE levels. These results suggest that the level of AQP-4 in serum, but not in CSF, is a candidate biomarker for evaluating the severity and prognosis of EV71-associated HFMD.

Comprehensive profiling and characterization of cellular microRNAs in response to coxsackievirus A10 infection in bronchial epithelial cells.

Coxsackievirus A10 (CV-A10), the causative agent of hand, foot, and mouth disease (HFMD), caused a series of outbreaks in recent years and often leads to neurological impairment, but a clear understanding of the disease pathogenesis and host response remains elusive. Cellular microRNAs (miRNAs), a large family of non-coding RNA molecules, have been reported to be key regulators in viral pathogenesis and virus-host interactions. However, the role of host cellular miRNAs defensing against CV-A10 infection is still obscure. To address this issue, we systematically analyzed miRNA expression profiles in CV-A10-infected 16HBE cells by high-throughput sequencing methods in this study. It allowed us to successfully identify 312 and 278 miRNAs with differential expression at 12 h and 24 h post-CV-A10 infection, respectively. Among these, 4 miRNAs and their target genes were analyzed by RT-qPCR, which confirmed the sequencing data. Gene target prediction and enrichment analysis revealed that the predicted targets of these miRNAs were significantly enriched in numerous cellular processes, especially in regulation of basic physical process, host immune response and neurological impairment. And the integrated network was built to further indicate the regulatory roles of miRNAs in host-CV-A10 interactions. Consequently, our findings could provide a beneficial basis for further studies on the regulatory roles of miRNAs relevant to the host immune responses and neuropathogenesis caused by CV-A10 infection.

Bioinformatics and Screening of a Circular RNA-microRNA-mRNA Regulatory Network Induced by Coxsackievirus Group B5 in Human Rhabdomyosarcoma Cells.

Hand, foot and mouth disease (HFMD) caused by Coxsackievirus Group B5 (CVB5) is one of the most common herpetic diseases in human infants and children. The pathogenesis of CVB5 remains unknown. Circular RNAs (CircRNAs), as novel noncoding RNAs, have been shown to play a key role in many pathogenic processes in different species; however, their functions during the process of CVB5 infection remain unclear. In the present study, we investigated the expression profiles of circRNAs using RNA sequencing technology in CVB5-infected and mock-infected human rhabdomyosarcoma cells (CVB5 virus that had been isolated from clinical specimens). In addition, several differentially expressed circRNAs were validated by RT-qPCR. Moreover, the innate immune responses related to circRNA-miRNA-mRNA interaction networks were constructed and verified. A total of 5461 circRNAs were identified at different genomic locations in CVB5 infections and controls, of which 235 were differentially expressed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis demonstrated that the differentially expressed circRNAs were principally involved in specific signaling pathways related to ErbB, TNF, and innate immunity. We further predicted that novel_circ_0002006 might act as a molecular sponge for miR-152-3p through the IFN-I pathway to inhibit CVB5 replication, and that novel_circ_0001066 might act as a molecular sponge for miR-29b-3p via the NF-κB pathway and for the inhibition of CVB5 replication. These findings will help to elucidate the biological functions of circRNAs in the progression of CVB5-related HFMD and identify prospective biomarkers and therapeutic targets for this disease.

[Overview of Meta-analysis of Lianhua Qingwen preparations in treatment of viral diseases].

This study aims to obtain higher-level evidence by overviewing the Meta-analysis of Lianhua Qingwen preparations in the treatment of viral diseases including influenza, coronavirus disease 2019(COVID-19), and hand, foot and mouth disease(HFMD). CNKI, Wanfang, VIP, China Clinical Trial Registry(ChiCTR), PubMed, EMbase, Web of Science, and Cochrane Library were searched for the Meta-analysis about the treatment of viral diseases with Lianhua Qingwen preparations from the database establishment to April 1, 2022. After literature screening and data extraction, AMSTAR2 and the grading of recommendations assessment, development and evaluations(GRADE) system were used to assess the methodological quality and evidence quality, respectively, and then the efficacy and safety outcomes of Lianhua Qingwen preparations in the treatment of viral diseases were summarized. Thirteen Meta-analysis were finally included, three of which were rated as low grade by AMSTAR2 and ten as very low grade. A total of 75 outcome indicators were obtained, involving influenza, COVID-19, and HFMD. According to the GRADE scoring results, the 75 outcome indicators included 5(6.7%) high-level indicators, 18(24.0%) mediate-level indicators, 25(33.3%) low-level evidence indicators, and 27(36.0%) very low-level indicators.(1)In the treatment of influenza, Lianhua Qingwen preparations exhibited better clinical efficacy than other Chinese patent medicines and Ribavirin and had similar clinical efficacy compared with Oseltamivir. Lianhua Qingwen preparations were superior to other Chinese patent medicines, Oseltamivir, and Ribavirin in alleviating clinical symptoms. They showed no significant differences from Oseltamivir or conventional anti-influenza treatment in terms of the time to and rate of negative result of viral nucleic acid test.(2)In the treatment of COVID-19, Lianhua Qingwen preparation alone or combined with conventional treatment was superior to conventional treatment in terms of total effective rate, main symptom subsidence rate and time, fever clearance rate, duration of fever, time to fever clearance, cough subsidence rate, time to cough subsidence, fatigue subsidence rate, time to fatigue subsidence, myalgia subsidence rate, expectoration subsidence rate, chest tightness subsidence rate, etc. Lianhua Qingwen preparations no difference from conventional treatment in terms of subsiding sore throat, nausea, diarrhea, loss of appetite, headache, and dyspnea. In terms of chest CT improvement rate, rate of progression to severe case, cure time, and hospitalization time, Lianhua Qingwen alone or in combination with conventional treatment was superior to conventional treatment.(3)In the treatment of HFMD, Lianhua Qingwen Granules was superior to conventional treatment in terms of total effective rate, average fever clearance time, time to herpes subsidence, and time to negative result of viral nucleic acid test.(4)In terms of safety, Lianhua Qingwen preparations led to low incidence of adverse reactions, all of which were mild and disappeared after drug withdrawal. The available evidence suggests that in the treatment of influenza, COVID-19, and HFMD, Lianhua Qingwen preparations can relieve the clinical symptoms, shorten the hospitalization time, and improve the chest CT. They have therapeutic effect and good safety in the treatment of viral diseases. However, due to the low quality of available studies, more high-quality clinical trials are needed to support the above conclusions.

A hSCARB2-transgenic mouse model for Coxsackievirus A16 pathogenesis.

BACKGROUND: Coxsackievirus A16 (CA16) is one of the neurotropic pathogen that has been associated with severe neurological forms of hand, foot, and mouth disease (HFMD), but its pathogenesis is not yet clear. The limited host range of CA16 make the establishment of a suitable animal model that can recapitulate the neurological pathology observed in human HFMD more difficult. Because the human scavenger receptor class B, member 2 (hSCARB2) is a cellular receptor for CA16, we used transgenic mice bearing human SCARB2 and nasally infected them with CA16 to study the pathogenicity of the virus. METHODS: Coxsackievirus A16 was administered by intranasal instillation to groups of hSCARB2 transgenic mice and clinical signs were observed. Sampled at different time-points to document and characterize the mode of viral dissemination, pathological change and immune response of CA16 infection. RESULTS: Weight loss and virus replication in lung and brain were observed in hSCARB2 mice infected with CA16, indicating that these animals could model the neural infection process. Viral antigens were observed in the alveolar epithelia and brainstem cells. The typical histopathology was interstitial pneumonia with infiltration of significant lymphocytes into the alveolar interstitial in lung and diffuse punctate hemorrhages in the capillaries of the brainstem. In addition, we detected the expression levels of inflammatory cytokines and detected high levels of interleukin IL-1ß, IL-6, IL-18, and IFN-γ in nasal mucosa, lungs and brain tissues. CONCLUSIONS: The hSCARB2-transgenic mice can be productively infected with CA16 via respiratory route and exhibited a clear tropism to lung and brain tissues, which can serve as a model to investigate the pathogenesis of CA16 associated respiratory and neurological disease.

Identifying pre-outbreak signals of hand, foot and mouth disease based on landscape dynamic network marker.

BACKGROUND: The high incidence, seasonal pattern and frequent outbreaks of hand, foot and mouth disease (HFMD) represent a threat for billions of children around the world. Detecting pre-outbreak signals of HFMD facilitates the timely implementation of appropriate control measures. However, real-time prediction of HFMD outbreaks is usually challenging because of its complexity intertwining both biological systems and social systems. RESULTS: By mining the dynamical information from city networks and horizontal high-dimensional data, we developed the landscape dynamic network marker (L-DNM) method to detect pre-outbreak signals prior to the catastrophic transition into HFMD outbreaks. In addition, we set up multi-level early warnings to achieve the purpose of distinguishing the outbreak scale. Specifically, we collected the historical information of clinic visits caused by HFMD infection between years 2009 and 2018 respectively from public records of Tokyo, Hokkaido, and Osaka, Japan. When applied to the city networks we modelled, our method successfully identified pre-outbreak signals in an average 5 weeks ahead of the HFMD outbreak. Moreover, from the performance comparisons with other methods, it is seen that the L-DNM based system performs better when given only the records of clinic visits. CONCLUSIONS: The study on the dynamical changes of clinic visits in local district networks reveals the dynamic or landscapes of HFMD spread at the network level. Moreover, the results of this study can be used as quantitative references for disease control during the HFMD outbreak seasons.

Functional Insights into Silymarin as an Antiviral Agent against Enterovirus A71 (EV-A71).

Enterovirus A71 (EV-A71) is a major neurovirulent agent capable of causing severe hand, foot and mouth disease (HFMD) associated with neurological complications and death. Currently, no FDA-approved antiviral is available for the treatment of EV-A71 infections. The flavonoid silymarin was shown to exert virucidal effects, but the binding site on the capsid was unknown. In this study, the ligand interacting site of silymarin was determined in silico and validated in vitro. Moreover, the potential of EV-A71 to develop resistance against silymarin was further evaluated. Molecular docking of silymarin with the capsid of EV-A71 indicated that silymarin binds to viral protein 1 (VP1) of EV-A71, specifically at the GH loop of VP1. The in vitro binding of silymarin with VP1 of EV-A71 was validated using recombinant VP1 through ELISA competitive binding assay. Continuous passaging of EV-A71 in the presence of silymarin resulted in the emergence of a mutant carrying a substitution of isoleucine by threonine (I97T) at position 97 of the BC loop of EV-A71. The mutation was speculated to overcome the inhibitory effects of silymarin. This study provides functional insights into the underlying mechanism of EV-A71 inhibition by silymarin, but warrants further in vivo evaluation before being developed as a potential therapeutic agent.

Epidemiological and clinical characteristics of severe hand-foot-and-mouth disease (HFMD) among children: a 6-year population-based study.

BACKGROUND: Hand-foot-and-mouth disease (HFMD) is considered to be self-limited, however, severe HFMD is a deadly threat for children worldwide, therefore, it is essential to define the clinical and epidemiologic characteristics of children with severe HFMD and identify the risk factors of death. METHODS: Between 2013 and 2018, children who diagnosed with severe HFMD from Chongqing, China were enrolled in this population-based study. A total of 459 severe HFMD children cases were identified during the study period, including 415 survivors and 44 fatal cases. Demographic, geographical, epidemiological and clinical data of the cases were acquired and analyzed. RESULTS: Risk factors of the death because of severe HFMD children included female, aged 1 ~ 3 years, enterovirus 71 infection, falling ill in winter, more than one children in home, being taken care of by grandparents, the caregivers' education not more than 9 years, having fever more than 3 days, consciousness disorders, general weakness, vomiting, general weakness, abnormal pupillary light reflex, repeated cough, tachypnea, moist rales, white frothy sputum, pink frothy sputum, and cyanosis on lips or the whole body, tachycardia, arrhythmia, cold limbs, pale complexion, weakened pulse. (all p < 0.05). Spatial-temporal analysis detected high-value clusters, the most likely cluster located at rural countries in the northern parts of Chongqing, from January, 2015 to July, 2017. (p < 0.01). Besides, some urban districts were also found high incidence of severe HFMD cases according to the incidence maps. CONCLUSIONS: The detection of clinical risk factors and the temporal, spatial and socio-demographic distribution epidemiological characteristics of severe HFMD contribute to the timely diagnosis and intervention, the results of this study can be the reference of further clinical and public health practice.

[Atypical hand, foot and mouth disease in adults: A note on 6 cases]. / Syndrome main-pied-bouche atypique de l'adulte : à propos de 6 observations.

INTRODUCTION: Hand, foot and mouth disease (HFMD) is form of viral dermatosis well known among the pediatric population, in whom it has a typical presentation. However, it is less common in adults, with a more heterogeneous presentation, potentially making diagnosis extremely challenging for the clinician. PATIENTS AND METHODS: This was a retrospective case series from 2013 to 2018 of HFMD in adults, with all cases being confirmed by cutaneous polymerase chain reaction (PCR). We studied the clinical, epidemiological and viral characteristics of each patient. RESULTS: This series of 6 cases comprised 4 men and 2 women, with a mean age of 42.5 years. Five patients presented extended purpuric lesions, four had bullous lesions, and three showed cutaneous signs without any mucosal lesions. Extended lesions on the trunk were found in four patients. One patient presented rosette-shaped pustular lesions on the limbs, one had eczema-like lesions on the scalp, and one presented extended purpuric lesions on the soles. DISCUSSION: These different cases of adult HFMD raise questions about differential diagnosis in relation to other acute cutaneous and mucous diseases. It is essential to be aware of these different types of presentation of the disease in order to determine the diagnosis and discuss preventive measures.

Low frequency, weak MCP-1 secretion and exhausted immune status of peripheral monocytes were associated with progression of severe enterovirus A71-infected hand, foot and mouth disease.

A minority of hand, foot and mouth disease (HFMD) caused by enterovirus A71 (EV-A71) results in severe neural complications. However, whether monocyte-mediated immunity is involved in the disease progression of HFMD remains unknown. One hundred and twenty mild and 103 severe HFMD patients were recruited and enzyme-linked immunosorbent assay (ELISA), flow cytometry and Transwell culture were performed in the study. Peripheral monocyte counts were lower in both absolute counts and frequencies in severe cases compared to mild cases. After screening 10 monocyte-related cytokines by ELISA, only monocyte chemoattractant protein-1 (MCP-1) was found at higher levels in sera of mild cases compared to those with severe symptoms. Monocytes purified from mild cases produced more MCP-1 than the cells from severe patients when stimulated in vitro. We observed that immune exhaustion markers programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) were highly regulated on the surface of monocytes from severe cases compared to mild cases. PD-L1 blockade induced a higher production of MCP-1 in the supernatant of a Transwell system. The production of MCP-1 also increased following PD-L1 blockade of purified monocytes activated by granulocyte-macrophage colony-stimulating factor (GM-CSF) combined with R848 or EV-A71 virus. Our results indicate that absolute count, frequency and levels of MCP-1 secretion of peripheral monocytes, together with their immune status, probably contribute to differential disease prognosis in EV-A71-associated HFMD.

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.

MRI reveals segmental distribution of enterovirus lesions in the central nervous system: a probable clinical evidence of retrograde axonal transport of EV-A71.

Enterovirus 71 (EV-A71) is a major causative agent for hand, foot, and mouth disease (HFMD), especially severe HFMD characterized by neurologic involvement. The objective of this study is to investigate the relationship between the distribution of neurologic infection and the outcomes of severe HFMD. A total of 139 suspected severe HFMD cases (92 were confirmed as EV-A71 infection) underwent clinical and laboratory diagnosis as well as magnetic resonance imaging (MRI) scans of the nervous system. Only those who were confirmed with EV-A71 infection were included in our study. The image data of severe EV-A71-related HFMD cases were retrospectively analyzed, and they were grouped according to lesion site location indicated by MRI. The distribution of lesions in the central nervous system shown by MRI indicated that there were 47 (51%) in brainstem, 33 (36%) in spinal nerve roots lower than T1 thoracic spine, four (5%) in brainstem plus cervical spinal cord involvement, three (3%) in cervical spinal cord, three (3%) in brainstem plus spinal nerve root lower than T1, and two (2%) in cervical and thoracic spinal cord lower than T1. Our analysis strongly substantiates the hypothesis of retrograde axonal transport (RAT) of EV-A71 pathogenesis, suggesting that the pharyngeal branch of the vagus nerve is a major route to the brainstem, and that ascending transportation via the spinal cord does not occur when spinal nerve roots are infected by EV-A71 via RAT. Graphical abstract ᅟ.

Acute unilateral maculopathy associated with adult onset of hand, foot and mouth disease: a case report.

BACKGROUND: To report the case of a 31-year-old patient with Hand, Foot and Mouth Disease (HFMD) and concurrent acute monocular maculopathy, and to describe multimodal imaging findings never before described including optical coherence tomography angiography (OCT-A). CASE PRESENTATION: Nine days after the onset of clinically highly probable but not laboratory-verified HFMD, a 31-year old male noticed a central scotoma, distorted lines and loss of visual acuity (Snellen visual acuity 20/400) in his right eye. Funduscopy revealed focal alterations in the retinal pigmented epithelium (RPE) and yellow retinal dots corresponding to focal dots of decreased fundus autofluorescence (FAF) surrounded by increased FAF. Spectral domain optical coherence tomography (SD-OCT) demonstrated irregularities in the ellipsoide zone, hyperreflective dots above the RPE and RPE thickening. Fundus fluorescein angiography (FAG) revealed central hypofluorescence in the macular area in the early phase, as well as increasing focal hyperfluorescence in the late phase corresponding with RPE defects observed in FAF. Indocyanine green angiography (ICGA) showed central hypofluorescence in the early and late phase, corresponding with areas of reduced flow in the choroidea and choriocapillaris as apparent in OCT-A. Visual acuity improved within 3 months without any systemic or local therapy. At his three-month follow-up, SD-OCT revealed subtle subretinal fluid that resolved spontaneously over time. No signs of choroidal neovascularization were observed. Twelve months following the onset of symptoms Snellen visual acuity was 400/400. Multimodal imaging revealed subtly changed, decreased FAF while the choroidal architecture recovered completely as demonstrated by OCT-A. CONCLUSIONS: HFMD-associated maculopahty is an uncommon but important differential diagnosis of chorioretinitis with macular involvement. The prognosis can be good and the initially observed morphological pathologies such as impaired perfusion of the choroidal vessels can recover spontaneously over a period lasting 12 months. OCT-A can be employed as a non-invasive tool to detect the reduced perfusion of the choroidal vessels and for monitoring the disease course.

The epidemic characteristics and spatial autocorrelation analysis of hand, foot and mouth disease from 2010 to 2015 in Shantou, Guangdong, China.

BACKGROUND: Hand, foot and mouth disease (HFMD) is the highest incidence of infectious diseases in China. Shantou is one of the most infected cities. Therefore, it is necessary for us to understand the epidemic characteristics and distribution trend of HFMD in Shantou. The purpose of this study is to investigate the spatial epidemiological characteristics of HFMD and analyse its spatial autocorrelation. METHOD: We collated and summarised the data of HFMD in Shantou from 2010 to 2015. SaTScan software and Moran's I were used to analyse the spatial correlation of HFMD, and the results were presented in ArcMap. RESULTS: The distribution of HFMD in Shantou was of a seasonal trend, mainly concentrating during May and June. Children under 5-years-old were the main group of cases of HFMD, accounting for 92.46%. The proportion of infected children, especially those aged zero to 1, was the largest in each year, accounting for 45.62%, meaning that smaller children were more susceptible to HFMD. The number of male patients with HFMD was greater than that of females (1.78:1, male: female). With regard to the potential impact of patients' living style on the incidence rate of HFMD, this study revealed that scattered children were the dominant infected population, accounting for as much 84.49% of cases. The incidence of HFMD was unevenly distributed among streets. The incidence interval of streets was in a range of 13.76/100,000 to 1135.19/100,000. Spatial autocorrelation analysis showed that there was no global spatial correlation in Shantou, except in 2013. The results of local spatial autocorrelation analysis showed that H-H correlation existed in the high incidence local area of Shantou. CONCLUSIONS: The incidence of HFMD across the various streets in Shantou not only varied widely but also represented local autocorrelation. Attention, as well as prevention and control measures, should be focused on those high-incidence areas, such as the Queshi street, Zhuchi street and Xinjin street.

Predicting the outbreak of hand, foot, and mouth disease in Nanjing, China: a time-series model based on weather variability.

Hand, foot, and mouth disease (HFMD) is a significant public health issue in China and an accurate prediction of epidemic can improve the effectiveness of HFMD control. This study aims to develop a weather-based forecasting model for HFMD using the information on climatic variables and HFMD surveillance in Nanjing, China. Daily data on HFMD cases and meteorological variables between 2010 and 2015 were acquired from the Nanjing Center for Disease Control and Prevention, and China Meteorological Data Sharing Service System, respectively. A multivariate seasonal autoregressive integrated moving average (SARIMA) model was developed and validated by dividing HFMD infection data into two datasets: the data from 2010 to 2013 were used to construct a model and those from 2014 to 2015 were used to validate it. Moreover, we used weekly prediction for the data between 1 January 2014 and 31 December 2015 and leave-1-week-out prediction was used to validate the performance of model prediction. SARIMA (2,0,0)52 associated with the average temperature at lag of 1 week appeared to be the best model (R 2 = 0.936, BIC = 8.465), which also showed non-significant autocorrelations in the residuals of the model. In the validation of the constructed model, the predicted values matched the observed values reasonably well between 2014 and 2015. There was a high agreement rate between the predicted values and the observed values (sensitivity 80%, specificity 96.63%). This study suggests that the SARIMA model with average temperature could be used as an important tool for early detection and prediction of HFMD outbreaks in Nanjing, China.