Expression and clinical significance of pattern recognition receptor-associated genes in hand, foot and mouth disease

Objective:To explore which pattern recognition receptors(PRRs)play a key role in the development of hand,foot,and mouth disease(HFMD)by analyzing PRR-associated genes.Methods:We conducted a comparative analysis of PRR-associated gene expression in human peripheral blood mononuclear cells(PBMCs)infected with enterovirus 71(EV-A71)which were derived from patients with HFMD of different severities and at different stages.A total of 30 PRR-associated genes were identified as significantly upregulated both over time and across different EV-A71 isolates.Subsequently,ELISA was employed to quantify the expression of the six most prominent genes among these 30 identified genes,specifically,BST2,IRF7,IFI16,TRIM21,MX1,and DDX58.Results:Compared with those at the recovery stage,the expression levels of BST2(P=0.027),IFI16(P=0.016),MX1(P=0.046)and DDX58(P=0.008)in the acute stage of infection were significantly upregulated,while no significant difference in the expression levels of IRF7(P=0.495)and TRIM21(P=0.071)was found between different stages of the disease.The expression levels of BST2,IRF7,IFI16 and MX1 were significantly higher in children infected with single pathogen than those infected with mixed pathogens,and BST2,IRF7,IFI16 and MX1 expression levels were significantly lower in coxsackie B virus(COXB)positive patients than the negative patients.Expression levels of one or more of BST2,IRF7,IFI16,TRIM21,MX1 and DDX58 genes were correlated with PCT levels,various white blood cell counts,and serum antibody levels that reflect disease course of HFMD.Aspartate aminotransferase was correlated with BST2,MX1 and DDX58 expression levels.Conclusions:PRR-associated genes likely initiate the immune response in patients at the acute stage of HFMD.

Characterization of Hand,Foot,and Mouth Disease in China between 2008 and 2009

Objective To investigate the epidemiological and cl （HFMD） since several outbreaks of HFMD caused between 2007 and 2008. inical features of hand, foot and mouth disease by enteroviruses were documented in China Methods HFMD cases reported to the National Infectious Disease Information Management System database between May 2008 and April 2009 were assessed. Clinical features in some of the severe and fatal cases were analyzed the etiology of the outbreaks was investigated. Results 89.1% of reported HFMD cases were found in children〈5 year-old with an age-specific incidence rate of 834.1/100 000 in the first year as the notifiable disease in China from May 2008 to April 2009. The incidence, mortality and percentage of severe cases were studied for three regions of China and found to be highest in the central region. The incidence of severe cases and mortality in rural population were significantly higher than those in urban population. Among the laboratory confirmed EV17 positive cases there were 52.6% mild, 83.5% severe, and 96.1% fatal cases. More myoclonic jerks were found in the severe case group than in group that died. Tachypnea, lip purpling, pink foaming and low limb temperature occurred more frequently in the fatal cases than in the severe cases. Conclusion The epidemic of HFMD in China was characterized predominantly by EV71 infections, had relatively high mortality rates especially in the central region, and was most prevalent in young, rural populations.

Using Interrupted Time Series Design to Analyze Changes in Hand, Foot, and Mouth Disease Incidence during the Declining Incidence Periods of 2008-2010 in China

Objective To identify patterns of hand, foot and mouth disease （HFMD） incidence in China during declining incidence periods of 2008, 2009, and 2010. Methods Reported HFMD cases over a period of 25 months were extracted from the National Disease Reporting System （NDRS） and analyzed. An interrupted time series （ITS） technique was used to detect changes in HFMD incidence rates in terms of level and slope between declining incidence periods of the three years. Results Over 3.58 million HFMD cases younger than 5 years were reported to the NDRS between May 1, 2008, and May 31, 2011. Males comprised 63.4% of the cases. ITS analyses demonstrated a significant increase in incidence rate level （P〈0.0001） when comparing the current period with the previous period. There were significant changes in declining slopes when comparing 2010 to 2009, and 2010 to 2008 （all P〈O.O05）, but not 2009 to 2008. Conclusion Incremental changes in incidence rate level during the declining incidence periods of 2009 and 2010 can potentially be attributed to a few factors. The more steeply declining slope in 2010 compared with previous years could be ascribed to the implementation of more effective interventions and preventive strategies in 2010. Further investigation is required to examine this possibility.

Molecular Epidemiological Analysis of Echovirus 19 Isolated From an Outbreak Associated With Hand, Foot, and Mouth Disease (HFMD) in Shandong Province of China

To elucidate the genetic characterization and molecular epidemiological features of Echovirus 19 （El9） isolates collected from an outbreak associated with hand, foot and mouth disease （HFMD） in Tai＇an city of Shandong Province of China from July to September, 2003. Methods Thirty seven Echovirus 19 isolates were isolated from stool specimens and throat swabs collected during the outbreak, then major capsid （VP1） genomic sequence was determined, and phylogenetic tree was done based on the VP1 sequences among these 37 and other El9 viruses deposited in the Genbank. Also a representative strain named CHN-SD03-TN12 was selected for sequencing of 5′-untranslated regions （5′-UTR）. Results The identity rate was about 98.9%-100% among all these 37 El9 viruses. The genetic relationships between these 37 El9 isolates and other strains reported were also depicted. The identity rate was about 78.4%-78.9% compared with El9 reference strain Burke. The substitutions in the sequence of 5′-UTR resulted in changes in the conjectural properties of 5′-UTR of El9 viruses. Condusion The genetic features of El9 viruses isolated during the outbreak in Shandong Province in 2003 may be associated with a genetic and antigenic drift that changes the virulence of the Shandong isolates, but the molecular changes in Shandong El9 viruses contributing to their phenotype remain to be further illuminated. However, the sequences described in this paper substantiate the changes taken place in capsid VPI and 5′UTR regions. These substitutions may contribute to their tropism and virulence, and play a significant role in pathogenesis and clinical manifestations of the disease.

Coxsackievirus A6 was the most common enterovirus serotype causing hand,foot,and mouth disease in Shiyan City,central China

BACKGROUND Hand,foot,and mouth disease(HFMD)has become one of the most common infectious diseases in China.Before 2016,the primary causal serotypes were enterovirus A71(EV-A71)and coxsackievirus A16(CV-A16).Following the introduction of EV-A71 vaccines in China since 2016,the situation could change.CV-A6 has recently replaced EV-A71 and CV-A16 in some areas of China.However,the epidemiological characteristics of central China remain unknown.AIM To investigate the clinical symptoms and pathogen spectrum of HFMD in Shiyan City,central China,in recent years.METHODS The epidemiological,clinical,and laboratory data from HFMD cases reported to the Shiyan Center for Disease Control and Prevention between January 2016 and December 2020 were analyzed.196 throat swab specimens were collected from hospitalized HFMD patients between January 2018 and December 2020.To detect and genotype enteroviruses,real-time reverse transcription-polymerase chain reaction and sequencing of the 5'-untranslated region were used.In Shiyan,168 laboratory-confirmed HFMD cases were studied using a logistic regression model to determine the effect of predominant enterovirus serotypes.Based on the logistic regression model,the least absolute shrinkage and selection operator model was used to analyze the correlation between CV-A6 infection and various clinical characteristics in HFMD patients in Shiyan.RESULTS From 2016 to 2020,35840 HFMD cases were reported in Shiyan.The number of cases decreased by 48.4%from 2016 to 2017.Approximately 1.58-fold increases were found in 2018 and 2019 when compared to the previous year,respectively.In 2020,a decrease of about 85.5%was reported when compared to 2019.The most common serotypes shifted from EV-A71 and CV-A16(about 60%-80%in 2016 and 2018)to others(more than 80.0%in 2017,2019,and 2020).EV-A71 lost its dominance in 2017 in Shiyan.Among 196 confirmed HFMD cases,85.7%tested positive for enterovirus,with CV-A6 being the most common serotype(121/168,72.0%).The positive rates for CV-A16 and CVA10 were 4.8%and 3.0%,respectively.There was no EV-A71 discovered.Infection with CV-A6 was linked to fever,myocardial damage,increased creatine kinase MB isoenzyme,and lactate dehydrogenase levels.CONCLUSION CV-A6 was the most common enterovirus serotype in Shiyan City,replacing EV-A71 and CV-A16 as the HFMD pathogen.Developing vaccines against CV-A6 or multiple pathogens,as well as rising CV-A6 surveillance,will help prevent HFMD in central China.

Evaluation on Common Hand, Foot and Mouth Disease Treated by Integrative Traditional Chinese Medicine and Western Medicine

Objective To evaluate the efifcacy and safety of traditional Chinese medicine (TCM) combined with Western medicine in the treatment of patients with common hand, foot and mouth disease (HFMD) by conducting a prospective, controlled, and randomized trial. Methods A total of 452 patients with common HFMD were randomly assigned to receive Western medicine alone (n=220) or combined with TCM (Reduning or Xiyanping injections) (n=232). The primary outcome was the incidence rate of rash/herpes disappearance within 5 days, while secondary outcomes included the incidence rate for fever, cough, lethargy, agitation, and vomiting clearance within 5 days. Results The rash/herpes disappearance rate was 45.5% (100/220) in Western medicine therapy group, and 67.2% (156/232) in TCM and Western medicine combined therapy group, with significant difference (P<0.001). Moreover, TCM remarkably increased the incidence rate of secondary disappearance, which was 56.4%in Western medicine therapy group and 71.4%in TCM and Western medicine combined therapy group (P=0.001). No drug-related adverse events were observed. Conclusions It’s suggested that the integrative TCM and Western medicine therapy achieved a better therapeutic efficacy. TCM may become an important complementary therapy on relieving the symptoms of HFMD.

Investigation on Factors Associated with Severe Hand, Foot and Mouth Disease

Objective To analyze the clinical and laboratory features of patients with mild and severe HFMD to identify early predictive or diagnostic markers for severe cases. Methods Samples of feces, nasopharyngeal-swab specimens, peripheral blood, serum and cerebral spinal fluid were collected. Postmortem pathological examination was conducted on 2 dead patients with complication due to neurogenic pulmonary edema. Reverse transcription-polymerase chain-reaction(RT-PCR), culture and isolation of enterovirus 71(EV71) were performed to detect EV71 infection. Both univariate and multivariate logistic analysis were used to identify factors associated with severe cases. Results EV71 was mainly responsible for HFMD. In this study, 5 isolated EV71 strains belonged to C4 gene subtype. Compared with mild patients, EV71-RNA detection rate was higher and Cox A16 detection rate was lower among severe patients(P < 0.01). Inflammatory cell infiltration in the lung, cardiac and liver tissues were mild by postmortem pathological examination. It was found that body temperature, vomitting, limb tremor, neutrophil, blood glucose and EV71 infection were significantly related to the severe cases by univariate logistic analysis. However, after multivariate logistic regression analysis, only vomiting(OR 16.1, CI 2.3-110.5, P < 0.01) and limb tremor(OR 117.6, CI 13.8-1004.5, P < 0.01) were significantly and independently correlated with the severe cases.Conclusions EV71 was mainly responsible for HFMD, particularly for severe cases. Vomiting and limb tremor were predictive markers for severe cases.

The Comparative Study on Two Models of Syndrome Differentiation of the Hand, Foot and Mouth Disease: An Investigation Analysis of the Signs and Symptoms on 2325 Cases

Objective To realize the characteristics of "zheng" differentiation-treatment for hand, foot and mouth disease(HFMD), a new methodology of syndrome differentiation for different stages of HFMD has been explored. Methods Total of 2 325 cases with HFMD were recorded by distributing them into exterior syndrome stage, interior syndrome stage, severe syndrome stage and recovered syndrome stage, respectively, and the main symptoms and subsidiary symptoms of different stages of HFMD have been observed. The major and minor pathogenesis of HFMD in different stages were obtained, and compared with the "2010 Guideline for the Diagnosis and Treatment of HFMD". Results It was found that the major pathogenesis of exterior stage was defined as "the invation of the wenevil to the defender of the body with the collaterals got involved ", and the minor as "qi deficiency"; in interior stage, "the fury of Gan-Yang" was the main pathogenesis, and "qi in chaos and qi deficiency" was the minor; in severe syndrome stage, "the damage of heart, liver and lung" was the main pathogenesis, and "qi in chaos" was the minor; and the pathogenesis of recovered stage was "qi-yin deficiency". Compared with the "2010 Guideline for the Diagnosis and Treatment of HFMD", it showed that "the obstruction of the fei-pi qi by the mixture of shi-re evil" and "the mixture of shi-re" in vivo was quite difficult to be explained in completely different context in the general situation; in the severe stage, the TCM clinical characteristics of syndrome differentiation might lose; in the early acute severe cases, the phenomenon that xin-yang and fei-qi almost ran out was difficult to be observed, then, the line between the severe and the acute severe became vague.Conclusions The theory of syndrome differentiation by stages of HFMD was reasonable in the actual situation of clinical description on HFMD which was expected to be further tested and widely applied in the "zheng" differentiation-treatment of HFMD in the future.

The impact of EV71 vaccination program on hand,foot and mouth disease in Zhejiang Province,China:A negative control study

Objective:To estimate the potential causal impact of Enterovirus A71(EV71)vaccination program on the reduction of EV71-infected hand,foot,and mouth disease(HFMD)in Zhejiang Province.Methods:We utilized the longitudinal surveillance dataset of HFMD and EV71 vaccination in Zhejiang Province during 2010-2019.We estimated vaccine efficacy using a Bayesian structured time series(BSTS)model,and employed a negative control outcome(NCO)model to detect unmeasured confounding and reveal potential causal association.Results:We estimated that 20,132 EV71 cases(95%CI:16,733,23,532)were prevented by vaccination program during 2017-2019,corresponding to a reduction of 29%(95%CI:24%,34%).The effectiveness of vaccination increased annually,with reductions of 11%(95%CI:6%,16%)in 2017 and 66%(95%CI:61%,71%)in 2019.Children under 5 years old obtained greater benefits compared to those over 5 years.Cities with higher vaccination coverage experienced a sharper EV71 reduction compared to those with lower coverage.The NCO model detected no confounding factors in the association between vaccination and EV71 cases reduction.

Diagnostic performance of different specimens in detecting enterovirus A71 in children with hand,foot and mouth disease

Hand,foot and mouth disease(HFMD)is a major public health problem among children in the Asia-Pacific region.The optimal specimen for HFMD virological diagnosis remains unclear.Enterovirus A71(EV-A71)neutralizing antibody titres detected in paired sera were considered the reference standard for calculating the sensitivity,specificity,positive and negative predictive value of throat swabs,rectal swabs,stool,blood samples and cerebrospinal fluid(CSF)by RT-PCR or ELISA assay.In this study,clinical samples from 276 HFMD patients were collected for analysing the sensitivity of different kind of specimens.Our results showed that stool had the highest sensitivity(88%,95%CI:74%–96%)and agreement with the reference standard(91%).The order of diagnostic yield for EV-A71 infection was stool samplerectal swab>throat swab>blood sample>CSF sample,and using a combination of clinical samples improved sensitivity for enterovirus detection.The sensitivity of ELISA for IgM antibody detection in sterile-site specimens was significantly higher than that of RT-PCR(serum/plasma:62%vs.2%,CSF:47%vs.0%)(P<0.002).In conclusion,our results suggest that stool has the highest diagnostic yield for EV-A71-infected HFMD.If stool is unavailable,rectal swabs can be collected to achieve a similar diagnostic yield.Otherwise,throat swabs may be useful in detecting positive samples.Although IgM in blood or CSF is diagnostically accurate,it lacks sensitivity,missing 40%–50%of cases.The higher proportion of severe cases and shorter interval between onset and sampling contributed to the increase in congruency between clinical testing and the serological reference standard.

Pattern Classification of Enterovirus 71-Associated Hand, Foot, and Mouth Disease in Chinese Medicine: A Retrospective Study in 433 Cases

Objective： To determine whether patterns of enterovirus 71（EV71）-associated hand, foot, and mouth disease（HFMD） were classified based on symptoms and signs, and explore whether individual characteristics were correlated with membership in particular pattern. Methods： Symptom-based latent class analysis（LCA） was used to determine whether patterns of EV71-HFMD existed in a sample of 433 cases from a clinical data warehouse system. Logistic regression was then performed to explore whether demographic, and laboratory data were associated with pattern membership. Results： LCA demonstrated a two-subgroup solution with an optimal fit, deduced according to the Bayesian Information Criterion minima. Hot pattern（59.1% of all patients） was characterized by a very high fever and high endorsement rates for classical HFMD symptoms（i.e., rash on the extremities, blisters, and oral mucosa lesions）. Non-hot pattern（40.9% of all patients） was characterized by classical HFMD symptoms. The multiple logistic regression results suggest that white blood cell counts and aspartate transaminase were positively correlated with the hot pattern（adjust odds ratio=1.07, 95% confidence interval： 1.006–1.115; adjust odds ratio=1.051, 95% confidence interval： 1.019–1.084; respectively）. Conclusions： LCA on reported symptoms and signs in a retrospective study allowed different subgroups with meaningful clinical correlates to be defined. These findings provide evidence for targeted prevention and treatment interventions.

Clinical characteristics of hand, foot and mouth disease in Harbin and the prediction of severe cases

Background Hand, foot and mouth disease （HFMD） is an emerging public health problem in China, not only threatening the health of children, but also causing tremendous loss and burden to both families and society. The aim of this study was to characterize the epidemiology and clinical features of HFMD, and to understand the key factors affecting HFMD in the Harbin region to provide scientific evidence for effective prevention and control strategies. Methods Epidemiological and clinical information from 2379 randomly chosen cases of HFMD treated at the Harbin Center for Disease Control and Prevention from May 2008 to November 2011 were analyzed. All cases were separated into common and severe HFMD, with key factors for severe HFMD analyzed using multivariable Logistic regression. Results Among the 2379 patients, 1798 were common cases and 581 severe cases, 14 of which resulted in death. Most cases were in children younger than 5 years. Morbidity peaked in July and was higher in the surrounding country and cities than in Harbin proper. Medical expenses were significantly higher for severe than for common cases （P 〈0.001）. The primary clinical symptoms were fever and erythema; laboratory examination showed leucocytosis together with pneumonia, carditis, and abnormal electrocardiogram and electroencephalogram in severe cases. Multivariabie Logistic regression analysis showed that the key factors for severe HFMD were age, morbidity location, morbidity area, fever duration, mouth mucosal symptoms, and abnormal serum levels of neutrophils （NEUT）, hemoglobin and glucose （P 〈0.05）. Conclusions To improve prognosis, reduce medical expense and prevent the development of severe cases, we should improve the epidemiological detection of HFMD to treat patients quickly. We should also closely monitor children with the EV71 virus, who present with continuous fever as well as abnormal laboratory results, from areas highly susceptible to

From Monovalent to Multivalent Vaccines, the Exploration for Potential Preventive Strategies Against Hand, Foot, and Mouth Disease(HFMD)

Hand,foot,and mouth disease(HFMD)recently emerged as a global public threat.The licensure of inactivated enterovirus A71(EV-A71)vaccine was the first step in using a vaccine to control HFMD.New challenges arise from changes in the pathogen spectrum while vaccines directed against other common serotypes are in the preclinical stage.The mission of a broad-spectrum prevention strategy clearly favors multivalent vaccines.The development of multivalent vaccines was attempted via the simple combination of potent monovalent vaccines or the construction of chimeric vaccines comprised of epitopes derived from different virus serotypes.The present review summarizes recent advances in HFMD vaccine development and discusses the next steps toward a safe and effective HFMD vaccine that is capable of establishing a crossprotective antibody response.

Surveillance, epidemiology, and pathogen spectrum of hand, foot, and mouth disease in mainland of China from 2008 to 2017

Hand,foot and mouth disease(HFMD)was reported in May 2,2008 to be the 38th legally notifiable disease in China's National Notifiable Disease Reporting and Surveillance System.In order to solve the infection,an extensive three-level HFMD surveillance laboratory network was established.In this study,the framework of that network is assessed and the incidence of HFMD in China from 2008 to 2017 is reported using a descriptive epidemiologic method.During these 10 years,a series of techniques have been widely applied in all the network laboratories.Using information and material obtained from the network,a virus bank and database containing 18,238 viruses were established.Nationally,18,184,834 HFMD cases,including 152,436 severe cases and 3633 fatal cases,were reported in mainland of China.The average annual incidence in the population was 133.99/100,000 people,with a maximum incidence of 205.06/100,000 people in 2014.The incidence and mortality rates of HFMD were the highest in children aged 1–2 years.The numbers of reported cases fluctuated,with a high incidence observed every 2 years.An overall increase in the number of reported cases was also observed throughout the study period.Despite this,the incidence of severe cases and the mortality rate have been decreasing.High-risk regions are located in southern,eastern,and central China.Two peaks of HFMD infection cases were observed annually except for Northeast China.Different proportions of enterovirus serotypes were observed during the studied years.The predominant enterovirus varies from year to year,but the disease severity is always closely related to the specific serotype.EV-A71 is the dominant serotype associated with severe and fatal cases,with constituent ratios of 70.03%and 92.23%,respectively.The studied highly sensitive and efficient surveillance network provides information that is critical for prevention and control of the disease.It is extremely necessary and important to continuously conduct extensive virological surveillance for HFMD.

Review of hand, foot and mouth disease

Hand,foot and mouth disease(HFMD)is an acute viral illness that primarily affects infants and young children,and often occurs in clusters or outbreaks.The major causative agents of HFMD are coxsackievirus A16(CVA16),human enterovirus 71(HEV71)and coxsack-ievirus A10(CVA10),of the genus Enterovirus in the family Picornaviridae.HFMD caused by EV71 is associated with severe neurological complications and death.Since the late 1990s,several major epidemics of EV71 HFMD have swept through the Asia-Pacific region,associated with a rapid fulminant course,severe neurolo-gical complications,and a large number of fatalities.Until now,little has been known about the genetics and transmission trends of the fast-mutation virus,and there is no effective and specific antiviral therapy or vaccine for HFMD.It is time to step up efforts to understand the molecular epidemics and pathogenesis so that we can develop effective management strategies and surveillance programs.

Rupintrivir is a promising candidate for treating severe cases of Enterovirus-71 infection

AIM:To evaluate the suitability of rupintrivir against Enterovirus 71(EV71)induced severe clinical symptoms using computational methods. METHODS:The structure of EV71 3C protease was predicted by homology modeling.The binding free energies between rupintrivir and EV71 3C and human rhinovirus 3C protease were computed by molecular dynamics and molecular mechanics Poisson-Boltzmann/ surface area and molecular mechanics generalized-born/ surface area methods.EV71 3C fragments obtained from clinical samples collected during May to July 2008 in Shanghai were amplified by reverse-transcription and polymerase chain reaction and sequenced. RESULTS:We observed that rupintrivir had favorable binding affinity with EV71 3C protease(-10.76 kcal/mol). The variability of the 3C protein sequence in isolates of various outbreaks,including those obtained in our hospital from May to July 2008,were also analyzed to validate the conservation of the drug binding pocket. CONCLUSION:Rupintrivir,whose safety profiles had been proved,is an attractive candidate and can be quickly utilized for treating severe EV71 infection.

IMB-0523 Inhibits Enterovirus 71 Replication by Activating Signal Transducer and Activator of Transcription 3 Signaling to Upregulate Interferon-Stimulated Genes Expression

Background Hand,foot,and mouth disease caused by enterovirus 71(EV71)infection is prevalent in the Asia-Pacific region in recent years.Currently,no drug is available for the prevention and treatment of EV71 infection.IMB-0523,a N-phenylbenzamide derivative,inhibits hepatitis B virus replication by upregulating the expression of APOBEC3G.In the present study,the effect of IMB-0523 on EV71 replication and related mechanism were investigated.Methods The cytotoxicity of IMB-0523 was determined by cell counting kit.Quantitative real-time polymerase chain reaction and Western blot assay were used to detect the effect of IMB-0523 on EV71 replication and related mechanism.Cytopathic effect assay was used to investigate the effect of IMB-0523 on different EV71 strains,coxsackievirus A16,and coxsackieviruses of group B.Results The results showed that IMB-0523 could dose-dependently inhibit EV71 replication.Preliminary mechanism studies showed that IMB-0523 could activate STAT3 signaling to upregulate the expression of interferon-stimulated genes to play an antiviral role.In addition,IMB-0523 inhibited the replication of different EV71 strains,coxsackievirus A16,and coxsackieviruses of group B.Conclusions IMB-0523 inhibits EV71 replication by activating the STAT3 signaling pathway to upregulate interferon-stimulated gene expression.IMB-0523 has broad-spectrum antiviral potential and may be used as a lead compound for the development of broad spectrum antiviral drugs.

Dynamic change of mother-source neutralizing antibodies against enterovirus 71 and coxsackievirus A16 in infants

Background Enterovirus 71 （EV71） and coxsackievirus A16 （Cox A16） are major causative agents for hand, foot and mouth disease （HFMD）. Studies indicate that the frequent HFMD outbreaks result in a few hundreds children＇s death in China in recent years. The vaccine and other research for HFMD need to be developed urgently. The aims of our study were： to explore dynamic development of mother-source neutralizing antibodies against EV71 and Cox A16 in infants from Jiangsu Province, China, and to provide the fundamental data for further establishing of corresponding immunization course. Methods Peripheral blood samples were collected from 133 of parturient women once immediately before delivery and their infants at two and seven months of age. Method of micro-dose cytopathogenic effect was used to measure neutralizing antibodies against EV71 and Cox A16, respectively. Results Seropositive rates of anti-EV71 and anti-Cox A16 in prenatal women were 79.7% （106/133） and 92.5% （123/133）, respectively; geometric mean titers （GMTs） were 29.0 and 61.9; 75.9% （101/133） prenatal women were both positive in anti-EV71 and anti-Cox A16; seropositive rates of anti-EV71 and anti-Cox A16 were 25.6% （34/133） and 38.3% （51/133） in infants at two months of age; GMTs were 12.3 and 18.0, respectively. GMTs of anti-EV71 were significantly higher for infants at seven months （82.6） compared with that at two months （P 〈0.05）, showing infants had inapparently infected by EV71 during two to seven months. Although only one offspring （0.75%） at seven months was found having anti-Cox A16 transfered from maternal, this observation suggested no maternal antibody may remain in infants at seven months. Conclusions The prevalence of EV71 and Cox A16 were relatively high in Jiangsu Province. Bivalent vaccine against both EV71 and Cox A16 should be developed, and the ideal time point for prime immunization for infants is around 2-5 months of age.

PLX8394,a RAF inhibitor,inhibits enterovirus 71 replication by blocking RAF/MEK/ERK signaling

Enterovirus 71(EV71)poses a serious threat to human health,with scattered outbreaks worldwide.There are several vaccines against a few EV71 strains but no efficient drug for the treatment of EV71 infection.Therefore,it is urgent and of significance to develop anti-EV71 drugs.Here,we found that PLX8394,a RAF inhibitor,possesses high antiviral activity against EV71 in vitro,being superior to the traditional clinical drug ribavirin.Moreover,PLX8394 exhibits broad-spectrum antiviral activity against enteroviruses.Notably,in a suckling mouse model,PLX8394 provided a 70%protection rate for EV71-infected mice,reduced the viral load in liver and heart tissues,and relieved the inflammatory response.A mechanistic study showed that PLX8394 inhibited EV71 by suppressing the RAF/MEK/ERK signaling pathway.Thus,PLX8394 lays a foundation for the development of new drugs against EV71.

Coxsackievirus B3 HFMD animal models in Syrian hamster and rhesus monkey

Coxsackievirus B3(CVB3)is the pathogen causing hand,foot and mouth disease(HFMD),which manifests across a spectrum of clinical severity from mild to severe.However,CVB3-infected mouse models mainly demonstrate viral myocarditis and pancreatitis,failing to replicate human HFMD symptoms.Although several enteroviruses have been evaluated in Syrian hamsters and rhesus monkeys,there is no comprehensive data on CVB3.In this study,we have first tested the susceptibility of Syrian hamsters to CVB3 infection via different routes.The results showed that Syrian hamsters were successfully infected with CVB3 by intraperitoneal injection or nasal drip,leading to nasopharyngeal colonization,acute severe pathological injury,and typical HFMD symptoms.Notably,the nasal drip group exhibited a longer viral excretion cycle and more severe pathological damage.In the subsequent study,rhesus monkeys infected with CVB3 through nasal drips also presented signs of HFMD symptoms,viral excretion,serum antibody conversion,viral nucleic acids and antigens,and the specific organ damages,particularly in the heart.Surprisingly,there were no significant differences in myocardial enzyme levels,and the clinical symptoms resembled those often associated with common,mild infections.In summary,the study successfully developed severe Syrian hamsters and mild rhesus monkey models for CVB3-induced HFMD.These models could serve as a basis for understanding the disease pathogenesis,conducting pre-trial prevention and evaluation,and implementing post-exposure intervention.