Neurologic complications in children with enterovirus 71 infection

Enterovirus 71 Induces Mitophagy via PINK1/Parkin Signaling Pathway to Promote Viral Replication

Enterovirus 71 (EV71) infection poses a global public health challenge, especially in infants and young children, with severe cases leading to fatal consequences. EV71 infection modulates various biological processes of the host and evades host immunity through multiple mechanisms. The balance of mitochondrial dynamics is important for cellular homeostasis. However, the mechanisms underlying EV71-induced cellular damage via mitophagy remain unclear. In the current study, we showed that EV71 infection significantly reduced the total and mitochondrial ATP contents in cells, as well as the expression of mitochondrial proteins TOM20 and TIM23. Then, EV71 infection increased the protein levels of PINK1, Parkin, and LC3B, suggesting that EV71 infection triggers the mitophagy. Silencing PINK1 caused a significant reduction in viral replication, while overexpressing Parkin promoted the replication of EV71. Moreover, CsA treatment, as a mitophagy inhibitor, alleviated pathological damage and suppressed the replication of EV71 in vivo. Mechanistic study showed that silencing PINK1 inhibited the cleavage of MAVS by EV71, while overexpressing Parkin enhanced the cleavage of MAVS by EV71, suggesting that PINK1-mediated mitophagy was involved in regulating innate immunity. Furthermore, we found that EV71 infection promoted the release of mitochondria carrying EV71 virions into the extracellular environment, which mediated infection of other cells, thus facilitating virus spreading. In addition, we also demonstrated that the extracellular mitochondria induced the degradation of MAVS and mitophagy promoted the release of mitochondria in EV71-infected HeLa cells. In conclusion, these findings suggest that EV71 infection induces PINK1-mediated mitophagy, which inhibits innate immunity and facilitates virus replication.

Severe Enterovirus A71 infection is associated with dysfunction of T cell immune response and alleviated by Astragaloside A

Enterovirus A71 (EV-A71) is the major causative pathogen for severe hand-foot-mouth disease (HFMD), a predominantly childhood-associated communicable disease. The mechanisms that children manifest severe disease progression while adults typically exhibit milder or asymptomatic infections remain incompletely characterized, which hinders the development of effective therapy against this disease. Herein, using the newborn mouse model of EV-A71 infection, we uncovered that the underdevelopment of T cells closely associated with the severity of EV-A71 infection, and EV-A71 infection dramatically impaired T-cell immune response. Moreover, the dysfunction of T-cell immunity contributes to the pathogenesis of EV-A71 infection, as the loss of T cells made neonatal mice highly vulnerable to EV-A71 infection. To further assess the relationship between T-cell immunity and HFMD, we enrolled a cohort of 145 pediatric patients with laboratory-confirmed EV-A71 infection and found that the compromised T-cell immune response is associated with the severity of EV-A71-caused HFMD in these children. Furthermore, we found that the treatment of newborn mice with Astragaloside A, a saponin from the medicinal herb Astragalus membranaceus, showed potent in vivo therapeutic efficacy against EV-A71 infection in a T-cell-dependent manner. In conclusion, these findings uncover the interaction between EV-A71 infection and T-cell immunity, provide novel insights onto the physiological impacts of T cells on the pathogenesis of EV-A71 infection and HFMD, and find a promising immunotherapeutic strategy to treat this viral disease.

A fatal case of enterovirus A71-induced meningoencephalitis following allogenic hematopoietic stem cell transplantation

Enterovirus A71 (EV-A71) is a major pathogen responsible for hand, foot, and mouth disease (HFMD) in infants and children. EV-A71 infection represents an epidemic in the Asia-Pacific region, and can cause serious central nervous system (CNS) infections in immunocompromised patients that can result in paralysis, disability, or death. There have been few reports in the literature concerning EV-A71 CNS infections after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in adult patients. We describe the case of a 63-year-old woman with EV-A71 meningoencephalitis who underwent a second allo-HSCT for relapsed refractory myelodysplastic syndrome. She developed disturbance of consciousness during intubation due to severe pulmonary impairment following allo-HSCT. Despite the absence of pleocytosis in the cerebrospinal fluid, enterovirus was detected in her cerebral spinal fluid using the Biofire® FilmArray® Meningitis/Encephalitis (ME) panel, which was later identified as EV-A71 at a referral center. Despite a transient improvement in her level of consciousness after intravenous immunoglobulin administration, she did not fully recover. The patient also showed muscle weakness as well as pulmonary impairment that necessitated a tracheotomy. Our case demonstrated the utility of the FilmArray® ME panel as a screening tool for detecting multiple potential pathogens until a specific pathogen could be identified using other diagnostic methods. Clinicians should be aware that EV-A71 CNS infection can occur among adults with severe immunodeficient conditions, and that it leads poor clinical outcomes. Our case suggests that continuous monitoring for this potentially fatal pathogen is warranted for immunocompromised patients.

Epidemiological characteristics and influencing factors of hand, foot and mouth disease reinfection cases in Jiulongpo District, Chongqing, China, 2009-2023

Objective

To analyze the epidemiological characteristics of Hand, Foot and Mouth Disease (HFMD) reinfection and its influencing factors in Jiulongpo District from 2009 to 2023 to provide targeted prevention and control recommendations for key factors.

Methods

HFMD cases in Jiulongpo District of Chongqing were derived from the China Information System for Disease Control and Prevention from 2009 to 2023. Descriptive analysis was used to analyze the epidemiological characteristics of HFMD reinfection, spatial autocorrelation to analyze the regional clustering, and binary logistic regression to analyze the influencing factors.

Results

From 2009 to 2023, 4,764 HFMD reinfection cases involving 2,436 individuals were reported in Jiulongpo District, with a reinfection rate of 5.48%. The interval between the two infections ranged from 26 to 3,863 days, and 71.51% of patients were reinfected within 2 years. There was a bimodal distribution in time (April-July and October-November). In the population, the reinfection rate was 5.87% in males and 4.93% in females, 3.97% in scattered children and 7.89% in kindergarten children, 8.61% in children >3 years old, and 4.68% in children ≤3 years old. There was a spatial positive correlation of HFMD reinfection in Jiulongpo District, with hot spots concentrated in the rural area and cold spots in the urban area. The multifactorial logistic regression analysis showed that reinfection risk was higher in non-epidemic years, male, rural areas, >3 years old, and kindergarten children (p < 0.05).

Conclusion

Post-epidemic prevention and control measures should prioritize interventions to target reinfection, focusing on children in rural areas and kindergartens. Improve rural infrastructure and sanitation, raise disease awareness in kindergartens, train healthcare workers, and promote hygiene to reduce HFMD reinfection.

Emerging and re-emerging viral infections of the central nervous system in Australasia and beyond

Viral infections of the central nervous system (CNS) have been emerging and re-emerging worldwide, and the Australasia region has not been spared. Enterovirus A71 and enterovirus D68, both human enteroviruses, are likely to replace the soon-to-be eradicated poliovirus to cause global outbreaks associated with neurological disease. Although prevalent elsewhere, the newly emergent orthoflavivirus, Japanese encephalitis virus (genotype IV), caused human infections in Australia in 2021, and almost certainly will continue to do so because of spillovers from the natural animal host-vector life cycle endemic in the country. Another orthoflavivirus, Murray Valley encephalitis virus, has re-emerged in Australia. The Hendra henipavirus together with Nipah henipavirus ​are listed as high-risk pathogens by the World Health Organization because both can cause lethal encephalitis. The former remains a health threat in Australasia because bats may still be able to spread the infection to unvaccinated Australian horses and other animals acting as intermediate hosts, and thence to humans. The global COVID-19 pandemic, caused by the emerging severe acute respiratory syndrome coronavirus-2, a virus transmitted from animals to humans that was first described and first arose in China, is associated with acute and long-lasting CNS pathology. Fortunately, the pathology and pathogenesis of these important neurotropic viruses are now better understood, leading to better management protocols and prevention strategies. Pathologists are in a unique position to contribute to the diagnosis and advancement in our knowledge of infectious diseases. This review summarises some of the current knowledge about a few important emerging and re-emerging CNS infections in Australasia and beyond.

Childhood acute flaccid myelitis, including the first confirmed cases of enterovirus D68 myelitis, in Singapore and Southeast Asia

AIM

We report the epidemiology, treatment and outcomes of acute flaccid myelitis (AFM), including the first two cases of enterovirus (EV) D68 myelitis, in Singapore.

METHODS

Retrospective observational study from a paediatric hospital in Singapore, from January 2012 to December 2022. Clinical, laboratory, neuroimaging and outcome data were analysed.

RESULTS

Eight patients were identified (all male). Median age at presentation was 3 (interquartile range (IQR) 2.2-10.0) years. Seven (87.5%) patients were clustered in two time periods (July 2018-January 2019 and April-August 2022). Presenting features were a preceding febrile respiratory illness (n = 6) or hand-foot-and-mouth disease (n = 2), upper limb weakness (n = 5, 62.5%) and neurogenic bladder (3, 37.5%), while the spinal cord lesions were predominantly in the cervical region (7, 87.5%). Five (62.5%) and six (75.0%) patients had elevated cerebrospinal fluid (CSF) white cells (median 7.5/mm3 (IQR 2.8-40.3)) and protein (median 0.6 g/L (IQR 0.4-0.7)), respectively. CSF was negative for pathogens. Two (50%) of four patients with EV detected in respiratory/rectal swabs had EVD68 (2022 cluster). All received intravenous methylprednisolone, six (75%) had additional intravenous immunoglobulin and either plasma exchange therapy (n = 1) or intravenous tocilizumab (n = 1). Median modified Rankin Scale (mRS) at acute illness was 4 (IQR grades 3-5), with an improvement (median 2 (IQR 1.8-2.3) mRS grades) on follow-up (median duration 3.7 (IQR 1.4-4.1) years). One patient (12.5%) had a full recovery and seven (87.5%) have moderate disability (mRS 2-3).

CONCLUSION

Disability risk in AFM is high despite aggressive immunotherapy. We report the first two confirmed cases of EV D68 AFM in Singapore and Southeast Asia.

Neuroinvasion via Peripheral Nerves in Epidemic Viral Encephalitis Caused by Enterovirus, Orthoflavivirus and SARS-Coronavirus

Pathogens invade the central nervous system (CNS) and cause infections either through the haematogenous route or via peripheral nerves. Neuroinvasion via peripheral nerves, involving spinal or cranial somatic nerves, is well-established for certain viral encephalitides such as rabies, herpes simplex encephalitis, and poliomyelitis. Advances in understanding emerging and re-emerging viruses that cause epidemic CNS infections have highlighted the growing importance of peripheral nerve pathways in viral neuroinvasion. This review focuses on epidemic viral encephalitides caused by three groups of RNA viruses, viz., enteroviruses (enterovirus A71 and enterovirus D68), orthoflaviviruses (West Nile virus and Japanese encephalitis virus), and severe acute respiratory syndrome coronaviruses (mainly severe acute respiratory coronavirus-2). We examine evidence supporting the hypothesis that peripheral nerve viral transmission may play an increasingly significant if not more critical role than the haematogenous route in neuroinvasion.

Reflecting on the 1998 enterovirus outbreak: A 25-year retrospective and learned lessons

Enterovirus A71 (EV-A71) infections are a major Asia-Pacific health issue. However, this infection can cause serious and potentially fatal neurological issues. We attempt to explain EV-A71's molecular virology, epidemiology, and recombination events in this review. The clinical and neurological signs of EV-A71 infections are well documented. The review discusses EV-A71 central nervous system infections' causes, diagnostic criteria, treatment choices, and prognosis. Some consequences are aseptic meningitis, acute flaccid paralysis, and acute transverse myelitis. These problems' pathophysiology and EV-A71's central nervous system molecular processes are examined in the review. EV-A71 infections must be diagnosed accurately for therapy. No particular antiviral medications exist for EV-A71 infections, thus supportive care is the main treatment. The study emphasises addressing symptoms including temperature, dehydration, and pain to ease suffering. EV-A71 CNS infections have different prognoses depending on severity. The review discusses long-term effects and neurological sequelae of EV-A71 infections. In conclusion, Asia-Pacific public health is threatened by EV-A71 infections. This review helps prevent, diagnose, and treat EV-A71 infections by addressing the mechanisms, diagnostic criteria, treatment choices, and prognosis. This study fully examines the challenges and considerations of managing and treating EV-A71 infections. It also recommends future research and development to generate effective viral infection treatments.

Paper-Based procalcitonin and Interleukin-6 test strip with Spectrum-Based optical reader for enterovirus severity differentiation in children

Infectious diseases significantly impact global health, necessitating prompt diagnosis to mitigate life-threatening sepsis risk. Identifying patients at risk of severe neurological complications from enterovirus infections is challenging due to nonspecific initial presentations. Point-of-care testing (POCT) has emerged as a transformative tool, with low-cost lateral-flow colorimetric assays showing promise in deployable POCT devices. We developed a PCT/IL-6 rapid diagnostic system integrating lateral flow assay (LFA) test strips and a portable optical spectrum reader, allowing simultaneous semi-quantitative measurement of serum PCT and IL-6 within 30 min at the point of care. The system demonstrated a strong correlation with traditional ELISA and effectively differentiated severe pediatric enterovirus cases using serum samples. IL-6 showed superior discriminatory ability over PCT in identifying patients with severe neurological complications. This novel diagnostic platform holds great potential for early sepsis recognition and infectious disease management, especially in resource-limited settings.

Childhood hand, foot and mouth disease sequelae cohort study in Henan, China: cohort profile

PURPOSE

The childhood hand, foot and mouth disease (HFMD) sequelae cohort study (HNHFMDCS) is an ambispective cohort study of patients with HFMD based in Henan Province, China, consisting of patients treated in a key hospital for the diagnosis and treatment of HFMD in Henan Province. The study aims to investigate the long-term sequelae of HFMD survivors and to provide a comprehensive understanding of the potential harm caused by this infectious disease.

PARTICIPANTS

In the retrospective phase of the cohort study, children diagnosed with HFMD from January 2014 to January 2023 were included, and clinical and demographic information about the patients was collected through a self-developed questionnaire. Patients hospitalised with HFMD since January 2023 were enrolled in the prospective cohort phase of the study, and long-term follow-up will be performed after completion of the baseline investigation (interview and comprehensive physical examination), clinical laboratory examination and biospecimen collection.

FINDINGS TO DATE

For the retrospective analysis of the cohort, a total of 18 705 HFMD cases (11 834 males and 6871 females) were observed between 2014 and 2022, of which 17 202 were mild cases (10 839 males and 6363 females) and 1503 were severe cases (995 males and 508 females). Statistical analysis was performed on the collected clinical examination data, and descriptive statistical methods, including mean value, SD and t-test, were used to compare the intergroup data. All tests were bilateral, and p<0.05 was considered statistically significant. There were significant differences in the hospitalisation duration and clinical examination indicators, such as platelets (PLT), C reactive protein (CRP), aspartate amino transferase (AST), alanine amino transferase (ALT), T lymphocyte subsets (CD3+ and CD3+CD4+) and B lymphocytes (CD19+) between mild and severe patients. The differences in these clinical examination indicators also help to detect changes in the disease in time so as to deeply understand the potential harm and social burden of the disease, and provide strong support for the rehabilitation of patients.

FUTURE PLANS

Prospective cohort studies are currently underway, primarily enrolling hospitalised patients with HFMD to participate in our study. After the baseline investigation is completed, we will conduct long-term follow-up of the enrolled cases. In the coming year, we expect to obtain preliminary data on the incidence of sequelae in patients with HFMD 1-10 years after discharge, as well as information on the occurrence of sequelae. This dataset will be updated and expanded on an annual basis to support the continuous monitoring of patient health and disease progression. From HNHFMDCS, the study will provide a comprehensive overview of the potential harm caused by this common infectious disease, assess the social burden caused by this disease and make recommendations for the rehabilitation of survivors and prevention of further disability.

Blocking CCL3-mediated neutrophil recruitment into the brain alleviates immunopathology following severe enterovirus 71 infection

Inflammatory cells infiltration in the cerebrospinal fluid is a hallmark of severe enterovirus 71 (EV71) infection, but which type of immune cells are critical for severe EV71 infection remains unclear. Here, we observe that both neutrophils and macrophages are increased in the brains of patients and mice with severe EV71 infection, and the depletion of neutrophils but not macrophages results in a marked enhancement of survival of EV71-infected mice. Furthermore, CCR1/3 may play an important role in CCL3 facilitating the accumulation of neutrophils in the brains of patients. Inhibition of CCL3 by anti-CCL3 antibodies or selected miRNAs significantly reduces the neutrophils infiltration in brains and the mortality of EV71-infected mice. Collectively, CCL3-mediated neutrophils recruitment into the brain contributes to the severe immunopathology of EV71 infection, which provides a potential diagnostic and therapeutic target for EV71 infection.

Will COVID-19 become mild, like a cold?

Several recent studies conclude that an increase in the pathogenicity of SARS-CoV-2 cannot be ruled out. However, it should be noted that SARS-CoV-2 is a 'direct' respiratory virus - meaning it is usually spread by the respiratory route but does not routinely pass through the lymphatics like measles and smallpox. Providing its tropism does not change, it will be unique if its pathogenicity does not decrease until it becomes similar to common cold viruses. Ewald noted in the 1980s that respiratory viruses may evolve mildness because their spread benefits from the mobility of their hosts. This review examines factors that usually lower respiratory viruses' severity, including heat sensitivity (which limits replication in the warmer lungs) and changes to the virus's surface proteins. Other factors may, however, increase pathogenicity, such as replication in the lymphatic system and spreading via solid surfaces or faecal matter. Furthermore, human activities and political events could increase the harmfulness of SARS-CoV-2, including the following: large-scale testing, especially when the results are delayed; transmission in settings where people are close together and not free to move around; poor hygiene facilities; and social, political, or cultural influences that encourage sick individuals to remain active, including crises such as wars. If we can avoid these eventualities, SARS-CoV-2 is likely to evolve to be milder, although the timescale is uncertain. Observations of influenza-like pandemics suggest it may take around two decades for COVID-19 to become as mild as seasonal colds.

Rational design of a DNA-launched live attenuated vaccine against human enterovirus 71

Human Enterovirus 71 (EV71) has emerged as one of the predominant causative agents of hand, foot and mouth disease (HFMD) with global impact. Despite the inactivated vaccine being licensed, other vaccine candidates based on advanced technology platforms are under development. In this report, we rationally designed and constructed two DNA-launched live attenuated vaccine candidates (pDL-EV71) under the control of specific promoters. In vitro and in vivo transfection with pDL-EV71 driven by the CMV promoter successfully yielded fully infectious EV71. More importantly, the administration of pDL-EV71 did not cause clinical symptoms following intracranial or intramuscular inoculation in neonatal and IFNα/βR-/- mice, demonstrating its safety profile. Moreover, a single-dose or two-dose immunization with pDL-EV71 elicited robust neutralizing antibodies against EV71 as well as an antigen-specific cellular response in mice. A single-dose immunization with 10 ​μg of pDL-EV71 conferred complete protection against lethal EV71 infection in neonates born to immunized maternal mice. Overall, our present results demonstrate that pDL-EV71 is a safe and effective vaccine candidate against EV71 for further development.

Monitoring the Influence of Hand, Foot, and Mouth Disease: New Guidelines on Patient Care during the 2011-2012 Multiwaves and Multivariant Outbreak in Hai Phong City, Vietnam

From 2011 to 2012, Northern Vietnam suffered its first large-scale hand, foot, and mouth disease (HFMD) epidemic. Two sets of official guidelines were issued during the outbreak to handle the HFMD crisis. The city of Hai Phong was used as a model to analyze the impact of the released guidelines. A total of 9621 HFMD cases were reported in Hai Phong city from April 2011 to December 2012. Three distinct waves of HFMD occurred. Enterovirus A71 and Coxsackievirus A16 were successively associated with the epidemics. Two periods, before and after the guidelines' release, could be distinguished and characterized by different patient patterns. The time to admission and severity changed notably. Guideline publications help the health system refocus on the 0.5-3 years age group with the highest incidence of the disease. The three waves showed different special distribution, but the main routes of infection were rivers and local secondary roads, most likely through local trade and occupational movements of people.

Epidemiology of Enterovirus Genotypes in Association with Human Diseases

Enteroviruses (EVs) are well-known causes of a wide range of infectious diseases in infants and young children, ranging from mild illnesses to severe conditions, depending on the virus genotypes and the host's immunity. Recent advances in molecular surveillance and genotyping tools have identified over 116 different human EV genotypes from various types of clinical samples. However, the current knowledge about most of these genotypes, except for those of well-known genotypes like EV-A71 and EV-D68, is still limited due to a lack of comprehensive EV surveillance systems. This limited information makes it difficult to understand the true burden of EV-related diseases globally. Furthermore, the specific EV genotype associated with diseases varies according to country, population group, and study period. The same genotype can exhibit different epidemiological features in different areas. By integrating the data from established EV surveillance systems in the USA, Europe, Japan, and China, in combination with other EV infection studies, we can elaborate a better understanding of the distribution of prevalent EV genotypes and the diseases associated with EV. This review analyzed the data from various EV surveillance databases and explored the EV seroprevalence and the association of specific EV genotypes with human diseases.

Effects of extreme meteorological factors and high air pollutant concentrations on the incidence of hand, foot and mouth disease in Jining, China

Background

The evidence on the effects of extreme meteorological conditions and high air pollution levels on incidence of hand, foot and mouth disease (HFMD) is limited. Moreover, results of the available studies are inconsistent. Further investigations are imperative to elucidate the specific issue.

Methods

Data on the daily cases of HFMD, meteorological factors and air pollution were obtained from 2017 to 2022 in Jining City. We employed distributed lag nonlinear model (DLNM) incorporated with Poisson regression to explore the impacts of extreme meteorological conditions and air pollution on HFMD incidence.

Results

We found that there were nonlinear relationships between temperature, wind speed, PM2.5, SO2, O3 and HFMD. The cumulative risk of extreme high temperature was higher at the 95th percentile (P95th) than at the 90th percentile(P90th), and the RR values for both reached their maximum at 10-day lag (P95th RR = 1.880 (1.261-2.804), P90th RR = 1.787 (1.244-2.569)), the hazardous effect of extreme low temperatures on HFMD is faster than that of extreme high temperatures. The cumulative effect of extreme low wind speeds reached its maximum at 14-day lag (P95th RR = 1.702 (1.389-2.085), P90th RR = 1.498(1.283-1.750)). The cumulative effect of PM2.5 concentration at the P90th was largest at 14-day lag (RR = 1.637 (1.069-2.506)), and the cumulative effect at the P95th was largest at 10-day lag (RR = 1.569 (1.021-2.411)). High SO2 concentration at the P95th at 14-day lag was associated with higher risk for HFMD (RR: 1.425 (1.001-2.030)).

Conclusion

Our findings suggest that high temperature, low wind speed, and high concentrations of PM2.5 and SO2 are associated with an increased risk of HFMD. This study not only adds insights to the understanding of the impact of extreme meteorological conditions and high levels of air pollutants on HFMD incidence but also holds practical significance for the development and enhancement of an early warning system for HFMD.

Square the Circle: Diversity of Viral Pathogens Causing Neuro-Infectious Diseases

Neuroinfections rank among the top ten leading causes of child mortality globally, even in high-income countries. The crucial determinants for successful treatment lie in the timing and swiftness of diagnosis. Although viruses constitute the majority of infectious neuropathologies, diagnosing and treating viral neuroinfections remains challenging. Despite technological advancements, the etiology of the disease remains undetermined in over half of cases. The identification of the pathogen becomes more difficult when the infection is caused by atypical pathogens or multiple pathogens simultaneously. Furthermore, the modern surge in global passenger traffic has led to an increase in cases of infections caused by pathogens not endemic to local areas. This review aims to systematize and summarize information on neuroinvasive viral pathogens, encompassing their geographic distribution and transmission routes. Emphasis is placed on rare pathogens and cases involving atypical pathogens, aiming to offer a comprehensive and structured catalog of viral agents with neurovirulence potential.

Miltefosine reduces coxsackievirus B3 lethality of mice with enhanced STAT3 activation

Coxsackievirus B3 (CVB3), one serotype of enteroviruses, can induce fatal myocarditis and hepatitis in neonates, but both treatment and vaccine are unavailable. Few reports tested antivirals to reduce CVB3. Several antivirals were developed against other enterovirus serotypes, but these antivirals failed in clinical trials due to side effects and drug resistance. Repurposing of clinical drugs targeting cellular factors, which enhance viral replication, may be another option. Parasite and cancer studies showed that the cellular protein kinase B (Akt) decreases interferon (IFN), apoptosis, and interleukin (IL)-6-induced STAT3 responses, which suppress CVB3 replication. Furthermore, miltefosine, the Akt inhibitor used in the clinic for parasite infections, enhances IL-6, IFN, and apoptosis responses in treated patients, suggesting that miltefosine could be the potential antiviral for CVB3. This study was therefore designated to test the antiviral effects of miltefosine against CVB3 in vitro and especially, in mice, as few studies test miltefosine in vitro, but not in vivo. In vitro results showed that miltefosine inhibited viral replication with enhanced activation of the cellular transcription factor, STAT3, which is reported to reduce CVB3 both in vitro and in mice. Notably, STAT3 knockdown abolished the anti-CVB3 activity of miltefosine in vitro. Mouse studies demonstrated that miltefosine pretreatment reduced CVB3 lethality of mice with decreased virus loads, organ damage, and apoptosis, but enhanced STAT3 activation. Miltefosine could be prophylaxis for CVB3 by targeting Akt to enhance STAT3 activation in the mechanism, which is independent of IFN responses and hardly reported in pathogen infections.

A hybrid model for hand-foot-mouth disease prediction based on ARIMA-EEMD-LSTM

BACKGROUND

Hand, foot, and mouth disease (HFMD) is a common infectious disease that poses a serious threat to children all over the world. However, the current prediction models for HFMD still require improvement in accuracy. In this study, we proposed a hybrid model based on autoregressive integrated moving average (ARIMA), ensemble empirical mode decomposition (EEMD) and long short-term memory (LSTM) to predict the trend of HFMD.

METHODS

The data used in this study was sourced from the National Clinical Research Center for Child Health and Disorders, Chongqing, China. The daily reported incidence of HFMD from 1 January 2015 to 27 July 2023 was collected to develop an ARIMA-EEMD-LSTM hybrid model. ARIMA, LSTM, ARIMA-LSTM and EEMD-LSTM models were developed to compare with the proposed hybrid model. Root mean square error (RMSE), mean absolute error (MAE) and coefficient of determination (R2) were adopted to evaluate the performances of the prediction models.

RESULTS

Overall, ARIMA-EEMD-LSTM model achieved the most accurate prediction for HFMD, with RMSE, MAPE and R2 of 4.37, 2.94 and 0.996, respectively. Performing EEMD on the residual sequence yields 11 intrinsic mode functions. EEMD-LSTM model is the second best, with RMSE, MAPE and R2 of 6.20, 3.98 and 0.996.

CONCLUSION

Results showed the advantage of ARIMA-EEMD-LSTM model over the ARIMA model, the LSTM model, the ARIMA-LSTM model and the EEMD-LSTM model. For the prevention and control of epidemics, the proposed hybrid model may provide a more powerful help. Compared with other three models, the two integrated with EEMD method showed significant improvement in predictive capability, offering novel insights for modeling of disease time series.

Staged Phrenic Nerve Elongation and Free Functional Gracilis Muscle Transplantation-A Possible Option for Late Reconstruction in Chronic Brachial Plexus Injury

PURPOSE

In patients with late brachial plexus birth injuries, sequelae after acute flaccid myelitis, or chronic adult brachial plexus injury, donor nerves for functioning muscle transplantation are often scarce. We present the results of a potential strategy using the phrenic nerve with staged free gracilis transplantation for upper extremity reanimation in these scenarios.

METHODS

A retrospective review was performed on an institutional database of brachial plexus injury or patients with palsy. All patients underwent a staged reconstruction in which the ipsilateral phrenic nerve was extended by an autogenous nerve graft (PhNG), followed by free-functioning gracilis transplantation (PhNG-gracilis).

RESULTS

Nine patients (6 cases of late brachial plexus birth injuries, 2 of acute flaccid myelitis, and 1 of adult chronic brachial plexus injury) were included in this study. The median follow-up period following the PhNG-gracilis procedure was 27 months (range, 12-72 months). The goals of the staged PhNG and PhNG-gracilis were primarily finger extension or finger flexion. In some patients, the technique was used to improve both elbow and finger function, tunneling the muscle through the flexor compartment of the upper arm and under the mobile wad at the elbow. All patients exhibited improvement of muscle strength, including in finger extension (4 patients) from M0 to M2; finger flexion (3 patients) from M0 to M3; elbow extension (1 patient) from M0 to M2; and elbow flexion (1 patient) from M2 to M4.

CONCLUSIONS

A 2-stage PhNG-gracilis may restore or enhance the residual elbow and/or finger paralysis in chronic brachial plexus injuries. A minimum follow-up period of 3 years is recommended. This technique may remain useful as one of the last reconstructive options to increase power in patients with scarce donor nerves.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Research progress on pathogenic and therapeutic mechanisms of Enterovirus A71

In recent years, enterovirus A71 (EV-A71) infection has become a major global public health problem, especially for infants and young children. The results of epidemiological research show that EV-A71 infection can cause acute hand, foot, and mouth disease (HFMD) and complications of the nervous system in severe cases, including aseptic pediatric meningoencephalitis, acute flaccid paralysis, and even death. Many studies have demonstrated that EV-A71 infection may trigger a variety of intercellular and intracellular signaling pathways, which are interconnected to form a network that leads to the innate immune response, immune escape, inflammation, and apoptosis in the host. This article aims to provide an overview of the possible mechanisms underlying infection, signaling pathway activation, the immune response, immune evasion, apoptosis, and the inflammatory response caused by EV-A71 infection and an overview of potential therapeutic strategies against EV-A71 infection to better understand the pathogenesis of EV-A71 and to aid in the development of antiviral drugs and vaccines.

Efficacy of an isoxazole-3-carboxamide analog of pleconaril in mouse models of Enterovirus-D68 and Coxsackie B5

Enteroviruses (EV) cause a number of life-threatening infectious diseases. EV-D68 is known to cause respiratory illness in children that can lead to acute flaccid myelitis. Coxsackievirus B5 (CVB5) is commonly associated with hand-foot-mouth disease. There is no antiviral treatment available for either. We have developed an isoxazole-3-carboxamide analog of pleconaril (11526092) which displayed potent inhibition of EV-D68 (IC50 58 nM) as well as other enteroviruses including the pleconaril-resistant Coxsackievirus B3-Woodruff (IC50 6-20 nM) and CVB5 (EC50 1 nM). Cryo-electron microscopy structures of EV-D68 in complex with 11526092 and pleconaril demonstrate destabilization of the EV-D68 MO strain VP1 loop, and a strain-dependent effect. A mouse respiratory model of EV-D68 infection, showed 3-log decreased viremia, favorable cytokine response, as well as statistically significant 1-log reduction in lung titer reduction at day 5 after treatment with 11526092. An acute flaccid myelitis neurological infection model did not show efficacy. 11526092 was tested in a mouse model of CVB5 infection and showed a 4-log TCID50 reduction in the pancreas. In summary, 11526092 represents a potent in vitro inhibitor of EV with in vivo efficacy in EV-D68 and CVB5 animal models suggesting it is worthy of further evaluation as a potential broad-spectrum antiviral therapeutic against EV.

Diagnosing viral encephalitis and emerging concepts

PURPOSE OF REVIEW

This review offers a contemporary clinical approach to the diagnosis of viral encephalitis and discusses recent advances in the field. The neurologic effects of coronaviruses, including COVID-19, as well as management of encephalitis are not covered in this review.

RECENT FINDINGS

The diagnostic tools for evaluating patients with viral encephalitis are evolving quickly. Multiplex PCR panels are now in widespread use and allow for rapid pathogen detection and potentially reduce empiric antimicrobial exposure in certain patients, while metagenomic next-generation sequencing holds great promise in diagnosing challenging and rarer causes of viral encephalitis. We also review topical and emerging infections pertinent to neuroinfectious disease practice, including emerging arboviruses, monkeypox virus (mpox), and measles.

SUMMARY

Although etiological diagnosis remains challenging in viral encephalitis, recent advances may soon provide the clinician with additional tools. Environmental changes, host factors (such as ubiquitous use of immunosuppression), and societal trends (re-emergence of vaccine preventable diseases) are likely to change the landscape of neurologic infections that are considered and treated in clinical practice.

Factors related to the mortality risk of severe hand, foot, and mouth diseases (HFMD): a 5-year hospital-based survey in Guangxi, Southern China

BACKGROUND

To understand the factors influencing clinical outcomes of severe hand, foot, and mouth diseases (HFMD), and to provide scientific evidence for reducing the mortality risk of severe HFMD.

METHODS

From 2014 to 2018, children diagnosed with severe HFMD cases in Guangxi, China, were enrolled in this hospital-based study. The epidemiological data obtained through face-to-face interviews with the parents and guardians. Univariate and multivariate logistics regression models were used to analyze the factors influencing the clinical outcomes of severe HFMD. The impact of the EV-A71 vaccination on inpatient mortality was analyzed by a comparison approach.

RESULTS

A total of 1565 severe HFMD cases were enrolled in this survey, including 1474 (94.19%) survival cases and 91 (5.81%) death cases. The multivariate logistic analysis demonstrated that HFMD history of playmates in the last three months, first visit to the village hospital, time from the first visit to admission less than two days, no correct diagnosis for HFMD at the first visit, and having no rash symptoms were the independent risk factors for severe HFMD cases (all p < 0.05). While EV-A71 vaccination was a protective factor (p < 0.05). The EV-A71 vaccination group versus the non-vaccination group showed 2.23% of death in the vaccination group and 7.24% of death in the non-vaccination group. The EV-A71 vaccination protected 70.80% of the death of severe HFMD cases, with an effective index of 4.79.

CONCLUSIONS

The mortality risk of severe HFMD in Guangxi was related to playmates had HFMD history in last 3 months, hospital grade, EV-A71 vaccination, patients visit hospital previously, and rash symptom. EV-A71 vaccination can significantly reduce mortality among severe HFMD. The findings are of great significance for the effective prevention and control of HFMD in Guangxi, southern China.

Challenges in the Clinical Recognition of Acute Flaccid Myelitis and its Implications

OBJECTIVES

To explore the challenges in diagnosing acute flaccid myelitis (AFM) and evaluate clinical features and treatment paradigms associated with under recognition.

STUDY DESIGN

This was a retrospective multicenter study of pediatric patients (≤18 years) who were diagnosed with AFM from 2014 to 2018 using the Centers for Disease Control and Prevention's case definition.

RESULTS

In 72% of the cases (126 of 175), AFM was not considered in the initial differential diagnosis (n = 108; 61.7%) and/or the patient was not referred for acute care (n = 90; 51.4%) at the initial clinical encounter, and this did not improve over time. Although many features of the presentation were similar in those initially diagnosed with AFM and those who were not; preceding illness, constipation, and reflexes differed significantly between the 2 groups. Patients with a non-AFM initial diagnosis more often required ventilatory support (26.2% vs 12.2%; OR, 0.4; 95% CI, 0.2-1.0; P = .05). These patients received immunomodulatory treatment later (3 days vs 2 days after neurologic symptom onset; 95% CI, -2 to 0; P = .05), particularly intravenous immunoglobulin (5 days vs 2 days; 95% CI, -4 to -2; P < .001).

CONCLUSIONS

Delayed recognition of AFM is concerning because of the risk for respiratory decompensation and need for intensive care monitoring. A non-AFM initial diagnosis was associated with delayed treatment that could have a clinical impact, particularly as new treatment options emerge.

Transverse myelitis in children and adults

Transverse myelitis is a noncompressive myelopathy of inflammatory origin. The causes are broad, ranging from infective or toxic to immuno-mediated etiology. They can be manifestations of systemic diseases, such as sarcoidosis and systemic lupus erythematous, or phenotypes of neuroinflammation; in a portion of cases, the etiology remains unknown, leading to the designation idiopathic. The clinical presentation of transverse myelitis depends on the level of spinal cord damage and may include sensorimotor deficits and autonomic dysfunction. The age of onset of the disorder can impact the symptoms and outcomes of affected patients, with differences in manifestation and prognosis between children and adults. Spinal cord magnetic resonance imaging and cerebrospinal fluid examination are the main diagnostic tools that can guide clinicians in the diagnostic process, even though the search for antibodies that target the structural components of the neural tissue (anti-aquaporin4 antibodies and anti-myelin-oligodendrocyte antibodies) helps in the distinction among the immune-mediated phenotypes. Management and outcomes depend on the underlying cause, with different probabilities of relapse according to the phenotypes. Hence, immunosuppression is often recommended for the immune-mediated diseases that may have a higher risk of recurrence. Age at onset has implications for the choice of treatment.

Clinical profile and molecular typing of viral etiological agents associated with Hand, Foot and Mouth Disease (HFMD): A study from Udhampur, Northern India

PURPOSE

Hand, Foot and Mouth disease (HFMD) is a contagious pediatric viral disease caused due to enteroviruses (EV) of the family Picornaviridae. Cases of HFMD were reported from a tertiary care health centre, Udhampur, (Jammu and Kashmir), Northern India. The present study highlights the clinical and molecular virological aspects of HFMD cases.

MATERIAL AND METHODS

Cases reported during August 2016-September 2017, and clinically diagnosed as HFMD of all age groups were included. Clinical, Biochemical and molecular virology aspects were compared. Clinical samples (n ​= ​50) such as vesicle swab, buccal and throat swabs were collected for enterovirus detection. EV-RNA was detected by 5'NCR based RT-PCR and genotyping by VP1 gene amplification and cycle sequencing.

RESULTS

Of the cases of HFMD enrolled (n ​= ​50), highest (84%) were of children aged <5 years, presented either or both anathemas and exanthemas with prodromal symptoms (fever, irritability). Clinical presentations involved mainly oral ulcers on lips and tongue (48%). Oral erosions were either single or multiple in numbers. Exanthemas were seen on hand and palm, widely spread up to buttocks, legs, arms and trunk. Of these, six patients were found anemic. Complete blood count (CBC) indicated lymphocytosis and C-reactive protein (n ​= ​10) in children aged <5 years. EV-RNA was detected in 78% (39/50) of the clinical samples. VP1 gene based typing indicated the presence of CV-A16, CVA6 and EV-A71 types.

CONCLUSIONS

The study highlights association of EVs in HFMD cases in the reported region. CV-A16, CV-A6 and EV-A71 types were reported for the first time from Udhampur (J&K), Northern India. No differences were observed in the clinical profile of EV strains detected. Circulation of the strains warrant and alarm outbreaks. More focused studies on HFMD and monitoring of viral strains is mandatory.

Recent advances in enterovirus A71 pathogenesis: a focus on fatal human enterovirus A71 infection

Enterovirus A71 (EV-A71) is one of the major pathogens responsible for hand, foot, and mouth disease (HFMD). Many HFMD outbreaks have been reported throughout the world in the past decades. Compared with other viruses, EV-A71 infection is more frequently associated with severe neurological complications and even death in children. EV-A71 can also infect adults and cause severe complications and death, although such cases are very uncommon. Although fatal cases of EV-A71 infection have been reported, the underlying mechanisms of EV-A71 infection, especially the mode of viral spread into the central nervous system (CNS) and mechanisms of pulmonary edema, which is considered to be the direct cause of death, have not yet been fully clarified, and more studies are needed. Here, we first summarize the pathological findings in various systems of patients with fatal EV-A71 infections, focussing in detail on gross changes, histopathological examination, tissue distribution of viral antigens and nucleic acids, systemic inflammatory cell infiltration, and tissue distribution of viral receptors and their co-localization with viral antigens. We then present our conclusions about viral dissemination, neuropathogenesis, and the mechanism of pulmonary edema in EV-A71 infection, based on pathological findings.

Disease burden in patients with severe hand, foot, and mouth disease in Jiangsu Province: a cross-sectional study

This study aimed to estimate the disease burden and health-related quality of life (HRQOL) among patients with severe hand, foot, and mouth disease (HFMD) in Jiangsu Province, China. We analyzed the surveillance data of HFMD cases in Jiangsu Province from 2009 to 2020. Moreover, a cross-sectional study was conducted in Nanjing and Suzhou, China, between January 2017 and May 2018. Patients with severe HFMD and their parents were recruited from selected hospitals. Questionnaires and hospital management systems were used to collect data on direct economic burden. The HRQOL of children was assessed using the TNO-AZL Preschool Quality of Life (TAPQOL) scale. A total of 1,348,737 confirmed cases of HFMD were reported to the NNDRS in Jiangsu province during 2009-2020. Of these, 9,622 were severe cases, with 62 (.64%) of these being fatal. From January 2017 to May 2018, data was collected from 362 severe HFMD cases using a structured questionnaire. The median per capita direct economic burden was RMB 16142.88, and was associated with the region and length of hospital stay (P < .05). The direct economic burden for all cases of severe HFMD in Jiangsu province between 2017 and 2018 was approximately RMB 16.64 million. Finally, the median (IQR) of the TAPQOL scale for children with severe HFMD was 69.23 (56.20, 82.27). Severe HFMD infection is a relatively large burden for individuals, and the burden of EV-A71 infection was seen to be even greater for the population. Prevention of severe HFMD should strengthen hygiene habits and targeted measures for EV-A71 vaccination.

Clinical evaluation of the lot-to-lot consistency of an enterovirus 71 vaccine in a commercial-scale phase IV clinical trial

OBJECTIVE

To evaluate the immunogenicity, safety and lot-to-lot consistency of an inactivated enterovirus 71 (EV71) vaccine cultured in bioreactors with different specifications after full immunization.

METHODS

A randomized, double-blind trial was performed in 3,000 children aged 6 ~ 35 months with six vaccine batches, which were prepared in 40 L and 150 L bioreactors for three consecutive batches respectively. Children were immunized on day 0 and 28, serum samples were collected on day 0 and 56, and neutralizing antibody titers were determined by the microcytopathic method. Immediate reactions were recorded within 30 min, local and systemic symptoms were recorded within 0 ~ 28 days, and serious adverse events were recorded within 6 months.

RESULTS

After immunization with two doses of the inactivated EV71 vaccine, the neutralizing antibody GMT was 825.52 ± 4.09, and the positive conversion rate was 96.18%, with no significant difference. The 95% CI of the serum neutralizing antibody GMT ratio between the two groups after immunization with the three vaccine batches produced in the 150 L and 40 L bioreactors ranged from .67 ~ 1.5. The overall incidence of adverse reactions, mainly grade 1 reactions, for all 6 batches from 0 to 28 days after vaccination was 49.62%, with no significant difference (p = .8736). The incidence of systemic adverse reactions, primarily fever and diarrhea, was 45.14%; the incidence of local adverse reactions, primarily erythema and tenderness, was 9.43%.

CONCLUSION

The EV71 vaccine was highly immunogenic and safe in children aged 6-35 months, and 6 consecutive batches produced by the two bioreactors with different specifications were consistent.

Evaluation of multiple consensus criteria for autoimmune encephalitis and temporal analysis of symptoms in a pediatric encephalitis cohort

Objective

To evaluate the sensitivity and specificity of current criteria for the diagnosis of autoimmune encephalitis (AE) and the temporal onset of neuropsychiatric symptoms (NP) in a pediatric encephalitis cohort.

Background

Multiple criteria for AE have been developed, including the Graus and pediatric-focused Cellucci consensus criteria, and the Determining Etiology in Encephalitis (DEE) score for patients with encephalitis. Early identification and treatment of AE is crucial to improve outcomes, but this can be difficult given the frequent overlap of clinical presentation between AE and infectious encephalitis (IE).

Design/methods

A retrospective review was conducted of patients seen at our institution from 2000 to 2021 with a final diagnosis of AE or IE. These were narrowed through multiple exclusions to etiology-confirmed IE or antibody-positive/negative AE. Time of onset or results of all symptoms and diagnostics were recorded. Sensitivity and specificity of each criterion under various clinical scenarios were calculated over the first month after initial NP symptom onset.

Results

A total of 23 antibody-positive AE, 9 antibody-negative AE and 23 IE patients were included in final analysis. Under an idealized scenario with rapid initial diagnostic evaluations, the sensitivity for pediatric AE by day 28 after onset of NP symptoms approached 90% for both Cellucci and Graus criteria. Specificity within these 28 days was low without infectious testing results, increasing the greatest with rapid PCR testing and second with infectious antibody testing-reaching ~90% with both. A DEE score of 3 provided a specificity of 100% in identifying IE, but low sensitivity (29%). Symptoms were noted to cluster within several days of onset in IE, but in AE were spread out. Personality/behavioral change, speech change, affective disorder, and sleep disturbance were noted more often in AE, while fever, elevated C-reactive protein or CSF protein, and abnormal MRI-Brain occurred more often in IE.

Conclusion

In this study, we provide the first evaluation of the Cellucci criteria and the first validation of the DEE score in the differentiation of pediatric AE and IE. Further refinement of AE criteria is needed to improve early detection and treatment of pediatric AE.

Molecular epidemiology and clinical features of hand, foot and mouth disease requiring hospitalization after the use of enterovirus A71 inactivated vaccine in Chengdu, China, 2017-2022: a descriptive study

Three inactivated enterovirus A71 (EV-A71) vaccines have been widely vaccinated among children in the targeted age group in mainland China since mid-2016. However, comprehensive virological surveillance of hand, foot and mouth disease (HFMD) over multiple years after the use of EV-A71 vaccines has rarely been conducted. Using long-term data extracted from the Public Health and Clinical Center of Chengdu, we described the clinical, aetiological, and epidemiological characteristics of HFMD inpatients after the use of EV-A71 vaccines from 2017 through 2022. A total of 5115 patients were selected for analysis with a male-to-female ratio of 1.63:1 and were mostly under 5 years of age (97.6%). Among these cases, 4.3% presented with severe symptoms, and 4.1% of severe cases experienced significant complications. EV-A71 was no longer the major serotype for laboratory-confirmed HFMD, responsible for 15.6% of severe cases and 1.2% of mild cases. A significant downwards trend of EV-A71 infections was observed after the use of EV-A71 vaccines (P for trend < 0.001). Coxsackievirus A6 was the predominant pathogen, accounting for 63.5% of mild cases and 36.2% of severe cases. Coxsackievirus A10 (CV-A10) and A16 were sporadically detected, and an upwards trend was observed in the proportion of CV-A10 infections. This study provides baseline molecular epidemiology for the evaluation of EV-A71 vaccination impact and potential serotype replacement based on HFMD inpatients. Additional nationwide and population-based epidemiologic and serologic studies are essential to elucidate HFMD dynamics after the use of EV-A71 vaccines, and to inform public health authorities to introduce optimized intervention strategies.

Mouse Scarb2 Modulates EV-A71 Pathogenicity in Neonatal Mice

Enterovirus A71 (EV-A71) is a human pathogen that causes hand, foot, and mouth disease, which can progress to severe neurological disease. EV-A71 infects humans via the human scavenger receptor B2 (hSCARB2). It can also infect neonatal mice experimentally. Wild-type (WT) EV-A71 strains replicate primarily in the muscle of neonatal mice; however, susceptibility lasts only for a week after birth. Mouse-adapted (MA) strains, which can be obtained by serial passages in neonatal mice, are capable of infecting both muscle and neurons of the central nervous system. It is not clear how the host range and tropism of EV-A71 are regulated and why neonatal mice lose their susceptibility during development. We hypothesized that EV-A71 infection in neonatal mice is mediated by mouse Scarb2 (mScarb2) protein. Rhabdomyosarcoma (RD) cells expressing mScarb2 were prepared. Both WT and MA strains infected mScarb2-expressing cells, but the infection efficiency of the WT strain was much lower than that of the MA strain. Infection by WT and MA strains in vivo was abolished completely in Scarb2^-/- mice. Scarb2^+/- mice, in which Scarb2 expression was approximately half of that in Scarb2^+/+ mice, showed a milder pathology than Scarb2^+/+ mice after infection with the WT strain. The Scarb2 expression level in muscle decreased with aging, which was consistent with the reduced susceptibility of aged mice to infection. These results indicated that EV-A71 infection is mediated by mScarb2 and that the severity of the disease, the spread of virus, and the susceptibility period are modulated by mScarb2 expression. IMPORTANCE EV-A71 infects humans naturally but can also infect neonatal mice. The tissue tropism and severity of EV-A71 disease are determined by several factors, among which the virus receptor is thought to be important. We show that EV-A71 can infect neonatal mice using mScarb2. However, the infection efficiency of WT strains via mScarb2 is so low that an elevated virus-receptor interaction associated with mouse adaptation mutation and decrease in mScarb2 expression level during development modulate the severity of the disease, the spread of virus, and the susceptibility period in the artificial neonatal mice model.

Thermal stabilization of enterovirus A 71 and production of antigenically stabilized empty capsids

Enterovirus A71 (EVA71) infection can result in paralysis and may be fatal. In common with other picornaviruses, empty capsids are produced alongside infectious virions during the viral lifecycle. These empty capsids are antigenically indistinguishable from infectious virus, but at moderate temperatures they are converted to an expanded conformation. In the closely related poliovirus, native and expanded antigenic forms of particle have different long-term protective efficacies when used as vaccines. The native form provides long-lived protective immunity, while expanded capsids fail to generate immunological protection. Whether this is true for EVA71 remains to be determined. Here, we selected an antigenically stable EVA71 virus population using successive rounds of heating and passage and characterized the antigenic conversion of both virions and empty capsids. The mutations identified within the heated passaged virus were dispersed across the capsid, including at key sites associated with particle expansion. The data presented here indicate that the mutant sequence may be a useful resource to address the importance of antigenic conformation in EVA71 vaccines.

Childhood encephalitis in the Greater Mekong region (the SouthEast Asia Encephalitis Project): a multicentre prospective study

BACKGROUND

Encephalitis is a worldwide public health issue, with a substantially high burden among children in southeast Asia. We aimed to determine the causes of encephalitis in children admitted to hospitals across the Greater Mekong region by implementing a comprehensive state-of-the-art diagnostic procedure harmonised across all centres, and identifying clinical characteristics related to patients' conditions.

METHODS

In this multicentre, observational, prospective study of childhood encephalitis, four referral hospitals in Cambodia, Vietnam, Laos, and Myanmar recruited children (aged 28 days to 16 years) who presented with altered mental status lasting more than 24 h and two of the following minor criteria: fever (within the 72 h before or after presentation), one or more generalised or partial seizures (excluding febrile seizures), a new-onset focal neurological deficit, cerebrospinal fluid (CSF) white blood cell count of 5 per mL or higher, or brain imaging (CT or MRI) suggestive of lesions of encephalitis. Comprehensive diagnostic procedures were harmonised across all centres, with first-line testing was done on samples taken at inclusion and results delivered within 24 h of inclusion for main treatable causes of disease and second-line testing was done thereafter for mostly non-treatable causes. An independent expert medical panel reviewed the charts and attribution of causes of all the included children. Using multivariate analyses, we assessed risk factors associated with unfavourable outcomes (ie, severe neurological sequelae and death) at discharge using data from baseline and day 2 after inclusion. This study is registered with ClinicalTrials.gov, NCT04089436, and is now complete.

FINDINGS

Between July 28, 2014, and Dec 31, 2017, 664 children with encephalitis were enrolled. Median age was 4·3 years (1·8-8·8), 295 (44%) children were female, and 369 (56%) were male. A confirmed or probable cause of encephalitis was identified in 425 (64%) patients: 216 (33%) of 664 cases were due to Japanese encephalitis virus, 27 (4%) were due to dengue virus, 26 (4%) were due to influenza virus, 24 (4%) were due to herpes simplex virus 1, 18 (3%) were due to Mycobacterium tuberculosis, 17 (3%) were due to Streptococcus pneumoniae, 17 (3%) were due to enterovirus A71, 74 (9%) were due to other pathogens, and six (1%) were due to autoimmune encephalitis. Diagnosis was made within 24 h of admission to hospital for 83 (13%) of 664 children. 119 (18%) children had treatable conditions and 276 (42%) had conditions that could have been preventable by vaccination. At time of discharge, 153 (23%) of 664 children had severe neurological sequelae and 83 (13%) had died. In multivariate analyses, risk factors for unfavourable outcome were diagnosis of M tuberculosis infection upon admission (odds ratio 3·23 [95% CI 1·04-10·03]), coma on day 2 (2·90 [1·78-4·72]), supplementary oxygen requirement (1·89 [1·25-2·86]), and more than 1 week duration between symptom onset and admission to hospital (3·03 [1·68-5·48]). At 1 year after inclusion, of 432 children who were discharged alive from hospital with follow-up data, 24 (5%) had died, 129 (30%) had neurological sequelae, and 279 (65%) had completely recovered.

INTERPRETATION

In southeast Asia, most causes of childhood encephalitis are either preventable or treatable, with Japanese encephalitis virus being the most common cause. We provide crucial information that could guide public health policy to improve diagnostic, vaccination, and early therapeutic guidelines on childhood encephalitis in the Greater Mekong region.

FUNDING

Institut Pasteur, Institut Pasteur International Network, Fondation Merieux, Aviesan Sud, INSERM, Wellcome Trust, Institut de Recherche pour le Développement (IRD), and Fondation Total.

Etiology, Clinical Phenotypes, Epidemiological Correlates, Laboratory Biomarkers and Diagnostic Challenges of Pediatric Viral Meningitis: Descriptive Review

Meningitis is an inflammation of the brain and spinal cord meninges caused by infectious and non-infectious agents. Infectious agents causing meningitis include viruses, bacteria, and fungi. Viral meningitis (VM), also termed aseptic meningitis, is caused by some viruses, such as enteroviruses (EVs), herpesviruses, influenza viruses, and arboviruses. However, EVs represent the primary cause of VM. The clinical symptoms of this neurological disorder may rapidly be observed after the onset of the disease, or take prolonged time to develop. The primary clinical manifestations of VM include common flu-like symptoms of headache, photophobia, fever, nuchal rigidity, myalgia, and fatigue. The severity of these symptoms depends on the patient's age; they are more severe among infants and children. The course of infection of VM varies between asymptomatic, mild, critically ill, and fatal disease. Morbidities and mortalities of VM are dependent on the early recognition and treatment of the disease. There were no significant distinctions in the clinical phenotypes and symptoms between VM and meningitis due to other causative agents. To date, the pathophysiological mechanisms of VM are unclear. In this scientific communication, a descriptive review was performed to give an overview of pediatric viral meningitis (PVM). PVM may occasionally result in severe neurological consequences such as mental retardation and death. Clinical examinations, including Kernig's, Brudzinski's, and nuchal rigidity signs, were attempted to determine the clinical course of PVM with various success rates revealed. Some epidemiological correlates of PVM were adequately reviewed and presented in this report. They were seen depending mainly on the causative virus. The abnormal cytological and biochemical features of PVM were also discussed and showed potentials to distinguish PVM from pediatric bacterial meningitis (PBM). The pathological, developmental, behavioral, and neuropsychological complications of PVM were also presented. All the previously utilized techniques for the etiological diagnosis of PVM which include virology, serology, biochemistry, and radiology, were presented and discussed to determine their efficiencies and limitations. Finally, molecular testing, mainly PCR, was introduced and showed 100% sensitivity rates.

Immunogenicity and Safety of an Inactivated Enterovirus 71 Vaccine Administered Simultaneously with Hepatitis B Virus Vaccine, Group A Meningococcal Polysaccharide Vaccine, Measles-Rubella Combined Vaccine and Japanese Encephalitis Vaccine: A Multi-Center, Randomized, Controlled Clinical Trial in China

Background: The aim of this study was to investigate the immunogenicity and safety of the enterovirus 71 vaccine (EV71 vaccine) administered alone or simultaneously. Methods: A multi-center, open-label, randomized controlled trial was performed involving 1080 healthy infants aged 6 months or 8 months from Shandong, Shanxi, Shaanxi, and Hunan provinces. These infants were divided into four simultaneous administration groups and EV71 vaccine separate administration group. Blood samples were collected from the infants before the first vaccination and after the completion of the vaccination. This trial was registered in the Clinical Trials Registry (NCT03519568). Results: A total of 895 were included in the per-protocol analysis. The seroconversion rates of antibodies against EV71 in four simultaneous administration groups (98.44% (189/192), 94.57% (122/129), 99.47% (187/188) and 98.45% (190/193)) were non-inferior to EV71 vaccine separate administration group (97.93% [189/193]) respectively. Fever was the most common adverse event, the pairwise comparison tests showed no difference in the incidence rate of solicited, systemic or local adverse events. Three serious adverse events related to the vaccination were reported. Conclusions: The evidence of immunogenicity and safety supports that the EV71 vaccine administered simultaneously with vaccines need to be administered during the same period of time recommended in China.

Enteroviral Rhombencephalitis with Abducens Nerve Palsy and Cardio-Pulmonary Failure in a 2-Year-Old Boy

Enterovirus infection is endemic in many areas, especially in Southeast Asia. Enterovirus infection with severe complications (EVSC) is life-threatening, and timely diagnosis and management are crucial for successful management. Here, we report on a 2-year-old boy with hand, foot, and mouth disease. Myoclonic jerks developed and left abducens nerve palsy followed. Brain magnetic resonance imaging (MRI) showed rhombencephalitis. Pulmonary edema and cardiopulmonary failure developed, and intravenous immunoglobulin and extracorporeal membrane oxygenation were administered. He had a tracheostomy with home ventilator use after 64 days of hospitalization. At a 5-year follow-up, his neurodevelopment was normal with complete recovery from the abducens nerve palsy. The progress of EVSC may be rapid and fulminant, and timely diagnosis is critical for patient prognosis and outcomes. The presence of abducens nerve palsy is an indicator of enteroviral rhombencephalitis, and immediate and appropriate management is suggested.

Nutritional Profile and Health Benefits of Ganoderma lucidum "Lingzhi, Reishi, or Mannentake" as Functional Foods: Current Scenario and Future Perspectives

Ganoderma lucidum has a long history of medicinal uses in the Far East countries of more than 2000 years due to its healing properties. Recently, G. lucidum has come under scientific scrutiny to evaluate its content of bioactive components that affect human physiology, and has been exploited for potent components in the pharmacology, nutraceuticals, and cosmetics industries. For instance, evidence is accumulating on the potential of this mushroom species as a promising antiviral medicine for treating many viral diseases, such as dengue virus, enterovirus 71, and recently coronavirus disease of 2019 (COVID-19). Still, more research studies on the biotherapeutic components of G. lucidum are needed to ensure the safety and efficiency of G. lucidum and promote the development of commercial functional foods. This paper provides an extensive overview of the nutraceutical value of Ganoderma lucidum and the development of commercial functional food. Moreover, the geo-origin tracing strategies of this mushroom and its products are discussed, a highly important parameter to ensure product quality and safety. The discussed features will open new avenues and reveal more secrets to widely utilizing this mushroom in many industrial fields; i.e., pharmaceutical and nutritional ones, which will positively reflect the global economy.

Aseptic Meningitis in Oral Medicine: Exploring the Key Elements for a Challenging Diagnosis: A Review of the Literature and Two Case Reports

Aseptic meningitis (AM) is a potentially severe and life-threatening disease characterized by meningeal inflammation, usually with mononuclear pleocytosis. It represents a challenging and controversial issue in medicine for multiple etiologies, classification, and difficult diagnosis in the face of nonspecific sets of signs and symptoms. In the area of interest of oral medicine, in specific clusters of patients, even if rare, the occurrence of aseptic meningitis can pose a diagnostic and management dilemma in the following potential etiologies: (i) systemic diseases with oral and meningeal involvement, which include Behçet’s disease and Sjögren syndrome; (ii) drug-induced aseptic meningitis; (iii) aseptic viral meningitis, mostly related to herpes simplex virus infection and hand, foot, and mouth disease, caused by enteroviruses. In this review, clinical manifestations, diagnostic methodologies, incidence, treatment, and prognosis for each of these clinical entities are provided. Furthermore, two illustrative case reports are described: a patient suffering from recurrent oral ulcers, in which a sudden onset of AM allows us to diagnose Neuro Behçet’s disease, and a patient affected by pemphigus vulgaris, manifesting a drug-induced AM. Exploring this complex clinical entity scenario, it is clear that an oral medicine specialist has a place on any multidisciplinary team in making such a challenging diagnosis.

Gasdermin E is required for induction of pyroptosis and severe disease during enterovirus 71 infection

Pyroptosis is an inflammatory form of programmed cell death that is executed by the gasdermin (GSDM)-N domain of GSDM family proteins, which form pores in the plasma membrane. Although pyroptosis acts as a host defense against invasive pathogen infection, its role in the pathogenesis of enterovirus 71 (EV71) infection is unclear. In the current study, we found that EV71 infection induces cleavage of GSDM E (GSDME) by using western blotting analysis, an essential step in the switch from caspase-3-mediated apoptosis to pyroptosis. We show that this cleavage is independent of the 3C and 2A proteases of EV71. However, caspase-3 activation is essential for this cleavage, as GSDME could not be cleaved in caspase-3-KO cells upon EV71 infection. Further analyses showed that EV71 infection induced pyroptosis in WT cells but not in caspase-3/GSDME double-KO cells. Importantly, GSDME is required to induce severe disease during EV71 infection, as GSDME deficiency in mice was shown to alleviate pathological symptoms. In conclusion, our results reveal that GSDME is important for the pathogenesis of EV71 via mediating initiation of pyroptosis.

A Single Amino Acid Substitution in Structural Protein VP2 Abrogates the Neurotropism of Enterovirus A-71 in Mice

Enterovirus 71 (EV-A71) causes hand, foot, and mouth disease (HFMD) in children and has been associated with neurological complications. With no specific treatment and a monovalent vaccine limited to the Chinese market, HFMD remains a serious public health concern and an economic burden to affected societies. The molecular mechanisms underpinning EV-A71 neurovirulence have yet to be fully elucidated. In this work, we provide experimental evidence that a single amino acid substitution (I to K) at position 149 in structural protein VP2 of a non-mouse-adapted EV-A71 strain completely and specifically abrogated its infectivity in murine motor neuron-like NSC-34 cells. We showed that VP2 I149K mutant was impaired in murine SCARB2-mediated entry step but retained the ability to attach at the cell surface. In vivo, VP2 I149K mutant was fully attenuated in a symptomatic mouse model of progressive limb paralysis. While viral titers in limb muscles were comparable to mice infected with parental wild-type strain, significantly lower viral titers were measured in the spinal cord and brain, with minimal tissue damage, therefore indicating that VP2 I149K mutant is specifically impaired in its ability to invade the central nervous system (CNS). This study highlights the key role of amino acid at position 149 in VP2 in EV-A71 neurovirulence, and lends further support that the EF loop of VP2 represents a potential therapeutic target.

Pharmacological perturbation of CXCL1 signaling alleviates neuropathogenesis in a model of HEVA71 infection

Hand, foot and mouth disease (HFMD) caused by Human Enterovirus A71 (HEVA71) infection is typically a benign infection. However, in minority of cases, children can develop severe neuropathology that culminate in fatality. Approximately 36.9% of HEVA71-related hospitalizations develop neurological complications, of which 10.5% are fatal. Yet, the mechanism by which HEVA71 induces these neurological deficits remain unclear. Here, we show that HEVA71-infected astrocytes release CXCL1 which supports viral replication in neurons by activating the CXCR2 receptor-associated ERK1/2 signaling pathway. Elevated CXCL1 levels correlates with disease severity in a HEVA71-infected mice model. In humans infected with HEVA71, high CXCL1 levels are only present in patients presenting neurological complications. CXCL1 release is specifically triggered by VP4 synthesis in HEVA71-infected astrocytes, which then acts via its receptor CXCR2 to enhance viral replication in neurons. Perturbing CXCL1 signaling or VP4 myristylation strongly attenuates viral replication. Treatment with AZD5069, a CXCL1-specific competitor, improves survival and lessens disease severity in infected animals. Collectively, these results highlight the CXCL1-CXCR2 signaling pathway as a potential target against HFMD neuropathogenesis.

Life-Threatening Enterovirus 71 Encephalitis in Unrelated Children with Autosomal Dominant TLR3 Deficiency

PURPOSE

Enterovirus A71 (EV71) causes a broad spectrum of childhood diseases, ranging from asymptomatic infection or self-limited hand-foot-and-mouth disease (HFMD) to life-threatening encephalitis. The molecular mechanisms underlying these different clinical presentations remain unknown. We hypothesized that EV71 encephalitis in children might reflect an intrinsic host single-gene defect of antiviral immunity. We searched for mutations in the toll-like receptor 3 (TLR3) gene. Such mutations have already been identified in children with herpes simplex virus encephalitis (HSE).

METHODS

We sequenced TLR3 and assessed the impact of the mutations identified. We tested dermal fibroblasts from a patient with EV71 encephalitis and a TLR3 mutation and other patients with known genetic defects of TLR3 or related genes, assessing the response of these cells to TLR3 agonist poly(I:C) stimulation and EV71 infection.

RESULTS

Three children with EV71 encephalitis were heterozygous for rare mutations-TLR3 W769X, E211K, and R867Q-all of which were shown to affect TLR3 function. Furthermore, fibroblasts from the patient heterozygous for the W769X mutation displayed an impaired, but not abolished, response to poly(I:C). We found that TLR3-deficient and TLR3-heterozygous W769X fibroblasts were highly susceptible to EV71 infection.

CONCLUSIONS

Autosomal dominant TLR3 deficiency may underlie severe EV71 infection with encephalitis. Human TLR3 immunity is essential to protect the central nervous system against HSV-1 and EV71. Children with severe EV71 infections, such as encephalitis in particular, should be tested for inborn errors of TLR3 immunity.

Mesenchymal Stromal/Stem Cells-Derived Exosomes as an Antimicrobial Weapon for Orodental Infections

The oral cavity as the second most various microbial community in the body contains a broad spectrum of microorganisms which are known as the oral microbiome. The oral microbiome includes different types of microbes such as bacteria, fungi, viruses, and protozoa. Numerous factors can affect the equilibrium of the oral microbiome community which can eventually lead to orodental infectious diseases. Periodontitis, dental caries, oral leukoplakia, oral squamous cell carcinoma are some multifactorial infectious diseases in the oral cavity. In defending against infection, the immune system has an essential role. Depending on the speed and specificity of the reaction, immunity is divided into two different types which are named the innate and the adaptive responses but also there is much interaction between them. In these responses, different types of immune cells are present and recent evidence demonstrates that these cell types both within the innate and adaptive immune systems are capable of secreting some extracellular vesicles named exosomes which are involved in the response to infection. Exosomes are 30-150 nm lipid bilayer vesicles that consist of variant molecules, including proteins, lipids, and genetic materials and they have been associated with cell-to-cell communications. However, some kinds of exosomes can be effective on the pathogenicity of various microorganisms and promoting infections, and some other ones have antimicrobial and anti-infective functions in microbial diseases. These discrepancies in performance are due to the origin of the exosome. Exosomes can modulate the innate and specific immune responses of host cells by participating in antigen presentation for activation of immune cells and stimulating the release of inflammatory factors and the expression of immune molecules. Also, mesenchymal stromal/stem cells (MSCs)-derived exosomes participate in immunomodulation by different mechanisms. Ease of expansion and immunotherapeutic capabilities of MSCs, develop their applications in hundreds of clinical trials. Recently, it has been shown that cell-free therapies, like exosome therapies, by having more advantages than previous treatment methods are emerging as a promising strategy for the treatment of several diseases, in particular inflammatory conditions. In orodental infectious disease, exosomes can also play an important role by modulating immunoinflammatory responses. Therefore, MSCs-derived exosomes may have potential therapeutic effects to be a choice for controlling and treatment of orodental infectious diseases.

3C protease of enterovirus 71 cleaves promyelocytic leukemia protein and impairs PML-NBs production

BACKGROUND

Enterovirus 71 (EV71) usually infects infants causing hand-foot-mouth disease (HFMD), even fatal neurological disease like aseptic meningitis. Effective drug for preventing and treating EV71 infection is unavailable currently. EV71 3C mediated the cleavage of many proteins and played an important role in viral inhibiting host innate immunity. Promyelocytic leukemia (PML) protein, the primary organizer of PML nuclear bodies (PML-NBs), can be induced by interferon and is involved in antiviral activity. PML inhibits EV71 replication, and EV71 infection reduces PML expression, but the molecular mechanism is unclear.

METHODS

The cleavage of PMLIII and IV was confirmed by co-transfection of EV71 3C protease and PML. The detailed cleavage sites were evaluated further by constructing the Q to A mutant of PML. PML knockout cells were infected with EV71 to identify the effect of cleavage on EV71 replication. Immunofluorescence analysis to examine the interference of EV71 3C on the formation of PML-NBs.

RESULTS

EV71 3C directly cleaved PMLIII and IV. Furthermore, 3C cleaved PMLIV at the sites of Q430-A431 and Q444-S445 through its protease activity. Overexpression of PMLIV Q430A/Q444A variant exhibited stronger antiviral potential than the wild type. PMLIV Q430A/Q444A formed normal nuclear bodies that were not affected by 3C, suggesting that 3C may impair PML-NBs production via PMLIV cleavage and counter its antiviral activities. PML, especially PMLIV, which sequesters viral proteins in PML-NBs and inhibits viral production, is a novel target of EV71 3C cleavage.

CONCLUSIONS

EV71 3C cleaves PMLIV at Q430-A431 and Q444-S445. Cleavage reduces the antiviral function of PML and decomposes the formation of PML-NBs, which is conducive to virus replication.

Molecular mechanism of L-SP40 peptide and in vivo efficacy against EV-A71 in neonatal mice

AIMS

Enterovirus A71 (EV-A71) is an etiological agent of hand foot and mouth disease (HFMD) and has the potential to cause severe neurological infections in children. L-SP40 peptide was previously known to inhibit EV-A71 by prophylactic action. This study aimed to identify the mechanism of inhibition in Rhabdomyosarcoma (RD) cells and in vivo therapeutic potential of L-SP40 peptide in a murine model.

MAIN METHODS

A pull-down assay was performed to identify the binding partner of the L-SP40 peptide. Co-immunoprecipitation and co-localization assays with the L-SP40 peptide were employed to confirm the receptor partner in RD cells. The outcomes were validated using receptor knockdown and antibody blocking assays. The L-SP40 peptide was further evaluated for the protection of neonatal mice against lethal challenge by mouse-adapted EV-A71.

KEY FINDINGS

The L-SP40 peptide was found to interact and co-localize with nucleolin, the key attachment receptor of Enteroviruses A species, as demonstrated in the pull-down, co-immunoprecipitation and co-localization assays. Knockdown of nucleolin from RD cells led to a significant reduction of 3.5 logs of viral titer of EV-A71. The L-SP40 peptide demonstrated 80% protection of neonatal mice against lethal challenge by the mouse-adapted virus with a drastic reduction in the viral loads in the blood (~4.5 logs), skeletal muscles (1.5 logs) and brain stem (1.5 logs).

SIGNIFICANCE

L-SP40 peptide prevented severe hind limb paralysis and death in suckling mice and could serve as a potential broad-spectrum antiviral candidate to be further evaluated for safety and potency in future clinical trials against EV-A71.