Epidemiology of Recurrent Hand, Foot and Mouth Disease, China, 2008-2015

Eco-evolutionary dynamics of pathogen immune-escape: deriving a population-level phylodynamic curve

The phylodynamic curve (Grenfell et al. 2004 Science 303, 327-332 (doi:10.1126/science.1090727)) conceptualizes how immunity shapes the rate of viral adaptation in a non-monotonic fashion, through its opposing effects on viral abundance and the strength of selection. However, concrete and quantitative model realizations of this influential concept are rare. Here, we present an analytic, stochastic framework in which a population-scale phylodynamic curve emerges dynamically, allowing us to address questions regarding the risk and timing of the emergence of viral immune escape variants. We explore how pathogen- and population-specific parameters such as strength of immunity, transmissibility, seasonality and antigenic constraints affect the emergence risk. For pathogens exhibiting pronounced seasonality, we find that the timing of likely immune-escape variant emergence depends on the level of case importation between regions. Motivated by the COVID-19 pandemic, we probe the likely effects of non-pharmaceutical interventions (NPIs), and the lifting thereof, on the risk of viral escape variant emergence. Looking ahead, the framework has the potential to become a useful tool for probing how natural immunity, as well as choices in vaccine design and distribution and the implementation of NPIs, affect the evolution of common viral pathogens.

Joint estimation of hand-foot-mouth disease model and prediction in korea using the ensemble kalman filter

BACKGROUND

In Korea, Hand-foot-and-mouth disease (HFMD) is a recurring illness that presents significant public health challenges, primarily because of its unpredictable epidemic patterns. The accurate prediction of the spread of HFMD plays a vital role in the effective management of the disease.

METHODS

We have devised a dynamic model that accurately represents the transmission dynamics of HFMD. The model includes compartments for susceptible, exposed, inpatients, outpatients, recovered, and deceased individuals. By utilizing monthly inpatient and outpatient data, the ensemble Kalman filter (EnKF) method was employed to perform a joint estimation of model parameters and state variables. The calibration of model parameters involved using data from the months of January to May, while generating forecasts for the timeframe spanning from June to December.

RESULTS

The findings reveal a significant alignment between the model and the observed data, as evidenced by root-mean-square error (RMSE) values below 1000 for inpatients and below 10000 for outpatients starting in June. The correlation coefficients surpassed 0.9, except for the year 2015. The implications of our findings suggest a notable shift in transmission and recovery rates, starting in 2015.

DISCUSSION

The model successfully predicted the peak and magnitude of HFMD outbreaks occurring between June and December, closely matching the observed epidemic patterns. The model's efficacy in predicting epidemic trends and informing preventive strategies is reinforced by the insights gained from monthly variations in parameter estimates of HFMD transmission dynamics.

Epidemiological characteristics of 5838 cases of enterovirus infection in children in Hangzhou from 2018 to 2023

This study retrospectively explored the characteristics of 5838 children with enterovirus infection in our hospital from 2018 to 2023. In addition, children with enterovirus (EV: EV typing was performed using RT-PCR) infection exhibiting clinical manifestations of viral encephalitis were investigated. Pharyngeal swabs or fecal samples from outpatients and inpatients from our hospital were collected from 2018 to 2023 and were subjected to EV nucleic acid detection using real-time fluorescence quantitative PCR. Furthermore, cerebrospinal fluid EV nucleic acid detection was performed for children with clinical manifestations of viral encephalitis. Descriptive epidemiological methods were used to analyze the age, sex, and etiology of EV infection cases. Statistical analyses were performed with SPSS 20.0. The statistical data were expressed as percentages, and the χ2 test was used for statistical analysis. A total of 9676 children were included in this study, and 5838 (60.33%) showed positive EV nucleic acid test results. These included 1909 cases of Coxsackievirus group A type 6 (CV-A6) (32.70%), 259 cases of Coxsackievirus group A type 16 (CV-A16) (4.44%), 252 cases of Coxsackievirus group A type 10 (CV-A10) (4.32%), and 34 cases of enterovirus type 71 (EV-A71) (0.58%). A total of 3384 other uncategorized EVs (57.97%) were found. The detection rates of EV-A71 and CV-A16 decreased year by year, while the detection rates of other EV nucleic acids increased year by year. Cerebrospinal fluid (CSF) EV nucleic acid detection was performed on 1520 children with positive EV nucleic acid throat swabs or stool samples showing clinical manifestations of viral encephalitis; a total of 140 positive cases (9.21%) were detected, including CV-A16 2.14% (3/140), CV-A10 1.43% (2/140), CV-A6 9.29% (13/140), EV-A71 0%(0/140), and other uncategorized EVs 87.14% (122/140). Among the 140 cerebrospinal fluid EV-positive children, 32 had typical hand-foot-mouth disease or herpetic angina, and 108 had only fever and upper respiratory tract infection. Real-time fluorescence quantitative PCR detection and virus typing can greatly improve the diagnosis rate of EV. Multi-sample EV nucleic acid detection and virus typing in children with viral encephalitis effectively improve the etiological diagnosis rate. Nonetheless, the development of multivalent vaccines remains the most economical and effective measure to prevent and control EV infection.

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.

Therapeutic effects of platelet-derived extracellular vesicles on viral myocarditis correlate with biomolecular content

Introduction

Extracellular vesicles (EVs) can potently inhibit inflammation yet there is a lack of understanding about the impact of donor characteristics on the efficacy of EVs. The goal of this study was to determine whether the sex and age of donor platelet-derived EVs (PEV) affected their ability to inhibit viral myocarditis.

Methods

PEV, isolated from men and women of all ages, was compared to PEV obtained from women under 50 years of age, which we termed premenopausal PEV (pmPEV). Because of the protective effect of estrogen against myocardial inflammation, we hypothesized that pmPEV would be more effective than PEV at inhibiting myocarditis. We injected PEV, pmPEV, or vehicle control in a mouse model of viral myocarditis and examined histology, gene expression, protein profiles, and performed proteome and microRNA (miR) sequencing of EVs.

Results

We found that both PEV and pmPEV significantly inhibited myocarditis; however, PEV was more effective, which was confirmed by a greater reduction of inflammatory cells and proinflammatory and profibrotic markers determined using gene expression and immunohistochemistry. Proteome and miR sequencing of EVs revealed that PEV miRs specifically targeted antiviral, Toll-like receptor (TLR)4, and inflammasome pathways known to contribute to myocarditis while pmPEV contained general immunoregulatory miRs.

Discussion

These differences in EV content corresponded to the differing anti-inflammatory effects of the two types of EVs on viral myocarditis.

Emerging and re-emerging viral exanthems among children: what a physician should know

Viral exanthems can present with diverse morphologies of rash, including macular, maculopapular, papular, urticarial and vesicular, or sometimes a combination of these. There has been an increasing trend towards emerging and re-emerging viral exanthems in recent years, the cause of which is multifactorial, including changing environmental conditions and altered host-vector-agent interaction. The significant temperature variations brought on by climate change and ever-increasing international travel has modified the host-agent interactions, and many re-emerging viral illnesses are now presenting with atypical presentations, including an increased frequency of affliction across broader age groups and heightened manifestations often posing as 'great imitators' mimicking a myriad of other dermatoses. Although final diagnosis often relies on serological and molecular tests, certain cutaneous clues can help arrive at a probable clinical diagnosis and help the clinicians order specific and relevant investigations, especially in resource-poor settings where access to laboratory diagnostic tests is likely to be limited. In this review we explore the changing disease dynamics of common viral infections, especially in resource-poor settings, including coronavirus disease 2019, chikungunya, hand-foot-and-mouth disease and some newly emerging ones like mpox (previously referred to as monkeypox), and highlight recent developments in our understanding of the clinical variations seen in their presentations.

Isothermal nucleic acid amplification for monitoring hand-foot-and-mouth disease: current status and future implications

With the global prevalence of the hand-foot-and-mouth disease (HFMD) epidemic, the development of reliable point-of-care testing (POCT) is crucial for the timely identification and prevention of outbreaks. Isothermal nucleic acid amplification techniques (INAATs) have attracted much attention because of their high efficiency for rapid diagnosis. In this work, we systematically summarize the current status of INAATs for HFMD and discuss advantages and drawbacks of various INAATs for HFMD. The INAATs for HFMD detection mainly include loop-mediated isothermal amplification (LAMP), simultaneous amplification and testing (SAT), and recombinase polymerase amplification (RPA). Among them, LAMP has excelled in several diagnostic metrics and has made significant progress in the field of POCT. SAT has been effective in overcoming the problem of RNA degradation. RPA is suited for on-site testing due to its rapid amplification rate and low reaction temperature. In addition, this study explores the potential of INAATs in lateral flow strips (LFS) test and microfluidic devices for HFMD. LFS is typically used for qualitative analysis and supports multiple detection. Microfluidics can integrate necessary processes of sample pre-processing, amplification, and signal output, enabling high-throughput qualitative or quantitative detection and demonstrating the potential of monitoring HFMD. We hope the current work will provide insights into INAATs for monitoring HFMD and serve as a reference for the implementation of on-site EV detection for public health.

Correlation analysis of serum inflammatory cytokine levels and immune markers in children with severe hand, foot and mouth disease

OBJECTIVE

To identify the correlation between serum inflammatory cytokines and immune markers in children with severe hand, foot and mouth disease (HFMD).

METHODS

Paediatric patients with severe or mild HFMD from Linping Campus, the Second Affiliated Hospital of Zhejiang University, were included in this retrospective study. Data comprising demographic characteristics, clinical symptoms and signs, laboratory findings and other factors were collected. Serum interleukin (IL)-1, IL-6, IL-10, tumour necrosis factor (TNF)-α, and interferon (IFN)-γ levels were measured by enzyme-linked immunosorbent assay at 1, 3, and 5 days after admission. Risk factors were screened using multivariate logistic regression analysis.

RESULTS

A total of 200 patients with HFMD (120 severe and 80 mild cases) were included. Younger age and longer fever duration were associated with severe HFMD, as were increased white blood cell, neutrophil and platelet counts, blood glucose, immunoglobulin (Ig)M and IgG. IL-6 and IL-10 levels were higher in patients with severe versus mild HFMD on days 1, 3 and 5. TNF-α was higher in the severe group on day 3. Increased white blood cell and neutrophil counts, IL-6, IL-10, and IgG levels, age, fever duration, and blood glucose level were found to be risk factors associated with the occurrence of severe HFMD.

CONCLUSIONS

Inflammatory cytokines and immune indexes may be related to the occurrence of severe HFMD.

Impact of non-pharmacological interventions on incidence of hand, foot and mouth disease during the COVID-19 pandemic: a large population-based observational study

BACKGROUND

Hand, foot, and mouth disease (HFMD) is a highly prevalent and contagious disease, particularly in children under five years old. Its transmission route resembles that of COVID-19. During the COVID-19 pandemic, non-pharmaceutical interventions (NPIs) were implemented to curb viral spread, which may have concurrently reduced HFMD incidence.

METHODS

Utilizing HFMD surveillance data from the Anhui Provincial Center for Disease Control and Prevention (2015-2020) and varying levels of COVID-19 emergency measures, a Bayesian structural time series model predicted the counterfactual HFMD incidence and quantified the causal relationships with NPIs.

RESULTS

During the implementation of NPIs, the 915 cases observed between weeks 4 and 20 of 2020 reflected a 94.9% reduction from the expected cases number (915 vs. 17,790), avoiding approximately 16,875 cases. The relative reduction of male cases (95.2%) was similar to that of female cases (94.3%). Different age groups the number of cases decline roughly similar were 93.1%, 95.3%, 97.8%, 94.9%.

CONCLUSION

During the COVID-19 pandemic, NPIs implemented in response to COVID-19 effectively reduced HFMD incidence. NPIs should be promoted for future control of enteric infectious diseases such as HFMD.

Highly Sensitive and Specific Diagnosis of Enterovirus A71 by Reverse Transcription Multiple Cross-Displacement Amplification-Labeled Nanoparticles Biosensor

Enterovirus A71 (EVA71) is a leading causative agent of hand, foot, and mouth disease, posing a significant threat to the health of young children, particularly in the Asia-Pacific region. Currently, there is no specific antiviral drug for EVA71 infection; therefore, early and rapid diagnosis is critical for disease prevention and control. Here, we report the development of a simple, rapid, and sensitive detection method for EVA71 infection using reverse transcription-multiple cross displacement amplification (RT-MCDA) combined with nanoparticle-based lateral flow biosensors (LFB). In the RT-MCDA system, a set of 10 primers was designed to target the highly conserved region of the VP1 gene of EVA71 and amplify the genes in an isothermal amplification device. The RT-MCDA amplification reaction products could then be identified by visual detection reagent (VDR) and LFB without the need for specialized equipment. The results demonstrated that the optimal reaction condition for the EVA71-RT-MCDA assay was 65℃ for 40 min. The EVA71-RT-MCDA assay could detect as low as 40 copies of plasmid and 50 copies of pseudotyped virus in a reaction. No cross-reaction was found between EVA71 strains and non-EVA71 strains. For 125 clinical anal swab samples, with EVA71-RT-MCDA assay, 30 samples were positive, which was in consistent with the the conventional real-time quantitative reverse transcription polymerase chain reaction assays. The entire procedure, including a 15-min specimen processing step, a 40-min MCDA reaction, and result reporting within 2 min, was completed in less than 60 min. In conclusion, the EVA71-RT-MCDA-LFB assay targeting the VP1 gene is a rapid, highly sensitive, simple, and specific test that could be widely applied in point-of-care settings and basic medical facilities in rural areas.

Enterovirus A71 and coxsackievirus A6 circulation in England, UK, 2006-2017: A mathematical modelling study using cross-sectional seroprevalence data

Enterovirus A71 (EV-A71) and coxsackievirus A6 (CVA6) primarily cause hand, foot and mouth disease and have emerged to cause potential fatal neurological and systemic manifestations. However, limited surveillance data collected through passive surveillance systems hampers characterization of their epidemiological dynamics. We fit a series of catalytic models to age-stratified seroprevalence data for EV-A71 and CVA6 collected in England at three time points (2006, 2011 and 2017) to estimate the force of infection (FOI) over time and assess possible changes in transmission. For both serotypes, model comparison does not support the occurrence of important changes in transmission over the study period, and we find that a declining risk of infection with age and / or seroreversion are needed to explain the seroprevalence data. Furthermore, we provide evidence that the increased number of reports of CVA6 during 2006-2017 is unlikely to be explained by changes in surveillance. Therefore, we hypothesize that the increased number of CVA6 cases observed since 2011 must be explained by increased virus pathogenicity. Further studies of seroprevalence data from other countries would allow to confirm this. Our results underscore the value of seroprevalence data to unravel changes in the circulation dynamics of pathogens with weak surveillance systems and large number of asymptomatic infections.

Increasing intensity of enterovirus outbreaks projected with climate change

Pathogens of the enterovirus genus, including poliovirus and coxsackieviruses, typically circulate in the summer months suggesting a possible positive association between warmer weather and transmission. Here we evaluate the environmental and demographic drivers of enterovirus transmission, as well as the implications of climate change for future enterovirus circulation. We leverage pre-vaccination era data on polio in the US as well as data on two enterovirus A serotypes in China and Japan that are known to cause hand, foot, and mouth disease. Using mechanistic modeling and statistical approaches, we find that enterovirus transmission appears positively correlated with temperature although demographic factors, particularly the timing of school semesters, remain important. We use temperature projections from Coupled Model Intercomparison Project Phase 6 (CMIP6) to simulate future outbreaks under late 21st-century climate change for Chinese provinces. We find that outbreak size increases with climate change on average, though results differ across climate models depending on the degree of wintertime warming. In the worst-case scenario, we project peak outbreaks in some locations could increase by up to 40%.

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.

Epidemiology and etiology of hand, foot, and mouth disease in Zhengzhou, China, from 2009 to 2021

BACKGROUND

Hand, foot, and mouth disease (HFMD) is a common childhood infectious disease caused by a variety of enteroviruses (EVs). To explore the epidemiological characteristics and etiology of HFMD in Zhengzhou, China, we conducted a systematic analysis of HFMD surveillance data from Zhengzhou Center for Disease Control and Prevention from January 2009 to December 2021 (https://wjw.zhengzhou.gov.cn/).

METHODS

Surveillance data were collected from Zhengzhou Center for Disease Control and Prevention from January 2009 to December 2021 (https://wjw.zhengzhou.gov.cn/). Cases were analyzed according to the time of onset, type of diagnosis, characteristics, viral serotype, and epidemiological trends.

RESULTS

We found that the primary causative agent responsible for the HFMD outbreaks in Zhengzhou was Enterovirus A71 (EVA-71) (48.56%) before 2014. After 2015, other EVs gradually became the dominant strains (57.68%). The data revealed that the HFMD epidemics in Zhengzhou displayed marked seasonality, with major peaks occurring from April to June, followed by secondary peaks from October to November, except in 2020. Both the severity and case-fatality ratio of HFMD decreased following the COVID-19 pandemic (severity ‰: 13.46 vs. 0.17; case-fatality ‰: 0.21 vs. 0, respectively). Most severe cases were observed in patients aged 1 year and below, accounting for 45.81%.

CONCLUSIONS

Overall, the incidence rate of HFMD decreased in Zhengzhou following the introduction of the EVA-71 vaccine in 2016. However, it is crucial to acknowledge that HFMD prevalence continues to exhibit a distinct seasonal pattern and periodicity, and the occurrence of other EV infections poses a new challenge for children's health.

The Milk of Cows Immunized with Trivalent Inactivated Vaccines Provides Broad-Spectrum Passive Protection against Hand, Foot, and Mouth Disease in Neonatal Mice

Hand, foot, and mouth disease (HFMD) is a contagious viral infection predominantly affecting infants and young children, caused by multiple enteroviruses, including Enterovirus 71 (EV71), Coxsackievirus A16 (CA16), Coxsackievirus A10 (CA10), and Coxsackievirus A6 (CA6). The high pathogenicity of HFMD has garnered significant attention. Currently, there is no specific treatment or broad-spectrum preventive measure available for HFMD, and existing monovalent vaccines have limited impact on the overall incidence or prevalence of the disease. Consequently, with the emergence of new viral strains driven by vaccine pressure, there is an urgent need to develop strategies for the rapid response and control of new outbreaks. In this study, we demonstrated the broad protective effect of maternal antibodies against three types of HFMD by immunizing mother mice with a trivalent inactivated vaccine targeting EV71, CA16, and CA10, using a neonatal mouse challenge model. Based on the feasibility of maternal antibodies as a form of passive immunization to prevent HFMD, we prepared a multivalent antiviral milk by immunizing dairy cows with the trivalent inactivated vaccine to target multiple HFMD viruses. In the neonatal mouse challenge model, this immunized milk exhibited extensive passive protection against oral infections caused by the three HFMD viruses. Compared to vaccines, this strategy may offer a rapid and broadly applicable approach to providing passive immunity for the prevention of HFMD, particularly in response to the swift emergence and spread of new variants.

EV71 5'UTR interacts with 3D protein affecting replication through the AKT-mTOR pathway

BACKGROUND

EV71 is one of the important pathogens of Hand-foot-and-mouth disease (HFMD), which causes serious neurological symptoms. Several studies have speculated that there will be interaction between 5'UTR and 3D protein. However, whether 5'UTR interacts with the 3D protein in regulating virus replication has not been clarified.

METHODS

Four 5'UTR mutation sites (nt88C/T, nt90-102-3C, nt157G/A and nt574T/A) and two 3D protein mutation sites (S37N and R142K) were mutated or co-mutated using virulent strains as templates. The replication of these mutant viruses and their effect on autophagy were determined.

RESULTS

5'UTR single-point mutant strains, except for EGFP-EV71(nt90-102-3C), triggered replication attenuation. The replication ability of them was weaker than that of the parent strain the virulent strain SDLY107 which is the fatal strain that can cause severe neurological complications. While the replication level of the co-mutant strains showed different characteristics. 5 co-mutant strains with interaction were screened: EGFP-EV71(S37N-nt88C/T), EGFP-EV71(S37N-nt574T/A), EGFP-EV71(R142K-nt574T/A), EGFP-EV71(R142K-nt88C/T), and EGFP-EV71(R142K-nt157G/A). The results showed that the high replicative strains significantly promoted the accumulation of autophagosomes in host cells and hindered the degradation of autolysosomes. The low replicative strains had a low ability to regulate the autophagy of host cells. In addition, the high replicative strains also significantly inhibited the phosphorylation of AKT and mTOR.

CONCLUSIONS

EV71 5'UTR interacted with the 3D protein during virus replication. The co-mutation of S37N and nt88C/T, S37N and nt574T/ A, R142K and nt574T/A induced incomplete autophagy of host cells and promoted virus replication by inhibiting the autophagy pathway AKT-mTOR. The co-mutation of R142K and nt88C/T, and R142K and nt157G/A significantly reduced the inhibitory effect of EV71 on the AKT-mTOR pathway and reduced the replication ability of the virus.

Long-term variations of urban-Rural disparities in infectious disease burden of over 8.44 million children, adolescents, and youth in China from 2013 to 2021: An observational study

BACKGROUND

An accelerated epidemiological transition, spurred by economic development and urbanization, has led to a rapid transformation of the disease spectrum. However, this transition has resulted in a divergent change in the burden of infectious diseases between urban and rural areas. The objective of our study was to evaluate the long-term urban-rural disparities in infectious diseases among children, adolescents, and youths in China, while also examining the specific diseases driving these disparities.

METHODS AND FINDINGS

This observational study examined data on 43 notifiable infectious diseases from 8,442,956 cases from individuals aged 4 to 24 years, with 4,487,043 cases in urban areas and 3,955,913 in rural areas. The data from 2013 to 2021 were obtained from China's Notifiable Infectious Disease Surveillance System. The 43 infectious diseases were categorized into 7 categories: vaccine-preventable, bacterial, gastrointestinal and enterovirus, sexually transmitted and bloodborne, vectorborne, zoonotic, and quarantinable diseases. The calculation of infectious disease incidence was stratified by urban and rural areas. We used the index of incidence rate ratio (IRR), calculated by dividing the urban incidence rate by the rural incidence rate for each disease category, to assess the urban-rural disparity. During the nine-year study period, most notifiable infectious diseases in both urban and rural areas exhibited either a decreased or stable pattern. However, a significant and progressively widening urban-rural disparity in notifiable infectious diseases was observed. Children, adolescents, and youths in urban areas experienced a higher average yearly incidence compared to their rural counterparts, with rates of 439 per 100,000 compared to 211 per 100,000, respectively (IRR: 2.078, 95% CI [2.075, 2.081]; p < 0.001). From 2013 to 2021, this disparity was primarily driven by higher incidences of pertussis (IRR: 1.782, 95% CI [1.705, 1.862]; p < 0.001) and seasonal influenza (IRR: 3.213, 95% CI [3.205, 3.220]; p < 0.001) among vaccine-preventable diseases, tuberculosis (IRR: 1.011, 95% CI [1.006, 1.015]; p < 0.001), and scarlet fever (IRR: 2.942, 95% CI [2.918, 2.966]; p < 0.001) among bacterial diseases, infectious diarrhea (IRR: 1.932, 95% CI [1.924, 1.939]; p < 0.001), and hand, foot, and mouth disease (IRR: 2.501, 95% CI [2.491, 2.510]; p < 0.001) among gastrointestinal and enterovirus diseases, dengue (IRR: 11.952, 95% CI [11.313, 12.628]; p < 0.001) among vectorborne diseases, and 4 sexually transmitted and bloodborne diseases (syphilis: IRR 1.743, 95% CI [1.731, 1.755], p < 0.001; gonorrhea: IRR 2.658, 95% CI [2.635, 2.682], p < 0.001; HIV/AIDS: IRR 2.269, 95% CI [2.239, 2.299], p < 0.001; hepatitis C: IRR 1.540, 95% CI [1.506, 1.575], p < 0.001), but was partially offset by lower incidences of most zoonotic and quarantinable diseases in urban areas (for example, brucellosis among zoonotic: IRR 0.516, 95% CI [0.498, 0.534], p < 0.001; hemorrhagic fever among quarantinable: IRR 0.930, 95% CI [0.881, 0.981], p = 0.008). Additionally, the overall urban-rural disparity was particularly pronounced in the middle (IRR: 1.704, 95% CI [1.699, 1.708]; p < 0.001) and northeastern regions (IRR: 1.713, 95% CI [1.700, 1.726]; p < 0.001) of China. A primary limitation of our study is that the incidence was calculated based on annual average population data without accounting for population mobility.

CONCLUSIONS

A significant urban-rural disparity in notifiable infectious diseases among children, adolescents, and youths was evident from our study. The burden in urban areas exceeded that in rural areas by more than 2-fold, and this gap appears to be widening, particularly influenced by tuberculosis, scarlet fever, infectious diarrhea, and typhus. These findings underscore the urgent need for interventions to mitigate infectious diseases and address the growing urban-rural disparity.

Temporal dynamic effects of meteorological factors and air quality on the physical health of the older adults in Shenzhen, China

Introduction

Meteorological and environmental factors can affect people's lives and health, which is crucial among the older adults. However, it is currently unclear how they specifically affect the physical condition of older adults people.

Methods

We collected and analyzed the basic physical examination indicators of 41 older adults people for two consecutive years (2021 and 2022), and correlated them with meteorological and environmental factors. Partial correlation was also conducted to exclude unrelated factors as well.

Results

We found that among the physical examination indicators of the older adults for two consecutive years, five indicators (HB, WBC, HbAlc, CB, LDL-C) showed significant differences across the population, and they had significantly different dynamic correlation patterns with six meteorological (air pressure, temperature, humidity, precipitation, wind speed, and sunshine duration) and seven air quality factors (NO2, SO2, PM10, O3-1h, O3-8h, CO, PM2.5).

Discussion

Our study has discovered for the first time the dynamic correlation between indicators in normal basic physical examinations and meteorological factors and air quality indicators, which will provide guidance for the future development of policies that care for the healthy life of the older adults.

Age-time-specific transmission of hand-foot-and-mouth disease enterovirus serotypes in Vietnam: A catalytic model with maternal immunity

Hand, foot and mouth disease (HFMD) is highly prevalent in the Asia Pacific region, particularly in Vietnam. To develop effective interventions and efficient vaccination programs, we inferred the age-time-specific transmission patterns of HFMD serotypes enterovirus A71 (EV-A71), coxsackievirus A6 (CV-A6), coxsackievirus A10 (CV-A10), coxsackievirus A16 (CV-A16) in Ho Chi Minh City, Vietnam from a case data collected during 2013-2018 and a serological survey data collected in 2015 and 2017. We proposed a catalytic model framework with good adaptability to incorporate maternal immunity using various mathematical functions. Our results indicate the high-level transmission of CV-A6 and CV-A10 which is not obvious in the case data, due to the variation of disease severity across serotypes. Our results provide statistical evidence supporting the strong association between severe illness and CV-A6 and EV-A71 infections. The HFMD dynamic pattern presents a cyclical pattern with large outbreaks followed by a decline in subsequent years. Additionally, we identify the age group with highest risk of infection as 1-2 years and emphasise the risk of future outbreaks as over 50% of children aged 6-7 years were estimated to be susceptible to CV-A16 and EV-A71. Our study highlights the importance of multivalent vaccines and active surveillance for different serotypes, supports early vaccination prior to 1 year old, and points out the potential utility for vaccinating children older than 5 years old in Vietnam.

Emerging concerns of blood-brain barrier dysfunction caused by neurotropic enteroviral infections

Enteroviruses (EVs), comprise a genus in the Picornaviridae family, which have been shown to be neurotropic and can cause various neurological disorders or long-term neurological condition, placing a huge burden on society and families. The blood-brain barrier (BBB) is a protective barrier that prevents dangerous substances from entering the central nervous system (CNS). Recently, numerous EVs have been demonstrated to have the ability to disrupt BBB, and further lead to severe neurological damage. However, the precise mechanisms of BBB disruption associated with these EVs remain largely unknown. In this Review, we focus on the molecular mechanisms of BBB dysfunction caused by EVs, emphasizing the invasiveness of enterovirus A71 (EVA71), which will provide a research direction for further treatment and prevention of CNS disorders.

Recurrent Hand, Foot, and Mouth Disease in a Saudi Girl

Hand, foot, and mouth disease (HFMD) is a viral illness that predominantly affects infants and children, causing blisters and sores on the hands, feet, and mouth. Recurrence is rare, but a case in a six-year-old girl in Saudi Arabia was reported. A six-year-old girl presented with a rash on her palms and soles, which was preceded by a mild sore throat and low-grade fever. She had been in contact with her two-year-old sister, who had similar symptoms but a different rash pattern.  During clinical examination, multiple erythematous deep-seated vesicles and papules were noted on the patient's palms and soles, with no involvement of mucous membranes or nails. The diagnosis of hand, foot, and mouth disease (HFMD) was made based on the characteristic clinical presentation, and the rash resolved within seven days without treatment or complications.  The patient had experienced a similar presentation six months ago, which was also diagnosed as HFMD, and the rash had resolved spontaneously within one week. In her second episode, the rash was less severe, with milder prodromal symptoms. In both episodes, the lesions were asymptomatic and had no mucosal involvement. The patient had experienced onychomadesis after her first episode, but no nail abnormalities were seen after her second episode. Although HFMD is rare to recur in children, outbreaks can lead to another episode. HFMD prevalence is underestimated in Saudi Arabia due to missed mild cases. Pediatricians and dermatologists should be aware of HFMD incidence and its complications, as early detection is vital in preventing outbreaks and transmission.

Preclinical safety evaluation of a bivalent inactivated EV71-CA16 vaccine in mice immunized intradermally

Hand, foot and mouth disease is a common acute viral infectious disease that poses a serious threat to the life and health of young children. With the development of an effective inactivated EV71 vaccine, CA16 has become the main pathogen causing HFMD. Effective and safe vaccines against this disease are urgently needed. In our previous study, a bivalent inactivated vaccine was shown to have good immunogenicity and to induce neutralizing antibodies in mice and monkeys. Repeated administration toxicity is a critical safety test in the preclinical evaluation of vaccines. In this study, BALB/c mice were used to evaluate the toxicity of the bivalent vaccine after multiple intradermal administrations. Clinical observation was performed daily, and body weight, food intake, hematological characteristics, serum biochemical parameters, antinuclear antibodies, CD4+/CD8a+ T-cell proportions, bone marrow smear results and pathology results were recorded. The results showed that there was no significant change at the injection site and no adverse reactions related to the vaccine. The bivalent inactivated EV71-CA16 vaccine exhibits good safety in mice, and these results provide a sufficient basis for further clinical trials.

A mouse model and pathogenesis study for CVA19 first isolated from hand, foot, and mouth disease

ABSTRACTCoxsackievirus A19 (CVA19) is a member of Enterovirus (EV) C group in the Picornaviridae family. Recently, we reported a case of CVA19-infected hand, foot, and mouth disease (HFMD) for the first time. However, the current body of knowledge on the CVA19 infection, particularly the pathogenesis of encephalomyelitis and diarrhoea is still very limited, due to the lack of suitable animal models. Here, we successfully established a CVA19 mouse model via oral route based on 7-day-old ICR mice. Our results found the virus strain could directly infect the neurons, astrocytes of brain, and motor neurons of spinal cord causing neurological complications, such as acute flaccid paralysis. Importantly, viruses isolated from the spinal cords of infected mice caused severe illness in suckling mice, fulfilling Koch's postulates to some extent. CVA19 infection led to diarrhoea with typical pathological features of shortened intestinal villi, increased number of secretory cells and apoptotic intestinal cells, and inflammatory cell infiltration. Much higher concentrations of serum cytokines and more peripheral blood inflammatory cells in CVA19-infected mice indicated a systematic inflammatory response induced by CVA19 infection. Finally, we found ribavirin and CVA19 VP1 monoclonal antibody could not prevent the disease progression, but higher concentrations of antisera and interferon alpha 2 (IFN-α2) could provide protective effects against CVA19. In conclusion, this study shows that a natural mouse-adapted CVA19 strain leads to diarrhoea and encephalomyelitis in a mouse model via oral infection, which provides a useful tool for studying CVA19 pathogenesis and evaluating the efficacy of vaccines and antivirals.

Emerging concerns of atypical hand foot and mouth disease caused by recombinant Coxsackievirus A6 variants in Henan, China

An increasing number of studies have reported that atypical hand, foot, and mouth disease (HFMD) is becoming a new concern for children's health. At present, there is no official definition for atypical HFMD, but some studies have defined that it occurs at anatomic sites not listed in the definition of HFMD issued by the World Health Organization. Several pathogens have been reported to cause atypical HFMD, such as Coxsackievirus (CV)A6. As one of the most prevalent enteroviruses in the world, CVA6 seems to affect a wider range of children and causes more severe and prolonged illness than other enteroviruses. The early lesions of atypical HFMD are very similar to the clinical presentations of other diseases, such as eczema, which poses a challenge for clinicians aiming to identify and diagnose HFMD in a timely manner. Here, we report on six atypical HFMD patients caused by recombinant CVA6 variants, and the atypical manifestations include eczema coxsackium, large herpes, rice-like red papules and herpes, purpuric rash, and onychomadesis, as well as and large red herpes on scalp, perianal, testicles, shoulders and neck, and other atypical eruption sites, hoping to draw the attention of other pediatricians. This study will provide scientific guidance for timely diagnosis of HFMD to prevent serious complications.

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.

Conclusions

This study suggested a potential causal effect of the EV71 vaccination, highlighting the importance of achieving higher vaccine coverage to control the HFMD.

Monitoring hand foot and mouth disease using long-term wastewater surveillance in Japan: Quantitative PCR assay development and application

Hand, foot, and mouth disease (HFMD) is a highly contagious disease that primarily affects children under five years of age. It is mainly caused by serotypes of Enterovirus A (EVA): EVA71, Coxsackievirus A types 6 (CVA6), 10 (CVA10), and 16 (CVA16). Despite being highly prevalent in Japan and other countries in the Asia-Pacific region, few studies have investigated HFMD pathogens in wastewater. The present study aimed to develop a highly sensitive and broadly reactive quantitative polymerase chain reaction (qPCR) assay of dominant serotype CVA6, to revise previously developed CVA6, CVA10, and CVA16 assays, and to test these assays in wastewater samples from Yamanashi Prefecture, Japan. The new-CVA6 qPCR assay was developed with maximal nucleotide percent identity among CVA6 isolates from Japan. The new-CVA6 and revised assays were highly sensitive and had the ability to quantify respective positive controls at levels as low as 1 copy/μL. Among the 53 grab influent samples collected between March 2022 and March 2023, EVA71, CVA10, and CVA16 RNA were not detected in any samples, whereas the new-CVA6 assay could detect CVA6 RNA in 38 % (20/53) of samples. CVA6 RNA was detected at a significantly higher concentration in the summer season (3.3 ± 0.8 log10 copies/L; 79 % (11/14)) than in autumn (2.7 ± 0.6 log10 copies/L; 69 % (9/13)). The seasonal trend of CVA6 RNA detection in wastewater aligned with the trend of HFMD case reports in the catchment of the wastewater treatment plant. This is the first study to report the detection and seasonal trends of the EVA serotypes associated with HFMD in wastewater samples in Japan. It provides evidence that wastewater-based epidemiology is applicable even for diseases that are prevalent only in specific population groups.

Non-linear association between daily mean temperature and children's hand foot and mouth disease in Chongqing, China

Chongqing was seriously affected by hand, foot, and mouth disease (HFMD), but the relationships between daily mean temperature and the incidence of HFMD remain unclear. This study used distributed lag nonlinear model to evaluate the effect of daily mean temperature on the incidence of HFMD in children aged < 5 years in Chongqing. Daily HFMD data from 2012 to 2019 in Chongqing were retrieved from the notifiable infectious disease surveillance system. A total of 413,476 HFMD cases aged < 5 years were reported in Chongqing from 2012 to 2019. The exposure-response curve of daily mean temperature and daily HFMD cases was wavy-shaped. The relative risks (RRs) increased as daily mean temperature below 5.66 °C or above 9.43 °C, with two peaks at 16.10 °C and 26.68 °C. The RRs reached the highest when the daily mean temperature at 26.68 °C on the current day (RR = 1.20, 95% CI 1.09-1.32), followed by the daily mean temperature at 16.10 °C at lag 5 days (RR = 1.07, 95% CI 1.05-1.08). The RRs for girls and daycare children were much higher than those for boys and scattered children, respectively. Taken together, daily mean temperature has strong effect on HFMD in children aged < 5 years old in Chongqing, particularly for girls and daycare children.

CUR-N399, a PI4KB inhibitor, for the treatment of Enterovirus A71 infection

Over the years, the hand, foot and mouth disease (HFMD) has sparked epidemics across many countries which mainly affected young children. While symptoms are usually mild, severe complications may arise, and some even lead to death. Such concerns, coupled with the lack of approved vaccines and antivirals to date, create an urgency in the identification of safe therapeutics against HFMD. The disease is mainly transmitted by enteroviruses like enterovirus A71 (EV-A71). Essential for enterovirus replication is the host protein, PI4KB. In this study, we investigate the antiviral efficacy of a novel PI4KB inhibitor, CUR-N399. We found that CUR-N399 displayed broad-spectrum antiviral activity against picornaviruses in cell culture models. Using a suckling mouse model of lethal EV-A71 infection, CUR-N399 was found to be well-tolerated, promote survival and reduce viral titre in mice organs. Together, these support the discovery of CUR-N399 as an antiviral against EV-A71 and potentially other closely related viruses.

Disparity in spectrum of infectious diseases between in-school and out-of-school children, adolescents, and youths in China: findings from a successive national surveillance from 2013 to 2021

Background

An accelerated epidemiological transition, economic development and urbanization have brought rapid reductions but a potential disparity in infectious diseases burdens in-school and out-of-school children, adolescents, and youths in China. This paper assesses the disparity in spectrum of infectious diseases between two groups, and described disparity's variation by age, year and province, and determined the priority diseases.

Methods

A total of 7,912,274 new incident cases (6,159,021 in school and 1,753,253 out of school) aged 6-21 years across 43 notifiable infectious diseases have been collected based on China's Notifiable Infectious Disease Surveillance System from 2013 to 2021. All infectious diseases are categorized into seven categories: vaccine preventable, bacteria, gastrointestinal and enterovirus, sexually transmitted and bloodborne, vectorborne, zoonotic, and quarantinable diseases. We used the index of incidence rate ratio (IRR) of by specific disease, category, year, and age to assess the disparity between those out-of-school and in-school, and determine their separate priority diseases.

Findings

From 2013 to 2021, a small disparity of notifiable infectious diseases existed with higher average yearly incidence for out-of-school children, adolescents, and youth than that in-school (327.601 v.s. 319.677 per 100,000, IRR = 1.025, 95%CI: 1.023-1.027, standardized IRR = 1.169, 95%CI: 1.155-1.183), and it gradually narrowed by surveillance years with IRR from 1.351 in 2013 to 1.015 in 2021 due to large decreased disparity in compulsory education stage group. Such disparity was mainly driven by sexually transmitted and bloodborne diseases, bacteria diseases, vectorborne diseases, quarantinable diseases and zoonotic diseases. However, vaccine preventable diseases, gastrointestinal and enterovirus diseases showed higher incidence of infectious diseases for those in-school than that out-of-school, particularly for seasonal influenza, mumps and hand-foot-and-mouth disease. Meanwhile, such disparity is obvious in most of ages and in eastern and coastal regions of China, and the narrowing trend is attributed to six categories diseases, except for sexually transmitted and bloodborne diseases with gradually widened disparity between two groups with surveillance years with IRR from 22.939 in 2013 to 23.291 in 2021 due to large disparity for those who have completed compulsory education.

Interpretation

A huge achievement has been achieved in reducing the burden and disparity of infectious diseases between out-of-school and in-school children, adolescents, and youths in China, particularly for the compulsory education stage population. The priorities for the coming decades will be to extend successful strategies to a broad scope and promote education, particularly for the investment of social health resources and the improvement of personal health literacy in the non-compulsory education stage. This should involve extending the years of compulsory school, improving sex health education, strengthening monitoring, expanding immunization programs coverage and prioritizing the prevention and control of sexually transmitted diseases and tuberculosis among out-of-school population.

Funding

National Natural Science Foundation of China and Beijing Natural Science Foundation.

Digital epidemiology and infodemiology of hand-foot-mouth disease (HFMD) in Italy. Disease trend assessment via Google and Wikipedia

BACKGROUND AND AIM

The study aimed to evaluate the epidemiological trend of hand, foot and mouth disease (HFMD) in Italy using data on Internet search volume.

METHODS

A cross-sectional study design was used. Data on Internet searches were obtained from Google Trends (GT) and Wikipedia. We used the following Italian search term: "Malattia mano-piede-bocca" (Hand-foot-mouth disease, in English). A monthly time-frame was extracted, partly overlapping, from July 2015 to December 2022. GT and Wikipedia were overlapped to perform a linear regression and correlation analyses. Statistical analyses were performed using the Spearman's rank correlation coefficient (rho). A linear regression analysis was performed considering Wikipedia and GT.

RESULTS

Search peaks for both Wikipedia and GT occurred in the months November-December during the autumn-winter season and in June during the spring-summer season, except for the period from June 2020 to June 2021, probably due to the restrictions of the COVID19 pandemic. A temporal correlation was observed between GT and Wikipedia search trends.

CONCLUSIONS

This is the first study in Italy that attempts to clarify the epidemiology of HFMD. Google search and Wikipedia can be valuable for public health surveillance; however, to date, digital epidemiology cannot replace the traditional surveillance system.

Tandem mass tag (TMT) labeling-based quantitative proteomic analysis reveals the cellular protein characteristics of 16HBE cells infected with coxsackievirus A10 and the potential effect of HMGB1 on viral replication

Coxsackievirus A10 (CV-A10) is recognized as one of the most important pathogens associated with hand, foot, and mouth disease (HFMD) in young children under 5 years of age worldwide, and it can lead to fatal neurological complications. However, available commercial vaccines fail to protect against CV-A10. Therefore, there is an urgent need to study new protein targets of CV-A10 and develop novel vaccine-based therapeutic strategies. Advances in proteomics in recent years have enabled a comprehensive understanding of host pathogen interactions. Here, to study CV-A10-host interactions, a global quantitative proteomic analysis was conducted to investigate the molecular characteristics of host cell proteins and identify key host proteins involved in CV-A10 infection. Using tandem mass tagging (TMT)-based mass spectrometry, a total of 6615 host proteins were quantified, with 293 proteins being differentially regulated. To ensure the validity and reliability of the proteomics data, three randomly selected proteins were verified by Western blot analysis, and the results were consistent with the TMT results. Further functional analysis showed that the upregulated and downregulated proteins were associated with diverse biological activities and signaling pathways, such as metabolic processes, biosynthetic processes, the AMPK signaling pathway, the neurotrophin signaling pathway, the MAPK signaling pathway, and the GABAergic synaptic signaling. Moreover, subsequent bioinformatics analysis demonstrated that these differentially expressed proteins contained distinct domains, were localized in different subcellular components, and generated a complex network. Finally, high-mobility group box 1 (HMGB1) might be a key host factor involved in CV-A10 replication. In summary, our findings provide comprehensive insights into the proteomic profile during CV-A10 infection, deepen our understanding of the relationship between CV-A10 and host cells, and establish a proteomic signature for this viral infection. Moreover, the observed effect of HMGB1 on CV-A10 replication suggests that it might be a potential therapeutic target treatment of CV-A10 infection.

Investigating the mechanism of Echovirus 30 cell invasion

Viruses invade susceptible cells through a complex mechanism before injecting their genetic material into them. This causes direct damage to the host cell, as well as resulting in disease in the corresponding system. Echovirus type 30 (E30) is a member of the Enterovirus B group and has recently been reported to cause central nervous system (CNS) disorders, leading to viral encephalitis and viral meningitis in children. In this review, we aim to help in improving the understanding of the mechanisms of CNS diseases caused by E30 for the subsequent development of relevant drugs and vaccines.

Diversity of Human Enterovirus Co-Circulations in Five Kindergartens in Bangkok between July 2019 and January 2020

Human enterovirus causes various clinical manifestations in the form of rashes, febrile illness, flu-like illness, uveitis, hand-foot-mouth disease (HFMD), herpangina, meningitis, and encephalitis. Enterovirus A71 and coxsackievirus are significant causes of epidemic HFMD worldwide, especially in children aged from birth to five years old. The enterovirus genotype variants causing HFMD epidemics have been reported increasingly worldwide in the last decade. We aim to use simple and robust molecular tools to investigate human enteroviruses circulating among kindergarten students at genotype and subgenotype levels. With the partial 5'-UTR sequencing analysis as a low-resolution preliminary grouping tool, ten enterovirus A71 (EV-A71) and coxsackievirus clusters were identified among 18 symptomatic cases and 14 asymptomatic cases in five kindergartens in Bangkok, Thailand, between July 2019 and January 2020. Two occurrences of a single clone causing an infection cluster were identified (EV-A71 C1-like subgenotype and coxsackievirus A6). Random amplification-based sequencing using MinION (Oxford Nanopore Technology) helped identify viral transmission between two closely related clones. Diverse genotypes co-circulating among children in kindergartens are reservoirs for new genotype variants emerging, which might be more virulent or better at immune escape. Surveillance of highly contagious enterovirus in communities is essential for disease notifications and controls.

Integrated analysis reveals important differences in the gut and oropharyngeal microbiota between children with mild and severe hand, foot and mouth disease

Little is known about alternation and difference in gut microbiota between patients with mild and severe hand, foot and mouth disease (HFMD). We investigated the differences in gut and oropharynx microbiotas between mild and severe HFMD in young children and changes in bacterial profiles as the disease progresses from acute to convalescent phase. Forty-two patients with confirmed HFMD were studied, among which thirty-two had severe HFMD and ten had mild HFMD. First rectal swabs were collected from all patients at an average of 2 days (acute phase) after the onset of symptoms, and second rectal swabs were collected from 8 severe patients at day 9 (convalescent phase) after the onset. Oropharyngeal swabs were obtained from 10 patients in the acute phase and 6 in the convalescent phase. 16S rRNA sequencing was performed for all 70 samples. Compared with mild HFMD, severe HFMD exhibited significantly decreased diversity and richness of gut microbiota. Gut microbiota bacterial profiles observed in the acute and convalescent phases resembled each other, but differed from those in mild cases. Additionally, 50% of patients with severe HFMD in the acute phase harbored a dominant pathobiontic bacterial genus. However, none of patients with mild HFMD had such bacteria. Similar bacterial compositions in oropharynx microbiota were detected between mild and severe cases. Our findings indicate that severe HFMD exhibits significantly impaired diversity of gut microbiota and frequent gut and oropharyngeal inflammation-inducing bacteria. However, the results should be interpreted with caution as the number of the subjects was limited.

Associations between ambient air pollutants and childhood hand, foot, and mouth disease in Sichuan, China: a spatiotemporal study

Hand, foot, and mouth disease (HFMD) is a major public health concern in the Asia-Pacific region. Previous studies have implied that ambient air pollution may affect the incidence of HFMD, but the results among different regions are inconsistent. We aimed to deepen the understanding of the associations between air pollutants and HFMD by conducting a multicity study. Daily data on childhood HFMD counts and meteorological and ambient air pollution (PM_2.5, PM₁₀, NO₂, CO, O₃, and SO₂) concentrations in 21 cities in Sichuan Province from 2015 to 2017 were collected. A spatiotemporal Bayesian hierarchical model framework was established, and then a distributed lag nonlinear models (DLNMs) was constructed to reveal exposure-lag-response relationships between air pollutants and HFMD while controlling for spatiotemporal effects. Furthermore, given the differences in the levels and seasonal trends of air pollutants between the basin region and plateau region, we explored whether these associations varied between different areas (basin and plateau). The associations between air pollutants and HFMD were nonlinear, with different lag responses. Low NO₂ concentrations and both low and high PM_2.5 and PM₁₀ concentrations were associated with a decreased risk of HFMD. No significant associations between CO, O₃, and SO₂ and HFMD were found. The associations between air pollutant concentrations and HFMD were different between the basin and plateau regions. Our study revealed associations between PM_2.5, PM₁₀, and NO₂ concentrations and HFMD, deepening the understanding of the relationships between air pollutants and HFMD. These findings provide evidence to support the formulation of relevant prevention measures and the establishment of an early warning system.

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.

Current status of hand-foot-and-mouth disease

Hand-foot-and-mouth disease (HFMD) is a viral illness commonly seen in young children under 5 years of age, characterized by typical manifestations such as oral herpes and rashes on the hands and feet. These symptoms typically resolve spontaneously within a few days without complications. Over the past two decades, our understanding of HFMD has greatly improved and it has received significant attention. A variety of research studies, including epidemiological, animal, and in vitro studies, suggest that the disease may be associated with potentially fatal neurological complications. These findings reveal clinical, epidemiological, pathological, and etiological characteristics that are quite different from initial understandings of the illness. It is important to note that HFMD has been linked to severe cardiopulmonary complications, as well as severe neurological sequelae that can be observed during follow-up. At present, there is no specific pharmaceutical intervention for HFMD. An inactivated Enterovirus A71 (EV-A71) vaccine that has been approved by the China Food and Drug Administration (CFDA) has been shown to provide a high level of protection against EV-A71-related HFMD. However, the simultaneous circulation of multiple pathogens and the evolution of the molecular epidemiology of infectious agents make interventions based solely on a single agent comparatively inadequate. Enteroviruses are highly contagious and have a predilection for the nervous system, particularly in child populations, which contributes to the ongoing outbreak. Given the substantial impact of HFMD around the world, this Review synthesizes the current knowledge of the virology, epidemiology, pathogenesis, therapy, sequelae, and vaccine development of HFMD to improve clinical practices and public health efforts.

Changing spatiotemporal patterns for hepatitis of unspecified aetiology in China, 2004-2021: a population-based surveillance study

Objectives

As global efforts continue toward the target of eliminating viral hepatitis by 2030, the emergence of acute hepatitis of unspecified aetiology (HUA) remains a concern. This study assesses the overall trends and changes in spatiotemporal patterns in HUA in China from 2004 to 2021.

Methods

We extracted the incidence and mortality rates of HUA from the Public Health Data Center, the official website of the National Health Commission of the People's Republic of China, and the National Notifiable Infectious Disease Surveillance System from 2004 to 2021. We used R software, ArcGIS, Moran's statistical analysis, and joinpoint regression to examine the spatiotemporal patterns and annual percentage change in incidence and mortality of the HUA across China.

Results

From 2004 to 2021, a total of 707,559 cases of HUA have been diagnosed, including 636 deaths. The proportion of HUA in viral hepatitis gradually decreased from 7.55% in 2004 to 0.72% in 2021. The annual incidence of HUA decreased sharply from 6.6957 per 100,000 population in 2004 to 0.6302 per 100,000 population in 2021, with an average annual percentage change (APC) reduction of -13.1% (p < 0.001). The same result was seen in the mortality (APC, -22.14%, from 0.0089/100,000 in 2004 to 0.0002/100,000 in 2021, p < 0.001). All Chinese provinces saw a decline in incidence and mortality. Longitudinal analysis identified the age distribution in the incidence and mortality of HUA did not change and was highest in persons aged 15-59 years, accounting for 70% of all reported cases. During the COVID-19 pandemic, no significant increase was seen in pediatric HUA cases in China.

Conclusion

China is experiencing an unprecedented decline in HUA, with the lowest incidence and mortality for 18 years. However, it is still important to sensitively monitor the overall trends of HUA and further improve HUA public health policy and practice in China.

Estimating the influence of high temperature on hand, foot, and mouth disease incidence in China

The burden of disease caused by ambient high temperature has become a public health concern, but the associations between high temperature and hand, foot, and mouth disease (HFMD) remain indistinct. We used distributed lag non-linear model (DLNM) to estimate the burden of disease attribute to high temperature, adjusting for long-term trend and weather confounders. Total 18,167,455 cases were reported in 31 Chinese provinces, the incidence of HFMD showed a gradually increasing trend from 2008 to 2017 in China. Minimum morbidity temperature (MMT) was mainly concentrated at 17 to 23 °C in ≤ 5 years old group, 18 to 25 °C in 6 ~ 10 years old group and 19 to 27 °C in > 10 years old group. The greatest relative risk (RR) in age group ≤ 5 years old was 2.06 (95% CI: 1.85 ~ 2.30) in Heilongjiang, and the lowest RR was 1.02 (95% CI: 1.00 ~ 1.05) in Guangdong; the greatest RR in age group 6 ~ 10 years old was 2.24 (95% CI: 1.72 ~ 2.91) in Guizhou, and the lowest RR was 1.01 (95% CI: 0.97 ~ 1.12) in Tianjin; the greatest RR in the age group > 10 years old was 2.53 (95% CI: 1.66 ~ 3.87) in Heilongjiang, and the lowest RR was 1.02 (95% CI: 0.71 ~ 1.46) in Henan. We found the positive association between high temperature and HFMD in China.

The lagged effect and attributable risk of apparent temperature on hand, foot, and mouth disease in Changsha, China: a distributed lag non-linear model

Hand, foot, and mouth disease (HFMD) is the leading Category C infectious disease affecting millions of children in China every year. In the context of global climate change, the understanding and quantification of the impact of weather factors on human health are particularly critical to the development and implementation of climate change adaptation and mitigation strategies. The aim of this study was to quantify the attributable burden of a combined bioclimatic indicator (apparent temperature) on HFMD and to identify temperature-specific sensitive populations. A total of 123,622 HFMD cases were included in the study. The non-linear relationship between apparent temperature and the incidence of HFMD was approximately M-shaped, with hot weather being more likely to be attributable than cold conditions, of which moderately hot accounting for the majority of cases (21,441, 17.34%). Taking the median apparent temperature (19.2 °C) as reference, the cold effect showed a short acute effect with the highest risk on the day of lag 0 (RR = 1.086, 95% CI: 1.024 ~ 1.152), whereas the hot effect lasted longer with the greatest risk at a lag of 7 days (RR = 1.081, 95% CI: 1.059 ~ 1.104). Subgroup analysis revealed that males, children under 3 years old, and scattered children tended to be more vulnerable to HFMD in hot weather, while females, those aged 3 ~ 5 years, and nursery children were sensitive to cold conditions. This study suggests that high temperatures have a greater impact on HFMD than low temperatures as well as lasting longer, of particular concern being moderately high temperatures rather than extreme temperatures. Early intervention takes on greater importance during cold days, while the duration of HFMD intervention must be longer during hot days.

Molecular mechanism of antibody neutralization of coxsackievirus A16

Coxsackievirus A16 (CVA16) causes hand, foot and mouth disease in infants and young children. However, no vaccine or anti-viral agent is currently available for CVA16. Here, the functions and working mechanisms of two CVA16-specific neutralizing monoclonal antibodies (MAbs), 9B5 and 8C4, are comprehensively investigated. Both 9B5 and 8C4 display potent neutralization in vitro and prophylactic and therapeutic efficacy in a mouse model of CVA16 infection. Mechanistically, 9B5 exerts neutralization primarily through inhibiting CVA16 attachment to cell surface via blockade of CVA16 binding to its attachment receptor, heparan sulfate, whereas 8C4 functions mainly at the post-attachment stage of CVA16 entry by interfering with the interaction between CVA16 and its uncoating receptor SCARB2. Cryo-EM studies show that 9B5 and 8C4 target distinct epitopes located at the 5-fold and 3-fold protrusions of CVA16 capsids, respectively, and exhibit differential binding preference to three forms of naturally occurring CVA16 particles. Moreover, 9B5 and 8C4 are compatible in formulating an antibody cocktail which displays the ability to prevent virus escape seen with individual MAbs. Together, our work elucidates the functional and structural basis of CVA16 antibody-mediated neutralization and protection, providing important information for design and development of effective CVA16 vaccines and antibody therapies.

Interactive effects of meteorological factors and air pollutants on hand, foot, and mouth disease in Chengdu, China: a time-series study

OBJECTIVES

Hand, foot, and mouth disease (HFMD) is a viral infectious disease that poses a substantial threat in the Asia-Pacific region. It is widely reported that meteorological factors are associated with HFMD. However, the relationships between air pollutants and HFMD are still controversial. In addition, the interactive effects between meteorological factors and air pollutants on HFMD remain unknown. To fill this research gap, we conducted a time-series study.

DESIGN

A time-series study.

SETTING AND PARTICIPANTS

Daily cases of HFMD as well as meteorological and air pollution data were collected in Chengdu from 2011 to 2017. A total of 184 610 HFMD cases under the age of 15 were included in our study.

OUTCOME MEASURES

Distributed lag nonlinear models were used to investigate the relationships between HFMD and environmental factors, including mean temperature, relative humidity, SO2, NO2, and PM10. Then, the relative excess risk due to interaction (RERI) and the proportion attributable to interaction were calculated to quantitatively evaluate the interactions between meteorological factors and air pollutants on HFMD. Bivariate response surface models were used to visually display the interactive effects.

RESULTS

The cumulative exposure-response curves of SO2 and NO2 were inverted 'V'-shaped and 'M'-shaped, respectively, and the risk of HFMD gradually decreased with increasing PM10 concentrations. We found that there were synergistic interactions between mean temperature and SO2, relative humidity and SO2, as well as relative humidity and PM10 on HFMD, with individual RERIs of 0.334 (95% CI 0.119 to 0.548), 0.428 (95% CI 0.214 to 0.642) and 0.501 (95% CI 0.262 to 0.741), respectively, indicating that the effects of SO2 and PM10 on HFMD were stronger under high temperature (>17.3°C) or high humidity (>80.0%) conditions.

CONCLUSIONS

There were interactive effects between meteorological factors and air pollutants on HFMD. Our findings could provide guidance for targeted and timely preventive and control measures for HFMD.

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 CV-A10 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.

Application of logistic differential equation models for early warning of infectious diseases in Jilin Province

Background

There is still a relatively serious disease burden of infectious diseases and the warning time for different infectious diseases before implementation of interventions is important. The logistic differential equation models can be used for predicting early warning of infectious diseases. The aim of this study is to compare the disease fitting effects of the logistic differential equation (LDE) model and the generalized logistic differential equation (GLDE) model for the first time using data on multiple infectious diseases in Jilin Province and to calculate the early warning signals for different types of infectious diseases using these two models in Jilin Province to solve the disease early warning schedule for Jilin Province throughout the year.

Methods

Collecting the incidence of 22 infectious diseases in Jilin Province, China. The LDE and GLDE models were used to calculate the recommended warning week (RWW), the epidemic acceleration week (EAW) and warning removed week (WRW) for acute infectious diseases with seasonality, respectively.

Results

Five diseases were selected for analysis based on screening principles: hemorrhagic fever with renal syndrome (HFRS), shigellosis, mumps, Hand, foot and mouth disease (HFMD), and scarlet fever. The GLDE model fitted the above diseases better (0.80 ≤ R2 ≤ 0.94, P <  0. 005) than the LDE model. The estimated warning durations (per year) of the LDE model for the above diseases were: weeks 12–23 and 40–50; weeks 20–36; weeks 15–24 and 43–52; weeks 26–34; and weeks 16–25 and 41–50. While the durations of early warning (per year) estimated by the GLDE model were: weeks 7–24 and 36–51; weeks 13–37; weeks 11–26 and 39–54; weeks 23–35; and weeks 12–26 and 40–50.

Conclusions

Compared to the LDE model, the GLDE model provides a better fit to the actual disease incidence data. The RWW appeared to be earlier when estimated with the GLDE model than the LDE model. In addition, the WRW estimated with the GLDE model were more lagged and had a longer warning time.

Modification effects of socioeconomic factors on associations between air pollutants and hand, foot, and mouth disease: A multicity time-series study based on heavily polluted areas in the basin area of Sichuan Province, China

BACKGROUND

Hand, foot, and mouth disease (HFMD) is a serious threat among children in China. Some studies have found that air pollution is associated with HFMD incidence, but the results showed heterogeneity. In this study, we aimed to explore the heterogeneity of associations between air pollutants and the number of HFMD cases and to identify significant socioeconomic effect modifiers.

METHODS

We collected daily surveillance data on HFMD cases in those aged less than 15 years, air pollution variables and meteorological variables from 2015 to 2017 in the basin area of Sichuan Province. We also collected socioeconomic indicator data. We conducted a two-stage multicity time-series analysis. In the first stage, we constructed a distributed lag nonlinear model (DLNM) to obtain cumulative exposure-response curves between each air pollutant and the numbers of HFMD cases for every city. In the second stage, we carried out a multivariable meta-regression to merge the estimations in the first stage and to identify significant socioeconomic effect modifiers.

RESULTS

We found that PM10, NO2 and O3 concentrations were associated with the number of HFMD cases. An inverted V-shaped association between PM10 and the number of HFMD cases was observed. The overall NO2-HFMD association was a hockey-stick shape. For the relationships of PM10, SO2, NO2, O3 and CO with HFMD counts, approximately 58.5%, 48.4%, 51.0%, 55.6% and 52.5% of the heterogeneity could be explained, respectively. The proportion of primary school students, population density, urbanization rate, number of licensed physicians and number of hospital beds explained part of the heterogeneity and modified the relationships.

CONCLUSION

Our study explored the heterogeneity of associations between air pollutants and HFMD counts. The proportion of primary school students, population density, urbanization rate, number of licensed physicians and number of hospital beds could modify the relationships. The results can serve as a reference for relevant public health decision making.

Explanation of hand, foot, and mouth disease cases in Japan using Google Trends before and during the COVID-19: infodemiology study

Background

Coronavirus Disease 2019 (COVID-19) pandemic affects common diseases, but its impact on hand, foot, and mouth disease (HFMD) is unclear. Google Trends data is beneficial for approximate real-time statistics and because of ease in access, is expected to be used for infection explanation from an information-seeking behavior perspective. We aimed to explain HFMD cases before and during COVID-19 using Google Trends.

Methods

HFMD cases were obtained from the National Institute of Infectious Diseases, and Google search data from 2009 to 2021 in Japan were downloaded from Google Trends. Pearson correlation coefficients were calculated between HFMD cases and the search topic “HFMD” from 2009 to 2021. Japanese tweets containing “HFMD” were retrieved to select search terms for further analysis. Search terms with counts larger than 1000 and belonging to ranges of infection sources, susceptible sites, susceptible populations, symptoms, treatment, preventive measures, and identified diseases were retained. Cross-correlation analyses were conducted to detect lag changes between HFMD cases and search terms before and during the COVID-19 pandemic. Multiple linear regressions with backward elimination processing were used to identify the most significant terms for HFMD explanation.

Results

HFMD cases and Google search volume peaked around July in most years, excluding 2020 and 2021. The search topic “HFMD” presented strong correlations with HFMD cases, except in 2020 when the COVID-19 outbreak occurred. In addition, the differences in lags for 73 (72.3%) search terms were negative, which might indicate increasing public awareness of HFMD infections during the COVID-19 pandemic. The results of multiple linear regression demonstrated that significant search terms contained the same meanings but expanded informative search content during the COVID-19 pandemic.

Conclusions

The significant terms for the explanation of HFMD cases before and during COVID-19 were different. Awareness of HFMD infections in Japan may have improved during the COVID-19 pandemic. Continuous monitoring is important to promote public health and prevent resurgence. The public interest reflected in information-seeking behavior can be helpful for public health surveillance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07790-9.

Epidemiological characteristics of hand, foot, and mouth disease clusters during 2016-2020 in Beijing, China

Hand, foot, and mouth disease (HFMD) is an infectious disease that usually occurs in children under 5 years and is caused by a group of enteroviruses. This study aimed to investigate the epidemiological characteristics of HFMD clusters from 2016 to 2020 in Tongzhou, Beijing, and explored the genetic evolution of CV-A6. The HFMD case information came from the Information System of China Center for Disease Control and Prevention (CDC), as well as the clusters information verification and on-site investigation by Tongzhou CDC. ARIMA model was applied to forecast HFMD clusters in 2020. Totally 440 HFMD clusters were reported during 2016-2020. The large peak of the clusters occurred in April-July, followed by a smaller peak in October-November during 2016-2019. However, in 2020, the two peaks disappeared. The main site of HFMD clusters was childcare facilities (65.0%) and mostly occurred in urban areas (46.1%). The detection rate of CV-A6 was the highest (36.1%), and cases with CV-A6 infection had the highest proportion of fever. The phylogenetic analysis based on CV-A6 VP1 gene showed that the predominant strains mainly located in Group F during 2016-2017, while changed into Group A during 2018-2020. HFMD clusters presented seasonality, mainly located in childcare facilities and urban areas, and CV-A6 was the major causative agent. Targeted prevention and control measures should be taken to reduce HFMD clusters.

Molecular docking study of various Enterovirus—A71 3C protease proteins and their potential inhibitors

Hand, foot, and mouth disease (HFMD) is a common infection that primarily affects children in preschool and kindergarten; however, there is yet no vaccination or therapy available. Despite the fact that current research is only focused on numerous strains of Enterovirus—A71 (EV-A71) 3C protease (3C^pro), these investigations are entirely separate and unrelated. Antiviral agents must therefore be tested on several EV strains or mutations. In total, 21 previously reported inhibitors were evaluated for inhibitory effects on eight EV-A71 3C^pro, including wild-type and mutant proteins in this study, and another 29 powerful candidates with inhibitory effects on EV-A71 were investigated using the molecular docking approach. This method is to determine the broad-spectrum of the antiviral agents on a range of strains or mutants because the virus frequently has mutations. Even though Rupintrivir is reported to pass phase I clinical trial, 4-iminooxazolidin-2-one moiety (FIOMC) was shown to have a broader anti-3C^pro spectrum than Rupintrivir. Meanwhile, Hesperidin possessed a better 3C^pro inhibitory capability than FIOMC. Thus, it could be considered the most promising candidate for inhibiting various strains of EV-A71 3C^pro proteins in the newly anti-EV compounds group. Furthermore, the mutation at E71A has the most significant impact on the docking results of all ligands evaluated. Future in vitro experiments on Hesperidin’s ability to inhibit 3C^pro activity should be conducted to compare with FIOMC’s in vitro results and validate the current in silico work.

Post-COVID-19 investor psychology and individual investment decision: A moderating role of information availability

This study aims to investigate the influence of psychological biases on the investment decision of Chinese individual investors after the pandemic of COVID-19 with a moderating role of information availability. A cross-sectional method with a quantitative research approach was employed to investigate the hypothesized relationships among variables. The snowball sampling technique was applied to collect the data through a survey questionnaire from individual investors investing in the Chinese stock market. Smart-PLS statistical software was used to analyze the data and for the estimation of hypotheses. Results indicated that overconfidence, representative bias, and anchoring bias have a significant and positive influence on investment decisions during the post-Covid-19 pandemic; however, the availability bias has insignificant and negative effects on the investment decision during the post-COVID-19 pandemic. Moreover, findings indicated that information availability has a significant moderating role in the relationship of psychological biases with the investment decision during the post-COVID-19 pandemic. This study contributes to the body of knowledge regarding behavior finance, psychological biases, and investment decision in emerging stock markets. The findings of the present study improve the understanding that how investors’ psychology affects their investment decisions.