Pancreatitis in hand-foot-and-mouth disease caused by enterovirus 71

Enteroviruses: epidemic potential, challenges and opportunities with vaccines

Enteroviruses (EVs) are the most prevalent viruses in humans. EVs can cause a range of acute symptoms, from mild common colds to severe systemic infections such as meningitis, myocarditis, and flaccid paralysis. They can also lead to chronic diseases such as cardiomyopathy. Although more than 280 human EV serotypes exist, only four serotypes have licenced vaccines. No antiviral drugs are available to treat EV infections, and global surveillance of EVs has not been effectively coordinated. Therefore, poliovirus still circulates, and there have been alarming epidemics of non-polio enteroviruses. Thus, there is a pressing need for coordinated preparedness efforts against EVs.This review provides a perspective on recent enterovirus outbreaks and global poliovirus eradication efforts with continuous vaccine development initiatives. It also provides insights into the challenges and opportunities in EV vaccine development. Given that traditional whole-virus vaccine technologies are not suitable for many clinically relevant EVs and considering the ongoing risk of enterovirus outbreaks and the potential for new emerging pathogenic strains, the need for new effective and adaptable enterovirus vaccines is emphasized.This review also explores the difficulties in translating promising vaccine candidates for clinical use and summarizes information from published literature and clinical trial databases focusing on existing enterovirus vaccines, ongoing clinical trials, the obstacles faced in vaccine development as well as the emergence of new vaccine technologies. Overall, this review contributes to the understanding of enterovirus vaccines, their role in public health, and their significance as a tool for future preparedness.

Hyperglycemia facilitates EV71 replication: Insights into miR-206-mediated regulation of G3BP2 promoting EV71 IRES activity

Background: Neurotropic virus infections actively manipulate host cell metabolism to enhance virus neurovirulence. Although hyperglycemia is common during severe infections, its specific role remains unclear. This study investigates the impact of hyperglycemia on the neurovirulence of enterovirus 71 (EV71), a neurovirulent virus relying on internal ribosome entry site (IRES)-mediated translation for replication. Methods: Utilizing hSCARB2-transgenic mice, we explore the effects of hyperglycemia in EV71 infection and elucidate the underlying mechanisms. Results: Remarkably, administering insulin alone to reduce hyperglycemia in hSCARB2-transgenic mice results in a decrease in brainstem encephalitis and viral load. Conversely, induced hyperglycemia exacerbates neuropathogenesis, highlighting the pivotal role of hyperglycemia in neurovirulence. Notably, miR-206 emerges as a crucial mediator induced by viral infection, with its expression further heightened by hyperglycemia and concurrently repressed by insulin. The use of antagomiR-206 effectively mitigates EV71-induced brainstem encephalitis and reduces viral load. Mechanistically, miR-206 facilitates IRES-driven virus replication by repressing the stress granule protein G3BP2. Conclusions: Novel therapeutic approaches against severe EV71 infections involve managing hyperglycemia and targeting the miR-206-stress granule pathway to modulate virus IRES activity.

Novel pathologic findings and viral antigen distribution in cattle and buffalo calves naturally infected with Foot-and-Mouth disease virus

The Foot-and-Mouth disease is highly contagious acute viral disease of livestock inflicting huge economic loss to the farmers. The limited knowledge regarding the pathological lesions vis-a-vis distribution of the FMDV in lesser explored endocrine glands and important vital organs other than the target organs of infected calves prompted us to take the present investigation to have detailed insight into the pathogenesis. The systematic necropsy of 37 dead calves (cattle-28 and buffalo-9) was conducted, and thin representative tissue pieces from the affected organs were collected in 10% neutral buffered formalin (NBF) for pathological and immunohistochemical investigations. The genomic detection and its serotyping were done by RT-PCR and multiplex-PCR, respectively. Necropsy examination in all cases showed myocardial lesions resembling 'tigroid heart appearance'. Other organ specific lesions include vesiculo-ulcerative stomatitis, edema of the lungs, petechial hemorrhages, edema of the endocrines, and gastroenteritis. Histopathological examination showed varying sizes of vesicles and ulcerations in stratified squamous epithelium of the tongue, acute necrotizing myocarditis, lymphoid depletion in lymphoid tissues, hepatitis, pancreatitis, thymic hyperplasia, thyroiditis, adrenitis, and enteritis. Positive immunolabeling for viral antigens was observed in endocrine glands, lymphoid organs, lungs, liver, kidneys, and intestine, in addition to other typical locations. The thyroid, adrenal glands, and pancreas, in addition to the tongue and heart, are the tissue of choice for sampling in the field during epidemics. Further, the viral genome and serotype A was confirmed in the affected tissues. This study provides insights into novel tissue tropism and pathogenesis in young calves naturally infected with FMDV.

Hand, Foot, and Mouth Disease: A Narrative Review

BACKGROUND

Hand, foot, and mouth disease is a common viral disease in childhood. Because the disease has the potential to reach epidemic levels and mortality is high in some countries, early recognition of this disease is of paramount importance.

OBJECTIVE

This purpose of this article is to familiarize pediatricians with the clinical manifestations and management of hand, foot, and mouth disease.

METHODS

A search was conducted in February 2022 in PubMed Clinical Queries using the key term "hand, foot, and mouth disease". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in English were included in this review.

RESULTS

Hand, foot, and mouth disease is characterized by a painful oral enanthem and asymptomatic exanthem on the palms and soles. Children younger than 5 years are most commonly affected. Hand, foot, and mouth disease caused by enterovirus A71 is more severe and has a higher rate of complications than that attributed to other viruses such as coxsackievirus A16. Circulatory failure secondary to myocardial impairment and neurogenic pulmonary edema secondary to brainstem damage are the main causes of death. Fortunately, the disease is usually benign and resolves in 7 to10 days without sequelae. Given the self-limited nature of most cases, treatment is mainly symptomatic and supportive. Intravenous immunoglobulin should be considered for the treatment of severe/complicated hand, foot, and mouth disease and has been recommended by several national and international guideline committees. Currently, there are no specific antiviral agents approved for the treatment of the disease. Drugs such as ribavirin, suramin, mulberroside C, aminothiazole analogs, and sertraline have emerged as potential candidates for the treatment of hand, foot, and mouth disease. Vaccination of susceptible individuals in high-risk areas and good personal hygiene are important preventative measures to combat the disease.

CONCLUSION

Familiarity of the disease including its atypical manifestations is crucial so that a correct diagnosis can be made, and appropriate treatment initiated. A timely diagnosis can help avoid contact with the affected individual and decrease the risk of an outbreak.

Structural, functional and molecular dynamics analysis of cathepsin B gene SNPs associated with tropical calcific pancreatitis, a rare disease of tropics

Tropical Calcific Pancreatitis (TCP) is a neglected juvenile form of chronic non-alcoholic pancreatitis. Cathepsin B (CTSB), a lysosomal protease involved in the cellular degradation process, has recently been studied as a potential candidate gene in the pathogenesis of TCP. According to the Cathepsin B hypothesis, mutated CTSB can lead to premature intracellular activation of trypsinogen, a key regulatory mechanism in pancreatitis. So far, CTSB mutations have been studied in pancreatitis and neurodegenerative disorders, but little is known about the structural and functional effect of variants in CTSB. In this study, we investigated the effect of single nucleotide variants (SNVs) specifically associated with TCP, using molecular dynamics and simulation algorithms. There were two non-synonymous variants (L26V and S53G) of CTSB, located in the propeptide region. We tried to predict the effect of these variants on structure and function using multiple algorithms: SIFT, Polyphen2, PANTHER, SDM sever, i-Mutant2.0 suite, mCSM algorithm, and Vadar. Further, using databases like miRdbSNP, PolymiRTS, and miRNASNP, two SNPs in the 3′UTR region were predicted to affect the miRNA binding sites. Structural mutated models of nsSNP mutants (L26V and S53G) were prepared by MODELLER v9.15 and evaluated using TM-Align, Verify 3D, ProSA and Ramachandran plot. The 3D mutated structures were simulated using GROMACS 5.0 to predict the impact of these SNPs on protein stability. The results from in silico analysis and molecular dynamics simulations suggested that these variants in the propeptide region of Cathepsin B could lead to structural and functional changes in the protein and thus could be pathogenic. Hence, the structural and functional analysis results have given interim conclusions that these variants can have a deleterious effect in TCP pathogenesis, either uniquely or in combination with other mutations. Thus, it could be extrapolated that Cathepsin B gene can be screened in samples from all TCP patients in future, to decipher the distribution of variants in patients.

Acute pancreatitis in hand, foot and mouth disease caused by Coxsackievirus A16: case report

Coxsackievirus A16 (CA16), which primarily causes hand, foot, and mouth disease (HFMD), is associated with complications, such as encephalitis, acute flaccid paralysis, myocarditis, pericarditis, and shock. However, no case of pancreatitis associated with CA16 has been reported in children. We report a case of CA16-associated acute pancreatitis in a 3-year-old girl with HFMD. She was admitted because of poor oral intake and high fever for 1 day. Maculopapular rashes on both hands and feet and multiple vesicles on the soft palate were observed on physical examination. She was treated conservatively with intravenous fluids. On the fourth hospital day, she had severe abdominal pain and vomiting. The serum levels of amylase and lipase were remarkably elevated (amylase, 1,902 IU/L; reference range, 28–100 IU/L; lipase, >1,500 IU/L; reference range, 13–60 IU/L), and ultrasonography showed diffuse swelling of the pancreas with a small amount of ascites. The real-time reverse transcription polymerase chain reaction result from a stool sample was positive for CA16. CA16 can cause acute pancreatitis, and should be considered in the differential diagnosis of abdominal pain in children with HFMD.

Echovirus 6 Infects Human Exocrine and Endocrine Pancreatic Cells and Induces Pro-Inflammatory Innate Immune Response

Human enteroviruses (HEV), especially coxsackievirus serotype B (CVB) and echovirus (E), have been associated with diseases of both the exocrine and endocrine pancreas, but so far evidence on HEV infection in human pancreas has been reported only in islets and ductal cells. This study aimed to investigate the capability of echovirus strains to infect human exocrine and endocrine pancreatic cells. Infection of explanted human islets and exocrine cells with seven field strains of E6 caused cytopathic effect, virus titer increase and production of HEV protein VP1 in both cell types. Virus particles were found in islets and acinar cells infected with E6. No cytopathic effect or infectious progeny production was observed in exocrine cells exposed to the beta cell-tropic strains of E16 and E30. Endocrine cells responded to E6, E16 and E30 by upregulating the transcription of interferon-induced with helicase C domain 1 (IF1H1), 2′-5′-oligoadenylate synthetase 1 (OAS1), interferon-β (IFN-β), chemokine (C–X–C motif) ligand 10 (CXCL10) and chemokine (C–C motif) ligand 5 (CCL5). Echovirus 6, but not E16 or E30, led to increased transcription of these genes in exocrine cells. These data demonstrate for the first time that human exocrine cells represent a target for E6 infection and suggest that certain HEV serotypes can replicate in human pancreatic exocrine cells, while the pancreatic endocrine cells are permissive to a wider range of HEV.