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Current Infectious Disease Reports 2022Japanese encephalitis (JE), a clinical indication of JE virus-induced brain inflammation, is the most prevalent cause of viral encephalitis in the world. This review... (Review)
Review
PURPOSE OF REVIEW
Japanese encephalitis (JE), a clinical indication of JE virus-induced brain inflammation, is the most prevalent cause of viral encephalitis in the world. This review gives a comprehensive update on the epidemiology, clinical features, therapeutic trials and approaches for preventing the spread of JE. It also outlines the different JE vaccines used in various countries and recommendations for administration of JE vaccines.
RECENT FINDINGS
According to the WHO, annual incidence of JE is estimated to be approximately 68,000 cases worldwide. It is widespread across Asia-Pacific, with a potential for worldwide transmission. In endemic locations, JE is believed to affect children below 6 years of age, but in newly affected areas, both adults and children are at risk due to a lack of protective antibodies. Various vaccines have been developed for the prevention of JE and are being administered in endemic countries.
SUMMARY
JE is a neuroinvasive disease that causes symptoms ranging from simple fever to severe encephalitis and death. Despite a vast number of clinical trials on various drugs, there is still no complete cure available, and it can only be prevented by adequate vaccination. Various nanotechnological approaches for the prevention and treatment of JE are outlined in this review.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s11908-022-00786-1.
PubMed: 36187900
DOI: 10.1007/s11908-022-00786-1 -
Viruses Mar 2023The flavivirus genus contains several clinically important pathogens that account for tremendous global suffering. Primarily transmitted by mosquitos or ticks, these... (Review)
Review
The flavivirus genus contains several clinically important pathogens that account for tremendous global suffering. Primarily transmitted by mosquitos or ticks, these viruses can cause severe and potentially fatal diseases ranging from hemorrhagic fevers to encephalitis. The extensive global burden is predominantly caused by six flaviviruses: dengue, Zika, West Nile, yellow fever, Japanese encephalitis and tick-borne encephalitis. Several vaccines have been developed, and many more are currently being tested in clinical trials. However, flavivirus vaccine development is still confronted with many shortcomings and challenges. With the use of the existing literature, we have studied these hurdles as well as the signs of progress made in flavivirus vaccinology in the context of future development strategies. Moreover, all current licensed and phase-trial flavivirus vaccines have been gathered and discussed based on their vaccine type. Furthermore, potentially relevant vaccine types without any candidates in clinical testing are explored in this review as well. Over the past decades, several modern vaccine types have expanded the field of vaccinology, potentially providing alternative solutions for flavivirus vaccines. These vaccine types offer different development strategies as opposed to traditional vaccines. The included vaccine types were live-attenuated, inactivated, subunit, VLPs, viral vector-based, epitope-based, DNA and mRNA vaccines. Each vaccine type offers different advantages, some more suitable for flaviviruses than others. Additional studies are needed to overcome the barriers currently faced by flavivirus vaccine development, but many potential solutions are currently being explored.
Topics: Animals; Humans; Flavivirus; Viral Vaccines; Mosquito Vectors; Flavivirus Infections; Yellow Fever; Zika Virus; Zika Virus Infection
PubMed: 37112840
DOI: 10.3390/v15040860 -
Journal of Biomedical Science Jun 2021Dysregulated formation of neutrophil extracellular traps (NETs) is observed in acute viral infections. Moreover, NETs contribute to the pathogenesis of acute viral... (Review)
Review
Dysregulated formation of neutrophil extracellular traps (NETs) is observed in acute viral infections. Moreover, NETs contribute to the pathogenesis of acute viral infections, including those caused by the dengue virus (DV) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Furthermore, excessive NET formation (NETosis) is associated with disease severity in patients suffering from SARS-CoV-2-induced multiple organ injuries. Dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) and other members of C-type lectin family (L-SIGN, LSECtin, CLEC10A) have been reported to interact with viral glycans to facilitate virus spreading and exacerbates inflammatory reactions. Moreover, spleen tyrosine kinase (Syk)-coupled C-type lectin member 5A (CLEC5A) has been shown as the pattern recognition receptor for members of flaviviruses, and is responsible for DV-induced cytokine storm and Japanese encephalomyelitis virus (JEV)-induced neuronal inflammation. Moreover, DV activates platelets via CLEC2 to release extracellular vesicles (EVs), including microvesicles (MVs) and exosomes (EXOs). The DV-activated EXOs (DV-EXOs) and MVs (DV-MVs) stimulate CLEC5A and Toll-like receptor 2 (TLR2), respectively, to enhance NET formation and inflammatory reactions. Thus, EVs from virus-activated platelets (PLT-EVs) are potent endogenous danger signals, and blockade of C-type lectins is a promising strategy to attenuate virus-induced NETosis and intravascular coagulopathy.
Topics: Blood Platelets; COVID-19; Cytokine Release Syndrome; Encephalitis Virus, Japanese; Encephalitis, Japanese; Extracellular Traps; Humans; Lectins, C-Type; Platelet Activation; SARS-CoV-2; Signal Transduction
PubMed: 34116654
DOI: 10.1186/s12929-021-00741-7 -
Human Vaccines & Immunotherapeutics Nov 2021Japanese encephalitis (JE) is an endemic disease dominantly in the Asia-Pacific region with mortality rate varying between 3% and 30%. Long-term neuropsychiatric...
Japanese encephalitis (JE) is an endemic disease dominantly in the Asia-Pacific region with mortality rate varying between 3% and 30%. Long-term neuropsychiatric sequelae developed in 30-50% of the survivors. There is no available antiviral therapy for JE. JE vaccines play a major role in preventing this devastating disease. The incidence of JE declined over years and the age distribution shifted toward adults in countries where JE immunization program exists. Mouse brain-JE vaccine is currently replaced by inactivated Vero cell-derived vaccine and live-attenuated vaccine using SA14-14-2 strain, and live chimeric JE vaccines. These three types of JE vaccines are associated with favorable efficacy and safety profiles. Common adverse reactions include injection site reactions and fever, and severe adverse reactions are rare.
Topics: Animals; Chlorocebus aethiops; Encephalitis Virus, Japanese; Encephalitis, Japanese; Japanese Encephalitis Vaccines; Mice; Vaccines, Attenuated; Vaccines, Inactivated; Vero Cells
PubMed: 34613870
DOI: 10.1080/21645515.2021.1969852 -
F1000Research 2019Japanese encephalitis (JE) is a clinical manifestation of the brain inflammation caused by JE virus (JEV). This virus imparts permanent neurological damage, thus... (Review)
Review
Japanese encephalitis (JE) is a clinical manifestation of the brain inflammation caused by JE virus (JEV). This virus imparts permanent neurological damage, thus imposing a heavy burden on public health and society. Neuro-inflammation is the hallmark of JEV infection. The prolonged pro-inflammatory response is due primarily to microglial activation, which eventually leads to severe encephalitis. A continual effort is going on in the scientific community toward an understanding of cellular and molecular factors that are involved in JEV neuro-invasion and inflammatory processes. This review not only gives a comprehensive update on the recent advances on understanding virus structure and mechanisms of pathogenesis but also briefly discusses crucial unresolved issues. We also highlight challenging areas of research that might open new avenues for controlling virus-induced neuro-inflammation.
Topics: Encephalitis Virus, Japanese; Encephalitis, Japanese; Humans; Inflammation; Microglia
PubMed: 31781366
DOI: 10.12688/f1000research.19693.1 -
Pathogens (Basel, Switzerland) Nov 2021Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus mainly spread by mosquitoes that currently has a geographic distribution across most of Southeast Asia... (Review)
Review
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus mainly spread by mosquitoes that currently has a geographic distribution across most of Southeast Asia and the Western Pacific. Infection with JEV can cause Japanese encephalitis (JE), a severe disease with a high mortality rate, which also results in ongoing sequalae in many survivors. The natural reservoir of JEV is ardeid wading birds, such as egrets and herons, but pigs commonly play an important role as an amplifying host during outbreaks in human populations. Other domestic animals and wildlife have been detected as hosts for JEV, but their role in the ecology and epidemiology of JEV is uncertain. Safe and effective JEV vaccines are available, but unfortunately, their use remains low in most endemic countries where they are most needed. Increased surveillance and diagnosis of JE is required as climate change and social disruption are likely to facilitate further geographical expansion of vectors and JE risk areas.
PubMed: 34959489
DOI: 10.3390/pathogens10121534 -
Frontiers in Cellular and Infection... 2023The Japanese encephalitis virus (JEV) is classified into five distinct genotypes, with genotypes 1 and 3 historically showing higher activity. These genotypes are the... (Review)
Review
The Japanese encephalitis virus (JEV) is classified into five distinct genotypes, with genotypes 1 and 3 historically showing higher activity. These genotypes are the primary agents of viral encephalitis in the Asian continent. Genotypes 4 and 5 have remained silent in low-latitude tropical regions since their discovery. From 2009, the hidden genotype 5 suddenly emerged simultaneously in mosquitoes from the Tibetan region of China and those from South Korea in East Asia. The detection of genotype 5 of JEV in these mosquitoes was associated with cases of viral encephalitis in the local population. Similarly, in 2022, the long-silent genotype 4 of JEV emerged in Australia, resulting in a local outbreak of viral encephalitis that primarily affected adults and caused fatalities. The emergence and outbreaks of genotypes 4 and 5 of JEV present new challenges for the prevention and control of Japanese encephalitis (JE). This study not only analyzes the recent emergence of these new genotypes but also discusses their implications in the development of JE vaccines and laboratory tests for newly emerging JEV infections.
Topics: Adult; Animals; Humans; Encephalitis Virus, Japanese; Encephalitis, Japanese; Culicidae; Genotype; Disease Outbreaks
PubMed: 38076463
DOI: 10.3389/fcimb.2023.1292693 -
Cureus Apr 2021Japanese encephalitis (JE) continues to be one of the world's most serious infections with no definitive treatment or guidelines. The high morbidity and mortality rate... (Review)
Review
Japanese encephalitis (JE) continues to be one of the world's most serious infections with no definitive treatment or guidelines. The high morbidity and mortality rate among symptomatic patients warrant the need for further investigation in this regard. Our review focuses on the recent updates on Japanese encephalitis treatment. For that reason, we used an advanced PubMed search with JE and drugs like minocycline, interferon, ribavirin, immunoglobulin, dexamethasone, and acyclovir. All research was done in full papers written in the English language and conducted in humans. This review aims to compare and analyze recent papers regarding JE treatment to guide healthcare providers with the latest information and make evidence-based decisions when presented with this infection. Overall, only minocycline had promising results because one of the two studies showed statistically significant results. The second study showed positive trends in children over 12 years and patients who survived on the first day of hospitalization. The study with intravenous immunoglobulin (IVIG) did not improve the outcomes; however, it increased the levels of neutralizing antibodies. Further study with higher doses may change the outcomes in patients with JE. The other drugs failed to show promising results.
PubMed: 34036000
DOI: 10.7759/cureus.14579 -
International Journal of Veterinary... 2021The increasing number of cases of acute encephalitis syndrome, a key presenting clinical sign of Japanese encephalitis infection in humans, along with increasing... (Review)
Review
The increasing number of cases of acute encephalitis syndrome, a key presenting clinical sign of Japanese encephalitis infection in humans, along with increasing laboratory confirmed cases in Bali over recent years have led to the Indonesian government developing a national program of vaccination against Japanese encephalitis virus. In order to inform multidisciplinary management, a review was conducted to assess Japanese encephalitis virus-related cases in humans and animals including their determinants and detection in vectors. Along with published literature, key data from local authorized officers in Bali have been used to convey the recent situation of the disease. Related surveys detected up to 92% of the local children had antibodies against the virus with the annual incidence estimated to be 7.1 per 100,000 children. Additionally, reports on young and adult cases of infection within international travellers infected in Bali were documented with both non-fatal and fatal outcomes. Further seroprevalence surveys detected up to 90% with antibodies to the virus in animal reservoirs. The detection of the virus in certain mosquito species and high levels of seropositivity may be associated with greater risk of the virus transmission to the human population. It was also highlighted that local sociocultural practices for agriculture and livestock were potentially associated with the high density of the vector and the reservoirs, which then may lead to the risk of the disease transmission in the ecology of Bali.
PubMed: 34589543
DOI: 10.1080/23144599.2021.1975879 -
Australian Journal of General Practice May 2023Japanese encephalitis virus (JEV) is a mosquito-borne arbovirus endemic to the Asia-Pacific that causes high morbidity and mortality in those who develop symptomatic... (Review)
Review
BACKGROUND
Japanese encephalitis virus (JEV) is a mosquito-borne arbovirus endemic to the Asia-Pacific that causes high morbidity and mortality in those who develop symptomatic disease. Prior to 2021, only five locally acquired cases had been detected in Australia, all in northern Australia. Following a sentinel case in 2021, widespread dissemination of JEV was detected in northern and south-eastern Australia, accompanied by an increase in locally acquired cases, which have been detected as far south as Victoria. This expansion has occurred in the setting of warmer and wetter conditions under the influence of climate change.
OBJECTIVE
To provide Australian general practitioners (GPs) an overview of JEV, given its recent expansion, and the potential for sustained endemicity.
DISCUSSION
As the distribution of JEV expands under the influence of climate change, Australian GPs need to be familiar with this condition, especially those practicing in rural areas and where detections have occurred.
Topics: Animals; Humans; Climate Change; Encephalitis Virus, Japanese; Encephalitis, Japanese; Victoria
PubMed: 37149766
DOI: 10.31128/AJGP-07-22-6484