In persons who develop symptoms, the incubation period time from infection until illness is typically 515 days. Japanese encephalitis is a viral infection caused by rna viruses belonging to the flavivirus genus. There are many causes including the latest eastern equine encephalitis eee. The time from infection to developing symptoms is between 515 days. Read about contagious, treatment, risk factors, and diagnosis. The virus exists in a transmission cycle between mosquitoes, pigs andor water birds. Pdf japanese encephalitis je is one of the most dreaded mosquitoborne viral encephalitis known.
Encephalitis generally begins with fever and headache. Japanese encephalitis virus is transmitted natu rally between wild and. Classification of the causative agent resistance to physical. Louis encephalitis, and murray valley encephalitis viruses. Initial symptoms often include fever, headache, and vomiting. Classification of the causative agent resistance to. On average, among people who are infected by a mosquito bite, very few will develop an illness. Japanese encephalitis je is the main cause of viral encephalitis in many countries of asia. It is the leading cause of epidemic viral encephalitis in humans worldwide.
Mar 02, 2020 most infected people get only mild symptoms that mimic the flu, although a small minority of cases need emergency medical care. Most people who are infected have only mild or no symptoms with 1 in 250 cases being severe. Causes of encephalitis include viruses, bacteria, parasites, chemicals, and even autoimmune reactions. Japanese encephalitis aetiology epidemiology diagnosis prevention and control references aetiology classification of the causative agent japanese encephalitis je virus is a member of the family flaviviridae, genus flavivirus. Japanese encephalitis definition of japanese encephalitis. The most common presenting symptoms in je patients were fever 100%. Japanese encephalitis continue to cause a huge health and economic burden to affected countries. Full text prevention, diagnosis, and management of japanese.
It is a mosquitoborne virus and cannot be transferred from one person to. The je virus is a flavivirus related to dengue, yellow fever and west nile viruses. Japanese encephalitis fact sheet japanese encephalitis is a rare but serious infection of the brain caused by a virus that is transmitted through mosquito bites. Clinical presentation at the onset of the disease patients present with severe rigors, fevers and headache. Japanese encephalitis je is a mosquito borne important emerging and reemerging viral metazoonosis with a major global health importance, responsible for ill health among thousands of people. But around 1 in every 250 people who become infected with japanese encephalitis develop more severe symptoms as the infection spreads to the brain. Aetiology epidemiology diagnosis prevention and control references.
Most people who have japanese encephalitis have either no symptoms or mild, shortlived symptoms that are flulike in presentation mildtomoderate fever, fatigue, headache and sometimes vomiting. Alternatively, a rapid schedule of two doses on days 0 and 7 can be used. Prevention, diagnosis, and management of japanese encephalitis in children rashmi kumar department of pediatrics, king george medical university, lucknow up, india abstract. Humans get infected when bitten by an infected mosquito. Disease symptoms fever, muscle aches, headaches can occur five to fifteen days after the infection. Japanese encephalitis virus is an important mosquitoborne human pathogen in much of asia including southeast asia, china, japan, the korean peninsula and adjacent areas of the russian federation, sri lanka, and portions of the indian subcontinent with recent incursions into the pacific islands and northern australia fig. Only a single serotype of je virus has been identified and subtipification has been described. Japanese encephalitis is a zoonotic disease caused by a mosquitoborne virus similar to west nile, dengue fever, st. Aug 29, 2019 japanese encephalitis fact sheet japanese encephalitis is a rare but serious infection of the brain caused by a virus that is transmitted through mosquito bites. Jul 24, 2019 japanese encephalitis virus, a flavivirus singlestranded ribonucleic acid rna, represents the most significant etiology of arboviral encephalitis worldwide. Rare clinical cases have also been reported in other species, such as cattle. While most infections result in little or no symptoms, occasional inflammation of the brain occurs. It is a mosquitoborne virus and cannot be transferred from one person to another.
Usually the cause is a viral infection, but bacteria can also cause it. In all of these areas, japanese encephalitis is mainly a rural disease. They are based on japanese encephalitis virus genotype iii but are crossprotective against the other genotypes. Symptoms range from nonspecific febrile illness to severe meningoencephalitis, occurring in about one out of 300 cases. Japanese encephalitis je virus is a singlestranded rna virus that belongs to the genus flavivirus and is closely related to west nile and saint louis encephalitis viruses.
Clinical manifestations of japanese encephalitis in. Japanese encephalitis vaccine japanese encephalitis cdc. However, a small percentage of infected people develop inflammation of the brain encephalitis, with symptoms including sudden onset of. Japanese encephalitis vaccine helps protect against the japanese encephalitis virus, an infection spread. It is usually caused by a viral infection, or by the immune system attacking brain tissue, and it is rarely lifethreatening. Japanese encephalitis virus has gradually expanded its geographic range within importance japanese encephalitis virus jev is a mosquitoborne agent that can cause encephalitis in equids and humans and reproductive disease in pigs.
For most travelers to asia, the risk for je is very low but varies based on destination, length of travel, season, and activities. Rapid diagnosis of japanese encephalitis by immunofluorescent examination of cerebrospinal fluid. Dec 07, 2017 encephalitis is an acute inflammation of the brain. This study was conducted to identify clinical symptoms and laboratory findings that may assist in early identification of this disease. Japanese encephalitis virus jev is endemic in much of asia and the western pacific. Japanese encephalitis je remains a public health threat in asia. Both of the diseases may be present at the same time, and both conditions share many of the same symptoms so they may be difficult to distinguish.
However, if there are symptoms, they will appear 5 to 15 days after being infected. Japanese encephalitis virus belongs to the japanese encephalitis serocomplex, which is composed of 9 genetically and antigenically related viruses of the flaviviridae family. Isolation of japanese encephalitis virus from clinical specimens using a continuous mosquito cell line. It is caused by a flavivirus whose natural cycle occurs in mosquito and vertebrate hosts ardeid birds and pigs and man is an.
As such, its very difficult to identify most cases of japanese encephalitis because it either causes no symptoms. It is characterized as acuteonset of fever and a change in mental status mental confusion, disorientation, delirium, or coma andor newonset of seizures in a person of any age at any time of the year. Japanese encephalitis virus is one of the leading causes of epidemic encephalitis worldwide. It is a mosquitoborne flavivirus, meaning it is related to dengue, yellow fever and west nile viruses. Japanese encephalitis is the single largest cause of viral encephalitis in the world today. Japanese encephalitis virus an overview sciencedirect topics.
Most jev infections are mild fever and headache or without apparent symptoms, but approximately 1 in 250 infections results in severe clinical illness. Japanese encephalitis je is the most important cause of viral encephalitis in asia. Japanese encephalitis virus jev is a mosquitoborne agent that can cause encephalitis in equids. Japanese encephalitis je is an infection of the brain caused by the japanese encephalitis virus jev. The risk of japanese encephalitis is very low for travellers, but it does increase with longterm stays or stays in rural areas. Most people infected with je do not have symptoms or have only mild symptoms. The rapid schedule may be used in all age groups from two months of age where there is. Meningitis and encephalitis fact sheet national institute. Acute encephalitis syndrome aes is a serious public health problem in india. Usa, and not in the uk, while japanese encephalitis is a major problem in asia, and is the most important cause of epidemic encephalitis worldwide, causing up to 15000 deaths annually. Description the virus that causes japanese encephalitis is called an arbovirus, which is an arthropodborne virus. Japanese encephalitis is predominantly seen in children, however, some adults who have no prior immunity may be at risk. In children, gastrointestinal pain and vomiting may be the dominant initial symptoms. Acute encephalitis syndrome national health portal of india.
In these cases, symptoms may include headache, vomiting, fever, confusion and seizures. Japanese b encephalitis je occurs in most domestic animals. Japanese encephalitis is an infection spread by culex mosquitoes. Less than 1% of people infected with japanese encephalitis je virus develop clinical illness. Japanese encephalitis virus in meningitis patients, japan. Recognizing symptoms of japanese encephalitis can be tricky, but its important to keep an eye on infected people usually kids in case they take a sudden turn for the worse.
Pdf japanese encephalitis je is a mosquito borne important emerging and. Background and purpose japanese encephalitis virus infection is a sporadic infectious disease in taiwan. Japanese encephalitis virus an overview sciencedirect. Who recommends having strong prevention and control activities, including je immunization in all regions where the disease is a recognized public health problem. Japanese encephalitis june 2018 adults 18 years and older the standard vaccine schedule is two doses of ixiaro 0. This swelling may destroy nerve cells, and cause bleeding in the brain and brain damage. It is a zoonosis an animal disease that can spread to humans primarily transmitted by evening biting culex mosquitoes that feed on infected birds, pigs and other mammals passing the infection to humans living and working in rural areas. Encephalitis is not the same as meningitis, which is inflammation of the membranes covering the brain. Mathur a, kumar r, sharma s, kulshreshtha r, kumar a, chaturvedi uc. Japanese encephalitis also occurs less often in republic of china taiwan, singapore, and hong kong. Most people infected by the japanese encephalitis virus have either no symptoms or mild shortlived symptoms, which are often mistaken for flu.
The symptoms rapidly worsen, and there may be seizures fits, confusion, drowsiness, and loss of consciousness, and even coma. Mar 16, 2020 nmdareceptor encephalitis is a type of autoantibodymediated encephalitis and is being increasingly recognized. A person with mild japanese encephalitis might get symptoms like headache and a fever. Je virus is transmitted to humans through the bite of an infected mosquito, primarily culex species. Clinical manifestations of japanese encephalitis in southern. With a mild case, you may just need rest, plenty of fluids, and a pain reliever. Aug 28, 2018 japanese encephalitis is a viral infection found mainly in asia. Clinical profile and outcome of japanese encephalitis in children.
The 4 vaccine classes include inactivated mouse brain vaccines, inactivated vero cellderived vaccines, live attenuated vaccines, and live recombinant chimeric. Jev is the main cause of viral encephalitis in many countries of asia with an estimated 68 000 clinical cases every year. This vaccine was approved in march 2009 for use in people aged 17 years and older and in may 20 for use in children 2 months through 16 years of age. Definition japanese encephalitis is an infection of the brain caused by a virus.
After the virus enters the body, the brain tissue swells. Inactivated vero cell culturederived japanese encephalitis je vaccine manufactured as ixiaro is the only je vaccine licensed and available in the united states. Encephalitis characterized by rapid onset with a 2 to. The virus is maintained in an enzootic cycle between. Despite progress in laboratory examinations and imaging studies, diagnosis of japanese encephalitis remains underestimated. Japanese encephalitis the center for food security and public. Japanese encephalitis je virus is the leading cause of vaccinepreventable encephalitis in asia and the western pacific. Before 1960, 1,000 japanese encephalitis cases were reported annually in japan. Eastern equine encephalitis virus echovirus japanese encephalitis, which occurs in asia west nile virus. Japanese encephalitis je is an arthropod borne viral disease. The brain symptoms of japanese encephalitis can cause lifelong complications, such as deafness, uncontrollable emotions, and weakness on one side of the body. Japanese encephalitis je is one of many viral encephalitides and results from infection with the japanese encephalitis virus. Encephalitis is a condition of inflammation of the brain parenchyma, occurs as a result of infectious or autoimmune causes, and can lead to encephalopathy, seizures, focal neurological deficits, neurological disability, and death.
In swine, the only evidence of disease may be reproductive failure. Japanese b encephalitis is an exotic, mosquitoborne disease affecting many animals, including wild birds, horses, swine and people. Japanese encephalitis is a viral infection found mainly in asia. Japanese encephalitis virus vaccine sa14142 uses, side.
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