Kunjin virus has been detected in sentinal chickens near Darwin!
Japanese Encephalitis Virus (JEV) belongs to the Japanese encephalitis serocomplex made up of 10 flavivures which include Kunjin, West Nile, Murray Valley and St. Lous encephalitis. It is the most significant arboviral encephalitis worldwide.
JEV is a systemic infection transmitted by the bite of mosquitoes in endemic areas in asia, primarily Culex tritaeniorhynchus (Aedes have also been implicated). After infection a viraemia develops, with resulting inflammation of heart, lungs, liver and reticuloendothelial system. The infection is usually cleared prior to CNS infection, resulting in subclinical disease. When CNS invasion does occur the virus has a direct toxic effect on brain cells and in particular neural progenitor cells. The infection can involve thalamus, basal ganglia, brain-stem, cortex, cerebellum and hippocampus
Symptomatic cases are approximately 1 in every 150,000 person-months spent in an endemic area, however only 1 in every 250 infections results in clinical disease. Mortality with good intensive care support approximates 5 - 10% and may exceed 35% in less well-developed areas. Up to 50% of survivors have major neurologic sequelae at 1 year. Previous Dengue infection may have a protective effect.
Incubation period is 6 - 8 days. Prodrome is characterised by an influenza-like illness with fevers, headache and myalgias. Subsequent altered mental state can range from confusion to coma. Seizures appear in 66% of cases. Tremor or other involuntary movements are common. Neurologic signs may vary but can include hypertonia and hyperreflexia. Papilloedema develops in less than 10% of patients, and 33% have cranial nerve findings. Extrapyramidal symptoms are common.
Test both blood and CSF for JEV IgM Ab. MRI and CT scan often show bilateral thalamic lesions with haemorrhage. Treatment is supportive, and may include interventions for raised ICP. Steroids have not shown benefit. JEV vaccine exists for prevention, has a risk of hypersensitivity reaction (such as angioedema) which can be delayed up to 10 days.
Information from eMedicine's Japanese Encephalitis page here
Japanese Encephalitis Virus (JEV) belongs to the Japanese encephalitis serocomplex made up of 10 flavivures which include Kunjin, West Nile, Murray Valley and St. Lous encephalitis. It is the most significant arboviral encephalitis worldwide.
JEV is a systemic infection transmitted by the bite of mosquitoes in endemic areas in asia, primarily Culex tritaeniorhynchus (Aedes have also been implicated). After infection a viraemia develops, with resulting inflammation of heart, lungs, liver and reticuloendothelial system. The infection is usually cleared prior to CNS infection, resulting in subclinical disease. When CNS invasion does occur the virus has a direct toxic effect on brain cells and in particular neural progenitor cells. The infection can involve thalamus, basal ganglia, brain-stem, cortex, cerebellum and hippocampus
Symptomatic cases are approximately 1 in every 150,000 person-months spent in an endemic area, however only 1 in every 250 infections results in clinical disease. Mortality with good intensive care support approximates 5 - 10% and may exceed 35% in less well-developed areas. Up to 50% of survivors have major neurologic sequelae at 1 year. Previous Dengue infection may have a protective effect.
Incubation period is 6 - 8 days. Prodrome is characterised by an influenza-like illness with fevers, headache and myalgias. Subsequent altered mental state can range from confusion to coma. Seizures appear in 66% of cases. Tremor or other involuntary movements are common. Neurologic signs may vary but can include hypertonia and hyperreflexia. Papilloedema develops in less than 10% of patients, and 33% have cranial nerve findings. Extrapyramidal symptoms are common.
Test both blood and CSF for JEV IgM Ab. MRI and CT scan often show bilateral thalamic lesions with haemorrhage. Treatment is supportive, and may include interventions for raised ICP. Steroids have not shown benefit. JEV vaccine exists for prevention, has a risk of hypersensitivity reaction (such as angioedema) which can be delayed up to 10 days.
Information from eMedicine's Japanese Encephalitis page here
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