Avian Encephalomyelitis Flashcards

Question	Answer		Article
Name the virus that causes avian encephalomyeltits (AE)?	Avian encephalomyelitis-like virus 1 (AEV).		Link to Article
Is avian encephalomyelitis virus (AEV) a RNA or DNA virus?	AEV is a single stranded RNA (ssRNA) virus		Link to Article
What genus does AEV belong to?	Hepatovirus		Link to Article
What family does the virus belong to?	Picornaviridae		Link to Article
What are the main economic concerns for breeders and layers about AE?	Temporary decrease in egg production in laying hens Decrease in egg hatchability Neurological disease and morbidity /mortality of chicks under three weeks of age Surviving chicks are considered unlikely to be profitable		Link to Article
How is AE spread and what is its epidemiology?	Horizontally via faecal-oral route (main route of infection) Vertical transmission from infected layer to their chicks The virus replicates in the epithial cells of the alimentary tract and is circulated in the bloodstream to other organs and the central nervous system (CNS). The virus is shed within 3 days of oral ingestion and in young chicks can continue to be shed for over two weeks. Shedding ceases once specific antibody's are produced.		Link to Article
What species of birds does AE affect?	Chickens (main domestic host) Species of partridge Turkey Quail Guineafowl Pheasants		Link to Article
What are the clinical signs of AE?	AE causes the most serious disease in chicks under 3 weeks of age. The clinical signs for this age group are: neurological signs ranging from ataxia, rapid tremor of the head and neck, drooping of the wings, weakness, paralysis, exercise intolerance to blindness and changes in vocalisation. Weight loss, lameness, and unthriftiness Affected chicks sit on their hocks, and cannot move well and many fall over onto their sides Laying hens rarely show clinical signs but the virus causes: Temporary reduction (2 weeks) in egg production Decrease in droppings Decrease in hatching rates		Link to Article
How can AE be diagnosed?	The following methods have been used to help diagnose Avian Encephalomyelitis (AE): Virus Neutralization test Agar Gel test Embryo Susceptibility test Elisa test All of the above tests indicate exposure to AE but not neccessarily a current infection. Diagnosis can be achieved confirmed by either histopathology or by virus isolation. Post mortem and identification of pathognomonic lesions in the: Midbrain and rotundua and ovidalis nucleus (microglisosis Proventriculus (dense nodules within the muscular wall) Lesions can also be present in the pancreas		Link to Article
What is the distribution of AE?	Worldwide, the disease has been documented in Africa, Asia, Australia, Europe, and North and South America.		Link to Article
What is the treatment for AE?	There is no treatment for chicks infected with avian encephalomyelitis (AE).		Link to Article
Can chicken and surviving chicks become immune to AEV?	Yes, surviving chicks, infected hens and birds that have been vaccinated will be immune to AE for life.		Link to Article
How many serotypes are there for AEV?	There is only one serotype for the AEV.		Link to Article
How can AE be controlled?	Vaccination of pullets several weeks before they come into lay. Vaccination protects the flock from a reduction in egg production and prevents vertical transmission of the virus to chicks by providing the chicks with a sufficient level of maternal derived antibodies. There are live and attenuated vaccinations available which can be administered in drinking water or as an eye drop, the latter being more effective.		Link to Article