An outbreak of Avian Encephalomyelitis in broilers in Greece

Published: Jan 31, 2018
Avian Encephalomyelitis broilers ELISA Greece histology

Avian Encephalomyelitis Virus (AEV) is an infectious viral disease, member in the family of Picornaviridae, with a preference for the central nervous system and various parenchymatous organs of chickens. AEV is an enteric infection and can be transmitted by oral ingestion, but also vertically from infected broiler breeders to the chick, resulting in clinical signs at hatching. A flock of 18,000 broilers, located in the Southern part of Ipirus, exhibited sudden neurological signs. Clinical examination of 16 days old chicks showed rapid head tremors, ataxia and paralysis, often falling on their sides and lie with their legs at unusual angles. No gross lesions were noted during post mortem examinations conducted at 16, 20 and 26 days of age, apart from gross lesions on the brain. Morbidity of the flock exceeded 25% and total mortality reached 20.9% at the end of flock’s cycle. In order to diagnose the suspected AEV, histological and serological examinations were performed. The results showed typical “flame-shape” proliferation of glia, neuron necrosis and neuronocytophagia in the gray matter and Purkinje cells as well. Also, foci of infiltrating lymphocytes were seen in the brain, the glandular part of pancreas, muscular layer of heart and muscle layer of proventriculus. All observed lesions were characteristic of AEV infection. Serological results in affected flock, conducted by ELISA, showed a consecutive marked increase in serum encephalomyelitis virus antibody titers through time. At 30 days of age onwards, no clinical signs appeared. This clinical case of AEV in broilers was the first case reported in Greece.

Article Details
  • Section
  • Research Articles
Download data is not yet available.
Biocheck Baselines (2012) In: Interpretation and Application of results manual,
Butterfield WK (1975) Avian encephalomyelitis: The virus and immune response. Am J Vet Res 36:557–559.
Butterfield WK, Helmboldt CM, Luginbuhl RE (1969) Studies on avian encephalomyelitis. IV. Early incidence and longevity of histopathologic lesions in chickens. Avian Dis 13:53–57.
Calnek BW (1998) Control of avian encephalomyelitis: a historical account. Avian Dis 42:632-647.
Calnek BW (2008) Avian encephalomyelitis. In (eds: Saif YM, Fadly AM, Glisson JR, McDougald LR, Nolan LK, Swayne DE) Diseases of Poultry 12th edn, Ames, IA: Blackwell Publishing, pp. 430-441.
Calnek BW, Taylor PJ, Sevoian M (1960) Studies on avian encephalomyelitis. IV Epizootology. Avian Dis 4:325-347.
Hishida N, Odagiri Y, Kotani T, Horiuchi T (1986) Morphological changes of neurons in experimental avian encephalomyelitis. Jap J Vet Sci 48:169-172.
Hoekstra J (1964) Experiments with avian encephalomyelitis. Br Vet J 120:322–335.
Hohlstein W M, Deshmukh DR, Larsen CT, Sautter JH, Pomeroy BS, MCDowell JR (1970) An epiornithic of avian encephalomyelitis in turkeys in Minnesota. Am J Vet Res 31: 2233–2242.
Jana PS, Baksi S, Kundu SK, Guha C, Biswas U (2005) Clinicopathological studies on avian encephalomyelitis. Indian Vet. J 82:1037-1039.
King AMQ, Lefkowitz E. Adams MJ, Carstens EB (2012) Virus Taxonomy: Ninth Report of the International Committee on Viral Taxonomy, Academic Press: Waltham, MA.
Marvil P, Knowles NJ, Mockett AP, Britton P, Brown TD, Cavanagh D (1999) Avian encephalomyelitis virus is a picornavirus and is most closely related to hepatitis A virus. J Gen Virol 80:653–662.
Ono M, Okuda Y, Yazawa S, Imai Y, Shibata I, Sato S, Okada K (2003) Adenoviral gizzard erosion in commercial broiler chickens. Vet. Pathol 40: 294-303.
Peckham MC (1957) Case report: lens opacities in fowls possibly associated with epidemic tremors. Avian Dis 1:247-255.
Shafren DR, Tannock GA (1988) An enzyme-linked immunosorbent assay for the detection of avian encephalomyelitis virus antigens. Avian Dis 32:209–214.
Smart IJ, Grix DC, Barr DA (1986) The application of the ELISA to the diagnosis and control of avian encephalomyelitis. Aust Vet J 63:297–299.
Suarez DL (2013) Avian encephalomyelitis. In (eds: Swayne DE, Glisson JR, McDougald LR, Nolan LK, Suarez DL, Nair V) Diseases of Poultry 13th edn, Ames, Wiley-Blackwell, pp. 486-493.
Tannock GA, Shafren DR (1994) Avian encephalomyelitis: a review. Avian Path 23:603-620.
Todd D, Weston JH, Mawhinney KA, Laird C (1999) Characterization of the genome of avian encephalomyelitis virus with cloned cDNA fragments. Avian Dis 43:219-226.
Toplu N, Alcigir G (2004) Avian encephalomyelitis in naturally infected pigeons in Turkey. Avian Path 33:381–386.
Van der Heide L (1970) The fluorescent antibody technique in the diagnosis of avian encephalomyelitis. Univ Maine Tech Bull 44:1–79.
Van Regenmortel MHV, Fauquet CM, Bishop DHL, Carsten EB, Estes MK, Lemon SM, Maniloff J, Mayo MA, McGeoch DJ, Pringle CR, Wickner RB (2000) In (eds. Van Regenmortel MHV, Fauquet CM, Bishop DHL) Virus Taxonomy: Seventh Report of the International Committee on Taxonomy of Viruses 1st edn, Academic Press: San Diego, pp. 1162.
Westbury HA, Sinkovic B (1978) The pathogenesis of infectious avian encephalomyelitis. IV. The effect of maternal antibody on the development of the disease. Aust Vet J 54:81–85.
Most read articles by the same author(s)