An unusual outbreak of inclusion body hepatitis on a broiler chicken farm: a case report

Abstract

ABSTRACT:This study investigated an outbreak of inclusion body hepatitis in ROSS 308 hybrid broiler type chickens between 19 and 25 days of fattening. For this purpose, clinical observation, ELISA fowl adenovirus and chicken anaemia virus antibody detection in serum at 21 and 42 days, mortality evaluation, epidemiological analysis, histology and genetic identification were performed. The six flocks of the farm consisted of 90,000 chickens. Only one flock of 15,000 chickens was affected on this farm. At 19 days of age, ill chickens showed clinical signs of depression, anorexia, somnolence, ruffled feathers, anaemic comb and wattles and occasionally nervous signs. Based on ELISA titres, the antibody response to fowl adenovirus increased greatly from 21 to 42 days. The antibody response to vaccination against infectious bursal disease virus and chicken anaemia virus was at the expected level in all broiler flocks. Necropsy showed diffuse petechial and ecchymotic haemorrhages in skeletal muscles, liver, pancreas, kidney, together with hepatomegaly, splenomegaly and catarrhal enteritis. Histologically, fatty liver degeneration, multifocal liver necrosis and intranuclear inclusions in hepatocytes, as well as focal necrosis in pancreas and spleen parenchyma were seen. The DNA of AAV-1 (avian adenovirus group 1) was detected using the PCR method in paraffin-embedded liver samples. The results revealed no association of inclusion body hepatitis with infectious bursal disease virus or chicken anaemia virus infection, and suggested primary disease. However, the involvement of only one chicken flock on the farm remains unexplained.

Fowl adenovirus induced different manifestations of the disease in two consecutive chicken breeding flocks in a poultry hall

“…The PCR analysis documented that both broiler flocks were infected with FAdV-A. Vertical and horizontal modes of FAdV-A transmission have both been described (Grafl et al 2012;Revajova et al 2017;Schachner et al 2018). Based on the serological evaluation of our data, we suggest the horizontal transmission of FAdV-A in both feeding flocks.…”

“…IBH is not a very serious disease with a low mortality rate ranging from 5% to 10%, although mortality can be up to 30% due to secondary infections (Mase et al 2012). In our recent investigation of an IBH outbreak with the findings of FAdV-A (Revajova et al 2017), the daily mortality during the culmination of the disease was only 0.8%. The second consecutive broiler flock in our current case report showed high positivity to FAdV in all the examined chickens at sampling day 41.…”

“…2012 ). In our recent investigation of an IBH outbreak with the findings of FAdV-A ( Revajova et al. 2017 ), the daily mortality during the culmination of the disease was only 0.8%.…”

“…In recent years, outbreaks of the hepatitishydro pericardium syndrome and adenoviral gizzard erosions have led to an increased concentration of fowl adenoviruses (FAdVs) which have become primary aetiologic agents particularly in broiler chickens (Gomis et al 2006;Hess 2017;Revajova et al 2017). FAdVs of the genus avian adenovirus cause inclusion body hepatitis (IBH) (Harrach et al 2011).…”

Efficacy, immunogenicity, and virus shedding in broiler chickens inoculated with live attenuated fowl adenovirus serotype 8b propagated a bioreactor

“…Fowl adenovirus (FAdV) 8b is a group E Aviadenovirus in the family Adenoviridae ( Islam et al 2023 ). It causes inclusion body hepatitis (IBH) mainly in broilers that are 3–7 weeks old and causes mortality ranging from 2% to 30%; and is characterized by sudden death without clinical signs, enlarged, friable, and discolored liver with petechial hemorrhages; and hemorrhages in other organs ( Norina et al ., 2016 ; Revajova et al ., 2017 ; Abd El-Ghany, 2023). Basophilic or eosinophilic intranuclear inclusion bodies are commonly detected in the liver and inflammatory mononuclear infiltration could be found in other organs ( Revajova et al ., 2017 ).…”