Adenoviruses Infections with Special Attention to Inclusion Body
Hepatitis/ Hydropericardium Syndrome and Egg Drop Syndrome
Hafez Mohamed Hafez*
Institute of Poultry
Diseases, Faculty of Veterinary Medicine, Free University Berlin,
Königsweg, 14163 Berlin, Germany
*Corresponding author: email@example.com
The first avian adenovirus (AAV) associated with clinical disease was
isolated from an outbreak of respiratory disease in quail in 1950 (Olson, 1950).
Since that time, AAVs have been found in all types and breeds of chickens and
from a variety of other avian species. The infections may be asymptomatic or
associated with several clinical and pathological conditions. Vertical
transmission via the egg is the most common way of transmission. Also horizontal
transmission through faeces, contaminated egg trays, crates and trucks plays a
role in the infection route. Studies have demonstrated the presence of
antibodies in healthy poultry, and viruses have been isolated from normal birds.
Avian adenoviruses in chickens are the etiologic agents of 2 diseases known as
inclusion body hepatitis (IBH) and hydropericardium syndrome (HP). In some cases
each condition is observed separately, however, recently the 2 conditions have
frequently been observed as a single entity; therefore, the name hepatitis
hydropericardium has been widely used to describe the pathologic condition. The
syndrome is an acute disease of young chickens associated with anemia,
haemorrhagic disorders, hydropericardium and high mortality.
Egg-Drop-Syndrome (EDS) is caused also by an adenovirus. The disease is
characterised by a severe drop in egg production as well as the production of
shell-less, thin-shelled, discoloured or misshapen eggs in apparently healthy
birds. Ducks and geese are the natural host of the EDS virus. It was first
described in chickens in the 1970s and spread to several countries world wide.
The birds usually do not show any other signs of disease, and mortality is not
expected. There is no specific treatment of the AAV infections. Active
immunization by vaccination using an inactivated is wide spread.