Hydropericardium hepatitis syndrome of broiler poultry: current status of research

A PREVIOUSLY unknown emerging disease with some clinical similarities to in clusion body hepatitis but characteristically causing severe hydropericardi um resulting in heavy mortality of broiler poultry was reported in specific areas of the world. Studies undertaken at various laboratories (Rabbani an d Naeem 1996, Voss et al 1996, Mazaheri et al 1998) have indicated that the causative agent is a fowl adenovirus (FAV) group I, Serotype 4. Sudden dea ths among broilers in the age group of 3 to 5 weeks with mortality levels r eaching up to 75 per cent, hydropericardium, hepatitis with focal necrosis, pulmonary oedema, and nephritis are the highlights of the episodes. Althou gh liver damage was also seen in inclusion body hepatitis (IBH), severe hyd ropericardium in 3-week-old chicks, due to an adenovirus infection, was not a feature noticed until very recently. In order to distinguish hydroperica rdium hepatitis syndrome (HHS) from classical IBH and to emphasise its infe ctious nature, the new disease was named as 'infectious hydropericardium IH ' (Abdul-Aziz and Hassan 1995, Mazaheri et al 1998). The disease is various ly termed as 'Angara disease' in Pakistan, after the place Angara Goth near Karachi (Akhtar 1994), 'Leechy' or 'Litchi disease' in India, after the lo ok of heart floating in pericardial fluid, simulating a de-skinned Leechy f ruit (Gowda and Satyanarayana 1994), or 'inclusion body hepatitis-hydroperi cardium syndrome IBH-HPS' (Jadhao et al 1997) and also as 'hydropericardium hepatitis syndrome HHS' (Shane 1996, Ganesh 1998) or 'hydropericardium hep atopathy syndrome HHS' (Asrani et al 1997) or 'hydropericardium syndrome HP S' (Naeem et al 1995a).