Hydropericardium hepatitis syndrome of broiler poultry: current status of research

A PREVIOUSLY unknown emerging disease with some clinical similarities to inclusion body hepatitis but characteristically causing severe hydropericardium resulting in heavy mortality of broiler poultry was reported in specific areas of the world. Studies undertaken at various laboratories (Rabbani and 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 deaths among broilers in the age group of 3 to 5 weeks with mortality levels reaching up to 75 per cent, hydropericardium, hepatitis with focal necrosis, pulmonary oedema, and nephritis are the highlights of the episodes. Although liver damage was also seen in inclusion body hepatitis (IBH), severe hydropericardium in 3-week-old chicks, due to an adenovirus infection, was not a feature noticed until very recently. In order to distinguish hydropericardium hepatitis syndrome (HHS) from classical IBH and to emphasise its infectious nature, the new disease was named as 'infectious hydropericardium IH' (Abdul-Aziz and Hassan 1995, Mazaheri et al 1998). The disease is variously termed as 'Angara disease' in Pakistan, after the place Angara Goth near Karachi (Akhtar 1994), 'Leechy' or 'Litchi disease' in India, after the look of heart floating in pericardial fluid, simulating a de-skinned Leechy fruit (Gowda and Satyanarayana 1994), or 'inclusion body hepatitis-hydropericardium syndrome IBH-HPS' (Jadhao et al 1997) and also as 'hydropericardium hepatitis syndrome HHS' (Shane 1996, Ganesh 1998) or 'hydropericardium hepatopathy syndrome HHS' (Asrani et al 1997) or 'hydropericardium syndrome HPS' (Naeem et al 1995a).