Chick Anaemia Virus is a hidden menace

摘要

Chick Anaemia Virus is a disease that may spread vertically as well as horizontally. Today, a full-blown clinical disease is rare in many countries, but it may still cause dramatic losses. Understanding the disease and its transmission will help to better prevent birds from contracting an infection. It is widely accepted in many parts of the world that Chick Anaemia Virus (CAV) can have a serious economic impact on the poultry industry through direct clinical and potentially even more damaging sub-clinical disease. CAV was first identified in 1979 and has since been found in all parts of the world where poultry are kept commercially. The causal virus is a very small circovirus, resistant to acid pH, ether, chloroform and heat. The disease it produces is important clinically through increased mortality, costs of treatment from secondary infection and poor growth. Classical infection is from breeders infected in lay, which transmit the virus vertically to give disease in broiler progeny at 10-14 daysof age. Mortality may reach 60%. Affected broilers are stunted, pale, show morbidity, severe skin infections, fungal infections and general immunosuppression. Additionally, these chicks are produced for 3-6 weeks after the infection first enters the susceptible breeder flock. It is estimated that the disease may cost the US industry alone approx. $50 million each year!