Simultaneous detection of astrovirus, rotavirus, reovirus and adenovirus type I in broiler chicken flocks

Enteric diseases cause substantial economic losses to the poultry industry. Astroviruses, rotaviruses, reoviruses, and adenovirus type 1 have been reported as a significant cause of intestinal symptoms in poultry. In the present study, intestinal samples from 70 commercial broiler chicken flocks were examined for the presence of astroviruses, rotavirus, and reovirus by reverse transcription-polymerase chain reaction, and for the presence of group I adenovirus by polymerase chain reaction. Astroviruses were identified in 38.6% of samples tested. Both avian nephritis virus and chicken astrovirus were identified in the astrovirus positive flocks, where 74.1% of these flocks were positive for only one type of astrovirus, whereas, 25.9% of these flocks were positive for both types of astrovirus. Reoviruses, rotaviruses, and adenoviruses were identified in 21.4, 18.6, and 14.3% of these flocks, respectively. Concomitant infection with two or more viruses in the same flock were also prominent, where 5.7, 5.7, 2.9, 2.9, 1.4, and 1.4% of these flocks were positive with both astrovirus and rotavirus; astrovirus and adenovirus; astrovirus and reovirus; rotavirus and adenovirus; rotavirus and reovirus; and reovirus and adenovirus respectively. Moreover, 4.3 and 2.7% of these flocks were positive for astrovirus, reovirus, and adenovirus; and astrovirus, reovirus, and rotavirus, respectively. Further studies will focus on identifying specific viral factors or subtypes/subgroups associated with disease through pathogenesis studies, economic losses caused by infections and co-infections of these pathogens, and the costs and benefits of countermeasures.