Scientists Study Causes of Poult Enteritis Complex06 May 2013
BRAZIL - Researchers tested growing and finishing turkeys from farms across the country for a number of viruses in order to gain a greater understanding of the cause(s) of poult enteritis complex.
Poult enteritis complex has been associated with enteritis and reduction in growth rates in commercial turkeys worldwide, report J. Moura-Alvarez of the University of São Paulo in Brazil and co-authors there and at the UK's University of Liverpool.
In a paper in Poultry Science, they report an experiment in which intestinal samples from 76 turkey flocks from different Brazilian states affected or not with intestinal disorders were evaluated for the presence of adenovirus groups 1 and 2 (TAV), astrovirus types 1 and 2 (TAstV-1 and TAstV-2), turkey coronavirus (TCoV), reovirus, rotavirus and avian nephritis virus (ANV) using PCR.
The percentage of positive samples was categorised according to the geographic origin, age of the flocks and presence of clinical signs of intestinal disease.
The percentage of samples that were positive for at least one virus was 93.4 per cent, whereas the percentage of samples that were positive for more than one virus was 69.7 per cent.
An average of 3.20 viruses per sample was detected in turkeys in the growing phase of the production cycle (one to four weeks of age). The TAstV-1 and TCoV were the most frequently observed viruses in growing phase turkeys and occurred simultaneously in 85 per cent of these samples.
In turkeys in the finishing phase of development (five to 18 weeks), a lower average number of viruses was observed (2.41), and the most frequent viruses isolated in these turkeys were TAstV-1 (57.1 per cent) and rotavirus (51.8 per cent).
Overall, every virus was detected more frequently in growing phase turkeys than in finishing phase turkeys with the exception of TAV.
Samples from flocks exhibiting clinical signs of intestinal disease showed a higher rate of positivity, and TAstV-1, TAstV-2 and TCoV were the most frequently occurring viruses in this cohort.
Birds without clinical signs most frequently harbored TAstV-1 and rotavirus.
Moura-Alvarez and co-authors suggested that future studies should focus on the description and elucidation of the role of each virus, as well as the pathogenic and immunological implications of the different combinations of viruses in turkeys.
Moura-Alvarez J., J.V. Chacon, L.S. Scanavini, L.F.N. Nuñez, C.S. Astolfi-Ferreira, R.C. Jones and A. J. Piantino Ferreira. 2013. Enteric viruses in Brazilian turkey flocks: Single and multiple virus infection frequency according to age and clinical signs of intestinal disease. Poult. Sci. 92(4):945-955. doi: 10.3382/ps.2012-02849
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