Haemorrhagic enteritis of turkeys – current knowledge
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Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
Taylor and Francis
Abstract
Haemorrhagic enteritis virus (HEV), an adenovirus associated with acute haemorrhagic gastrointestinal
disease of 6–11-week old turkeys predominantly hampers both humoral and cellular
immunity. Affected birds are more prone to secondary complications (e.g. colibacillosis and
clostridiosis) and failure to mount an effective vaccine-induced immune response. HEV belongs
to the new genus Siadenovirus. Feco-oral transmission is the main route of entry of the virus
and it mainly colonizes bursa, intestine and spleen. Both naturally occurring virulent and
avirulent strains of HEVs are serologically indistinguishable. Recent findings revealed that ORF1,
E3 and fib genes are the key factors affecting virulence. The adoption of suitable diagnostic
tools, proper vaccination and biosecurity measures have restrained the occurrence of disease
epidemics. For diagnostic purposes, the best source of HEV is either intestinal contents or
samples from spleen. For rapid detection highly sensitive and specific tests such as quantitative
real-time PCR based on Taq man probe has been designed. Avirulent strains of HEV or MSDV
can be effectively used as live vaccines. Novel vaccines include recombinant hexon proteinbased
subunit vaccines or recombinant virus-vectored vaccines using fowl poxvirus (FPV)
expressing the native hexon of HEV. Notably, subunit vaccines and recombinant virus vectored
vaccines altogether offer high protection against challenge or field viruses. Herein, we converse
a comprehensive analysis of the HEV genetics, disease pathobiology, advancements in
diagnosis and vaccination along with appropriate prevention and control strategies.
Description
TNV_VQ_2017_37(1)31-42
Keywords
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