''Avastrovirus 2'', also called avian nephritis virus, is an

astrovirus Astroviruses are a type of virus that was first discovered in 1975 using electron microscopes following an outbreak of diarrhea in humans. In addition to humans, astroviruses have now been isolated from numerous mammalian animal species (and are ...

which causes 'avian nephritis' in

chicken The chicken (''Gallus gallus domesticus'') is a domestication, domesticated junglefowl species, with attributes of wild species such as the grey junglefowl, grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster ...

s. Causes: Infectious Stunting Syndrome — ISS — Baby Chick Nephritis — BCN. The virus has been reported in Japan,

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

, USA and

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

. The disease is mainly transmitted horizontally by the oro-faecal route, but rarely

vertical transmission Vertical transmission of symbionts is the transfer of a microbial symbiont from the parent directly to the offspring. Many metazoan species carry symbiotic bacteria which play a mutualistic, commensal, or parasitic role. A symbiont is acquired ...

may occur. Clinical signs of the disease are normally only seen in chicks less than two weeks old, and these signs should be mild unless the chick is

immunosuppressed Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse react ...

Clinical signs and diagnosis

In mild cases

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin ...

stunted growth Stunted growth is a reduced growth rate in human development. It is a primary manifestation of malnutrition (or more precisely undernutrition) and recurrent infections, such as diarrhea and helminthiasis, in early childhood and even before birth ...

and

skin lesions A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of thi ...

are the common clinical signs. Clinical signs are more severe in immunosuppressed, under-nourished or stressed chicks, with infection causing

nephrosis Nephrosis is any of various forms of kidney disease (nephropathy). In an old and broad sense of the term, it is any nephropathy, but in current usage the term is usually restricted to a narrower sense of nephropathy without inflammation or neopla ...

emaciation Emaciation is defined as the state of extreme thinness from absence of body fat and muscle wasting usually resulting from malnutrition. Characteristics In humans, the physical appearance of emaciation includes thinned limbs, pronounced and protrud ...

and even sudden death. On

postmortem An autopsy (post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death or to evaluate any dis ...

examination

nephritis Nephritis is inflammation of the kidneys and may involve the glomeruli, tubules, or interstitial tissue surrounding the glomeruli and tubules. It is one of several different types of nephropathy. Types * Glomerulonephritis is inflammation ...

with accumulation of uric acid (gout) and

enteritis Enteritis is inflammation of the small intestine. It is most commonly caused by food or drink contaminated with pathogenic microbes,Dugdale, David C., IIII, and George F Longretc"Enteritis" MedlinePlus Medical Encyclopedia, 18 October 2008. Acces ...

are commonly present. A presumptive diagnosis may be based on clinical signs. For definitive diagnosis the virus or viral

antigen In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...

s must be demonstrated in the affected tissue(s). Diagnostic techniques used are virus neutralisation,

ELISA The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presence ...

immunofluorescence Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on microbiological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to speci ...

and RT-PCR.

Treatment and control

There is currently no effective treatment for avian nephritis. Hygiene measures such as the use of an "all-in-all-out" policy and thorough

disinfection A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than s ...

of housing between batches should be employed to control disease. Adequate nutrition and a stress-free environment should decrease the amount of clinical disease seen in flocks.

References

Bibliography

*Avian Nephritis, reviewed and published by

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Avian Nephritis - WikiVet English
accessed 16/08/2011. {{Taxonbar, from1=Q18966498, from2=Q4828556 Animal viral diseases Poultry diseases Astroviridae