Changes

Also Known As: '''''Baby Chick Nephritis — BCN — Infectious Stunting Syndrome — ISS'''''

Also Known As: '''''Baby Chick Nephropathy — BCN'''''

Caused By: Avian Nephritis Virus (ANV)

Caused By: Avian Nephritis Virus (ANV)

==Introduction==

==Introduction==

Avian nephritis is caused by an '''RNA [[:Category:Astroviridae|astrovirus]]''' and affects '''solely chickens.'''

Avian nephritis is caused by an '''[[:Category:Astroviridae|astrovirus]]''' and affects '''solely chickens.'''

 

==Distribution==

==Distribution==

Disease is more severe when combined with '''other immunosuppressive agents''' such as [[Infectious Bursal Disease]] and also with cold stress and poor nutrition.

Disease is more severe when combined with '''other immunosuppressive agents''' such as [[Infectious Bursal Disease]] and also with cold stress and poor nutrition.

In cases of '''baby chick nephropathy''', incidence peaks at ~5 days of age, and mortality rates may rise to 6%. This condition is thought to occur at a low level in most broiler flocks and is merely exacerbated by many factors.<ref>Jones, B. A. H (1992) '''Avian nephritis virus'''. Publication - ''Veterinary Continuing Education, Massey University'', No. 147:53-58; [Proceedings Solvay chicken health course, Massey University, 1992]; 12</ref>

In cases of '''baby chick nephropathy''', incidence peaks at ~5 days of age, and mortality rates may rise to 6%. This condition is thought to occur at a low level in most broiler flocks and is exacerbated by many factors.<ref>Jones, B. A. H (1992) '''Avian nephritis virus'''. Publication - ''Veterinary Continuing Education, Massey University'', No. 147:53-58; [Proceedings Solvay chicken health course, Massey University, 1992]; 12</ref>

==Diagnosis==

==Diagnosis==

'''Smears of kidney tissue''' can be fixed onto slides and '''[[immunofluorescence]] or immunohistochemistry''' can be used to demonstrate viral antigens.  

'''Smears of kidney tissue''' can be fixed onto slides and '''[[immunofluorescence]] or immunohistochemistry''' can be used to demonstrate viral antigens.  

Faeces and liver can also be used for viral isolation. Viral presence can be confirmed by immunofluorescence or neutralisation.

Faeces and liver can also be used for viral detection. Viral presence can also be confirmed by immunofluorescence, neutralisation and RT-PCR.

Serological tests comprise of '''virus neutralisation, [[ELISA testing|ELISA]] and indirect immunofluorescence''', of which neutralisation is the most sensitive and can be used from one week after initial infection. Antibodies to ANV are however often an incidental finding.

Serological tests comprise of '''virus neutralisation, [[ELISA testing|ELISA]] and indirect immunofluorescence''', of which neutralisation is the most sensitive and can be used from one week after initial infection. Antibodies to ANV are however often an incidental finding.

==Control==

==Control==

Maternal antibodies are usually protective so immunisation of breeding hens is potentially possible but no vaccine is available despite experimental success. This is due to the economic impact of AN being unknown and therefore investment seeming unjustified.

Maternal antibodies are usually protective so immunisation of breeding hens is potentially possible but no vaccine is available despite experimental success. This is due to the economic impact of AN being unclear, and knowledge of avian astroviruses insufficient, and therefore investment seeming unjustified.

An '''all-in-all-out policy''', thorough emptying of sheds between batches and formaldehyde disinfection have all been demonstrated to reduce incidence of AN and ISS.<ref>Reece, R, Frazier, J (1991) '''Infectious stunting syndrome breakthrough'''. ''Poultry International,'' Nov:16-24.</ref>

An '''all-in-all-out policy''', thorough emptying of sheds between batches and formaldehyde disinfection have all been demonstrated to reduce incidence of AN and ISS.<ref>Reece, R, Frazier, J (1991) '''Infectious stunting syndrome breakthrough'''. ''Poultry International,'' Nov:16-24.</ref>