Dr. Naresh Jindal College of Veterinary Sciences Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar (INDIA)

 Introduction  Clinical findings  Necropsy findings  Present situation  Economic losses  Future research

 Enteritis is an infectious multifactorial disease of young chicks with clinical signs of diarrhea, depression, lethargy and gross lesions of pale intestines and/or ceca with watery contents.

 Runting stunting syndrome (RSS)  Maldigestion syndrome  Malabsorption syndrome  Infectious stunting syndrome  Helicopter syndromeTurkeys  Poult enteritis complex  Poult enteritis syndrome  Poult enteritis mortality syndrome  Light turkey syndrome

 Multifactorial  Bacteria: ◦ Salmonella ◦ Escherichia coli ◦ Enterococcus ◦ Clostridium  Protozoa: o Coccidia and Cryptosporidia  Viruses

RNA - Rotavirus (RV) - Reovirus (ARV) - Astrovirus (AstV) - Picornavirus - Picorna-like virus DNA -Adenovirus (CAdV) - Parvovirus (CPV)

 Reovirus - Pathogenic and non-pathogenic - Limited homology with turkey isolates  Rotavirus - Group A: Mammals and birds - Group D: Exclusive to birds  Astrovirus - Avian nephritis virus (ANV) - Chicken astrovirus (CAstV) - Turkey astrovirus-1 (TAstV-1) & -2 (TAstV-2)

 Picornavirus - Cause transmissible viral proventriculitis  Adenovirus - Ubiquitous in all avian species  Parvovirus - Induces RSS in broilers - Important determinant in the complex etiology of enteric diseases of poultry

 RNA viruses are unstable  Mutation and recombination are common  Genotype – serotype – pathotype

 Differences in antigenicity and pathogenicity: ◦ Disease presentation ◦ Problems for diagnosis ◦ Epidemiology ◦ Potential vaccines

 Watery faeces  Pasty vent  Poor growth / retarded feather development  Lameness in some of the affected birds  Mortality

Pasty vent Watery feaces

 Pale and thin-walled intestines  Watery and frothy intestinal contents  Distended caeca with watery and foamy contents

Watery contents

Gross lesions- Duodenum ▪Undigested feed ▪Erythema of villi

▪ Watery contents ▪ Undigested feed ▪ Increased mucus

USA  CAstVs in 86% (19/22) of the samples (Pantin- Jackwood et al., 2006)  43 commercial broiler chicken flocks Astroviruses detected in 86% of the flocks (Pantin-Jackwood et al., 2008)

Occurrence of various pathogens in PES- affected flocks (n=151) Pathogen No. (%) of PES flocks Rotavirus 73 (48) Small round virus 26 (17) Reovirus 1 (0.6) Adenovirus 1 (0.6) Salmonella 85 (56) E. coli 54 (36) Enterococcus 16 (11) Eimeria 44 (29) Unknown 9 (6) Jindal et al. (2009).

Detection of enteric viruses from poult enteritis syndrome (PES)-affected cases Method Number (%) of cases positive for Rotavirus TAstV-2/SRV1 Reovirus EM25 (58) 13 (30) 0 RT-PCR40 (93) 36 (84) 17 (40) TAstV-2 = turkey astrovirus-2 (detected by RT-PCR); SRV = small round viruses (detected by electron microscopy). EM = electron microscopy; reovirus and coronavirus were not detected in any of the PES cases by EM. RT-PCR = reverse transcription-PCR; none of the PES cases were positive for coronavirus by RT-PCR. Jindal et al. (2010)

Detection of enteric viruses alone or in combination from poult enteritis syndrome (PES)-affected cases Method Number (%) of cases positive for 1 virus 2 viruses 3 viruses EM16 (59) 11 (41) 0 RT-PCR8 (19) 20 (46) 15 (35) TAstV-2, Rotavirus or reovirus alone or in combination None of the PES cases were positive for coronavirus by RT-PCR. Jindal et al. (2010)

- Tested 34 commercial flock (2010 and 2012) % flocks positive for enteric viruses - Detected combinations of two or more enteric viruses simultaneously in 51.7% of enteric virus-positive chicken farms - ANV, CAstV, RV, ARV major enteric viruses detected (Koo et al., 2013)

 280 intestinal contents samples from chicken  111 samples (39.6%) positive for one virus while 115 (41.1%) samples for two or more enteric viruses  Combination of two viruses detected in 74 samples  ANV, CAstV, RV, FAdV, and ARV were the major viruses detected (Mettifogo et al., 2014)

Pathogen(s) Number (%) of samples positive for indicated viruses CAstV alone31 (47.69) ANV alone04 (6.15) CAstV + ANV26 (40.98) Total61 (93.84) India - Intestinal contents from 65 enteritis-affected chicken flocks ( ) were examined. - Samples collected from birds of 1-3 weeks of age. All samples were negative for ARV and RV

Gp I Gp II Gp III Phylogenetic analysis based on polymerase gene of chicken astrovirus

Amino acid from Amino acid toPosition No. of strains showing the change IsoleucineValine2569/12 LysineAspartic acid2578/12 ValineGlycine2622/12 LeucineGlutamic acid3103/12 SerinePhenylalanine3303/12 GlycineCysteine3312/12 Amino acid changes in polymerase gene of chicken astrovirus

Phylogenetic analysis based on polymerase gene sequences of ANV

Amino acid from Amino acid toPosition No. of ANV strains showing the change ArginineTryptophan12718/9 ThreonineAlanine12898/9 ArginineLysine13022/9 PhenylalanineValine13478/9 Amino acid changes in polymerase gene of avian nephritis virus

-Conducted a study in five breeder flocks -Flocks sampled for nine weeks -Maximum viral load upto 3 weeks of age Age in weeks Viral load 6 Jindal et al. (2011)

 Estimated losses from growth depression due to poult enteritis between US$300 and US$400 million annually considering 10% -15% growth depression throughout the turkey industry in the US (Barnes et al., 2000)  Experimental studies revealed growth depression upto 31% in turkey poults ( Jindal et al., 2009, 2010) Economic losses

 birds broiler chicken farm  Necrotic enteritis resulted in a 12% reduction in body weight and a 10.9% increase in feed conversion ratio compared to healthy birds  Final body weights ranged from 4.63 to 7.94 lb  Loss to producer ranged from US$ to US$ per flock due to weight loss  Increased feed cost ranged from US$ to US$ per flock ( Skinner et al., 2010 ) Economic losses contd…

 Second largest egg (65 billion eggs) and third largest broiler chicken meat (3.8 million tonnes) producer in the world as in  Market is estimated to be worth about Rs 90,000 crore (equal to 900 billion USD).  By 2016 total chicken meat consumption forecast at 4.19 million tons, up by approximately 8% over 2015.

▪Experimental reproduction of the disease ▪Surveillance studies ▪NGS study ▪Potential pathogens and viral interactions ▪Economic losses ▪Prevention and control measures

1.Prof. Sagar M. Goyal 2.Dr. Andre F. Ziegler 3.Dr. Devi P. Patnayak 4.Dr. Sunil K. Mor 5. Dr. Babita Kaithal 6. Dr. Pawan Bagri