FINAL WVPC Cairo September 2024 Immunosuppression.pptx

adeno virus in poultry from pathogenesis til vaccination

1. Inmunosupressive disease agents: new challenges in the field Dr. Aris Malo independent poultry consultant Dr med vet hanover , Germany Poultry specialist Utrecht, the netherlands

2. Impairment of the immune response Infectious and non-infectious causes Temporary or permanent Results PRIMARILY in AN increased susceptibility to disease agents One of the main causes of economic losses in the poultry industry “ INmunosuppresion ”

3. Interactive immunosuppressive agents MDV CAV IBDV CAV REO 1+1 = 3 or MORE

4. Marek’s disease INCREase in Virulence Witter. Avian Pathol (1998)

5. 5 Immunosuppresion (early / late) Tumoral Lesions and associated syndromes Non tumoral lesions and associated syndromes Consequences, clinical signs and Lesions

6. Chickens challenged with MDV Relative weight of the Bursa of Fabricius (B.W. CALNEK ET AL, 1998) % of body weight 8 Days Post Inoculation 14 Days Post Inoculation Control GA5 Md5 RK1 Control GA5 Md5 RK1 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 vMDV vvMDV JM1 6 RB1B 584A 648A JM1 6 RB1B 584A 648A vv+ MDV vMDV vvMDV vv+ MDV

7. Control JM1 6 GA5 RB1B Md5 RK1 584A 648A Control JM1 6 GA5 RB1B Md5 RK1 584A 648A 0.1 0.2 0.3 0.4 0.5 0.6 0.7 8 Days Post Inoculation 14 Days Post Inoculation Chickens challenged with MDV Relative weight of the Thymus (B.W. CALNEK ET AL, 1998) % of body weight

8. M V VV VV + INFLAMATION TUMORS IMMUNOSUPPRESSION SOURCE: I. JIMENO CLINICAL MANIFESTATION INDEX MDV EVOLUTION AND CONSEQUENCES ON MD MDV PATHOTYPE

9. Immunosuppression by MDV Transitory/permanent atrophy (V+) of the lymphoid Organs The most critical problem with MD nowadays is the reactivation of the virus due to vv + strains causing permanent immunosuppression Alteration of the Humoral / cellular immune response (deregulation of the immune system) Increase in susceptibility to other pathogens Synergistic Effect in birds co-infected with CAV - gumboro - REovirus

10. vaccination against marek’s disease CURRENT VACCINES DO NOT PROTECT AGAINST LATE IMMUNOSUPPRESSION GEN DELETED VACCINES (MEQ –) OR CHIMERA VACCINES

11. F52 /70 STD F 91168 I 77165 CA 2009 Asia Africa Latin America Del-E; Ph- B24 ; AL-2; AL-10; AVS-EL Classical vIBDV Hypervirulent vvIBDV Variants High Mortality INFECTIOUS BURSAL DISEASE

12. INFECTIOUS BURSAL DISEASE

13. genogroup 1– classical strain present worldwide genogroup 2 - antigenic variant predominantly usa and central america genogroup 3 - vvIBDV pathotype present worldwide Genogroup 4 – early european and recent south american Genogroup - 5 atypical and recombinant strains ( classical / variants ) from Mexico Genogroup 6 – atypical italian genogroup 7/8 – Australian strains (2 groups ( classical and variants )

14. VIRUS OF serotYpE 1 IS pathogenic FOR CHICKENS THE GENOME OF THE virus HAS 2 segments , A AND B AND ARE DIVIDED in different genogroups Segment A: A1 (classical), A2 (antigenic variant usa ), A3 (VERY virulent), A4 ( dIBDV ), A5 (atypical Mexican), A6 (atypical Italian), A7 (Australian) AND A8 (Australian variant) Segment B : B1 (classical), B2 (VERY virulent), B3 (Australian), B4 (Polish and Tanzanian) AND B5 (Nigerian) 45 possible combinations AND the recognition of 15 genotypes ClaSsificaTION OF THE virus (BY RT-PCR/RFLP) NEW TYPES - REASSORTANTS A3B1

15. NEW TYPES - REASSORTANTS ClasSificaTION BY RT-PCR/RFLP WESTERN EUROPE – A3B1 EGYPT – A1B2 NOVEL VARIANT A2B1 CLASSICAL – A1B1 VERY VIRULENT – A3B2 US VARIANTS – A2B1

16. INFECTIOUS BURSAL DISEASE

17. Results Efficacy study “new reASSORTANT strainS ” Efficacy of a live attenuated infectious bursal disease intermediate vaccine against challenge with divergent isolates from different parts of the world   Malo, A. et al Classical strain

18. AVIAN Reovirus CAUSATIVE Agent: Viral Arthritis /Tenosynovitis AssociateD TO: MALABSORBTION Syndrome (MAS)/RUNTING STUNTING Syndrome ( rss ) Enteric Problems FEMORAL HEAD necrosis Proventriculitis Pericarditis/myocarditis Hepatitis

19. Avian Reovirus Immunosuppression Mainly due to atrophy of the bursa of Fabricius (virus present 2 – 12 days p.i. ) Infection of macrophages affecting their response Lymphoid Depletion in organs of the immune System and Apoptosis

20. Avian Reovirus : VARIANTS

21. Avian Reovirus: variants

22. Avian Reovirus: 7 genetic Groups Avian Reovirus: classification H. Sellers, Avian Diseases 2022

23. Have been identified in different parts of the world: Gc1* - Costa Rica, Bangladesh, Chile, Brazil Gc2 - Nicaragua, Poland, Korea, Bangladesh, Panama, Colombia, Chile, costa Rica Gc3 - Colombia, Chile, Jamaica Gc4 - Nicaragua, Poland Gc5 - USA, Argentina, Honduras, Peru, Mexico, Bolivia, Chile, Nicaragua, Costa Rica, Brazil, Colombia, Poland, The Netherlands, Germany, Belgium, United Kingdom, Spain, Ireland, France, Switzerland, Denmark, South Africa, Indonesia, Philippines, China, UAE, Iran Gc6 - Chile, PanamA GC7 - north America * subgroups different to vaccine strains Avian Reovirus: variant strains

24. AVIAN REOVIRUS VARIANT STRAINS ALL GROUPS OF AVIAN reovirus MAY CAUSE MAS, VA, immunosuppression variants STRAINS HAVE BECOME important IN THE LAST YEARS No ASSOCIATION BETWEEN genotypes AND geographical zones Theoretically VACCINES SHOULD INCLUDE THE DIFFERENT GENOTYPES FOR BROAD PROTECTION NEED TO UPDATE / DEVELOP LIVE AND inactivated VACCINE FOR GOOD DISEASE control

25. Conclusion: Immunosuppression is a MULTIFACTORIAL problem - Difficult to Diagnose (subclinical character) - Economic losses Important Changes in disease agents represent A NEW challenge for the industry and must be followed up carefully ( MONITORING ) Vaccination against MD, CAV, IBD, REO, etc In PS and in the progeny

26. Thank you Peristeria elata