The Occurrence, Diagnosis and Control of Variant Infectious Bronchitis (a coronavirus) in Asia
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A presentation by Dr. Rafael Monleon at the Asia Poultry Health Conference in Bangkok, Thailand - 14th and 15th May 2012
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The Occurrence, Diagnosis and Control of Variant Infectious Bronchitis (a coronavirus) in Asia
- 1. Dr. Rafael Monleon, DVM, MSpVM, ACPV, PAS Regional Veterinarian (Asia) Poultry Health Conference 14-15 May 2012, Bangkok (Thailand) The Occurrence, Diagnosis and Control of Variant Infectious Bronchitis in Asia
- 2. Objectives • Infectious bronchitis virus (IBV) and Infectious bronchitis virus variants (IBVv) • Distribution and prevalence • Disease manifestations • Diagnostics and Monitoring • Current methods to control IBV
- 3. Current Issue • From mid-2000s one of the biggest disease problems in Asia – Breeders and Broilers • Massive egg production losses and mortality • Sometimes hard to recognize as it is mixed with other respiratory infections – Often blame problems on ND/AI/APV/Mycoplasma – Poor diagnosis facilities across the regions • Vaccination with classic vaccines do not protect – Variants not licensed
- 4. • Family coronaviridae – Genus Coronavirus • Single stranded RNA Virus – High mutation rate • Envelope of 120 nm diameter • Spike projections about 20 nm in length (S1) Infectious Bronchitis Virus (IBV)
- 5. Infectious Bronchitis Virus (IBV) • Highly contagious • Airborne, mechanical vectors • Short incubation period (18-36h) • Replicates in respiratory, urinary, genital and gastrointestinal tract tissues • Shed in respiratory tract and faeces – Persists After Clinical Signs Gone • Not vertically transmitted (trans-ovarian) • Virus easily killed by disinfectants and heat – Except in presence of organic material
- 6. What is an IBV variant (IBVv)? • IBV virus that have changed (mutated) from the originally identified Massachusetts (classic) • Variant = Serotype = Strain • Generally cross-protect poorly with Mass vaccines • Variable pathogenicity • Worldwide vs. Local distribution
- 7. Distribution • 1931 – IBV First reported in the U.S. • 1940 - Massachusetts strain • 1951 - Connecticut strain • 1960s - Worldwide • 1991 - 793/B (4/91) (UK) • 1997 - QX genotype (Shandong, China) • 2000s - Variant Strains – Europe • QX, Italy02, 793/B (4/91), D274, B1648 – USA • Conn, Ark, Del, CAL99, GA98, GA08 – Australia • T, N1/88, N4//02 – Asia • 793/B (4/91), QX, QX-like, K2, A2
- 8. Distribution
- 9. Distribution Countries where we have seen signs or lesions compatible with IBVv strains
- 10. Disease Manifestations • Respiratory • Nephritic-Nephropathogenic • Reproductive • Male Infertility • Digestive-Enteric
- 11. Respiratory • Any Age ; All Strains • Main site of virus replication • Ciliated epithelial cells • Mucus secreting cells • Respiratory signs • Snicking, head shaking, conjunctivitis, rales – Chronic respiratory disease • E. coli / Mycoplasma – Condemnations at processing • Often only sign prior to reproductive form © Dorko, 2009 © Dorko, 2009
- 12. Respiratory Pathology © R. Monleon © R. Monleon
- 13. © Dorko, 2009 © Dorko © Dorko, 2009 Respiratory Pathology
- 14. © Dorko, 2009 © Barnes, NCSU 2005 © Barnes, NCSU 2005 Respiratory Pathology
- 15. © Dorko, 2009 © Barnes, NCSU 2005 © Barnes, NCSU 2005 Respiratory Pathology
- 16. Nephritic-Nephropatogenic • Some Strains • Mostly Young Chickens (week 2-5) • High mortality – Up to 20% • Interstitial Nephritis and urolithiasis – Structural alterations in the tubular epithelial cells of the kidneys – Impaired fluid and electrolyte transport • Renal failure ; diarrhea • Increased uric acid levels -> GOUT • Secondary Bacterial Infections ( Mortality)
- 17. © Rafael Monleon / Aviagen © Rafael Monleon / Aviagen Nephritic-Nephropatogenic Pathology
- 18. HJ Barnes, NCSU, 2005 HJ Barnes, NCSU, 2005 Nephritic-Nephropatogenic Pathology
- 19. Nephritic-Nephropatogenic Pathology “Indian Gout” © Rafael Monleon / Aviagen
- 20. HJ Barnes, NCSU, 2005 HJ Barnes, NCSU, 2005 Nephritic-Nephropatogenic Pathology
- 21. Reproductive • Highly prevalent in Asia since 2000s • Some strains • 2 Critical Times – Baby chick – Sexual Maturation and onwards (>16-18wks) • Variable pathology – Egg yolk peritonitis – Drops in egg production – Oviduct Cysts – Deterioration in eggshell – Watery albumen
- 22. 1. 2. 0w 0w 18wks 65wks18wks 65wks INFECTION IN BABY CHICKS No homologous MDA, “false layers” MATURE INFECTION FROM DEVELOPMENT OF SEXUAL MATURITY AND ONWARDS Egg production loss Poor egg quality Reproductive Period of infection
- 23. Day-old Chick Role Maternal Antibodies Biosecurity Early Infection and Damage Vaccination Management Reproductive IBVv and Day-old chick
- 24. • Baby chicks are exposed to IBVv soon after they hatch • If they do not have MA the reproductive tract is easily infected • The virus damages the oviduct (ovary?), and develops abnormalities • This can lead to birds cannot lay eggs externally, or poor quality eggs • Real Damage Unnoticed until beginning of Lay Reproductive Early infection of baby chick
- 25. • “The younger the chickens when exposed, the more severe the resulting lesion” - Crinion, 1971 • “pathogenicity [..] lowered with increasing age of chickens at inoculation” – Crinion, 1971 • Damage – Height reduction of epithelial cells – Dilation of the tubular glands – Glandular hypoplasia • Reduction of albumen proteins Reproductive Age-related susceptibility
- 26. Benyeda et al., 2009 Reproductive Variable pathogenicity followed by day-old infection
- 27. Reproductive Abnormalities Jones, 2008 • Occlusion of the oviduct lumen (“false layers” - hens that cannot lay eggs externally) • Other alterations in the reproductive tract that lead to: – Oviduct / Ovary development – Poor egg shell quality / Reduced Hatchability
- 28. Crinion et al., 1970 Reproductive Abnormalities induced by exposure at day-old
- 29. • IBV Infection Damages the Reproductive Tract • Oviduct of a female chick infected at day-old after respiratory infection • IF stain shows virus in epithelium 3 days p.i., Jones 1972 Reproductive How “false layers” happen?
- 30. Reproductive How “false layers” happen? • Repair Of the Oviduct After Virus Damage Causes the Oviduct to Close • Cyst Develop During Growing Period Jones 1972
- 31. © Dorko Reproductive “False layer” – egg yolk peritonitis
- 32. 1971 - USA 2009 - China Reproductive Obstructed oviduct
- 34. Reproductive IBVv in mature hens 1.- Inhalation of virus 2.- Replication in trachea and lungs 3.- Virus reaches ovary and oviduct via bloodstream UOK
- 35. W. Wu Reproductive Effect on egg production
- 36. © R. Monleon © R. Monleon © R. Monleon Reproductive IBVv Egg Production
- 37. © R. Monleon © R. Monleon © R. Monleon © R. Monleon Reproductive Pathology
- 39. © R. Monleon © R. Monleon © R. Monleon © R. Monleon Reproductive Pathology
- 41. © R. Monleon © R. Monleon © R. Monleon © R. Monleon Reproductive Pathology
- 42. © R. Monleon © R. Monleon © R. Monleon
- 43. © R. Monleon
- 44. Infertility & Enteric • Infertility in Mature Cockerels • USA and Brazil • Bolz et al., 2004; Villareal et al., 2007 • Enteritis Broilers (Brazil) • Villareal, 2007 • Proventricular Lesions (China) • Wang, 2001 • Swollen / Hemorrhagic Ulcers
- 45. Diagnosis • Histopathology • VN / HI – Labour intensive and high cost • ELISA – Useful but cannot distinguish between serotypes • RT-PCR / Real-Time PCR – Trachea, airsac, lung, kidney, proventriculus and caecal tonsils – Sequencing • Monoclonal Antibodies
- 46. Diagnosis
- 47. • Evaluation of field challenge Source: Biochek Diagnosis
- 49. Diagnosis
- 50. Diagnosis • Difficult in Asia – No Many Available Labs • Samples – Difficulties Due to AI Restrictions • FTA • Serum / Tissues • Laboratories – UGA-PDRC – IZE – Italy – CESAC – Spain – Deventer - Holland
- 51. Control of IBV • Management • Biosecurity • Vaccination
- 52. Control of IBV • Management • Biosecurity • Vaccination
- 53. • Feed – Highly nutritious / balanced formulation – Good physical quality – Clean contaminants • Water – Good P-C quality / Sanitized • Temperature – Brooding • Ventilation – Formaldehyde • Lighting Control of IBV Management
- 54. • Immunosuppressive Agents – IBD / CAV / MD / Reovirus – Others • Clinical vs. Subclinical • Vaccination – IBD / CAV / Reovirus • Offspring vs. Parents • Can Affect Greatly The Response From the Birds to Vaccination and Disease Challenge! © R. Monleon © R. Monleon © R. Monleon Control of IBV Management - Immunosuppression
- 55. • Mycotoxins play a very important role on IBV control • Aflatoxins are potent immunosuppressant agents Liver Damage > Low Immunoglobulin > Low Immunity > Vaccination Failures • Detection / Monitoring Difficult – Even slightly increased levels should raise flags Control of IBV Management - Mycotoxins
- 56. Control of IBV • Management • Biosecurity • Vaccination
- 57. • First and cheapest barrier of prevention • Many times neglected especially in PS-Broiler – Poor structural facilities – Poor cleaning + disinfection – Decreased downtime • Poor biosecurity = High challenge for baby chick Control of IBV Biosecurity
- 58. • Seal the Farm …Keep disease out – Do not let disease come into your farm • Avoid unnecessary visits • Disinfection of equipment • Shower In-Out • Clothing • Manure • Mortality / Cull disposal Control of IBV Biosecurity - Basics
- 59. • Cleaning technique • Removal Equipment • Cleaning (Detergent + Hot Water) • Disinfectants – Correct Dilution • Waste Water • Hand Sanitizers • Pest Control • Monitoring Salmonella Rodents, Darkling Bettle, Flies Mycoplasma Rodents E. coli Rodents, Darkling Bettle, Flies Aspergillus Darkling Bettle NDV Darkling Bettle, Flies IBDV Darkling Bettle, Flies Ascaris & Taenias Darkling Bettle, Flies © R. Monleon Control of IBV Biosecurity – Cleaning and Disinfection
- 62. Disease Lifespan away from birds Infectious Bursal Disease Months Coccidiosis Months Fowl Cholera Weeks Coryza Hours to Days Marek's Disease Months to Years Newcastle Disease Days to Weeks Mycoplasmosis (MG, MS) Hours to Days Salmonellosis (Pullorum) Weeks Infectious Bronchitis Days to Weeks Control of IBV Biosecurity – Cleaning and Disinfection
- 63. • Very important to allow resting the farm • Dry – UV -> bad for pathogens • Minimum 14d Broilers / 1 months PS / 2 months GP • Do Not Rush to Place Birds! Control of IBV Biosecurity – Downtime
- 64. Control of IBV • Management • Biosecurity • Vaccination
- 65. • Most Controversial Area • Research Work Shows good protection by combination of Mass + Variant – No need for new vaccine for every new variant – Research Done of Protection Respiratory Tract • NEED MORE RESEARCH ON THIS AREA • Interaction of Maternal Antibodies – Lack Maternal Antibodies for IBVv in certain ares • Some Programs: Mass day 0 + Variant day 14 – Does not take consideration of “day 0 challenge” • Poor Biosecurity + Management Control of IBV Vaccination
- 66. • Early challenge difficult to control with vaccination – Maternal antibodies are a great asset • Limited research on IBVv and maternal antibodies – Wit JJ (Sjaak) de, 2011 • Generally homologous serotypes protect well from IBV – not that good heterologous challenges • Baby chicks lack Maternal Antibodies specific for the variant present – ALMOST SPF BIRDS • Biosecurity + Adjustment of Vaccination Control of IBV Vaccination – Maternal Antibodies
- 67. Control of IBV Vaccination – Factors • Determination of challenge – Laboratory Confirmation • Vaccine selection • Vaccine scheduling • Vaccination hatchery vs. farm • Vaccine handling / application • Control vaccine reactions • Revaccination during production – MAb • Titer Monitoring
- 68. Control of IBV Vaccination – Breeders High Challenge • Day 0 – Mass + Variant • Day 14 Mass • Week 4 - Mass • Week 6 – Variant • Week 8 – Mass • Week 12 – IB (K) Multi Variant • Week 16 – Variant + IB (K) Multi Variant Disclaimer: This is an example of IBVv vaccination program. Always consult your veterinarian before implementing a new vaccination program in your flocks
- 69. Control of IBV Vaccination – Broilers High Challenge • Day 0 – Mass + Variant • Day 12-14 Mass Disclaimer: This is an example of IBVv vaccination program. Always consult your veterinarian before implementing a new vaccination program in your flocks
- 70. First vaccine Challenge Outcome Mass type Mass type Protection 793/B No protectionMass type None or Little protection Against Non–Mass Strains Control of IBV IB Live Vaccination Based on Intervet
- 71. First vaccine Challenge Outcome IB88 - 4/91 Mass type Protection793/B No protection IB88 - 4/91 Even Revaccination With Same Vaccine Strain Will Not Give Cross Protection Control of IBV IB Live Vaccination Based on Intervet
- 72. First vaccine Challenge Outcome Mass type Protection793/B IB88 - 4/91* IB88 - 4/91* Second vaccine Mass Mass Protection Expected to give general protection against other IBV *Second Vaccine can be combined with First Vaccine to cover opportunity window at day of age Control of IBV IB Live Vaccination
- 73. First vaccine Challenge Outcome D388 (QX)IB88 - 4/91 Second vaccine Mass Protection Control of IBV IB Live Vaccination There is no need to develop a vaccine for each new serotype, as different “old” serotypes generally confer protection over “new” serotypes – PROTECTOTYPE CONCEPT Based on Intervet
- 74. • Classic – H120; Ma5; M41; H52; 28/86 • Variants – 793/B • Nobilis 4/91 (793/B) (SP-Intervet) • Gallivac IB88 (793/B) (Merial) • Vir 117 (793/B) (BioVac) – D274 • IB Primer (Holland + D274) (Pfizer) • Nobilis IBmulti / IB3 (SP-Intervet) • Vaksindo (M41, QX, IB 771) – Others • Conn (SP) • Poulvac QX (Pfizer) • Nobilis D1466 (SP-Intervet) • Ark-99 (Pfizer) • QX-like strain Korea (K2) • Australian VIC S / A3 Control of IBV Vaccination – Vaccines Available
- 75. The Road Ahead IBVv Challenges • Overlapping with Other Diseases – ND / AI / APV / Mycoplasma / Others • Diagnosis – Laboratories • Poor Biosecurity • Vaccine Availability – License • Vaccine Misuse – Technique / Scheduling
- 76. Summary - IBV • IBV Variant strains have been reported with high prevalence in many Asian countries and are causing significant damage • Diagnostics and monitoring are sometimes scarce, however utmost necessary to control the disease • Biosecurity + Vaccination are currently the most effective ways of protection • Current Vaccination programs across the area are not homogenous and are based in combination of scientific and empiric beliefs, further research is needed