Jin-An Huang VMRD Beijing

Transcription

1 Jin-An Huang VMRD Beijing

2 Neonatal Scours BRD Septicemia Parasites Clostridia Anaplasma Babesia FMDV Different serotypes/subtypes, biosecurity, needs of marker vaccines with sterilizing immunity Johne s Disease chronical wasting disease, difficult to establish a disease model for efficacy assessment

3 Farm practice/management Environment (disease epidemiology)/ weather Stresses living conditions/herd size/animal density/movements, Sensitive to diseases (genetic) Weaning age Malnutrition poor feed sources Lack of timely/affordable diagnosis for early/quick decisions Inadequate prevention program No vaccine/poor vaccines/incorrect vaccination programs Poor colostrum

4 Main Causes: Clinical signs: Diagnosis Treatment (supportive) Rotavirus (G6/G10; P5/P11) Coronavirus, Norovirus, E. coli, Salmonella, Coccidia, Cryptosporidia -Yellow, discolored, malodorous diarrhea -Severe dehydration -Depression / Lethargy -Inappetance -Weight Loss -Death -Observation -Fecal sample -Necropsy -Fluids -Electrolytes -Antibiotics

5 Multifactorial consideration Timely diagnosis and early intervention Improved farm management Adequate living conditions controlled density, clean/dry environment, with good ventilation Appropriate application of disinfectants Good nutrition Quality colostrum Minimal handling/transportation Vaccination of dams during gestation to improve the colostrum quality

6 Stress factors Stress Viral infection Lowered Immunity Weaning Sale yards Transport Injury Dehydration Comingling Infectious agents Pen competition Pen additions and movements Handling Weather extremes Dust Feed and water changes Damage to respiratory tract Bacterial proliferation* BRD complex** Viruses IBR BVD BRSV PI3 +/- Coronavirus Bacteria * At times, a bacterial infection may occur without prior viral infection ** Symptoms could include pneumonia, lung damage, or other infection Source: Meat and Livestock Australia; team analysis Pasteurellas Mannheimia haemolytica Pasteurella multocida Pasteurella trehalose Histophilus somni Mycoplasma bovis 6

7 Deng M, Ji S, Fei W, Raza S, He C, et al. (2015) Prevalence Study and Genetic Typing of Bovine Viral Diarrhea Virus (BVDV) in Four Bovine Species in China. PLoS ONE 10(4): e doi: /journal.pone Classification RNA virus in the pestivirus family CPE/Non-CPE biotypes Three serotypes (BVDV1, 2 &3) and many subtypes Disease Respiratory disease Reproductive loss Immunosuppression Diarrhoea Sources of infection PI (1-2%) Direct contact with acutely infected animals AI/Embryo transfer Indirect sources

8 VNT - Pre- and Post-Vaccination and Pre- and Post-Challenge Treatment Group Pre-vaccination 2 weeks post-second vaccination (VNT Range) Day 230 (pre- PI challenge) (VNT Range) Day 287 (post- PI challenge) (VNT Range) Negative Controls (15) <2 <2 to 4 <2 64 to 768 Ultravac BVD (8) <2 512 to 2048* 8 to to 2048* Bovilis BVD (15) < 2 to 4 24 to 1024 <2 to * *VNT were not end pointed, BVDV1a was used in the assay Ultravac BVD (Zoetis) - Containing 2 Australian strains of BVDV Type 1c antigens Bovilis BVD (MSD Animal Health) - Containing BVDV Type 1a antigens Challenge was performed using PI animal carrying BVDV1a

9 VNT not end pointed = 2048 Memory responses to vaccination VNT Responses to natural challenge Treatment Groups/Heifer IDs

10 IBR1.1 IBR1.2a IBR1.2b Classification DNA virus in Herpesviridae family One serotype further classified into 3 subtypes J. Rola and J. F. Żmudzinski, Bull Vet Inst Pulawy 54, , 2010 Diseases Respiratory disease Reproductive loss Immunosuppression Sources of infection Latently infected animals Direct contact with acutely infected animals Indirect sources

11 T01 Controls T TCID 50 IBR T TCID 50 IBR T TCID 50 IBR Vaccination Single dose by SQ Challenge Intranasal (3 wks post vaccination)

12 T01 Controls T TCID 50 IBR T TCID 50 IBR T TCID 50 IBR Vaccination Single dose by SQ Challenge Intranasal (3 wks post vaccination)

13 Serum Antibody Total Sample Number % +ve IBR BVDV PI Data source: Zoetis/Sinovet collaboration

14 Clinical signs: (CAN HAVE ACUTE ONSET) Diagnosis Treatment - Fever - Depression / Lethargy - Dyspnea - Nasal discharge - Ocular discharge - Inappetance - Coughing - Weight Loss Death - Observation - Nasal swabs - Necropsy - Fluids - Antibiotics - Anti-inflammatories

15 Multifactorial consideration Improved farm management Reduce stresses Adequate living conditions controlled density, clean/dry/warm environment, with good ventilation Minimal handling/transportation Good nutrition Elimination of infection sources Quick/affordable diagnostic tests Removal of latently infected or PI animals Appropriate application of disinfectants Controlled movements Biosecurity Vaccination Program - Vaccination of dams to improve the colostrum quality Verification (Surveillance)

16 Herd history Disease epidemiology outbreaks Farm performance Diseases prevalence: Seasonal Viral or bacterial Genotypes and subtypes Types of vaccines to use Inactivated (killed) MLV (modified-live virus) Combination vaccines Marker vaccines OOI and DOI Safety and cross-protection Timing of vaccination Gestation

17 1 4 C o n t r o l s T 6 m o T 1 m o antibody titre (log2 SN50) V 1 6 m o t i m e ( m t h ) V 1 1 m o V 2 V 3