Molecular epidemiology of BVD during the final phase of the Swedish BVD-programme

1. Molecular epidemiology of BVD during the final phase of the Swedish BVD-programme Photo courtesy http:// philip.greenspun.com Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

2. Background Swedish BVD-programme • Running since 1993 • Based on increased herd biosecurity in free herds & identification and elimination of carrier animals • All dairy and beef herds affiliated • 96.3 % of herds officially free Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

3. Background Swedish BVD-programme • 1996 1997 1998 1999 2000 2001 2002 2003 2004 Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

4. Background Swedish BVD-programme • New infections are occasionally being detected • Established routines to trace sources of new infections However,in 40-50 % of cases where new infections are detected in previously free herds, the source remains unknown Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

5. Molecular epidemiology of BVDbackground BVDV type-2 The situation in Sweden Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

6. Molecular epidemiology of BVDbackground BVDV type-2 • Subtypes 1a, 1b & 1d Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

7. Molecular epidemiology of BVDbackground BVDV type-2 • Subtypes 1a, 1b & 1d • Herd specific clustering • Unique isolates Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

8. To build up a bank of BVDV isolates from all infected herds To characterise BVDV strains circulating in Sweden Molecular epidemiology of BVDaims • Unique possibility to trace routes of infection • Surveillance of the national BVDV situation • Speed up the final phase of the programme Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

9. Sera from all viruspositive individuals detected between Oct -02 and June -04 One isolate from each infected herd selected 5´NCR used for phylogenetic analysis Results from phylogenetic analysis compared with reports on suspected transmission routes Molecular epidemiology of BVDMaterial & methods Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

10. Molecular epidemiology of BVDResults & discussion • 329 individuals from 112 herds tested viruspositive • 112 isolates selected for further analysis Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

11. Molecular epidemiology of BVDResults & discussion • 329 individuals from 112 herds tested viruspositive • 112 isolates selected for further analysis • 7 isolates of subtype 1a Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

12. Molecular epidemiology of BVDResults & discussion • 329 individuals from 112 herds tested viruspositive • 112 isolates selected for further analysis • 7 isolates of subtype 1a • 28 isolates of subtype 1b Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

13. Molecular epidemiology of BVDResults & discussion • 329 individuals from 112 herds tested viruspositive • 112 isolates selected for further analysis • 7 isolates of subtype 1a • 28 isolates of subtype 1b • 77 isolates of subtype 1d Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

14. 67 different sequences distinguished • 19 groups of identical sequences Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

15. 67 different sequences distinguished • 19 groups of identical sequences Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

16. We found cases, where phylogenetic analysis supported suspected transmission routes: Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

17. We found cases, where phylogenetic analysis supported suspected transmission routes: Case A Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

18. We found cases, where phylogenetic analysis supported suspected transmission routes: Case B Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

19. We found cases, where phylogenetic analysis supported suspected transmission routes: Case C Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

20. BVDV type1, subtypes 1a, 1b, 1d Sequences not unique Confirm or rule out suspected transmission routes Valuable tool in any attempt to control BVDV Molecular epidemiology of BVDconclusions Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

21. Further sequencing of Npro and E2 region Herd specific clustering Regional variation- spatial analysis Molecular epidemiology of BVD coming projects Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

22. Ann Lindberg, DVM, PhD, Swedish Dairy Association, Uppsala, Sweden Claudia Baule, PhD, National Veterinary Institute, Uppsala, Sweden Mats Isaksson, National Veterinary Institute, Uppsala, Sweden Jaruwan Kampa, SLU, Uppsala, Sweden Stefan Alenius, DVM, PhD, SLU, Uppsala, Sweden This study was supported by the Swedish Farmers’ Foundation for Agricultural Research (SLF; Project no. 0330007) Molecular epidemiology of BVDacknowledgements Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden

23. Molecular epidemiology of BVD Karl Ståhl Dep. of Biomedical Sciences and Veterinary Public health SLU, Uppsala, Sweden