1. Update on West Nile Virus – United States, 1999-2006 Eileen C. Farnon, MD Arboviral Diseases Branch Division of Vector-Borne Infectious Diseases Centers for Disease Control and Prevention Fort Collins, Colorado Blood Products Advisory Committee 89 th Meeting April 27, 2007

2. WNV Transmission Cycle Enzootic (Maintenance/Amplification) Epizootic Epidemic Amplifying hosts Dead-end hosts (usually)

4. ArboNET Arboviral national electronic surveillance system Humans Ecologic Mosquitoes Birds Animals WNV, SLE, EEE, WEE, LAC, DEN, VEE All data current as of April 12, 2007

5. Human WNV Syndromes Reported to ArboNET WN fever (WNF) WN neuroinvasive disease (WNND) Meningitis Encephalitis Acute flaccid paralysis Other Unspecified illness

6. Incidence per million.01-9.99 10-99.99>=100 Any WNV Activity WNV Neuroinvasive Disease Incidence, by County, US, 1999 N=59

7. WNV Neuroinvasive Disease Incidence, by County, US, 2000 Incidence per million.01-9.99 10-99.99>=100 Any WNV Activity N=19

8. WNV Neuroinvasive Disease Incidence, by County, US, 2001 Incidence per million.01-9.99 10-99.99>=100 Any WNV Activity N=64

9. WNV Neuroinvasive Disease Incidence, by County, US, 2002 Incidence per million.01-9.99 10-99.99>=100 Any WNV Activity N=2,946

10. WNV Neuroinvasive Disease Incidence, by County, US, 2003 Incidence per million.01-9.99 10-99.99>=100 Any WNV Activity N=2,866

11. WNV Neuroinvasive Disease Incidence, by County, US, 2004 Incidence per million.01-9.99 10-99.99>=100 Any WNV Activity N=1,148

12. WNV Neuroinvasive Disease Incidence, by County, US, 2005 Incidence per million.01-9.99 10-99.99>=100 Any WNV Activity N=1,309

13. WNV Neuroinvasive Disease Incidence, by County, US, 2006 Incidence per million.01-9.99 10-99.99>=100 Any WNV Activity N=1,491 *Reported as of 4/12/2007

15. Onset of Human WNV Disease, United States 1999-2006* *Reported as of 4/12/2006

16. Cumulative WNND Incidence, by County, US, 2002-2006 *Reported as of 11/14/06 Lindsey N, et al, in press

17. Median Annual WNND Incidence Rank versus Cumulative WNND Incidence Rank by County, 2002-2006 *Reported as of 11/14/06 Lindsey N, et al, in press

18. Counties with Persistently High WNND Incidence, 2002-2006

19. Reported WNV Disease Cases in Humans – United States, 1999-2006* YearTotalWNNDWNF/otherDeaths 1999-2001149142718 20024,1562,9461,210284 20039,8622,8666,996264 20042,5391,1481,391100 20053,0001,3091,691119 20064,2611,4912,770176 Total23,9679,90214,065961 *Reported as of 4/12/2007

20. WNV Blood Screening 2002 – 23 cases of transfusion-associated transmission (TAT) 2003 – Nucleic acid amplification tests (NAT) MP-NAT (6-16 units)  ID-NAT Blood banks report presumptively viremic donors (PVDs) to local public health department Remove infectious blood products from circulation Public health departments report to ArboNET Perform clinical follow-up Perform trace-back investigations

21. WNV PVDs by Year* YearPVDs 2003818 2004224 2005417 2006361 Total1820 *Reported as of 4/12/2007

22. West Nile Viremic Blood Donors, by State of Residence, 2006* *Reported as of 4/12/2007

23. PVDs Reported to ArboNET*, 2006 Over 8 million donations screened 361 PVDs reported to ArboNET 84 (23%) WNF 4 (0.1%) WNND 2 (0.1%) other 118 (33%) reported from 3 states: NE, ID, TX *Reported as of 4/12/2007

24. WNV Transfusion-associated Transmission, 2006 – Case 1 82 y male resident of SD recently post-kidney transplant 4d post-transplant: 2U PRBC 21d post-transplant: encephalitis WNV IgM detected in serum and CSF Organ donor tested negative for WNV Blood donor tested positive for WNV IgM negative MP-NAT MMWR 2/2/07

25. WNV Transfusion-associated Transmission, 2006 – Case 2 60 y male resident of IA 5y post-kidney transplant Spinal fracture repair in SD: 15 blood products 6U FFP from blood donor 11d post-operatively: encephalomyelitis WNV IgM detected in CSF MMWR 2/2/07

26. Summary WNV occurs throughout the continental U.S. Western plains have highest incidence of WNND Dates of onset for WNV disease span the year 2 cases of transfusion-associated transmission despite MP-NAT testing New approaches to triggering ID-NAT considered

27. Acknowledgements The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. Jennifer Lehman Nicole Lindsey Stephanie Kuhn Margaret Collins Kate Ellingson Matt Kuehnert Mark Duffy Marc Fischer Edward Hayes John Jones Nicholas Komar Roger Nasci John Roehrig Janet McAllister Harry Savage James Sejvar Theresa Smith Grant Campbell Brad Biggerstaff Lyle Petersen All reporting states, jurisdictions, and local health departments

28. Photo: Meggan Gould

29. Cumulative Incidence of WNND by State – United States, 2002-2006* *Reported as of 11/14/06