1. Theresa L. Smith, MD, MPH Division of Vector-Borne Infectious Diseases Centers for Disease Control and Prevention Fort Collins, CO West Nile Virus Epidemiology & Surveillance Update 2005 Blood Product Advisory Committee Gaithersburg, MD November 3, 2005

2. West Nile Virus (WNV) Update* VirologyVirology Epidemiology of WNV in US 1999 – 2005Epidemiology of WNV in US 1999 – 2005 2005 surveillance update2005 surveillance update Blood donation surveillance eventsBlood donation surveillance events *Unless marked, all data including 2005 was in ArboNET as of 11/1/05

3. WNV: Virology Flavivirus in the Japanese encephalitis serogroup WNV & St. Louis encephalitis in the US Primarily bird pathogen Bird – mosquito – bird transmission cycle Mammals are dead-end hosts in natural cycle Low-level viremia before illness onset

4. WNV Update VirologyVirology Epidemiology of WNV in US 1999 – 2005Epidemiology of WNV in US 1999 – 2005 2005 surveillance update2005 surveillance update Blood donation surveillance eventsBlood donation surveillance events

5. ArboNET: A National Arbovirus Surveillance System Web-based passive system begun in 2000 57 area health departments to DVBID Mosquito, bird, horse, other animal surveillance Year, state, county, date of collection Human cases Age, sex, race/ethnicity Residence Clinical illness, onset date and outcome Blood or organ donation/receipt

6. First Reported WNV Activity, by State, 1999-2005 Human 2001 2000 19992002 2003 2004

7. 2,539 human cases 1,142 WNND 100 deaths 40 states + DC 523 counties

8. 2005 2,581 human cases 1,053 WNND 83 deaths 40 states 563 counties

9. WNV Update VirologyVirology Epidemiology of WNV in US 1999 – 2005Epidemiology of WNV in US 1999 – 2005 2005 surveillance update2005 surveillance update Blood donation surveillance eventsBlood donation surveillance events

10. Human WNV Disease Cases by week of illness onset and date reported to ArboNET United States, 2004

11. Reported Human WNV disease cases, United States, 1999-2005 YearCasesStates/District 1999621 2000213 20016610 20024,15639 + DC 20039,86245 + DC 20042,53940 + DC 20052,58142

12. Human WNV Disease, ArboNET 2005 2,581 case reports 42 states Neuroinvasive – 1,053 Fever – 1,363 Deaths – 83* Median age: 78 yrs Age range: 36 – 98 yrs States with > 100 case reports California824 Illinois 241 South Dakota235 Texas139 Louisiana111 Arizona102 64% of all reports * 78 fatalities had age available

13. WNV Update VirologyVirology Epidemiology of WNV in US 1999 – 2005Epidemiology of WNV in US 1999 – 2005 2005 surveillance update2005 surveillance update Blood donation surveillance eventsBlood donation surveillance events

14. WNV Blood Screening, US, 2003-2005 YearScreened*PVDsWNNDWNFTAT 20036.281861376 20048.22244661 2005 NA3743821 *In millions

17. Data unavailable

18. Reported PVDs to ArboNET, 2004 vs. 2005 2004 224 in 29 states Top four states: California66 Arizona36 Colorado 24 Texas16 2005 374 in 30 states Top four states: California87 Texas57 Nebraska 53 Louisiana22

19. Implicated Donation Viral Concentrations 2002 16 implicated donations had virus titers ranging from 0.8 to 75.1 pfu/mL with a of median of 10.5 pfu/mL 2003 Four implicated donations had virus titers ranging from 0.06 to 0.5 pfu/mL with a median of 0.11 pfu/mL 2004 One implicated donation had a viral titer of 0.12 pfu/mL

20. 2005 Investigations Blood Transmission 6 investigations 3 negative 3 pending plasma return from Switzerland Organ Transplantation Transmission Likely mosquito-borne infection in donor Possible febrile illness IgM positive, PCR negative before donation Three of four organ recipients PCR positive Two became ill

21. Organ Donor Timeline August 2005 Serum, Plasma PCR (-) IgM, IgG (+) 28 WNV + Mosquitoes In Nearby Park Injury and Surgery Organ Recovery Brain Death 262316 Febrile Illness? 27

22. 2005 Summary WNV activity over most of the continental US Continued westward expansion Full season of transmission in CA Human cases reported from all states except Alaska, Hawaii, Maine, & Washington Risk of WNV TAT unknown Continue to investigate possible TAT TAT less likely to cause organ transplant related WNV transmission