1. 1 West Nile Virus Update Tom Gibbs Washington State Department of Health

2. 2 WNV in the U.S.

3. 3 WNV Background vFirst isolated from in the West Nile District of Uganda, 1937 vRecognized as a cause of inflammation of the spinal cord and brain with outbreak in elderly patients, Israel, 1957 vEquine disease noted in Egypt and France in the early 1960s v1999 “Old World” virus arrives in the “New World”

4. 4 WNV Outbreaks vIsrael - 1951-1954, 1957, 2000-2002 vFrance – 1962, 2000 vSouth Africa - 1974 vRomania – 1996 vItaly 1997 vRussia - 1999 vUnited States –1999-2003

5. 5 Timeline Israel 1957 Uganda 1937 Israel 1951-54 France 1962 South Africa 1974 Romania 1996 Italy 1997 Russia 1999 US 1999-2003 Israel 2000-2002 France 2000 Encephalitis Condition Identified Equine Disease Identified

6. 6 Transmission Cycle Incidental infections Bird reservoir hosts Incidental infections Mosquito vector

7. 7 Related Viruses The Japanese Encephalitis Serocomplex of the Family Flaviviridae, 1999

8. 8 WNV in the U.S. vSome Speculated Pathways of Introduction äHuman-transported bird l Illegal (Black market “exotics”) l Legal (zoos & legitimate breeders) äHuman-transported mosquitoes äStorm-transported bird äIntentional introduction (terrorist event) - not likely äInfected human traveler - not likely

9. 9 The Disease vSymptoms: äHigh Fever äHeadache and body aches äSkin rash äSwollen lymph glands äNeck stiffness äDisorientation äConvulsions vIncubation period: äGenerally 3-14 days (following a bite from an infected female mosquito)

10. 10 States with WNV (0) Cumulative Distribution of WNV in the United States Before 1999

11. 11 States with WNV (4) Cumulative Distribution of WNV in the United States November 1999

12. 12 States with WNV (12) + DC Cumulative Distribution of WNV in the United States November 2000

13. 13 States with WNV (27) + DC Cumulative Distribution of WNV in the United States November 2001

14. 14 States with WNV (43) + DC Cumulative Distribution of WNV in the United States November 2002

15. 15 States with WNV (46) + DC Cumulative Distribution of WNV in the United States October 2003

16. 16 2003 WNV Activity (As of October 29, 2003)

17. 17 WNV Prevalence 2002 & 2003

18. 18 Year Humans (deaths) Horses (deaths) 2003*7,718 (166)3,487 (?) 20024,156 (284)15,257 (>5,000) 200166 (9)738 (156/470) 200021 (2)60 (23) 199962 (7)25 (8) Case Summary * As of October 29, 2003

19. 19 Demographics & Mortality United States, 1999-2002 1999-200020012002 No. of Cases 83662,661 Median Age 656855 Age Range (in years) 5 - 9019 - 901 mo. - 99 Males 54%65%54% Fatality Rate 11%14%9% Mean Fatality Age 78 (24-99)

20. 20 WNV Cases Weekly 2003 (U.S.)

21. 21

22. 22 Analysis of WNV Cases by Age (Colorado) Analysis Variable : Age CasesMeanMedianMinimumMaximum 2,54347.247.00.095.0

23. 23

24. 24 Protecting the Public’s Health vSurveillance vPersonal Protection and Education vMosquito Control

25. 25 WNV Surveillance 2003 vDead birds äEspecially crows, jays, magpies vMosquitoes vCaptive sentinels (e.g. chickens) vVeterinary surveillance vHuman surveillance

26. 26 Packed with dry ice in preparation for trapping. EVS Mosquito Traps

27. 27 Setting the trap in proper location EVS Mosquito Traps

28. 28 In operation EVS Mosquito Traps

29. 29 WNV Mosquitoes in Washington Mosquito species Counties (39) Aedes cinereus 29 Aedes vexans 27 Culex pipiens 28 Culex restuans 1 Culex tarsalis 35 Anopheles punctipennis 26 Coquilletidia perturbans 10 Ochlerotatus canadensis 5 Ochlerotatus japonicus 1

30. 30 Estimated Sensitivity of WNV Surveillance Methods Human cases Veterinary cases Mosquitoes Dead birds Time Disease Activity Sentinel hosts

31. 31 Personal Protection vWear long sleeves & pants in mosquito- infested areas vUse repellant containing DEET (N,N- diethyl-3-methylbenzamide) and follow directions carefully vLimit outdoor activities at dawn and early evening vRepair holes in door & window screens

32. 32 Habitat Reduction vEliminate standing water (flower pots; tires; wheelbarrows; wading pools) vChange the water in birdbaths at least weekly vAerate and chlorinate swimming pools and hot tubs; cover if possible vConsider mosquito-eating fish for your pond vKeep gutters clean to prevent standing water vSpread the word: educate your friends and neighbors

34. 34 Washington’s Response vStatewide mosquito-borne disease response plan äguidance for state/local agencies and organizations äresponse protocols for disease-related events ätiered response based on severity ärecommendations on public information and education, surveillance and control vRe-establish, develop new partnerships vConduct ongoing training

35. 35 Want More? vWeb Resources äwww.doh.wa.gov/WNVwww.doh.wa.gov/WNV äwww.cdc.govwww.cdc.gov äenvironmentalrisk.cornell.edu/wnv

36. 36