# Presentation: 782704

## West Nile Virus Preparedness in California

- <date/time>

**West Nile Virus Preparedness in California**

**Vicki Kramer, Ph.D.**
**Vector-Borne Disease Section**
**California Department of Health Services**

## WNV Surveillance Initiated in California in 2000

- <date/time>

**WNV Surveillance Initiated in California in 2000**

**1. Sentinel Chicken Testing **
**2. Mosquito Testing**
**3. Encephalitis Case Surveillance**
**	****• ****Human**
**	****• ****Equine **
**	****• ****Ratite (emus and ostriches)**
**4.****  ****Dead Bird Testing**
**	**

## Sentinel Chicken Testing

**Program established in 1979 with 31 flocks**
**Early 1990s, number of chickens/flock reduced from 20-25 to 10 and number of flocks increased to expand geographical coverage**
**Bleeding method changed from jugular puncture to a lancet prick of the hen’s comb**
**Flock placement is based on history of arbovirus activity and mosquito abundance **

## Counties with sentinel flocks in 2001

- <date/time>

**Counties with sentinel flocks in 2001**

**Sentinel flocks and mosquito pools**

**Sentinel flock surveillance only**

**46 agencies **
**    ****191 flocks**
**24 agencies**
**     ****mosquito pools**

## The first SLE seroconversion in each geographic area was tested for WNV because SLE and WN cross-react 
20,837 sera tested in 2001; 62 chickens were SLE positive (10 flocks, 2 counties)
69 sera (9 counties) tested for WNV

**20,837 sera tested in 2001; 62 chickens were SLE positive (10 flocks, 2 counties)**
**69 sera (9 counties) tested for WNV**

**Sentinel Chicken ****Testing for WNV**

## Mosquito Testing

**Program initiated in 1969; 3500 pools tested**
** ****range 2000 – 8000 pools per year**
***Culex tarsalis***
***Cx. pipiens, Cx. quinquefasciatus, Cx. stigmatosoma, Oc. melanimon***

## Mosquito Testing for WNV

**SLE positive pools tested for WN**
**24 agencies submitted 3,919  mosquito pools for testing in 2001**
**70 SLE positive pools (Riverside County) were negative for WN**

## Equine Surveillance

- <date/time>

**Equine Surveillance**

**Letter sent in spring to over 6000 veterinarians and  agencies regarding WN virus program; offered free testing**
**13 suspect cases tested; all negative for WEE and WNV**

## Human Case Surveillance California Encephalitis Project (CEP)

- <date/time>

**Human Case Surveillance ****California Encephalitis Project (CEP)**

**600 cases referred to CEP since 1998 **
** ****Core testing of 15 pathogens**
**Suspect human cases of encephalitis / meningitis tested in 2001 for WEE and SLE:  210 (all negative)**
**166 tested for WNV**
** ****(6 patients had traveled**
**   ****to east coast)**

## Dead Bird Testing 2001

- <date/time>

**Dead Bird Testing 2001**

**Over 600 agencies notified about WN dead bird surveillance program**
**68 dead birds were reported from 19 counties**
**18 birds (16 crows, 1 raven, 1 scrub jay) were tested for WNV; all negative **
**Dead birds must meet certain criteria to be tested (dead <24 hours)**

## California West Nile Surveillance Program (Dead Birds)

**  **

**	**** ****Counties (16) that**
**    ****submitted dead birds**

**California West Nile Surveillance Program (Dead Birds)**

## West Nile Virus Preparedness Workshop:  December 2001

**Identify “gaps” in our WNV surveillance system**
**Develop goals and recommendations to address identified “gaps”**
**Enhance California’s preparedness for detection and response to the introduction of West Nile virus**

## Four “Break-out” Groups

**Surveillance:  Dead birds, chickens, mosquitoes**
**Surveillance:  Equine, human**
**Mosquito Control**
**Public Relations**

## Dead Bird Surveillance

**Enhance lab capacity for dead bird testing**
**Develop a preliminary matrix to assist with prioritization of dead bird testing**
**Enhance public information regarding program to increase number of dead bird call-ins**

## WN Dead Bird ReportingProtocol for Sample Submission

## Establish a toll free number for dead bird call-ins
		(877) WNV-BIRD

Develop a web site with dead bird submission form and  information 

**	****	****(877) WNV-BIRD**
**Develop a web site with dead bird submission form and **_[ ](http://www.dhs.ca.gov/)_**information**_[ ](http://westnile.vectorcontrol.net/)_

## http://westnile.ca.gov

**http://westnile.ca.gov**

## Educate health or EH departments in regions without a vector control program so they will be prepared to submit dead birds once WN arrives
Contact zoos for surveillance purposes and information distribution
Provide training on ID of key bird species, and dead bird handling and shipping procedures

**Contact zoos for surveillance purposes and information distribution**
**Provide training on ID of key bird species, and dead bird handling and shipping procedures**

## Human Case Surveillance

**Enhance the CA Encephalitis Project in likely regions of introduction**
**Expand emergency room surveillance regionally for aseptic meningitis**
**Prepare information for rapid dissemination to medical community once WN detected**

## Human Case SurveillanceLab Capacity

**VRDL currently has the capacity to handle a surge in the number of human specimens that would be submitted subsequent to WN detection**

## Equine Case Surveillance

## Enhance dissemination of information to  veterinarians
Develop a fact sheet on equine movement restrictions that would be initiated if WN detected in California
Prior to WN detection, administer a questionnaire and collect baseline sera at an equine horse show
	(Indio 2002)

**Develop a fact sheet on equine movement restrictions that would be initiated if WN detected in California**
**Prior to WN detection, administer a questionnaire and collect baseline sera at an equine horse show**
**	****(Indio 2002)**

## Public Relations

**Prepare boiler-plate press releases **
**Prepare and disseminate a spring press release on dead bird surveillance program**
**Develop fact sheets targeted to different interest groups**
**Develop a brochure for the general public**

## California Mosquito-Borne Virus Surveillance and Response Plan

**Provide response guidelines for vector control and public health agencies during periods of normal and increased risk for virus activity**
**Identify key agency responsibilities**
**Quantify the risk of WEE and SLE outbreaks in California**

**Notes:**
The California encephalitis virus surveillance response plan has been developed by the California Dept. of Health Services and the Mosquito and Vector Control Assoc. of California to quantify risk for virus activity within the state and to provide guidelines for appropriate agencies to respond when risk increases.  The risk model quantifies a variety of factors related to vector abundance and virus activity and amplification, and there are three overall risk categories:  normal season, emergency planning, and epidemic conditions.  The lower threshold for emergency planning conditions is the level at which public awareness and vector control and surveillance measures should be increased to avoid reaching epidemic conditions.  

## Risk Factors

**Notes:**
Each risk factor is assigned a value between 1 and 5 based on data from the previous half-month, and risk levels for all available factors are averaged to determine the overall risk value, which is also on a scale from 1 to 5. 

## Risk Factors Rated

**   ****Average rating determined for seven risk factors and correlated with response level**
**	****  ****Normal season****	****	****  1.0 to 2.5**
**	**** ****Emergency planning****	****  2.6 to 4.0**
**	**** ****Epidemic****	****	****	****	****  4.1 to 5.0**

**Notes:**
Risk factors are rated on a scale of 1 to 5 (point to1 then to 5)

## Surveillance Factor

**Surveillance Factor**

**Value**

**Benchmark**

## Case Studies

**Kern County**
**1952, 1989 SLE**
**1952, 1983, 1996 WEE**
**1995 No Activity**

**Sutter-Yuba**
**1993 WEE**

**Sacramento-Yolo**
** ****1993 WEE**

**Greater L.A.**
**1984 SLE**

**Case Studies**

**Data analysis by C. Barker and W.K. Reisen, UC Davis**

**Notes:**
To evaluate the response plan, we used historical data during years with varying levels of virus activity.  We included the epidemic years of 1952 and 1989 in Kern County and 1984 in Greater Los Angeles and years with enzootic Western activity without human cases, including 1993 in Sac-Yolo and Sutter-Yuba and 1983 and 1996 in Kern County.  We also examined 1995 in Kern County, which was a year in which no virus activity occurred.

## Case Studies:  Summary

**In general, model is predictive of SLE and WEE epidemics; emergency planning conditions reached**
**Epidemic conditions occurred following first human case**
**Definitions of risk factor benchmarks need to be improved**
**Conditions for amplification of WEE and SLE differ; separate models required**
**Modify for WNV:  Add dead bird component**

## West Nile Virus:

- <date/time>

**West Nile Virus:**
**Are We Prepared?**** **

## Yes, we are relatively well prepared, but we still have a lot of work ahead of us.

**Advice is welcome!**

## Thanks to the California West Nile Virus Steering Committee

**DHS:  Carol Glaser, Michele Jay, Evelyn Tu, Stan Husted & Al Hom**