Download West Nile Virus - Environmental Public Health Today

California’s Risk
WEST NILE VIRUS
Presented by: Amanda Billings
INTENDED AUDIENCE AND PURPOSE
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The intended audience is California residents
To educate California residents on the
transmission, health risks and prevention of
West Nile Virus (WNV)
An ongoing concern in California is the number
of foreclosed homes with pools, a potential
breeding ground for WNV carrying mosquitoes
LEARNING OUTCOMES
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What WNV is and History
Who is at Risk
Transmission
Symptoms
Prevention
California Statistics
Impact of Neglected Pools
Who to Call to Report Dead Birds and Abandoned
Pools
WEST NILE VIRUS WHAT & WHEN
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Flavivirus
Closely related to St. Louis encephalitis virus found in
United States
First isolated from febrile adult woman in West Nile
District of Uganda in 1937
Appeared in North America in 1999
First appeared in California in July 2003
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Cx. Tarsalis
El Centro, Imperial County
Reisen,W., Lothrop, H., Chiles, R., Madon, M., Cossen, C., Woods, L., Husted, S., et al. (2004). West Nile Virus in California. Emerging
Infectious Diseases, 10(8). Retrieved July 15, 2009 from http://www.cdc.gov/ncidod/eid/vol10no8/04-0077.htm
WHO IS AT RISK?
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All California Residents
Over 50 years of age- Greater Risk
Immunocompromised- Questionable Risk
TRANSMISSION
West Nile
Virus
Mosquito Vector
West
Nile
Virus
West Nile Virus
Bird Reservoir
Host
CDC. (2006). Transmission of West Nile Virus. Retrieved July 15, 2009 from
http://www.cdc.gov/ncidod/dvbid/westnile/qa/transmission.htm
Incidental Infection
Incidental Infection
SYMPTOMS
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Asymptomatic
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West Nile Fever
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4 out of 5 people
~20% people infected
Fever, headache, tiredness, and body aches, occasional
skin rash and swollen lymph nodes
Severe West Nile Disease
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1 in 150 people infected
West Nile encephalitis; West Nile poliomyelitis
CDC. (2006). Symptoms of West Nile Virus. Retrieved July 15, 2009 from
http://www.cdc.gov/ncidod/dvbid/westnile/qa/symptoms.htm
PREVENTION
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Protection from Mosquito Bites
Reduce Number of Mosquitoes
Vector Management Programs
CDC. (2006). Prevention of West Nile Virus. Retrieved July 15, 2009 from
http://www.cdc.gov/ncidod/dvbid/westnile/qa/prevention.htm
CALIFORNIA STATISTICS
CDPH West Nile Virus. (2009). Latest West Nile Virus Activity in California. Retrieved July 17, 2009 from
http://westnile.ca.gov/
CALIFORNIA STATISTICS CONT.
CDPH West Nile Virus. (2009). Latest West Nile Virus Activity in California. Retrieved July 17, 2009 from
http://westnile.ca.gov/
IMPACT OF NEGLECTED POOLS
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Study conducted in Kern County, CA (2007)
Findings
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205%-280% increase WNV cases since 2004
Unanticipated increase based on weather conditions
Decreased key bird species
Cx. pipiens quinquefasciatus infection incidence
increased (18.5 females/ 1000 mosquitoes) one
month earlier than previous year
Reisen, W., Takahashi, R.M., Carroll, B.D., Quirimg, R. (2008). Delinquent Mortgages, Neglected Swimming Pools, and West
Nile Virus, California. Emerging Infectious Disease, 14(11), Retrieved July 15, 2009 from
http://www.cdc.gov/eid/content/14/11/1747.htm
IMPACT OF NEGLECTED POOLS
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Aerial Survey
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17% of 42 visible pools and Jacuzzis appeared green and
likely producing mosquitoes
In 2008 unmaintained pools previously positive for Cx.
p. quinquefasciatus were now occupied by Cx. tarsalis, ,
a more competent vector of WNV
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February-August 2008; 31 neglected pools produced 8,978
emerging adult mosquitoes
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59% Cx. tarsalis,
41% Cx. p. quinquefasciatus
Reisen, W., Takahashi, R.M., Carroll, B.D., Quirimg, R. (2008). Delinquent Mortgages, Neglected Swimming Pools, and
West Nile Virus, California. Emerging Infectious Disease, 14(11), Retrieved July 15, 2009 from
http://www.cdc.gov/eid/content/14/11/1747.htp
IMPACT OF NEGLECTED POOLS
Aerial photograph of a representative Bakersfield, California, neighborhood taken during
August 2007. Red arrows indicate neglected or green swimming pools.
Reisen, W., Takahashi, R.M., Carroll, B.D., Quirimg, R. (2008). Delinquent Mortgages, Neglected Swimming Pools, and West Nile
Virus, California. Emerging Infectious Disease, 14(11), Retrieved July 15, 2009 from http://www.cdc.gov/eid/content/14/11/1747.htp
WHO TO CONTACT
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State and Local Government West Nile Virus
Web Sites
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http://www.cdc.gov/ncidod/dvbid/westnile/city_st
ates.htm
http://westnile.ca.gov/
Vector Control locator
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http://westnile.ca.gov/ziplocator.php
ADDITIONAL RESOURCES
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CDC West Nile Virus Website
http://www.cdc.gov/ncidod/dvbid/westnile/ind
ex.htm
Mosquito and Vector Control Association of
California http://www.mvcac.org/
California Department of Pesticide Regulation.
Fight the Bite.
http://www.cdpr.ca.gov/docs/dept/factshts/re
pellents.pdf
Reduce Mosquitoes, Clean the Green
Do Your Part and Report
QUESTIONS?