Disease and Vector Management of West Nile Virus

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Disease and Vector Management of West Nile Virus

• Douglas Passaro, M.D., M.P.H.
• Daniel Tessier, Ph.D.
• School of Public Health
• University of Illinois Chicago

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Mosquito Vectors of Disease
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West Nile Virus North American Transmission Cycle
Enzootic (Maintenance/Amplification)
Epidemic
Dead-end hosts
Epizootic
Amplifying hosts
No disease
Disease
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Mosquito Species That Vector WNV

• Primarily (90) Culex spp.
• Cx. Pipiens (northern house mosquito)
• Cx. Quinquefasciatus (southern house mosquito)
• Cx. Salinarius
• Cx. Restuans
• Other genera
• Aedes, Anopholese, Culicita,
• Etc.

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Host-Use Patterns of WNV-positive species
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Culex spp
know thine enemy
adult
eggs
pupa
larva
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Vector ecology what should we know for optimal
vector control?

• Life cycle timing
• Breeding sites
• Feeding habits / periods of activity
• Resting habits / periods of inactivity
• Preferred blood hosts
• Natural predators

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Vector and Disease Control

• Integrated Mosquito Management
• Source Reduction
• Larviciding
• Targeted adult mosquito spray
• Population Monitoring
• Personal Protection / Public Education
• WNV surveillance

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WNV Surveillance

• Mosquitoes
• Dead birds (especially crows)
• Live wild bird sentinels
• Live captive sentinels (e.g.,
  chickens)
• Veterinary surveillance (equines)
• Human surveillance

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Personal Protection / Public Education

• Standing water around the home
• House screens
• Avoidance / clothing
• Insect repellants

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Chemical Vector Control

• Larvacides
• Methoprene (Altosid)
• B.sphaericus (Vectolex)
• Adulticides
• Penothrin (sumithrin) / PBO (Anvil)
• Malathion
• Personal Protection
• DEET

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Pesticide Applications Cause for Concern?
No pesticide can be considered 100 safe
and
The dose makes the poison
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Pyrethroids / Phenothrin

• Moderately toxic (EPA Cat II), effects in highly
  exposed workers
• Isolated reports of irritant / allergic effects
• Risks / recommendations for Anvil fogging
• Environmental Impact

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DEET

• Does it work?
• Is it safe for me the kids?
• Ill be better off with a Natural product

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Alternative control measures if spending
makes you feel better
Dragonfly Mosquito System?
1092.00
Mosquito Barrier 84.99 Mosquito Barrier is a
very potent liquid garlic
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Summer 2003 and beyond

• 2002 may have been a worst-case scenario
• Pesticide use wont create widespread public
  dissent
• Health effects possible admits for respiratory
  distress associated w/ spray events?

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And as for human cases of West Nile Virus..?
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Grateful Acknowledgements to John E. Edman,
Ph.D. Director Center for Vector Borne
Diseases University of California Davis Bill
Paul, M.D. City of Chicago Department of Public
Health