Multnomah County Health Department

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Multnomah County Health Department
Environmental Health Services Kari Lyons, Health
Educator
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AgendaVector Control Mission Scope of Work
Integrated Pest ManagementControl
ProductsMosquito Control at Various City of
Gresham sites Public Outreach and WNv
PreventionNext Steps
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Vector Control

• The mission of Multnomah County Vector and
  Nuisance Control is to protect individuals and
  communities from illness, injury, and health
  hazards. We are concerned with rats, mosquitoes
  and health related nuisance codes.
• A vector is any organism capable of transmitting
  disease. Some examples are fleas, ticks,
  mosquitoes and rodents. Vectors are able to
  spread disease to humans by biting, burrowing or
  contaminating our living spaces.

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Integrated Pest ManagementVector Control and
Surveillance

• A successful pest management program should
• include the following elements
• Larval and adult mosquito control
• Source reduction
• Biological control using native or introduced
• predators and parasites of mosquitoes
• 4) Disease surveillance
• Public education on vector prevention, personal
  protection and services
• 6) Public complaint response
• Rodent Control
• Nuisance Control

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Why we control mosquitoes?

• Disease
• Malaria 300-500 million cases yearly 2-3
  million fatalities 1 child dies every 12 seconds
• West Nile virus
• Dengue 50-100 million cases
• Encephalitis
• Economics
• Agriculture
• Tourism
• Cost of disease
• Annoyance (quality of life)

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Mosquito Species

• 22 species Culex, Aedes, Anopheles
• Introduction of 3 new species in 2005 and 2006

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Why mosquito control?

• Multnomah species that prefer storm water
  structure habitats have
• highest vector potential
• most abundant (90)
• capacity to over-winter as adult females
• Found in close proximity within urban habitat
• High host populations to sustain vector and
  disease (human and vector relationship)

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Example Stormwater Mosquitoes

• - Subsurface stormwater (catch basin,manholes)
• Cx pipiens Cx stigmatosoma, Cs incidens
• Clean to Highly Organic
• Sedimentation Detention Facilities
• Cx tarsalis, Anopholes
• Clean Water
• Culex (Primary) and Anopholes vectors of WNV
• Biting times sunrise and sunset
• Multiple broods as long as the weather and water
  remain
• Over winter as adult female
• Over 12 species

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Mosquito Control in Multnomah County
NATURAL LARVAL REARING SITES
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Why mosquito control in Gresham?

• Vectors do not adhere to boundaries and migrate
  with intent to discover a blood meal.
• Complaints are one way to look at community
  livability, however routine trapping, sampling
  for larval mosquitoes and other surveillance in
  lakes, storm water collection structures, etc.
  indicates the presence of disease-carrying
  vectors.
• Example Ochlerotatus japonicus

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AUTHORITY

• ORS 452 State Vector and Weed Control
• City County titles and codes Title 8,13

REGULATION

• Oregon Dept. of Agriculture
• Fish Wildlife (Federal State)
• Oregon Health Division
• Environmental Protection Agency DEQ
• Federal Insecticide, Fungicide and Rodenticide
  Act, Clean Water Act, Endangered Species Act,

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Mosquito Surveillance and Control

• Surveillance
• CO2 Attracts females looking for a blood meal,
  encephalitis virus surveillance
• Gravid Collects females already fed, trying to
  lay eggs (water)
• NJ light male, female, population counts mostly
• Sentinel Chicken Flocks, Dead Birds, Horses,
  Humans
• Control
• - Larvicides Biorationals, Insect Growth
  Regulator, Oils
• - Adulticides Pyrethrin

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Mosquito Life Cycle ControlMeasures
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Control Products
Insect Growth Regulator
Oil
Biorationals
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Larviciding ProductsVectoBac VectoLex Mode of
Action

• Bacteria produce a crystal
• Crystal is made up of proteins
• Proteins in the Crystal act against mosquito
  larvae

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Larviciding ProductsMicrobial Larvicides

• Bti,Bs

• Larvae eat Bti crystals or Bs bacteria containing
  crystals
• Proteins in the crystals are activated by the
  enzymes and alkaline pH in the larval midgut
• Activated proteins attack the gut lining.
• Larvae can no longer digest food and die.

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Larviciding ProductsInsect Growth Regulators

• Altosid
• Hormone Mimic
• Disrupts normal mosquito development
• Prevents metamorphosis to adult
• Product Absorbed
• Must contact 4th instar larvae
• Extremely Low toxicity
• Minimal non-target impacts

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Winter/Spring 2006

• Culex perturbans production is especially high
  due to wet rainfall and abnormal hot temperatures
• Inspection by hand application of Vectolex CG
  (BS) and Vectobac B (Bti)

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Summer 2006

• Sub surface treatments for catch basins in the
  streets in mid-June until September with Vectolex
  CG
• Sedimentary manholes treated in mid-May with
  Altosid 90-day briquettes until August
• Sub surface sites like schools and parks on
  similar schedule
• Natural sites are inspected and treated on a
  routine basis January through October, primarily
  with Vectobac G, Vectolex CG, and Altosid.

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Education and OutreachVirus Prevention

• Grassroots Outreach in Culturally Competent
  Manner
• Fix-it fairs
• Social Marketing Policy Advocacy
• Workforce Development
• Emergency Community Response Plan, Doorhanger
• Public Notification

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Public Health Education West Nile Virus

• Mosquito-borne virus
• Symptoms include fever, headache, nausea and
  encephalitis or meningitis
• Transmitted from mosquito to birds, horses and
  other mammals

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West Nile Virus in U.S.
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Count the breeding sites
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Prevention

• Insect repellents containing DEET or Oil of lemon
  eucalyptus
• Dusk and Dawn
• Wear long sleeves and pants
• Good Screen on windows and doors
• Get rid of mosquito breeding sites

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Keeping the Public Informed Next Steps .

• Kari Lyons, Vector Control
• 503-988-3400 Ext. 25860