Progress in DWFP and Related Research

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Progress in DWFP and Related Research

• Ulrich R. Bernier
• USDA-ARS-CMAVE
• Mosquito Fly Research Unit
• 352-374-5917
• ubernier_at_gainesville.usda.ufl.edu
• 2007 DoD Pest Management Workshop
• 12-16 February 2007

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DWFP Projects to be Discussed

• Chemical structure activity studies
• Development of portable devices
• Biting protection assessment of uniforms
• Development of inhibitor sustained release
  delivery systems
• Laboratory and field studies with sand flies in
  Egypt

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Structure-Activity Studies of Known Arthropod
Repellents and Toxicants Using CODESSA and QSAR

• Collaboration Agreement with University of
  Florida Department of Chemistry
• Research problem Characterize the molecular
  structural and electronic properties that
• correlate with level of repellent activity
  against multiple insect species
• lead to insecticidal activity
• Key point Since 1942, USDA has compiled records
  for thousands of compounds tested for repellent
  and insecticidal properties.
• Military relevance Development of novel
  repellents and insecticides will enhance the
  arsenal of products to control insects that
  transmit disease to personnel.

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MFRU Repellent Testing Paradigm
Candidate repellent
Toxicant track
in vivo
in vitro
Spatial inhibition
GC/MS Purity
Olfactometer
Candidate toxicant
Cloth patch cage test
HITSS
Toxicology tests
Commercial partner
Product
Registration
Topical cage test
Field evaluation
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Experimental Classes of Repellents Used in Models
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Model-Predicted Classification vs. Experimental
Classification of Repellents
Predicted Classes
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Carboxamides and Piperidines
Piperidine
DEET
1-(3-methylbenzoyl)piperidine
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Bioassay of Synthetic Piperidines as Candidate
Attraction-Inhibitors(Candidates are coded P1-33)
USDA Inhibitor
Deet
Attractant Blend
P13 AI3-38739
P6 3-Methyl AI3-33510
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Structure-Activity Studies (cont.)

• Current database contains over 30,000 compounds
  tested by USDA
• Spatial repellency has been assayed with the
  olfactometer for the 33 synthetic piperidines.
  Analysis of the carboxamides will take place in
  2007.
• Work is in progress on 5 database sets
• House fly residual insecticides
• Anopheles spp. larvicides
• Ae. aegypti repellents
• Anopheles spp. residual insecticides
• Oc. taeniorhyncus insecticides
• Repellents assays (cloth patch test) completed
  for 6 piperidines- both CPT and MED have been
  determinedthe remaining 27 piperidines and
  carboxamides should be completed by 30 Jun 2007.

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Development of Portable Devices for Detection and
Quantification of Insecticides, Repellents, and
Inhibitors

• Collaboration Agreement with University of
  Florida Dept. of Chemistry
• Research problem An economical field device
  for airborne detection and quantification ULV
  spray fate and dispersal, repellents, and
  inhibitors is not currently available.
• Key point FAIMS devices
• are small, low-cost units
• exhibit high chemical sensitivity and selectivity
  with low noise and can separate isomers
• can be used for continuous monitoring and work at
  atmospheric pressure
• Military relevance Addition of a low-cost,
  field deployable device to mask attraction of
  personnel from biting insects can result in
  reduced disease risk to deployed personnel.

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Field Asymmetric Ion Mobility Spectrometry (FAIMS)
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Field-Deployable Devices
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Development of Portable Devices (cont.)

• Preliminary results with naled and malathion have
  demonstrated that this technique can separate
  isomers and be used in the field.
• Currently exploring FAIMS optimization of naled,
  malathion, permethrin, d-phenothrin, resmethrin,
  bifenthrin, cyfluthrin, and deltamethrin
• Next step is the evaluation of FAIMS as a
  stand-alone detector and determination of
  detection limits for target compounds

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Assessment of Biting Protection of U.S. Military
Uniforms and Development of Criteria to Protect
Deployed Troops in the Future

• Collaboration Agreement with Natick Soldier
  CenterMIPR initiated by USMC
• Research problems
• Determine if application of permanent press
  finish affected performance of permethrin-treated
  Marine Corps Combat Utility Uniforms (MCCUUs)
• Develop a protocol to determine biological
  efficacy of factory-treated MCCUUs against
  mosquitoes
• Key point DWFP component of this work is to
  establish baseline efficacy data of sand fly bite
  protection from factory-treated MCCUUs.
• Military relevance Factory-treated MCCUUs that
  retain biologically efficacious levels of
  permethrin over their lifetime preclude the need
  for field-treatment of uniforms and may
  ultimately reduce disease risk.

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Untreated sleeve - Female mosquitoes land
and probe in search of a blood meal
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Treated sleeve after 2 min - Many females are
still on the sleeve but few obtain blood
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Treated sleeve after 8 min - Few mosquitoes
remain on the sleeve and many have left the
garment
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American Apparel First ArticleQuantitation of
Permethrin in Fabricby Gas Chromatography
(Natick Soldier Center)
0 washes
20 washes
50 washes
Treated MCCUUs in 2004 (phase 2) exhibited rapid
initial losses of permethrin when laundered.
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Assessing Biting Protection in Uniforms (cont.)

• Summary
• Initial assessment of fabrics started on March
  17, 2006
• Three companies have qualified, one is undergoing
  first article validation
• There have been three failures, one company has
  failed twice
• Future
• Bite protection for first article validation will
  be completed by 10 Mar 2007
• Continue MCCUU evaluation as needed
• ACU study involving field treatment
• Evaluation of factory-treated MCCUU field
  performance (with JAX NECE, CDR Rankin and LT
  Doud at Lejeune)
• Development of new treatments spatial effect

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Development and Testing of Sustained Release
Delivery Mechanisms for Repelling Mosquitoes and
Biting Insects

• Collaboration Agreement with Bioguard RD to
  develop delivery devices for field release of
  attraction-inhibitors
• Research problem USDA-developed attraction
  inhibitors require encapsulation or binding of
  active ingredients in suitable non-reactive media
  to
• produce a sustained release at efficacious
  delivery rates
• to facilitate transport to the field where they
  will produce repellency in the field for 30 days.
• Key point Inhibitors that prevent host
  detection by biting insects are a novel method of
  personal protection technology.
• Military relevance Improvement of insecticide
  application technology, personal protection and
  vector inhibitors used in the field can yield
  more effective protection of deployed personnel
  and result in reduced disease risk.

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Volatile samples are contained in pressurized
canisters and delivered into an olfactometer port
to test mosquito attraction or inhibition
22
Kairomones alert mosquitoes that a host is near.
Mosquitoes follow the plumes upwind (anemotaxis)
toward the source of the odor.
Adapted from Bernier, U.R., Laboratory Research
and Development of Attractants, Inhibitors and
Repellents, Tech. Bull. Florida Mosq. Control
Assoc., 2006, 99-16.
23
Many of the less volatile repellents, like DEET,
are a feeding deterrent or contact irritant that
prevent biting. The chemical on the skin surface
is unappealing for the mosquito to land, remain
on, or feed through.
Adapted from Bernier, U.R., Laboratory Research
and Development of Attractants, Inhibitors and
Repellents, Tech. Bull. Florida Mosq. Control
Assoc., 2006, 99-16.
24
An attraction-inhibitor decreases host-finding
ability by masking or cloaking the kairomones,
producing anosmia or hyposmia in the mosquitoes.
?
Adapted from Bernier, U.R., Laboratory Research
and Development of Attractants, Inhibitors and
Repellents, Tech. Bull. Florida Mosq. Control
Assoc., 2006, 99-16.
25
Addition of a small amount of inhibitor to an
attractant blend or to human emanations decreased
attraction of mosquitoes
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Bioassay of Candidate Spatial Repellents for Use
in Field-Deployed Devices to Cloak Humans from
Mosquitoes
Attractant Blend
Efficient Inhibition
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Examples of carriers
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Development of Field Kits to Deliver Sustained
Release of Attraction-Inhibitors
Outer packaging of durable material to contain
the system
Air-activated warmer to elevate and maintain a
constant temperature
Nanoclay containing attraction-inhibitors
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Second version of prototype release
devicesPackage size approximately 3 x 3
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Current device to be tested in Egypt. It
delivers 40-80 mg/day for 3-5 days at wind speed
of 3-5 mph and provides coverage up to 10-15 m
from the device. Capsule is 1.5 diameter, 0.5
height.
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Development of Sustained Release Mechanisms
(cont.)

• Advantages of prototype devices
• Predicted release of active ingredients at
  efficacious levels for 30 days at 1 m from
  source and 3-5 days at 10-15 m from source
• Next generation device is easily transportable to
  field in glass ampule
• Packaging meets DOT and IATA requirements for
  unregulated transport
• Final designs for laboratory and field testing
  are related to individual personnel protection
  (IPP) requirements.
• Future
• Preliminary design and evaluation of the broad
  area pack (BAP)
• Design and evaluation of nano-carrier for
  permethrin-based fiber systems for extended
  release-based longevity

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Laboratory and Field Experiments with
Attractants, Inhibitors and Repellents against
Sand Flies in Egypt

• Collaboration LCDR David Hoel, NAMRU-3, Cairo,
  Egypt
• Research problems
• Explore chemical and physical means to enhance
  collections of sand flies in commercial field
  traps
• Explore inhibition of sand fly host-seeking in
  the laboratory and field.
• Develop baseline efficacy of MCCUUs against sand
  flies.
• Key point NAMRU-3 conducts field experiments in
  Aswangt90 Phlebotomus papatasi
• Military relevance Permethrin-treated uniforms
  are less protective against sand fly bites than
  against mosquitoes. Development of novel
  personal protectants for use against sand flies
  will improve protection of troops.

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Spacious laboratories for visiting scientists
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Office space for the taking
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Field Site in Bahrif, Aswan
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LCDR Hoel working on a different trap study
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Jerry Hogsette conducting research with fly traps
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Trap site 1 - Typically the most productive site
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Sample acquisition Human hair as one of the
treatments
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1-Octen-3-ol lure and human lure
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Baited trap- Traps are operated overnight (1700
to 0700 hrs)
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Trap site 4 Measuring overnight loss of lure
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Insects/Night
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Laboratory and Field Experiments in Egypt (cont.)

• Three sets of field data have been collected
  August-September, 2006).
• No significant difference observed between trap
  lures.
• In future laboratory studies inhibitors will be
  tested against sand fly species in colonies at
  NAMRU-3
• Future field studies will involve
• exploration of trap location and physical
  arrangement
• examination of best LED-lure-placement
  combination
• incorporation of inhibitors in experiments
• determination of daytime resting sites of sand
  flies