stephen l. doggett senior hospital scientist

Stephen L. DoggettStephen L. DoggettSenior Hospital ScientistSenior Hospital Scientist

Department of Medical EntomologyDepartment of Medical EntomologyInstitute for Clinical Pathology & Medical Research, Institute for Clinical Pathology & Medical Research,

Westmead Hospital, Westmead NSW 2145Westmead Hospital, Westmead NSW 2145

Ticks – introductionTicks – introduction

Biology/ecology/lifecycleBiology/ecology/lifecycle

ManagementManagement

AvoidanceAvoidance

OverviewOverview

Worldwide – about 800 sp.Worldwide – about 800 sp. Australia – 75 (~15 attack humans)Australia – 75 (~15 attack humans) 2 groups – Soft & Hard ticks2 groups – Soft & Hard ticks

Most important - Most important - Ixodes holocyclusIxodes holocyclus Paralysis tick, scrub, bush, shell back Paralysis tick, scrub, bush, shell back Seed, grass (larval stage)Seed, grass (larval stage)

TicksTicks

1988-2013: 671 specimens1988-2013: 671 specimens AmblyommaAmblyomma: 3.7%: 3.7% AponommaAponomma: 0.3%: 0.3% HaemaphysalisHaemaphysalis: 1.8%: 1.8% RhipicephalusRhipicephalus: 1.3%: 1.3% IxodesIxodes: 93% : 93%

Ixodes holocyclus:Ixodes holocyclus: (98%) (98%) Adults: 37%, Nymph: 26%, Larvae: 37%Adults: 37%, Nymph: 26%, Larvae: 37%

Tick Samples to DMETick Samples to DME

1mm

LarvaLarvaNymphNymph

AdultAdultMaleMale

AdultAdultFemaleFemale

Tick Life CycleTick Life Cycle

Paralysis tick,Paralysis tick,

Ixodes holocyclusIxodes holocyclus

3m

0.5m

Host Seeking Host Seeking BehaviourBehaviour

Most of the yearMost of the year

Survival dependant on humiditySurvival dependant on humidity

Most activeMost active:: Following rainFollowing rain Periods of high humidityPeriods of high humidity

Larvae far more common than other stagesLarvae far more common than other stages High mortality in larval stage to nymphHigh mortality in larval stage to nymph

When are ticks active?When are ticks active?

Animal HostsAnimal Hosts

Red-necked Wallaby

House Mouse

Magpie

Australian Raven

Domestic Fowl

Human

Dog

Cat

Pig

Eastern Grey Kangaroo

Norwegian Rat

Bush Rat

Grasslands Melomys

Water Rat

Crimson Rosella

Pied Butcherbird

Echidna

Common Dunnart

Feathertail Glider

Red-legged Pademelon

Northern Brown Bandicoot

Southern Brown Bandicoot

Long-nosed Bandicoot

Mountain Brushtail Possum

Common Brushtail Possum

Brush-tailed Phascogale

Koala

Swamp Wallaby

Rabbit

Black Rat

After Roberts (1970)

Main Host Main Host BandicootBandicoot

MAKE SURE MAKE SURE YOU REMOVE YOU REMOVE THE HEAD!!!THE HEAD!!!

Tick RemovalTick Removal

Cultural Control: Cultural Control: Behaviour modificationBehaviour modification

Physical Control: Physical Control: Exclusion fencingExclusion fencing

Biological ControlBiological Control Parasites/pathogens/predatorsParasites/pathogens/predators Host removalHost removal Habitat modificationHabitat modification

Chemical ControlChemical Control RepellentsRepellents Habitat treatmentHabitat treatment Host treatmentHost treatment

Tick ManagementTick Management

Tick Control MethodsTick Control Methods

Habitat Modification

Fire

Host Removal

Chemical Treatment

Personal Protection

Con

trol

Dur

atio

nE

nvironmental Im

pactControl Method

Avoid ticky habitatAvoid ticky habitat

Avoid good ticky timesAvoid good ticky times After rain, high humidityAfter rain, high humidity

Wear light coloured clothingWear light coloured clothing

Check oneself regularly during & afterCheck oneself regularly during & after

Tuck pants into socks, shirts into pantsTuck pants into socks, shirts into pants

Remove clothing, place into hot dryerRemove clothing, place into hot dryer

Use repellents/permethrin on clothingUse repellents/permethrin on clothing

Cultural ControlCultural Control

FormulationsFormulations

GimmicksGimmicks

Australian Pesticides & Veterinary Australian Pesticides & Veterinary Medicines AuthorityMedicines Authority(National Registration Authority: NRA)(National Registration Authority: NRA)

For insecticides/repellents, assess:For insecticides/repellents, assess: Human ToxicityHuman Toxicity Product EfficacyProduct Efficacy Environmental ImpactsEnvironmental Impacts

APVMAAPVMA

ActiveActive

Approved useApproved use

Registered?Registered?

DirectionsDirections

DEET (N,N-Diethyl-meta-toluamide)DEET (N,N-Diethyl-meta-toluamide) PicaridinPicaridin Lemon Eucalyptus Oil (PMD)Lemon Eucalyptus Oil (PMD) IR3535IR3535 Citronella, melaleuca oilCitronella, melaleuca oil

Repellent ActivesRepellent Actives

““Natural”Natural”“Organic”“Organic”

““Safe” & Safe” & “Effective”“Effective”==

ActiveActive %% Protection TimeProtection Time

Repellent EfficacyRepellent Efficacy MosquitoesMosquitoes

Fradin & Day, NEJM (2002)Fradin & Day, NEJM (2002)


DEETDEET 24%24% 302m302m







DEETDEET 6.7%6.7% 112m112m




DEETDEET 6.7%6.7% 112m112m

CitronellaCitronella 10%10% 20m20m




DEETDEET 6.7%6.7% 112m112m






DEETDEET 6.7%6.7% 112m112m



Citronella (WB)Citronella (WB) 25%25% 0.2m0.2m

PermethrinPermethrin = toxicant not a repellent = toxicant not a repellent

Two formsTwo forms:: DIY, ‘dip’ clothingDIY, ‘dip’ clothing Impregnated fabrics (IF)Impregnated fabrics (IF)

Studies show:Studies show: IF better protection than DIYIF better protection than DIY IF more washes than DIYIF more washes than DIY IF less environmental impactsIF less environmental impacts Permethin better protection than repellentsPermethin better protection than repellents Widely used by armiesWidely used by armies

Permethrin Impregnated ClothingPermethrin Impregnated Clothing

Permethrin Impregnated Clothing?Permethrin Impregnated Clothing?

Human SafetyHuman Safety Risk analysisRisk analysis

What is worse: bites or repellents?What is worse: bites or repellents?

DEET first registered, 1957DEET first registered, 1957 Billions of usesBillions of uses Recommended by WHO & CDCRecommended by WHO & CDC Only product recommended by CDCOnly product recommended by CDC US EPA: adverse reactions 1:100millionUS EPA: adverse reactions 1:100million

EPA: EPA: ““permethrin factory-treated clothing is unlikely to permethrin factory-treated clothing is unlikely to pose any significant acute or chronic hazard to peoplepose any significant acute or chronic hazard to people””

Read & heed the label!Read & heed the label!

Host Exclusion FencingHost Exclusion Fencing

Reduce overhanging foliageReduce overhanging foliage

Clearing brush/bushesClearing brush/bushes

Removal of leaf litter/mulchRemoval of leaf litter/mulch

Maintain lawns <15cmMaintain lawns <15cm

CementingCementing

Inc. sunlight to ground, dec. humidityInc. sunlight to ground, dec. humidity

Achieves most prolonged level of controlAchieves most prolonged level of control

Habitat ModificationHabitat Modification

AdvantagesAdvantages Rapid control, 97% within 24 hoursRapid control, 97% within 24 hours Cost effectiveCost effective Less environmental damageLess environmental damage

DisadvantagesDisadvantages Not tick specificNot tick specific Relatively short termRelatively short term

Pyrethroids: Pyrethroids: Permethrin, Betacyfluthrin, Permethrin, Betacyfluthrin, BifenthrinBifenthrin

Chemical ControlChemical Control

PyrethroidPyrethroid

Toxic to lower vertebratesToxic to lower vertebrates

Strongly binds to the soilStrongly binds to the soil reduced contamination riskreduced contamination risk

Recommended by WHO for mosquito c.Recommended by WHO for mosquito c.

BUT DOES IT WORK?BUT DOES IT WORK?

Two formulationsTwo formulations:: Emulsifiable Concentration, GranularEmulsifiable Concentration, Granular

BifenthrinBifenthrin

Bifenthrin - FormulationsBifenthrin - Formulations

Granular Granular (Bithor, Brigade, Vigilanti)(Bithor, Brigade, Vigilanti)

Can be used against all stagesCan be used against all stages

Directions for use:Directions for use:““Applications should be made in the spring to control Applications should be made in the spring to control

larvae and nymphs that reside in the soil and leaf larvae and nymphs that reside in the soil and leaf litter…”litter…”

ApplicationApplication::

Hand, fertilizer spreaders, Hand, fertilizer spreaders,

backpack, aerialbackpack, aerial

WE WANT WE WANT YOUR YOUR TICKS!TICKS!

www.medent.usyd.edu.auwww.medent.usyd.edu.au

stephen l. doggett senior hospital scientist

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