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,

Pathology West, Westmead Hospital, Westmead NSW 2145Pathology West, Westmead Hospital, Westmead NSW 2145

Ticks: overviewTicks: overview

Biology: lifecycle & ecologyBiology: lifecycle & ecology

Tick ManagementTick Management

AvoidanceAvoidance RepellentsRepellents EfficacyEfficacy Human safetyHuman safety

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

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 Host removal Host removal Habitat modificationHabitat modification

Chemical ControlChemical Control Habitat treatment Habitat treatment Personal Protection Personal Protection 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

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

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)

ActiveActive %% Protection TimeProtection Time

DEETDEET 24%24% 302m302m

ActiveActive %% Protection TimeProtection Time

DEETDEET 24%24% 302m302m

DEETDEET 20%20% 234m234m

ActiveActive %% Protection TimeProtection Time

DEETDEET 24%24% 302m302m

DEETDEET 20%20% 234m234m

DEETDEET 6.7%6.7% 112m112m

ActiveActive %% Protection TimeProtection Time

DEETDEET 24%24% 302m302m

DEETDEET 20%20% 234m234m

DEETDEET 6.7%6.7% 112m112m

CitronellaCitronella 10%10% 20m20m

ActiveActive %% Protection TimeProtection Time

DEETDEET 24%24% 302m302m

DEETDEET 20%20% 234m234m

DEETDEET 6.7%6.7% 112m112m

CitronellaCitronella 10%10% 20m20m

CitronellaCitronella 5%5% 14m14m

ActiveActive %% Protection TimeProtection Time

DEETDEET 24%24% 302m302m

DEETDEET 20%20% 234m234m

DEETDEET 6.7%6.7% 112m112m

CitronellaCitronella 10%10% 20m20m

CitronellaCitronella 5%5% 14m14m

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?

Registered Registered

EquipEquip The Travel DoctorThe Travel Doctor Impregnation packsImpregnation packs 10ml/4L H10ml/4L H22O, soak 2mO, soak 2m Effective 6 monthsEffective 6 months

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””

““Naturals” are a greater risk to human health!!!Naturals” are a greater risk to human health!!!

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

WE WANT WE WANT YOUR YOUR TICKS!TICKS!