NC Ticks: the Common Species, their Biology, Behavior, and Medical Importance

This presentation is presented by: Minor Barnette, NCSWEOA 10/22/2015

(Created by: Bruce A. Harrison, PhDTaxonomist/Public Health Entomologist

Clemmons, NC )Thank you Dr. Harrison!

Questing behavior

Lone Star Tick

Proper tick removal

Avoiding Ticks• Avoid activity in tick infested areas. • Stay on paths, avoid brush and tall grass.• Wear light colored clothing so ticks are easier to

spot.• Wear long pants and long sleeved shirt. Tuck

pant cuffs into socks or boots; tuck shirt-tails into pants.

• Use repellents. Permethrin is most effective against ticks. Follow label directions.

• Check frequently for ticks on clothing and skin. • Remove attached ticks quickly.

Avoiding ticks

Ticks have evolved along with and are primarily parasites of various wildlife host species.

Tick stages = egg, larva, nymph, and adult. The last three stages require a blood meal to complete their life cycle.

• Growth = by shedding skin (molts) between stages.

• Reproduction = oviposition of fertilized eggs.

Humans are incidental hosts for ticks.

Tick life cycle

Common wildlife hosts of ticks in NCAmerican dog tick (Dermacentor variabilis)

larvae and nymphs

vole white-footedmouse

adults

dograccoon

Lone Star tick (Amblyomma americanum)

dograccoonbirds deergray squirrel

larvae, nymphs and adults (except birds)

larvae and nymphs adults

birds w-f mouse

Black-legged tick (Ixodes scapularis)

skink dog deer

X

Why are ticks efficient vectors?

• Environmentally tolerant.• Each stage may feed on a different host, or the

same host.• Feed on a variety of wildlife species.• Feed for a long period of time.• Consume a large volume of blood.• Long-lived.• Often transmit pathogens transovarially.

Tick bites occasionally result in transmission of pathogens.

For Lyme disease, the erythema migrans rash occurs at the site of the tick bite.

For RMSF, the rash occurs on the wrists and ankles, palms and soles, and spreads to the trunk of the body.

Ticks and Disease in NC

• Lyme disease (Borrelia burgdorferi s.s.)

• Southern tick associated rash illness (STARI) ?• Spotted fevers (Rickettsia rickettsii, parkeri, etc.)

• Ehrlichiosis (Ehrlichia chaffeensis, ewingi, etc.)

• Anaplasmosis (Anaplasma phagocytophilum)

• Tick paralysis (caused by a tick neurotoxin)

Ticks Commonly Found in North Carolina

• Dermacentor variabilis - American dog tick, only adults on people. Common throughout the state.

• Amblyomma americanum - Lone star tick, adults, nymphs and larvae on people. Most common in eastern 1/2 of the state. Range is spreading.

• Ixodes scapularis - Black-legged tick, only adults on people. Nymphs rarely on people in the south. State wide, but most common in Coastal Plain counties.

• Rhipicephalus sanguineus - Brown dog tick, common on dogs, rarely on people. Widespread but less common since new topical treatments on dogs.

Identification: Short mouthparts, festoons,

white markings

Distribution: Throughout North Carolina

Vector of: Spotted fevers, Tularemia, Ehrlichiosis, tick paralysis

Female Male

Larva Nymphshortmouthparts

festoons

Dermacentor variabilis

American Dog Tick

whitemarkings

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Early symptoms of RMSF and related rickettsial infections

• Patients usually much sicker than with Lyme/STARI

• Higher fever• Bad headache• Shaking chills• Muscle aches• Often no rash• MUST BE TREATED PROMPTLY ON

SUSPICION• After 6 days, if left untreated, there

is a 25% or higher mortality rate

Black-legged tick(= Ix. scapularis)

Identification: Long mouthparts, black legs,

red color, no festoons

Distribution: In North Carolina primarily in the coastal plain and piedmont counties

Vector of: Lyme, Anaplasmosis, Babesiosis

Female Male

Nymph

no festoons

black legs

long mouthparts

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Larva NymphM adult F adult

Black-legged tick, the primary vector of Lyme Disease(= Ixodes scapularis)

Note Small size of Nymphs 7

Rash Examples- STARI and Lyme Disease

Multiple lone star tick larval biteswww.tic-nc.org

Erythema migrans:STARI

Erythema migrans: Lyme disease (Master’s NY-MO)

Lyme disease

Lone star tick

Identification: Long mouthparts, round shape

females with white spot, festoons

Distribution: Exceptionally common throughout coastal plain and eastern piedmont, less common in western NC

Vector of: Ehrlichiosis, STARI, tick paralysis, ? Lyme disease

Female Male

Nymph

“lone star” spot

round shape

white markings along festoons

long mouthparts

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Lone Star TickAmblyomma americanum

Lone Star tick is the most important nuisance species in NC.

• Most abundant tick species in the southeastern US.

• All stages readily attack humans.

Rhipicephalus sanguineus

Brown dog tick

IdentificatioIdentification:n:

Short mouthparts, festoonsShort mouthparts, festoons

no white markingsno white markings

Distribution:Distribution: Throughout North CarolinaThroughout North Carolina

can reproduce indoorscan reproduce indoors

VectorVector of:of: RMSF, dog pathogens, othersRMSF, dog pathogens, others

Male

Female

LarvaEngorged tick

festoons

short mouthparts

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Typical peridomestic environment surrounding case-patient homes, found to be heavily populated by Rh. sanguineus ticks

Environmental Assessment

Rocky Mountain spotted fever

View from belowView from above