Ticks

Question 1

tick paralysis

Answer 1

block Ca2+ in nervous system that causes paresis

Question 2

general tick characteristics

Answer 2

fused 2 piece body plan
-fused head/ thorax
-abdomen
(no constriction between head and body)
Chitinous exoskeleton w hard scutum (dorsal shield)
Toothed hypostome to embed in host
ADULT & NYMPH 8 legs
LARVAE 6 legs
ALL STAGES PARASITIC AND ALL SUCK BLOOD

Question 3

1 host

Answer 3

uses 1 host for entire lifecycle
molt occurs on host
eggs deposited off host
susceptible to control efforts
-Transovarial disease transmission

Question 4

2 host

Answer 4

uses2 host to complete lifecycle
Larvae/nymph feed on same host
adults acquire new host to complete lifecycle
eggs off host
-interstadial disease transmission

Question 5

3 host

Answer 5

uses 3 hosts to complete lifecycle
-leaves to develop, could go back. doesn’t require different host species
eggs off host
-interstadial disease transmission
**common for ticks in US

Question 6

transovarial transmission

Answer 6

infectious agent passed to progeny through ovaries
only mechanism for one host ticks to vector disease

Question 7

interstadial transmission

Answer 7

infectious agent acquired by larvae/nymph from host and passed to successive stages

Question 8

ixodes scapularis associated with

Answer 8

Lyme disease

Question 9

amblyomma americanum associated with

Answer 9

STARI
Ehrlichiosis

Question 10

dermacentor varriabilis associated with

Answer 10

rocky mountain spotted fever

Question 11

what characteristics to look at to tell tick species apart

Answer 11

capitulum
scutum
festons
spiracles (ventral)
anal groove (ventral)

Question 12

Dermacentor

Answer 12

short mouthparts
host seeking tick

Question 13

d. varriabilis

Answer 13

american dog tick
3 host lifecycle
adults on large vertebrae
—RMSF, Q fever, tick paralysis

Question 14

rocky moutain spotted fever

Answer 14

acute disease associated w rickettsial infection by d. varriabilis
non-specific muscle aches and fever initially
rash 2-5 days post tick exposure
**April-September
easily treated w antibiotics, early diagnosis is key

Question 15

tick paralysis

Answer 15

associated w neurotoxic salivary component
rapid ascending paresis-> respiratory failure and fatal
can be caused by single tick
associated w d. varriablis
ZOONOTIC

Question 16

Amblyomma americanum

Answer 16

Lonestar tick
long mouthparts
prominent white spot on dorsal scutum
festoons along distal margin
host seeking, 3 host tick

Question 17

STARI

Answer 17

southern tick associated rash illness
associated w lone star tick
matches w Lyme disease timing

Question 18

ehrlichiosis

Answer 18

acute disease of human and animals
gram neg bacteria invade white blood cells
low white blood cell count/ platelets
principle vector= ambylomma americanun

Question 19

rhipcephalus sanguineus

Answer 19

brown dog tick
3 host life cycle
tropical distribution
-adapted to living indoors
-central heating offers optimal temp and humidity
rapid lifecycle= huge populations (short as 2 months)
LATERAL EXPANSION
disease vector for RMSF, hepatozoon canis, b. gibsoni

Question 20

haemaphysalis longicornus

Answer 20

longhorn tick
invasive 3 host tick species
significant vector potential MANY (ehrlichiosis)
reproduce pathenogenically, males rare b/c unnecessary
REPORTABLE TO STATE VET/ USDA
**expansion of mouthparts on 2nd ridge of palpi

Question 21

severe fever w thrombocytopenia syndrome

Answer 21

anorexia, weight loss, fever
more severe in BIG cats
dogs not as susceptible
-clinical signs but not fatal
-resolve without treatment

Question 22

ixodes scapularis

Answer 22

black legged deer tick
host seeking
**LYME DISEASE
3 host life cycle
small w long mouthparts
black scutum and legs
no festoons

Question 23

are ixodes scapularis born with Lyme disease

Answer 23

NO
no transovarial transmission

Question 24

ixodes scapularis disease transmission cycle ?

Answer 24

ticks feed as larvae in summer/fall
-infected w borrelia burgdorferi
-transmitted to humans in the following spring
*Small size allows for prolonged feeding

Question 25

Lyme disease

Answer 25

reactive arthritis
-irregular/ slow heartbeat
flu-like illness
early diagnosis and treatment w tetracycline

Question 26

rhipicephalus annulatus & R. microplus

Answer 26

1 host life cycle
vector of texas cattle fever
R. microplus related to wild ungulates/horses
**persistent cases may facilitate spread and reintroduction of TCF w/ climate change
ridged palpi !
reportable disease

Question 27

why are nymphs associated with efficient transmission of infectious disease? ***

Answer 27

Can be infected trans-stadially and then infect other hosts

Question 28

why is feeding time regarded important for successful transmission of an infectious agent vectored by 3-host tick? ***

Answer 28

smaller tick stages feed longer without being noticed, so have greater potential to transmit

Question 29

soft tick general morphology

Answer 29

leathery body
head not visible from above, underneath
feed via vampire model
lay eggs in small batches multiple times

Question 30

vampire model

Answer 30

feed @ night when hosts sleep

Question 31

argas

Answer 31

poultry tick
3 host, all stages parasitic
adults rarely seen bc vampire model feeding
transmit avian spirochetosis and tick paralysis
all stages withstand starvation up to 2 years

Question 32

ornithodoros

Answer 32

avian, rodent, deer, & cattle
larvae do not feed
Nymph requires blood meal for each molt (M=4 F=5)
adults rarely seen bc vampire model feeding
all stages withstand starvation
transmission of borreliosis

Question 33

otobius

Answer 33

spinose ear tick
cattle, horse, livestock
pawing at ears
1 host life cycle
ONLY LARVAE & NYMPHS PARASITIC !!
adults w vestigial mouthparts do not feed, females lay one clutch of eggs

Question 34

preventing tickborne diseases

Answer 34

limit tick exposure activities
wear light clothing
use repellents
body check
infectious disease transmission function of duration of tick feed
–timely removal is key