Ticks Flashcards
what are the two types of ticks?
soft ticks: argasids
hard ticks: ixodids
how do the feedings differ between types of ticks?
soft: multiple short feeds
hard: single long feed per stage
what enhances the survival of hard ticks?
thick waxy cuticle
how do hard ticks expand?
internal cuticular pleats must soften over several days
how do hard ticks prepare the site of their bite?
lacerate and lyse cells to create pools of lymph and blood
what does it mean for a tick to be nidicolous?
nest-dwelling
what does it mean for a tick to be non-nidicolous?
host seeking: active hunter or passive questing
what allows ticks to “bridge” infection to humans zoonotically?
wide host range: “two host” or “three host” ticks
what are attributes of ticks that make them good vectors?
obligatory parasite- blood
salivary pharmacopeia promotes infection
extended life cycle
wide host range
long duration of feeding
high reproductive potential: dense infestations
exploit disturbed environments
what does pharmacopeia in tick spit prevent?
hemostasis
immune attack
what direct injuries can ticks cause?
cellulitis
granulomatous dermal reactions
tick paralysis
red meat allergy
how do ticks cause tick paralysis?
small protein toxin acts presynaptically and inhibits acetylcholine release
which ticks are nidicolous?
all argasids
some ixodids
what are some tick borne infections from deer ticks?
lyme disease
Borrelia miyamotoi disease
babesiosis
human granulocytic ehrlichiosis/anaplasmosis
deer tick encephalitis/fever
what tick-borne infections can dog ticks transmit?
tularemia
rocky mountain spotted fever
what tick-borne infections can lone star ticks transmit?
masters’ disease
“spotless fever”
ehrlichiosis
heartland virus hemorrhagic fever
bourbon virus hemorrhagic fever
what tick-borne infection can woodchuck ticks likely transmit?
powassan encephalitis
what are the reproductive hosts of american dog ticks (Dermacentor variabilis)?
carnivores: dogs, skunks, raccoons, foxes, coyotes
what are the main hosts for lone star ticks?
deer- all development stages
what distinguishes red meat allergies from other allergies?
delay in signs/symptoms
what specifically is linked to red meat allergy?
alpha gal
why are adult deer ticks not contributing a lot of cases of Lyme disease?
clothing
size of tick and prompt removal
inoculum
what is the seasonality of Lyme disease transmission?
mostly May-Aug
deer tick nymphs are main vector
why does anti-OspA immunity matter?
Lyme disease
infected ticks ingest anti-OspA antibody while feeding on a vaccinated host
anti-OspA antibody incapacitate spirochetes before reactivation: prevent antigenic shift to OspC and thereby transmission
