Ectoparasites III- Other Tick-Borne Pathogens Flashcards by Anika Eidson

How long do most hard ticks attach and feed?

Days

How well did you know this?

Not at all

Perfectly

Why do immature and adult female ticks take day to complete feeding/engorge?

They have an incomplete scutum

How well did you know this?

Not at all

Perfectly

What is feeding like for soft ticks?

Feed quickly and often

Usually go back to same host repeatedly

How well did you know this?

Not at all

Perfectly

What are methods of direct disease?

Tick bites
Paralysis (toxicosis)
…red meat allergy

How well did you know this?

Not at all

Perfectly

What are methods of indirect disease?

Transmission of pathogens

-viruses
-bacteria
-protozoa

How well did you know this?

Not at all

Perfectly

What is the clinical presentation of direct disease from tick bites?

Pain and inflammation at site
Possible complications (anemia, secondary infections, "tick worry")

How well did you know this?

Not at all

Perfectly

What are methods of treatment and prevention for direct disease from tick bites?

Manual removal vs. acaricide

Year-round control

How well did you know this?

Not at all

Perfectly

What is an example of a severe direct disease due to bites?

Dermacentor albipictus (Winter Tick) is a 1-host tick known for causing hair and blood loss primarily in moose

How well did you know this?

Not at all

Perfectly

What is tick paralysis (direct disease) caused by?

Toxin in tick saliva

Often female hard ticks

How well did you know this?

Not at all

Perfectly

Why do female ticks often cause tick paralysis?

They stay on longer

How well did you know this?

Not at all

Perfectly

What are the tick species that can cause tick paralysis?

Argasid: Argas persicus
Ixodid: Dermacentor* variabilis, Ambylomma maculatum, A. americanum

How well did you know this?

Not at all

Perfectly

What is the clinical presentation of tick paralysis?

Acute ascending flaccid paralysis

How well did you know this?

Not at all

Perfectly

What is Red Meat Allergy?

Direct disease
Allergic reaction to pork, beef, lamb
Described in humans
IgE antibodies to galactose-α-1,3-galactose (α-gal)

How well did you know this?

Not at all

Perfectly

What is galactose-α-1,3-galactose (α-gal)?

Oligosaccharide blood group component found in non-primate species

How well did you know this?

Not at all

Perfectly

What are the 2 processes that that transmission via vectors can occur with indirect disease?

Biological transmission (most vector-borne diseases) with reproduction or developmental changes in pathogen
Mechanical transmission without reproduction or developmental changes in pathogen

How well did you know this?

Not at all

Perfectly

What makes a tick a good vector?

Persistent blood-feeder
Wide host range
Few natural enemies
High reproductive potential
Pathogen can be maintained in tick populations

How well did you know this?

Not at all

Perfectly

What makes up the tick-host-pathogen system?

Vector competency

Reservoir host

How well did you know this?

Not at all

Perfectly

What is vector competency?

Capable of acquiring, maintaining, and transmitting an infectious agent

How well did you know this?

Not at all

Perfectly

What is a reservoir host?

Capable of acquiring, maintaining, and transmitting infectious agents
May be the vertebrate host or arthropod vector

How well did you know this?

Not at all

Perfectly

What was the first described vector-borne disease?

Texas cattle fever (1893), Babesia/Rhipicephalus

How well did you know this?

Not at all

Perfectly

What is the time line for the first VBD described?

1893: Texas cattle fever, Babesia/Rhipicephalus
1905: relapsing fever (Africa), Borrelia/Ornithodoros)
1906: Rocky mountain spotted fecer, Rickettsia/Dermacentor

How well did you know this?

Not at all

Perfectly

Describe tick-borne encephalitis

Powassan Encephalitis:
Vector(s)- Ixodes spp.
Clinically affected: humans
Mainly midwestern, northeastern US; Canada

How well did you know this?

Not at all

Perfectly

Describe tick-borne hemorrhagic disease

Nairobi sheep disease
Vector(s)- various hard tick species
Hemorrhagic gastroenteritis- small ruminants
Africa; Asia

How well did you know this?

Not at all

Perfectly

Describe tick-borne systemic disease

African Swine Fever:
Vector(s)- Ornithodoros
Systemic hemorrhagic disease
Domestic swine; warthogs- asymptomatic reservoirs
Africa
Colorado Tick Fever:
Human cases

How well did you know this?

Not at all

Perfectly

What are vectors of Lyme disease?

``` Ixodes scapularis (eastern US) Ixodes pacificus (western US) ```

What is the agent of Lyme disease?

Borrelia burgdorferi

What are the reservoir hosts for Lyme disease?

Rodents (white-footed mouse; reservoir for bacteria) | White-tailed deer (required host for tick only)

Where is Lyme disease commonly found?

Northeastern and north-central US

How do the most exposed dogs to Lyme disease appear?

Clinically normal

What are the clinical signs and pathogenesis of lyme disease in dogs?

Shifting leg lameness, fever, anorexia, lymphadenopathy | Polyarthritis, renal disease

What are sentinels for Lyme disease risk in humans?

Dogs

What are lyme-like illnesses in humans in the south often associated with?

Lone star tick bite

What are vectors of tularemia?

Dermacentor variabilis | Amblyomma americanum

What is the agent of tularemia?

Francisella tularensis

What is the pathology of tularemia in wild and domestic animals?

Abscesses in liver and spleen

What are the clinical signs of tularemia in humans?

Ulcerated lesions Fever Headache

What causes rickettsial diseases?

In general, obligate intracellular, gram negative bacteria | Rickettsia spp., Ehrliche spp., Anaplasma spp.

What are the signs that Rickettsial infections usually cause?

Nonspecific signs

How are Rickettsiae transmitted?

Transstadially | Transovarially

What are Rickettsial disease treatable with?

Tetracyclines

What are vectors of Heartwater disease?

Amblyomma app where endemic | A. maculatum– experimentally

What is the causative agent of Heartwater disease?

Ehrlichia ruminantium

What is the vector of tropical canine pancytopenia?

Rhipicephalius sanguineus

What is the causative agent of tropical canine pancytopenia?

Ehrlichia canis

What are the acute clinical signs of tropical canine pancytopenia?

Fever Anorexia Lethargy

What are the sublicnical signs of tropical canine pancytopenia?

E. canis in blood

What are the chronic signs of tropical canine pancytopenia?

``` Ocular, neurologic abnormalities Scrotal/limb edema Hemorrhage Weight loss Death ```

What is tropical canine pancytopenia common in?

German Shepherds

What is the vector if canine granulocytic ehrlichiosis?

Ambylomma americanum

What is the causative agent of canine granulocytic ehrlichiosis?

Ehrlichia ewingii

What is the vector of canine cyclic thrombocytopenia?

Rhipicephalus sanguineus

What is the causative agent of canine cyclic thrombocytopenia?

Anaplasma platys

What is the vector of granulocytic anaplasmosis?

Ixodes scapularis | I. pacificus

What is the causative agent of granulocytic anaplasmosis?

Anaplasma phagocytophilum

What are the clinical signs of granulocytic anaplasmosis in equine hosts?

Usually mild/subclinical | Fever, lethargy, stocking edema, petechiae

What are the clinical signs of granulocytic anaplasmosis in dogs and cats?

May be asymptomatic or have nonspecific or acute signs

What is the vector of bovine anaplasmosis?

Dermacentor adersoni– mechanical transmission

What is the causative agent of bovine anaplasmosis?

Anaplasma marginale

What are the clinical signs of bovine anaplasmosis in cattle?

Fever,hemoltic anemia | Severity increases with age (up to 50% mortality in adults)

What are the vectors Rocky Mountain Spotted Fever?

Dermacentor variabilis | D. andersoni

What is the causative agent of Rocky Mountain Spotted Fever?

Rickettsia rickettsii

What are the clinical signs of Rocky Mountain Spotted Fever?

``` Fever Lymphadenopathy Polyarthritis Edema Petechiae Ocular lesions ```

What are examples of bacterial diseases with soft tick vectors?

Epizootic bovine abortion | Relapsing fever

What is the vector of epizootic bovine abortion?

Ornithodoros coriaceus

What is the causative agent of epizootic bovine abortion?

Deltaproteobacterium

Where does epizootic bovine abortion occur?

California

What is the vector of relapsing fever?

Ornithodoros spp.

What is the causative agent of relapsing fever?

Borrelia spp.

Where does relapsing fever occur?

Western US, Texas, Florida

What are causes of canine hepatozoonosis (protozoal disease)?

Hepatozoon americium, H. canis

What is the cause of feline cytauxzoonosis (protozoal disease)?

Cytauxzoon felis

What are causes of canine piroplasmosis (protozoal disease)?

Babesia canis vogeli B. gibsoni B. conradae

What are causes of bovine piroplasmosis (protozoal disease)?

Babesia bigemina | B. bovis

What are causes of equine piroplasmosis?

Theileria equi | Babesisa caballi