1. Ixodidae Ticks & Tick-borne Diseases
Michael Lehrke

2. Ixodidae Ticks Ixodidae ticks are hard ticks Taxonomy:
Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida (Eight legs)
Subclass: Acari (Ticks & Mites)
Superorder: Parasitiformes (Parasitic ticks)
Order: Ixodida
Family Ixodidae (Hard ticks)
702 species in 14 genera

3. Notable Species Amblyomma americanum Dermacentor andersoni
The lone star tick
Dermacentor andersoni
Wood tick
Dermacentor variabilis
American dog tick
Ixodes scapularis (Ixodes dammini)
Black-legged deer tick
Rhipicephalus sanguineus
Brown dog tick

4. General Morphology
Hard scutum or shield, on females it is partial on males it is full
A capitulum (mouth parts) that projects from the body
Opposed to soft ticks in which the head is beneath the body

5. A. americanum Morphology
Red-brown color, females have white spot posterior to scutum, males have more than one spot around body
Mouth parts are particularly long
Festoons are present

6. Dermacentor Morphology
Females have a white scutum and brown body, males are brown with white markings (D. variabilis has more white)
Eleven festoons
Basis capituli is straight
Coxae get larger from anterior to posterior

7. I. scapularis Morphology
They have reddish bodies with black scutum, males are usually mostly black
Lack of festoons
Have anal groove on ventral side, anterior to the anus
Adults are “1/2 sesame” sized and nymphs are “poppy seed” sized

8. R. sanguineus Morphology
Brown abdomen and scutum
Festoons present
Hexagonal basis capituli
Coxae remain same size

9. Morphology

10. Amblyomma americanum
Definitive hosts: Cats, cattle, sheep, goats, horses, rodents, primates
Intermediate hosts: Cats, rodents, rabbits
It is a three-host tick
Southern US and Mexico

11. Dermacentor andersoni
Definitive hosts: Dogs, cattle, sheep, goats, horses, primates, raccoons
Intermediate hosts: Rodents, rabbits
It is a three-host tick
Western North America
and Canada

12. Dermacentor variabilis
Definitive hosts: Dogs, cats, cattle, rodents, primates, raccoons
Intermediate hosts: Rabbits
It is a three-host tick
Central and Eastern US

13. Ixodes scapularis
Definitive hosts: Dogs, cats, cattle, rodents, horses, pigs, rabbits, birds, primates
Intermediate hosts: Rabbits, rodents, snakes/turtles
It is a three-host tick
Central, Midwest and
Eastern US

14. Rhipicephalus sanguineus
Definitive hosts: Dogs, rodents, rabbits, primates
Intermediate hosts: Dogs, rodents, rabbits
It is a three-host tick
Entire US (your dog is
not safe!!)

15. Life Cycle Three host tick: feeds on three hosts during life cycle
Can be all different or the same individual
Molt in between feedings
Usually winter before each feeding and after molting
Progress from Egg -> Larvae -> Nymph -> Adult
Larvae, aka rebels, have 6 legs (nymphs keep it real with 8 again)

16. Life Cycle

17. Life Cycle

18. Pathology Usually asymptomatic, like a normal insect bite
Tick cuts into skin (can take 10 min to 2 hours to prepare), inserts feeding tube, and secrete anesthetic saliva! (Sucks, literally)
Dermacentor and Ixodes have been implicated with tick paralysis
Acute, ascending, flaccid motor paralysis, can result in death
Thought to be caused by toxins
Ticks can transmit diseases!

19. Treatment/Control Remove the tick, duh
DO NOT use ointments/Vaseline or heat, ticks vomit, possibly forcing pathogens into you!
Avoid tick infested areas
Repellent (DEET)

20. Tick-borne Diseases Anaplasmosis Babesiosis Ehrlichiosis Lyme disease
Rocky Mountain Spotted Fever

21. Anaplasmosis
Formerly human granulocytic ehrlichiosis (HE), now referred to human granulocytic anaplasmosis
Caused by bacteria Anaplasma phagocytophilum, transmitted by Ixodes scapularis
Symptoms include fever, headache,
chills, muscle aches usually
1-2 weeks after bite
Diagnosed on symptoms and
can be confirmed by lab tests,
treated with doxycycline

22. Babesiosis
Caused by blood parasite Babesia microti, transmitted by Ixodes scapularis
Usually asymptomatic, can cause flu-like symptoms, dangerous to immunocompromised people
Diagnosed with blood smears, visualizing “Maltese-cross” formations, treated, usually clears itself or can be treated with drug combinations

23. Ehrlichiosis
Caused by Ehrlichia species of bacteria, transmitted by lone-star tick
Flu-like symptoms, malaise, confusion, rash, red eyes
Diagnosed on clinical signs and lab tests, treated with doxycycline

24. Rocky Mountain Spotted Fever
Caused by the bacteria Rickettsia rickettsi, transmitted by Dermacentor variabilis, Dermacentor andersoni, and Rhipicephalus sanguineus
Flu-like symptoms, spotted rash, can be deadly if not treated
Suspicion, blood tests, platelet count, treated with doxycycline

25. Lyme Disease NOT “Lyme’s Disease” – Named after
Caused by the spirochete bacteria Borrelia burgdorferi, transmitted by Ixodes scapularis
Acute: Flu-like symptoms, erythema migrans (bull’s-eye rash), Bell’s palsy, joint pain, fatigue
Chronic: Arthritis, neurological issues, persistent fatigue
Post-treatment: fatigue, sleep disturbance, cognitive defects, joint problems

26. Lyme Disease
Diagnosed with blood tests (after several weeks), treated with doxycycline, Ceftin, or amoxicillin

27. Lyme Disease
Prevalent on the East Coast and in the Midwest (particularly around this area and Wisconsin)
Prevalence is dramatically climbing
In 2000 MN had 465 cases, in 2010 that rose to 1293 (270% increase)!
In 2000 WI had 631 cases, which rose to 2505 in 2010 (400% increase)!

28. Lyme Disease

29. Lyme Disease

30. Lyme Disease

31. Prevention
These diseases can be prevented by avoiding ticks, using repellents (DEET), and promptly removing ticks

32. Questions?