Infectious Diseases and Critters

Question 1

The Ixodes tick transmits which diseases (4)?

Answer 1

Lyme disease, Babesiosis, Ehrlichiosis, Tick Paralysis.

I.pacificus (California), I.ricinus (Europe), I.scapularis (Eastern US)

Question 2

Which HPV subtypes are high risk? Which HPV genes induce neoplasia?

Answer 2

High risk HPV = 16, 18, 31, 33

HPV early genes E6 and E7 bind tumor suppressor p53 and Rb proteins, inactivating them, initiating oncogenesis

Question 3

A bad interaction with this spider can cause blindness…

Answer 3

Tarantula (Theaphosidae) – urticating hairs can cause ophthalmia nodosa and blindness if the cornea is injured.

Question 4

What is the real name and toxin of the black widow spider?

Answer 4

Lactrodectus mactans
*toxin = alpha-lactrotoxin –> systemic toxicity with abdominal pain, paralysis, vomiting, etc

Remember: “Lactro sounds like lactate….”

Question 5

What toxin does Loxosceles reclusa contain? What effects does it have on skin?

Answer 5

Loxosceles reclusa = brown recluse spider

*Toxin = Sphingomelinase –> extensive gangrene and necrosis

Question 6

The human body louse is a vector for what (3)?

Answer 6

Trench fever (Bartonella Quintana)
Epidemic Typhus (Rickettsia prowazekii)
Relapsing Fever (Borelia recurrentis)

Question 7

Which organisms cause verrucous dermatosis (5) and what is the treatment?

Answer 7

Causes of Chromoblastomycosis: Fonsecaea pedrosoi (#1), F.compacta, Cladosporium carrionii, Phialophora verrucosa, Rhinocladiella aquaspersa.
Mnemonic: Pedro’s compact car is very wet.
Treatment: surgery and/or itraconazole for months

Question 8

Why can VZV lesions on the nasal tip be a sign of ocular involvement?

Answer 8

External nasal branch of anterior ethmoidal (AE) nerve supplies nasal tip. AE nerve is a branch of the nasociliary nerve, which is a branch of the ophthalmic nerve of CNV. The ciliary branch, which supplies the orbit is also a brach of the ophthalmic nerve.

Question 9

Damage to the zygomatic branch of the facial nerve causes what?

Answer 9

Eyelid ectropion and inability to close eyelid

Question 10

What are the 4 phases of wound healing and important cells in each phase?

Answer 10

1. Vascular phase: platelets/thrombin/exposed collagen achieve hemostasis
2. Inflammatory phase: neutrophils are 1st to arrive; macrophages are most important
3. Proliferative phase: re-epithelialization and production of type III collagen; fibronectin stimulates granulation tissue development
4. Wound contraction / remodeling phase

Question 11

What are the stages of skin graft survival?

Answer 11

1. Imbibition (24-48 hours)
2. Inosculation (begins 48-72 hours and lasts 7-10 days)
3. Neovascularization (same time as inosculation)
4. Maturation (months)

Question 12

HPV types associated with SCC in EV

Answer 12

5,8