Zoonoses with Skin Manifestations Flashcards
Morphology of Rickettsia?
G- bacili
Why can’t Rickettsia be cultured?
How is it diagnosed?
obligate, intracellular parasite
appearance, pt hx, confirmed with serology
All rickettsia are sensitive to:
doxy
Phyla of Rickettsia
Rickettsia
Ehrlichia
Coxiella
Rickettsia symptoms
Fever-headache-rash
Where do Rickettsia replicate? What does this cause?
- -in endothelial cells of small blood vessels
- -vasculitis
2 diseases caused by rickettsia
RMSF
Epidemic typhus
RMSF is transmitted by:
ticks
Typical RMSF symptoms?
- “Flu” with severe headache
- Rash starts at ankles and wrists, spreads to palms, soles, trunk (***very characteristic!!!)
- sore muscles, especially in calves
RMSF can progress to:
Septicemia
DIC
What test is used to diagnose RMSF?
immunofluorescent antigens
What was the old test used to dx RMSF?
Explain it
Weil-Felix test
Non-specific test in which anti-rickettsial Abs cross-react with Proteus OX antigens
R. prowazekii is likely transmitted:
human-to-human by body lice feces
maybe flying squirrels?
R. prowazekii symptoms:
Rash similar to RMSF except spreads from trunks to extremities
Not found on palms or soles
R. prowazekii has a (high/low) untreated mortality rate.
What are possible bad complications?
high mortality rate (10-60% untreated)
Myocarditis, CNS involvement
Ehrlichia are “_____ ___-borne” diseases
Southern
tick
Human monocytic ehrlichiosis (HME) is transmitted by:
Human granulocytic anaplasmosis is transmitted by:
Lone Star deer tick
Ixodes deer tick
Human monocytic ehrlichiosis (HME) replicates in:
monocytes, within inclusions called morulae
Human monocytic ehrlichiosis (HME) is diagnosed by:
Confirmed by:
treated with:
blood smear
serology
doxy
Human granulocytic anaplasmosis is often called:
Why?
“Rocky Mtn Spotless Fever”
RMSF symptoms WITHOUT rash
Human granulocytic anaplasmosis is diagnosed by:
Blood smear
look for morulae in granulocytes
2 types of Spirochetes
Borrelia and Leptospira
What disease is caused by Borrelia burgdorferi?
Lyme disease
B. burgdorferi is transmitted by:
Ixodes deer tick nymph
(saliva)
Note: if you remove the tick in t get sick!
Symptoms of early lyme disease:
- Flu-like (milder than RMSF)
2. Erythema chronicum migrans (**Usually!)
Symptoms of secondary lyme disease:
Disseminated disease, weeks or months later
- Arthritis
- facial palsy
- peripheral neuropathy
Symptoms of chronic lyme disease:
Erosive arthritis (autoimmune; **esp bad in knees) Bell palsy
Diagnosis of Lyme disease:
Step 1: ELISA (sensitive, false positives**)
Step 2: Must be confirmed by Western blot
Treatment of Lyme disease
Early:
Chronic:
Early: doxy or amoxicillin
Chronic: IV cephalosporins for extend time
What is notable about Borrelia?
they undergo antigenic variation
change surface antigens, which causes a cyclical pattern of infection
B. recurrentis is transmitted via:
B. hermsii is transmitted via:
louse (rare in US)
tick
B. hermsii and B. recurrentis are endemic to:
high desert of Western US
What are symptoms of B. hermsii and B. recurrentis infections?
- Fever for a week, then recurs two weeks later (due to antigenic variation)
- Skin rash uncommon
How are B. hermsii and B. recurrentis diagnosed?
Blood smear
Serology to confirm
How are B. hermsii and B. recurrentis treated?
doxy
How is Leptospira interrogans transmitted?
urine contaminated water gets into cuts
Symptoms of Leptospira interrogans?
- Flu-like
- Jaundice and renal damage (Weil’s disease)
- Meningitis
Diagnosis of Leptospira interrogans?
Treatment?
Serologic diagnosis
Treat with penicillin
Note: there’s a vaccine for cattle and pets
What causes Cat-Scratch disease?
Bartonella henselae
Who is often infected with Cat-Scratch disease?
How does it present?
children
Swollen gland near site of scratch
most will clear up on own in a couple of weeks
How do you treat Cat-Scratch disease?
Erythromycin, but only for long-lasting infections
