Bacterial Pathogens of the CNS Flashcards
Can you see Borrelia with standard light microscopy?
You betcha
Spirochete that causes Lyme Disease
B. burgdorferi
Vector of B. burgdorferi
Ixodes ticks
What does a diagnosis of Lyme depend on?
History of geographic area, season, and activity
Can serology confirm a diagnosis?
It can confirm exposure, but not disease and not promptly
Why is pulling out the tick a good idea?
Lyme takes 24 hours for transmission
Stage 1 of Lyme
Flu like symptoms with erythema migrans
Stage 2 of Lyme
2 Musculoskeletal and/or neurologic symptoms
Stage 3 of Lyme
3 addition neurologic symptoms
Post Lyme Syndrome
Lingering Neurological sequelae
Treatment for Lyme
Doxycycline or amoxicillin (early stage and not if pregnant). Alt: ceftriaxone, cefuroxime, axetil. 10-30 days
Two vectors for Relapsing Fever
Louse (B. recurrentis) or Tick (B. hermsii)
Which vector of Relapsing Fever is more severe?
Louse
Which vector of Relapsing Fever is more likely to be seen in the U.S.
Tick
What is Relapsing Fever?
Repeated high fevers with well periods between. Complication of pregnancy
Pathogenesis of Relapsing Fever
- Immediately enters bloodstream from bite site
- Repeated rounds of bacteremia and cleanup by IL10 neutralizing antibodies
- Antigenic variation by spirochete
How to diagnose Relapsing Fever
Peripheral blood smear
When are spirochetes visible on blood smear in Relapsing Fever?
During febrile periods
Treatment of Relapsing Fever
Tetracycline and Doxycycline. Erythromycin for children, pregnant, and nursing women
Prophylaxis for all Borrelia
Avoid ticks, protective clothing, DEET, perhaps doxycycline
Successful treatment of any spirochete infection causes this
Jarisch-Herxheimer Reaction
Can you see Leptospira on standard microscopy. How do you view them?
No- use darkfield
Does leptospira encode toxins?
Yes
How does leptospirosis spread?
Contact with contaminated fluids
What does letospira invade right away
Lymphatics and bloodstream
Anicteric disease of leptospirosis
Acute sepsis, break, mild organ symptoms, delayed or immune phase (phase 2)
Icteric disease of leptospirosis
Acute sepsis, little or no break before major organ failure (Weil Disease)
In which disease of leptospirosis do you see conjunctival suffusion?
Both!
Treatment for leptospirosis
Penicillin G. Alt: doxycycline, third generation cephalosporins
