Vector-Borne Transmission Flashcards
Describe the structure of Borrelia
Long spirochete
0.4uM (big enough for light microscope)
Stain G-, but NO LPS
Inflamm. lipoproteins in outer membrane
Four indicators of sepsis?
Hypotension
Fever
Heightened HR/BR
Infection Signs
Clinical Presentation of Borrelia recurrentis, hermsii, and 20 others
Bacteremia within week of inoculation
Fever, Intense Headache, Muscle Pain for 3-5 days
Symptoms Recurr after 5-10 days latency
May eventually form necrotic foci at parenchymatous organs
Why does Borrelia recurrentis keep on coming back?
Antigenic variation (may go through 5-10 cycles)
Borrelia burgdorferi (and 9 others in Eurpose) cause…
Lyme Disease
Symptoms of Lyme Disease?
Early – Flu-like, Bull’s Eye Rash
Early Disseminated – Facial Nerve Palsy, Meningitis, Carditis
Chronic – Arthritis, Joint Pain, Affect Heart/Nerves
Classy name for Bull’s Eye Rash?
Erythema chronicum migrans
How is Borrelia recurrentis spread?
Human Louse
How is Borrelia hermsii spread?
Soft bodied ticks with a rodent reservoir
– Transovarian and through bite
How is Borrelia burgdorferi spread?
Deer tick nymph with deer, mouse, or bird reservoir
Pathogenesis of Borrelia recurrentis and hermsii
Uses VMP (variable major protein) antigen Mostly the same, with a few mutants Abs select for the mutants
What leads to Borrelia recurrentis latency? relapse?
Latency – Most of the population killed
Relapse – Mutant variety grows to repopulate
Pathogenesis of Borrelia burgdorferi
Multiple rounds of symptoms probably means multiple infections with difference burgdorferi strains
How is Borrelia controlled?
- Avoid Vectors
- No effective vaccine
How is Borrelia treated?
Doxycycline or synthetic penicillins
can use 3rd gen cephalosporins
Describe the structure of Rickettsiae
Small G- Rods
Growth conditions required for Rickettsiae?
Obligate intracellular parasite
How is Rickettsiae cultured?
Yolk sac of embryonated egg
Four groups of Rickettsiae?
Typhus group
Spotted Fever Group
Enlichia, Anaplasma
Coxiella burnetti
Which of the four Rickettsiae groups isn’t really a Rickettsiae, but is likely classified that way according to our shelf materials
Coxiella burnetti
Who is in the Rickettsiae Typhus group?
Where do they grow?
prowazekii, typhi, akari
Cytoplasm of Host Cell
Who is in the Rickettsiae Spotted Fever group?
Where do they grow?
rickettsii
Cytoplasm of host cell
Describe the lifecycle of Rickettsiae ehrlichia, anaplasma.
Chlamydia-like (RB-EB alternation) in monocytes (Ehr) or granulocytes (Ana)
What is structurally unique about Rickettsiae ehrlichia, anaplasma
NO PG or LPS
