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Flashcards in Vector-Borne Transmission Deck (49)
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1

Describe the structure of Borrelia

Long spirochete
0.4uM (big enough for light microscope)
Stain G-, but NO LPS
Inflamm. lipoproteins in outer membrane

2

Four indicators of sepsis?

Hypotension
Fever
Heightened HR/BR
Infection Signs

3

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

4

Why does Borrelia recurrentis keep on coming back?

Antigenic variation (may go through 5-10 cycles)

5

Borrelia burgdorferi (and 9 others in Eurpose) cause...

Lyme Disease

6

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

7

Classy name for Bull's Eye Rash?

Erythema chronicum migrans

8

How is Borrelia recurrentis spread?

Human Louse

9

How is Borrelia hermsii spread?

Soft bodied ticks with a rodent reservoir
-- Transovarian and through bite

10

How is Borrelia burgdorferi spread?

Deer tick nymph with deer, mouse, or bird reservoir

11

Pathogenesis of Borrelia recurrentis and hermsii

Uses VMP (variable major protein) antigen
Mostly the same, with a few mutants
Abs select for the mutants

12

What leads to Borrelia recurrentis latency? relapse?

Latency -- Most of the population killed
Relapse -- Mutant variety grows to repopulate

13

Pathogenesis of Borrelia burgdorferi

Multiple rounds of symptoms probably means multiple infections with difference burgdorferi strains

14

How is Borrelia controlled?

- Avoid Vectors
- No effective vaccine

15

How is Borrelia treated?

Doxycycline or synthetic penicillins
can use 3rd gen cephalosporins

16

Describe the structure of Rickettsiae

Small G- Rods

17

Growth conditions required for Rickettsiae?

Obligate intracellular parasite

18

How is Rickettsiae cultured?

Yolk sac of embryonated egg

19

Four groups of Rickettsiae?

Typhus group
Spotted Fever Group
Enlichia, Anaplasma
Coxiella burnetti

20

Which of the four Rickettsiae groups isn't really a Rickettsiae, but is likely classified that way according to our shelf materials

Coxiella burnetti

21

Who is in the Rickettsiae Typhus group?
Where do they grow?

prowazekii, typhi, akari
Cytoplasm of Host Cell

22

Who is in the Rickettsiae Spotted Fever group?
Where do they grow?

rickettsii
Cytoplasm of host cell

23

Describe the lifecycle of Rickettsiae ehrlichia, anaplasma.

Chlamydia-like (RB-EB alternation) in monocytes (Ehr) or granulocytes (Ana)

24

What is structurally unique about Rickettsiae ehrlichia, anaplasma

NO PG or LPS

25

Where do Coxiella burnetti grow?

Host cell phagolysosome

26

What should you never treat coxiella burnetti with?

Sulfonamides -- they enhance the growth

27

Clinical presentation of Rickettsiae Typhus group?

Parasite of BV endothelium
Vasculitis, Rash (Chest-->Extremities)
Weakness, Fever

28

Clinical presentation of Rickettsiae Spotted Fever group?

Rash from extremities (Palms and Soles) --> Trunk
Rocky Mountain Spotted Fever

29

What does Rocky Mountain Spotted Fever entail?

Abrupt fever, headache, nausea, vomiting
Muscle, Joint, Ab pains from vasculitis of organs
50% fatal untreated

30

Clinical presentation of Rickettsiae Ehrlichia chaffeensis (monocytic erlyichiosis, HME)

Headache, Myalgia, Thrombocytopenia, lymphopenia, Marrow Granuloma

Like RMSF< but no vasculitis

31

What cells does Rickettsiae ehrlichia chaffeensis infect?

Monocytes/Macrophages

32

What tends to cause the primary pathology of Rickettsiae ehrlichia chaffeensis?

Immune Response
Decrease in TNF-a early, Increase late

33

Clinical presentation of Rickettsiae anaplasma phagocytophilum?

Rarely rash, but otherwise like ehrlichosis

34

What cells does Rickettsiae anaplasma phagocytophilum infect?

Neutrophils and Granulocytes

35

Other name for Coxiella burnetti

Q-Fever

36

Clinical presentation of Coxiella burnetti?

Typically: Fever w/ Pneumonia/Hepatitis 2-3 week post exposure

Can be:
-Chronic infections leading to endocarditis in pts w/ defective heart valves
- Granulomas in liver, spleen, BM

37

How is Rickettsiae Typhus Group spread?

Human Louse or Rat Flea
Transmit Human-Louse-Human
Rats are also reservoir

38

Where is Rickettsiae Typhus Group typically seen?

People together with low hygiene.
(POWs, refugees)

39

How is Rickettsiae-Spotted Fever Group spread?

Bite of Dog-tick or Wood-tick

40

How is Rickettsiae-Spotted Fever group maintained in reservoir?

Transovarian cycle

41

What part of the country is most prone to dvelop Rickettsiae-Spotted Fever group? What time of year?

Southeast US
Summer, Fall

42

How is Rickettsiae-Ehrlichia/Anaplasma spread?
Where is it commonly found?

Ticks.
WI, MN

43

How is Coxiella burnetti spread to humans?

Via dust or aerosols from infected animals
Especially in placental aerosols

44

Common carriers of Coxiella burnetti include...

Goats
Cattle
Sheep
Cats

45

Pathogenesis of Rickettsial diseases?

Arthropod bite site --> Endothelium
Multiply Intracellularly and Spread to other tissues
Phospholipase A targets Cell Membranes

46

What does Rickettsiae phospholipase A do?

Lyses blood vessels (rash) and other epithelial cells

47

How does R. Rickettsii one up the norman Rickettsiae vessel lysis?

It lyses smooth muscle cells

48

How are Rickettsial diseases controlled?

Remove Vector Contact
Vaccine for Q-fever (only in Australia)

49

How are Ricketsial diseases treated?

Tetracycline/Doxycycline