Bacterial infections of blood and vasculature

Question 1

Borrelia, unlike treponema

Answer 1

are large enough to see with standard microscopy

Question 2

B burgdorferi causes

Answer 2

Lyme disease, vectored by deer ticks (not dog ticks); with mice and rats preferred by nymphs and deer preferred by adults

Question 3

Lyme diagnosis depends on; serology

Answer 3

history of geographic area, season (highest risk in summer when nymphs are feeding) and activity; can confirm exposure but not disease and not promptly

Question 4

Lyme requires

Answer 4

about 24 hours to transmit (REMOVE TICK SOONER)

Question 5

Lyme disease has three stages:

Answer 5

1. flulike with erythema migrans rash (bulls-eye appearance in a minority)
2. Musculoskeletal and/or neurologic symptoms (intermittent arthritis; in Europe, bluish borrelial lymphocytoma and Acrodermatitis Chronica Atrophicans (ACA) on biopsy, a progressive fibrosing skin
3. Additional neurologic symptoms, also Post-Lyme syndrome with lingering neurological sequelae (chronic progressive encephalomyelitis, subacute encephalopathy);
   worry about COINFECTION with ERLICHIA or BABESIOA meaning high fever

Question 6

Treat Lyme with; give for

Answer 6

amoxicillin or doxycycline, alternatives ceftriaxone, cefuroxime axetil;
10-30 days, NO MORE (lingering symptoms due to DAMAGE, NOT lingering bacteria);
Can see Jarisch-Herxheimer reaction and erythema migrans could expand!

Question 7

Relapsing fever may be

Answer 7

louse- or tick-borne, louse- is more severe (reservoir is humans; louse crushing and inoculation by scratching), tick- more likely in US (bite of infected tick, usually nocturnal); REPEATED HIGH FEVERS with well periods between, complications of pregnancy

Question 8

Relapsing fever Borrelia

Answer 8

immediately enter bloodstream from bite site, repeated rounds of bacteremia and cleanup by IL10+neutralizing Ab’s vs. antigenic variation by spirochete

Question 9

Diagnose relapsing fever by

Answer 9

peripheral blood smear; spirochetes are usually visible during febrile periods

Question 10

Treat relapsing fever with

Answer 10

tetracyclines (doxy); erythromycin (kids, pregnant women, and adults) and penicillin G in adults

Question 11

Relapsing fever and lyme:

Answer 11

avoid ticks (protective clothing, DEET), daily tick checks in at-risk areas in season

Question 12

Successful treatment of any spirochete infection

Answer 12

may cause Jarisch-Herxheimer reaction (that and response to treatment may be needed to empirically diagnose Lyme)

Question 13

____, ___, ____ are all what?

Answer 13

Rickettsia, Ehrlichia, and Anaplasma; small cocci-to-short-rods are transferred to mammalian hosts by arthropod vectors

Question 14

Rickettsiae are sensitive

Answer 14

to tetra (doxycycline)

Question 15

Rickettsiae are ____ parasites and can

Answer 15

obligate intracellular; only be grown IN VITRO in tissue culture (like VIRUSES)

Question 16

Rickettsiae diseases present; they can also cause

Answer 16

with headache, fever, and body aches; a rash (particularly RMSF, petechial, or epidemic typhus, any) or eschar (particularly Mediterranean Spotted Fever and scrub typhus)

Question 17

For Rickettsiea, proper removal of a potentially-infected tick

Answer 17

is with tweezers, while wearing GLOVES, promptly (bacteria take time to transit)

Question 18

Host, reservoir, and uniqueness for epidemic typhus? What’s characteristic of the other rickettsial diseases?

Answer 18

Humans are the proper host and reservoir for ONLY epidemic typhus, and is also unique in having a RECRUDESCENT form (Brill-Zinsser disease), VECTORED by body louse;
accidental transmission to humans by promiscuous vectors

Question 19

All four Rickettsiae group (Rickettsia, Coxiella burnetti, Ehrlichia, Anaplasma) replicate

Answer 19

within infected cells; Rickettsia divide throughout the cell, Ehrlichia and anaplasma from morulae in phagocytic vacuoles

Question 20

All of the rickettsiae are

Answer 20

difficult to stain chemically and require microimmunofluorescent assay to visualize (blood and/or biopsy)

Question 21

Because of the gravity of the Rickettsiae illnesses; alternate treatments for ___ and ____ patients are

Answer 21

small children may be treated with tetracyclines but pregnant women are not; pregnant, allergic, use chloramphenicol (Rickettsia) or fluoroquinolones (Ehrlichia, Anaplasma)

Question 22

T/F: B burgdorferi has a definitive test for lyme disease

Answer 22

No, there is no definitive lab test (e.g. seropositivity won’t tell much, though seronegativity is relatively reliable)

Question 23

B. burgdorferi prevention includes

Answer 23

protective clothing, DEET, avoid woodsy areas, tick collars on pets

Question 24

Rickettsia, Ehrlichia, and Anaplasma are like borrelia and unlike borrelia:

Answer 24

Like Borrelia: arthropod vectors, mammalian reservoirs, tetra sens;
unlike Borrelia: small cocci-to-short-rods, intracellular replication

Question 25

RMSF is vectored by

Answer 25

ticks

Question 26

RMSF virulence factors include:

Answer 26

1. OmpA&B for adhesion
2. T4SS: entry
3. Phospholipase A2: escape from endosome
4. ActA: actin-based cell-cell spread

Question 27

Epidemic typhus usually begins on

Answer 27

trunk and spreads peripherally (the opposite of RMSF which begins on extremities)

Question 28

What season would you expect to see epidemic, murine, and scrub typhus?

Answer 28

Cold weather: epidemic;

warm weather: murine and scrub

Question 29

Brill-Zinsser disease risk factors include

Answer 29

malnutrition and improper or incomplete antibiotic therapy

Question 30

Ehrlichia (e.g. Human Monocytic ehrlichiosis) and anaplasma (human granulocytic anaplasmosis) can grow

Answer 30

within neutrophils