Micro U2 L2.

Question 1

Borrelia burgdorferi bacteriology

Answer 1

motile spirochete, flat wave shape, NOT spiral - larger (stain with silver, IF, standard microscopy), tick borne, mammal reservoirs, transmits in summer in 24-48 hrs

Question 2

What is the pathogenesis of borrelia burgdorferi?

Answer 2

Lyme disease - 1. bite site to 2. blood to 3. heart, joints, CNS. NO toxins, primarily immune evasion

Question 3

Signs/symptoms stage one of borrelia burgdorferi?

Answer 3

expanding macular rash (bullseye), some flu like symptoms (high fever if there is confection with erlichia or babesioa

Question 4

Signs/symptoms stage two of borrelia burgdorferi?

Answer 4

months: cardiac and neurologic involvement: myocarditis, heart block, aseptic meningitis, bell’s palsy, bilateral facial nerve palsy

Question 5

Signs/symptoms stage three of borrelia burgdorferi?

Answer 5

months: arthritis in large joints (knees) -> younger, chronic progressive CNS disease -> older

Question 6

What are signs/symptoms of post treatment lyme?

Answer 6

lingering fatigue, joint pain, mental status changes

Question 7

What labs can be done to confirm borrelia burgdorferi?

Answer 7

serology (ELISA) or IF (usually negative less than 2 weeks post infection) - will look the same if they’ve had lyme before. confirm with western blot or PCR

Question 8

Treatment for stage 1 borrelia burgdorferi

Answer 8

doxycycline or amoxicillin

Question 9

Treatment for late stage borrelia burgdorferi

Answer 9

ceftrixone

Question 10

How do you know if treatment is working for borrelia burgdorferi/lyme?

Answer 10

jarisch herxheimer reaction

Question 11

What is borrelia recurrentis and borrelia hermsii?

Answer 11

relapsing fever

Question 12

Borrelia recurrentis and borrelia hermsii bacteriology

Answer 12

microscopically visible in blood smears, grow on special media

Question 13

What is the vector/reservoir for b. recurrentis?

Answer 13

vector: body louse (from too much scratching) reservoir: humans

Question 14

What is the vector/reservoir for b. hermsii?

Answer 14

vector: soft ticks; reservoir: small mammals, ticks

Question 15

Which has a worse prognosis: b. recurrentis or b. hermsii?

Answer 15

b. recurrentis

Question 16

What is a way to tell the difference between b. recurrentis and b. hermsii clincally?

Answer 16

b. hermsii has 3 relapses while b.recurrentis typically only has one

Question 17

B. recurrentis and hermsii pathogenesis

Answer 17

spirochetes invade blood from bite site, multiply in many tissues -> general malaise and organ dysfunction -> neutralizing antibodies develop -> killing by immune system creates selective pressure for antigen variation -> disease resumes -> repeat

Question 18

Diagnosis for B. recurrentis and hermsii

Answer 18

history of tick bite, fever (2+ episodes 3-5 days with well week inbetween), chills, headaches, organ dysfunction Labs: blood smear, culture optional

Question 19

Treatment for B recurrentis and hermsii

Answer 19

tetracycline - Jarisch Herxheimer reaction

Question 20

Rickettsia bacteriology

Answer 20

very short rods, hard to gram stain, arthropod vectors, obligate intracellular parasites, human is dead end host (infected by accident)

Question 21

What are the similarities between Borrelia and Rickettsia?

Answer 21

1. arthropod vectors 2. mammalian vectors 3. tetracycline sensitivity

Question 22

What are the differences between Borrelia and Rickettsia?

Answer 22

1. very short rods, hard to gram stain (borrelia large) 2. obligate intracellular parasites (borrelia not)

Question 23

What are the three forms of Rickettsia?

Answer 23

1. rocky mountain spotted fever 2. mediterranean spotted fever 3. typhus

Question 24

Rocky mountain spotted fever

Answer 24

vectored by ticks, bacteremia (easily enter blood stream), invade and multiply in vascular endothelium, blood vessels leak as infected cells die causing a rash

Question 25

What virulence factors do the spotted fevers have?

Answer 25

1. omp A&B for adhesion 2. Type 4 secretion system for entry 3. phospholipase A2 to escape endosome 4. Act A - actin based cell-cell spread

Question 26

Mediterranean spotted fever

Answer 26

dog ticks - not common in US - cause eschar type thing on skin

Question 27

What is seen on exam of rocky mountain spotted fever?

Answer 27

headache, fever, myalgia, vasculitis rash (begins in extremities and then to trunk), history of tick, progresses to delirium, coma, DIC

Question 28

Treatment of the spotted fevers

Answer 28

doxycycline if not pregnant (even for children). alternate for pregnant: chloramphenicol

Question 29

Epidemic Typhus pathogenesis

Answer 29

bacteria multiply in vascular endothelium - untreated course ~2 weeks - mortality from vascular collapse or pneumonia

Question 30

What is different about typhus compared to other vectored bacterial infections?

Answer 30

***humans are normal host and reservoir**** - vectored by lice which die from the bacteria!!!!

Question 31

Brill-Zinsser Disease

Answer 31

recrudescent typhus - less severe than initial course, risk factors include malnutrition or inadequate antibiotics during first typhus

Question 32

Murine Typhus pathogenesis

Answer 32

accidental transmission to humans of cat/rat typhus - seen in S and SW US

Question 33

Scrub Typhus pathogensis

Answer 33

accidental transmission to humans of O. tsutsugamushi - vectored by chigger - milder than epidemic typhus

Question 34

Diagnosis of typhus

Answer 34

epidemic: abrupt onset fever, chills, unremitting headache, lymphadenopathy, rash (TRUNK TO PERIPHERY), CNS symptoms, cough, deafness, flea bite, natural disaster, war, medical ro military personnel - more common in cold weather

Question 35

How can you tell the difference between typhus and rocky mountain spotted fever by rash?

Answer 35

typhus: trunk to periphery while RMSF is peripher to trunk rash

Question 36

Murine and Scrub difference from Epidemic clinically

Answer 36

more common in warm weather - cough and lymph node involvement more common - milder

Question 37

Lab for ricketssia

Answer 37

IF assay, immunoassay, PCR

Question 38

Treatment for ricketssia

Answer 38

antibiotics before labs come back - doxycycline or chloramphenicol (preg)

Question 39

Ehrlichia bacteriology

Answer 39

tiny gram -; obligate intracellular; replicate in cytoplasm of WBC; form clusters called morulae(look like blackberries); accidental transmission to humans

Question 40

Ehrlichia pathogenesis

Answer 40

asymptomatic - can have flulike symptoms, GI symptoms, meningitis, and/or DIC

Question 41

Diagnosis for ehrlichia

Answer 41

severe headache, myalgias, fever, shaking chills, history of travel. LAB: CBC

Question 42

Treatment for ehrlichia

Answer 42

doxycycline, alternate fluoroquinolones

Question 43

Anaplasma bacteriology

Answer 43

small gram -; obligate intracellular; survive and multiply in early endosome of WBC (esp neutrophils); grow in morulae, vectored by ticks

Question 44

Difference between anaplasma and ehrlichia

Answer 44

anaplasma: endosome of WBC instead of cytoplasm - more serious - can put healthy people in intensive care

Question 45

Similarities of rickettsia, ehrlichia, anaplasma

Answer 45

small cocci-to-short rods transferred by arthropod vectors