Rickettsia-Erlichia

Question 1

List the causative agent for Rocky Mountain Spotted Fever.

Answer 1

-Rickettsia rickettsii

Question 2

List the causative agent for Rickettsialpox.

Answer 2

Rickettsia akari

Question 3

List the causative agent for Epidemic typhus.

Answer 3

-Rickettsia prowazekii

Question 4

List the causative agents for Ehrlichiosis.

Answer 4

• E. chaffeensis (HME)
• A. phagocytophilum, E. ewingii (HA)

Question 5

List the causative agent for Q fever.

Answer 5

Coxiella burnetii

Question 6

List the causative agent for Murine Typhus (Endemic Typhus)

Answer 6

R. typhi

Question 7

Where do Ehrlichia and Anaplasma bacteria replicate inside the host?

Answer 7

-Phagosome

Question 8

Where do Coxiella replicate inside the host?

Answer 8

Phagolysosome-like vesicle

Question 9

Where do Rickettsia and Orientia replicate inside the host?

Answer 9

Cytoplasm

Question 10

What is the causative agent of Scrub typhus?

Answer 10

Orientia tsutsugamushi

Question 11

How do Ehrlichia and Anaplasma survive once inside the host?

Answer 11

Prevents lysosomal fusion

Question 12

How does Coxiella survive once inside the host?

Answer 12

• Requires low pH for growth
• Delayed lysosomal fusion

Question 13

Which of these 3 species of Rickettsia does not migrate intracellularly using actin polymerization during pathogenesis:

• R. rickettsia
• R. prowazekii
• R. typhi

Answer 13

-R. prowazekii

Question 14

How do these Rickettsia species exit the host:

• R. rickettsii
• R. typhi
• R. prowazekii

Answer 14

Budding = rickettsii, typhi

Lysis = prowazekii

Question 15

What are the vectors and reservoirs of Rocky Mountain Spotted Fever?

Answer 15

Vectors: Tick

Reservoir: Rodents, Dogs

Question 16

What are the vectors and reservoirs of Ehrlichiosis?

Answer 16

Vector: tick

Reservoir: Rodents = HA

Deer = HME

Question 17

What are the vectors and reservoirs of Rickettsialpox?

Answer 17

Vector: Mites

Reservoir: Rodents

Question 18

What are the vectors and reservoirs of Scrub typhus?

Answer 18

V = Mites = R

Question 19

What are the vectors and reservoirs of Epidemic typhus?

Answer 19

V = Lice

R = Flying squirrels

Question 20

What are the vectors and reservoirs of Murine typhus (endemic)?

Answer 20

• V= Fleas
• R= Rodents

Question 21

Describe transmission of Q fever (Coxiella).

Answer 21

Inhalation of dust from large mammals

Cattle, sheep, goats

Slaugher house workers susceptible

Question 22

What is the distribution of RMSF?

Answer 22

World wide

SE and South Central US

Question 23

What is the distribution of Rickettsia akari (Rickettsialpox)?

Answer 23

Northern US, Russia, Africa, Korea

Question 24

What is the distribution of Rickettsia prowazekii (Epidemic typhus)?

Answer 24

Central America

South America

Africa

Question 25

What is the distribution of Murine typhus (endemic)?

Answer 25

Temperate/subtropical coastal areas

Question 26

What is the distribution of Scrub Typhus (Orientia tsutsugamushi)?

Answer 26

- Far East - SW Pacific - SE Asia - Japan

Question 27

What is the distribution of Ehrlichiosis?

Answer 27

HME: Midwest, coastal Atlantic HA: Upper midwest, NE Atlantic

Question 28

What is the distribution of Q fever (Coxiella burnetii)?

Answer 28

World-wide

Question 29

What are the clinical manifestations of RMSF?

Answer 29

**-Rash on extremities** - high fever - headache

Question 30

What are clinical manifestations of Rickettsialpox (R. akari)?

Answer 30

**-Vesicular rash** - Phase 1: firm red papule \> vesicle \> black eschar - Phase 2: high fever, chills, photophobia, **vesicular rash** - Self limiting after 1 week

Question 31

What are the clinical manifestations of Epidemic typhus (R. prowazekii)?

Answer 31

**Rash on trunk** fever headache

Question 32

List clinical manifestations of Murine typhus (Endemic/R. typhi).

Answer 32

**Maculopapular rash on trunk** Abrupt fever, chills, myalgia, nausea

Question 33

What are clinical manifestations of Scrub Typhus (O. tsutsugamushi)?

Answer 33

**Necrotic eschar** fever headache lymphadenopathy maculopapular rash after 5 days

Question 34

List clinical manifestations of Ehrlichiosis.

Answer 34

**No rash** Fever headache **Leukopenia** **Thrombocytopenia** **Elevated liver enzymes**

Question 35

What clinical features are associated with Q fever (Coxiella burnetii)?

Answer 35

Mostly NON-apparent **No rash** Acute: mild, dry, hacking cough/pneumonia Chronic: subacute endocarditis

Question 36

Describe treatment, prevention/control of RMSF.

Answer 36

**Tetracyclines, fluoroquinolones** No vaccine Avoid/reduce tick contact (**requires 24hrs contact**) Control = impossible

Question 37

Describe treatment/prevention/control of Epidemic Typhus.

Answer 37

**Tetracyclines and chloramphenicol** Louse control Vaccine available for high risk patients

Question 38

Describe treatment options for Endemic Typhus (Murine typhus).

Answer 38

**Tetracycline, Doxycycline, Chloramphenicol**

Question 39

What treatment options are available for Scrub Typhus?

Answer 39

**Tetracycline, doxycycline, and chloramphenicol** (same as Endemic Typhus)

Question 40

What are treatment/prevention options for Ehrlichiosis?

Answer 40

**Doxycycline** **Rifampin** = pregnant women No vaccine

Question 41

What are treatment/prevention options for Q fever?

Answer 41

**Tetracycline, doxycycline** (or combo) Vaccine available for **unexposed**