Vector Infections

Question 1

Endemic in Asia Pacific rim.
Maculopapular rash. Spreads centrifugally.
CNS complications. Heart failure.
Serology by IFA

Answer 1

Orientia tsutsugamushi

Question 2

___________ is drug of choice for rickettsial and orientia infections

Answer 2

Doxycycline

Question 3

Empiric treatment with doxycycline should be started as soon as it is suspected. Do not wait for confirmatory serology

Answer 3

Rickettsial and orientia infections

Question 4

For RMSF, doxycycline is drug of choice regardless of _________

Answer 4

age of patient

Question 5

RMSF has fatality of _________ if untreated

Answer 5

30%

Question 6

Obligate intracellular bacteria. No peptidoglycan or LPS. Beta lactams will not work for treatment.

Answer 6

Ehrlichia and Anaplasma

Question 7

Grow on hematopoietic cells. Replicate in phagosomes of host cells.

Answer 7

Ehrlichia and anaplasma

Question 8

Microcolony of ehrlichiae within a vacuole

Answer 8

morula

Question 9

Human monocytic ehrlichiosis

Answer 9

Ehrlichia chaffeensis

Question 10

Human granulocytic anaplasmosis

Answer 10

Anaplasma phagocytophilum

Question 11

Intracytoplasmic vacuole in a neutrophil

Answer 11

morulae

Question 12

Reservoir - dogs and deer

Vector - ticks (amblyomma americanum)

Answer 12

Ehrlichia chaffeensis

Question 13

Southeast, South Central and Midwest states

Answer 13

Ehrlichia chaffeensis

Question 14

1-3 weeks after tick bite - flu like illness
Late onset (1 week after) rash that spares hands and feet 

Mortality 3%

Answer 14

Ehrlichia chaffeensis

Question 15

Serology by IFA (paired specimens see increase in IgG)

PCR in blood

Answer 15

Ehrlichia chaffeensis

Question 16

Scrub typhus.
Reservoir and vector - mites.
Larval mites (chiggers) via transovarian. Feed only once in lifetime. Live in vegetation

Answer 16

Orientia tsutsugamushi