Vectors

Question 1

Disease, Vector and Locale: Rickettsie rickettsii

Answer 1

• RMSF (no eschar)
• Dermacentor wood tick
• North and South America

Question 2

Disease, Vector and Locale: Ricketssia akari

Answer 2

• Rickettsial pox
• Mite bite from a house mouse + eschar (scab lesion)
• USA, USSR, Korea, Africa

Question 3

Disease, Vector and Locale: Rickettsia africae

Answer 3

• African tick fever, eschar
• Tick
• Africa

Question 4

Disease, Vector and Locale:** Rickettsia prowazekii**

Answer 4

• Epidemic Typhus (no eschar)
• Louse
• World wide

Question 5

Disease, Vector and Locale: Rickettsia typhi

Answer 5

• Murine typhus
• Flea (ty-phee)
• World Wide

Question 6

Disease, Vector and Locale: O. tsutsumagushi

Answer 6

• Typhus (no eschar)
• human mite (chigger)
• South East Asia

Question 7

Disease, Vector and Locale: Coxiella burnetti

Answer 7

• Q fever
• no vector
• no locale

Question 8

What is Rocky Mounted Spotted Fever pathogenesis?

Answer 8

• attach to vascular endothelium
  
  • phagocytized
  • reproduce within endothelium
  • spread into nearby cells
• Focal vasculitis
  
  • fluid loss
  • perfusion difficulties (can lead to gangrene)

Question 9

What is treatment for RMSF?

Answer 9

• Doxycycline
• Chloramphenicol (as second choice)

Question 10

RMSF is (centripetal/centrifugal)

Answer 10

Centripetal (wrists, ankles –> trunk)

from R. rickettsii- think of the rock climbing!

Question 11

What are the two typhus-group rickettsia?

Answer 11

1. R. prowezekii
2. R. typhi

Question 12

R. prowazekii is (centripetal/centrifugal)

Answer 12

Centrifugal (from trunk–>extremities, sparing palsm and soles and face)

(think of football game!)

Question 13

Clinical illness and transmission for R. typhi

Answer 13

tranmission: rat flea (reservoir is rat or cat)

Clinical illness: abrupt fever, HA, half have rash of chest and abdomen, extremities spared

Question 14

O. tsutsumagushi is (centrifugal/centripetal) spread

Answer 14

Centrifugal

Question 15

3 important characteristics of Ehrlichia and Anaplasma

Answer 15

1. obligate intracellular organisms
2. parasitize white blood cells
3. tick transmission (summer-time illnesses)

Question 16

What are the 4 Ehrlichial Diseases and what do they infect?

Answer 16

1. Sennetsu Fever (infectious mono like)
2. Human Monocyte Ehrlichiosis (infects blood monocytes
3. Human Granulocyte Anaplasmosis (infects blood granulocytes)
4. E. minnesota

Question 17

Which two organisms are associated with Human Monocyte Ehrlichiosis (HME)?

Answer 17

• Anaplasma phagocytophilum
• E. chaffeensis

Question 18

What is the reservoir and vector for E. ewingii?

Answer 18

causes HGA

Reservoir: dogs

Vector: Lone star tick

Question 19

What is the vector for E. chafeensis?

Answer 19

Lone-star tick

Question 20

What is the reservoir and vector associated with Human granulocytic ehrlichiosis?

Answer 20

Reservoir: small mammals (mice, chipmunks, voles)

Vector: Ixodes scapularis (deer tick)

Question 21

Q fever from ____ is usually self-limiting, so you dont need antibiotics. If conditions become more serious (pneumonia, hepatitis, endocarditis, granuloma formation in liver), then treat with ____

Answer 21

• Coxiella burnetti
• Tetracycline

Question 22

What is the vector for Chlamydia?

Answer 22

No vector- transmitted host to host

Question 23

Treatment of choice for Chlamydia:

Answer 23

Azithromycin (macrolide)

alternatives: Tetracycline, or Erythromycin in Pregnancy

Question 24

Ixodes scapularis tick is involved in the tranmission of these three diseases:

Answer 24

1. borrelia (lyme)
2. anaplasmosis
3. babesiosis (protozoal)- fever and hemolytic anemia, have butterfly look in blood smear