Intro to Arbo Infections

Question 2

what has caused the recent resurgence of vector-borne disease in the last century?

Answer 2

insecticide resistance, drug resistance, breakdown in vector control, environmental changes, global commerce and travel

Question 3

name 6 important arthropod vectors (all rely on human blood as a food source)

Answer 3

mosquito, dog tick, black legged tick, flea, kissing bug, tsetse fly

Question 4

the plague is caused by _____ and transmitted by ______.

Answer 4

yersinia pestis, fleas

Question 5

RMSF is caused by ____ and transmitted by ____.

Answer 5

R. rickettsii, dog ticks/Dermacentor (only North & South America)

Question 6

Human monocytic ehrlichiosis is caused by _____ and transmitted by ______.

Answer 6

ehrlichia chaffeensis, Lone Star ticks

Question 7

The agent of human granulocytic ehrlichiosis is _______ and transmitted by ______.

Answer 7

anaplasma phagocytophila, black legged ticks

Question 8

The agent of tularemia is ______ and transmitted by ______.

Answer 8

francisella tularensis, ticks

Question 9

The agent of Lyme disease is _____ and transmitted by _____.

Answer 9

borrelia burgdorferi, black legged ticks

Question 10

Most bacterial vector-borne diseases are transmitted by ____.

Answer 10

ticks

Question 11

Name 3 flaviviruses with mosquito vectors. Which 2 are present in the US?

Answer 11

dengue, west nile, yellow fever (not in US)

Question 12

name an alphavirus that causes arthritis

Answer 12

chikungunya

Question 13

what is the only parasitic vector-borne disease present in the US?

Answer 13

babesiosa (from babesia parasite)

Question 14

The agent of malaria is _____ and transmitted by ______.

Answer 14

plasmodium spp., mosquito

Question 15

The agent of leishmaniasis is ______; it is transmitted by ______.

Answer 15

leishmania, sandflies

Question 16

The agent of African Sleeping Sickness is _____; it is transmitted by ______.

Answer 16

trypanosome brucei, tsetse flies

Question 17

name 3 exceptions to the fact that humans are dead end hosts for vector-borne pathogens.

Answer 17

malaria, urban plague, dengue are all human reservoirs

Question 18

intrinsic incubation period

Answer 18

time from host infection to the host being infectious

Question 19

extrinsic incubation period

Answer 19

time from vector infection to the vector being infectious

Question 20

grace period

Answer 20

time after which human has been infected with virus, but we can still prevent disease

Question 21

how long is the extrinsic incubation period for malaria?

Answer 21

10 days (mosquito)

Question 22

how long is the extrinsic incubation period for Lyme ds?

Answer 22

1-6 months! (tick-borne)

Question 23

why are vectors so specific?

Answer 23

pathogen must replicate within the vector, moving from the gut to hemocoel (bloodstream) to salivary gland, etc. to reinfect – this requires very specific receptors all along the way!

Question 24

what does the tick release when feeding on the host?

Answer 24

anticoagulants, vasodilators, anesthetics, anti-inflamm agents, immunosuppressive agents, etc.