Zoonotic infxns Flashcards

1
Q

Stable rodent-flea infxn cycle that is maintained in a resistant host population w/o excessive host mortality
(long term reservoir of infxn)

A

Enzootic plague

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2
Q

Plague bacilli are introduced into rodent or small mammal populations that are moderately or highly susceptible to lethal effects of the infxn

A

epizootic plague

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3
Q

PLague that results in lymph gland swelling resulting from bite of flea 2-5 days earlier
(60-90% mortality if untreated)

A

bubonic plague

- most common form of plague

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4
Q

primary or secondary lung infxn which is highly infectious and 100% fatal if untreated

A

pneumonic plague

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5
Q

Type of plague that results in invasion of almost all organs, no sig evidence of prior disease

  • death occurs in 12-24 hrs
  • can see ecchymosis
A

septicemic

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6
Q

stain seen with yersinia

A

giemsa stain: see bipolar “safety pin”

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7
Q

Virulence of yersinia pestis

- plasmic encoded factors

A

Type III secreted proteins:

  1. tyrosine phosphatase
  2. cytotoxic factors

VW surface antigens

Flea associated virulence factors

Coagulase fibrinolysin

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8
Q

Yersinia pestis virulence

- chromosomally encoded

A
  1. iron acquisition systems
  2. attachment and invasion factors
  3. endotoxin
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9
Q

Phase variation

A

ability to change protein on its surface
- immune system can no longer recognize it

Francisella tularensis can do that

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10
Q

Which can be spread person to person?

Yersinia or Francisella?

A

Yersinia only

  • no need to isolate indiv w/ francisella
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11
Q

How many % of Ixodes deer tick carry borrelia burgdorferi?

A

10-36%

  • most of these ticks associated with lyme diseases are assoc. with the nymphal stage bite
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12
Q

When do the ticks mainly infect humans?

A

Late spring and summer in their 2nd year of life

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13
Q

Reservoir for lyme disease (borrelia burg)

A

mouse

White tailed deer

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14
Q

Where are the ticks for lyme disease endemic to?

A

Northeastern US

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15
Q

Vector for rickettsial diseases

  • Rickettsia rickettsii
  • Prowazekii
  • Typhi
A
  • Rickettsia rickettsii: ticks
  • Prowazekii: lice
  • Typhi: fleas

can lay 8 nits (eggs)/day

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16
Q

Stain used to stain rickettsiae?

A

Giema stain

17
Q

Where do rickettsia invade?

A

endothelial cells and disseminate throughout vascular system

18
Q

Which rickettsial disease starts at wrist and ankle and spreads to trunk and palms?
Which starts centally and spreads out?

A

Rockey mountain spotted fever:
- starts at wrist and ankle and spreads to trunk and palms

Typhus:
- starts centally and spreads out

19
Q

Which organisms are found in south atlantic states (North carolina, oklahoma, TN?)

A

Rocky mt spotted fever

- also the most frequently reported rickettsial illness in US

20
Q

virulence of anaplasmosis and erlichia

A
  1. Enters via lipid rafts
  2. Prevents phagosome fusion with lysosome
  3. downregulates ROS generation
  4. Inhibits host cell apoptosis
21
Q

Vector for:
Erlichiosis
Anaplasmosis
Q fever

A

Erlichiosis: tick
Anaplasmosis: tick
Q fever: no arthropod vector - inhaled spores from cattle/sheep

22
Q

YOPS

A

tyrosine phosphatase

Secreted protein that subverts nl activation mechanism of phagocytic cells

23
Q

Virulent strains of F. tularensis requires what for growth?

A

cysteine

24
Q

is cellular or humoral immunity required for F. tularensis required for recovery?
Peak incidence?

A

Cellular immunity

Summer (ticks)
Winter (hunting)

25
Q

Scrub typhus

  • etiologic agent
  • common reservoirs
  • modes of transmission
A

Scrub typhus

  • Orientia tsutsugamushi
    reservoir: Chiggers (larval mites)
  • Chigger mite bite –> eschar
  • rash absent
26
Q

Classic triad of rocky mt spotted fever

A
  1. HA
  2. Fever
  3. Rash (petechial lesions)
27
Q

Brills disease

  • etiologic agent
  • common reservoirs
  • modes of transmission
A

Rickettsia prowazekii

  • no rash
  • occurs many yrs after primary infxn

*prowazekii also cause epidemic typhus which does cause rash

28
Q

Host cells of rickettsiae are endothelial cells, what are the target cells of erlichia and anaplasma?

A

Phagocytic cells
- multiply in phagosome instead of cytosol

Erlichiosis: infects monocytes and macrophages

Anaplasmosis:
infects neutrophils

29
Q

Geographical location of erlichia and anaplasma?

A

erlichia: South central and south eastern US

anaplasma: Northeast and upper midwest US