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Flashcards in Infectious disease Deck (19):
1

Define: Normal Flora

Organisms that live symbiotically on or within humans but rarely cause disease

2

Example of normal flora on skin

staphylococci, steptococci

3

Example of normal flora in the oropharynx

streptococci, neisseria

4

Example of normal flora in the large intestine

E. Coli, Enteroccoci, Candida

5

Obligate pathogen

Causes disease in normal healthy humans

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Opportunistic pathogen

Causes disease in compromised humans

7

Nosocomial Flora

Acquired from a health care setting

8

The establishment of infectious disease (stages)

1. encounter
2. entry
3. multiplication and spread
4. host tissue injury

9

Outcome(s) of infection

1. Resolution (eradification )
2. Chronic infection (HIV)
3. Latent infection (herpes zoster)
4. Death

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Modes of transmission

1. Contact
2. Vehicle Transmission
3. Vector Transmission

11

Modes of contact transmission

Direct: handshakes
Indirect: drinking classes, tooth brushes

12

Modes of Vehicle transmission

Airborne
Waterborne
Foodborne

13

Modes of vector transmission

1. Mechanical- on insect bodies
2. Biological- Lice, mosquitoes, ticks

14

Cause of aspiration pneumonia

Inhaled infiltrate from the oropharynx that is colonized with upper airway flora
-Bacteria

15

Cause of aspiration pneumonitis

-chemical pneumonia
-Acidity of gastric contents results in chemical burns to the tracheobronchial tree, followed by an inflammatory response fueled by the release of cytokines

16

How does HIV affect the cellular component of the acquired immune system?

HIV produces a cellular immune deficiency characterized by the depletion of Helper T cells (CD4). The loss of CD4 results in the development of opportunistic infections and neoplastic processes.

17

CD4 counts less than what level is diagnostic of AIDS?

200

18

Tests used to diagnose HIV

Western blot, PCR HIV RNA and p24 antigen tests

19

How does HIV gain entry into Th Cells?

HIV gains access to mucosal surfaces by binding first to tissue macrophages
-Macrophages interact with CD4 T cells and CD4 cells become activated and infected.