HIV/Atypical Mycobacterium Lecture Flashcards Preview

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Flashcards in HIV/Atypical Mycobacterium Lecture Deck (26)
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1

A unique type of virus (a retrovirus)
Invades the helper T cells (CD4 cells) in the body of the host (defense mechanism of a person)

*preventable, manageable but NOT curable

HIV

2

RNA virus
Retrovirus, subfamily lentivirus
Cytopathic
CD4 + lymphocyte is primary target but monocyte/macrohages also express CD4 and become infected

HIV

3

type 1= most common

type 2=West Africa, less aggressive

HIV

4

Disease limits the body’s ability to fight infection due to markedly reduced helper T cells.
Patients have a very weak immune system (defense mechanism)
Patients predisposed to multiple opportunistic infections leading to death.

AIDS

5

Positive HIV who have ever had a CD4 lymphocyte count below 200 cells/mcL or a CD4 lymphocyte percentage below 14%

AIDS

6

*Icosahedral (20 sided), enveloped virus of the lentivirus subfamily of retroviruses.
*Retroviruses transcribe RNA to DNA.
*Two viral strands of RNA found in core surrounded by protein outer coat.

HIV

7

-Outer envelope contains a lipid matrix within which specific viral glycoproteins are imbedded.
-These knob-like structures responsible for binding to target cell.

HIV

8

-direct cytopathic effects
-bystander (syncytia formation)
-failure to regenerate cells (bone marrow infect, thymus infexn)
-autoimmunity

Pathology of CD4 plus lymphocyte depletion

9

Sexual
Vertical – mother to child, perinatal
Parenteral – injection drug users
Transfusion
Nosocomial

HIV modes of transmission

10

Blood products
Semen
Vaginal fluids

HIV transmission thru bodily fluids

11

*Short, flu-like illness - occurs one to six weeks after infection
*Mild symptoms
*Infected person can infect other people

Which HIV stage?

Stage 1

12

*Lasts for an average of ten years
*This stage is free from symptoms
*There may be swollen glands
*The level of HIV in the blood drops to low levels
*HIV antibodies are detectable in the blood

Which HIV stage?

Stage 2

13

After a period of latency lasting up to 10 years viral replication is triggered and occurs at high rate.
CD4 cell may be destroyed in the process, body attempts to replace lost CD4 cells, but over the course of many years body is unable to keep the count at a safe level.
Destruction of large numbers of CD4 cause symptoms of HIV to appear with increased susceptibility to opportunistic infections, disease and malignancy.

Viral replication during latent stage (stage 2)

14

*HIV continues to reproduce, CD4 count gradually declines from its normal value of 500-1200.
*Once CD4 count drops below 500, HIV infected person at risk for opportunistic infections.
*The following diseases are predictive of the progression to AIDS:
-persistent herpes-zoster infection (shingles)
-oral candidiasis (thrush)
-oral hairy leukoplakia
-Kaposi’s sarcoma (KS)

Clinical latency period

15

SYMPTOMATIC
The immune system deteriorates
Opportunistic infections and cancers start to appear.

Which HIV stage?

Stage 3

16

HIV to AIDS
*The immune system weakens too much as CD4 cells decrease in number.

Which HIV stage?

Stage 4

17

Generalized lymphadenopathy
Unexplained thrush
New severe psoriasis, skin disorder
Unexplained weight loss
Unexplained thrombocytopenia, etc
Neurologic disease (CNS/peripheral)
Recurrent bacterial pneumonia
Chronic diarrhea

Clinical presentation of HIV

18

Bacterial infections
Tuberculosis (TB)
Herpes Simplex
Herpes Zoster
Vaginal candidiasis
Hairy leukoplakia
Kaposi’s sarcoma

CD4 under...

500

19

Pneumocystic carinii
Toxoplasmosis
Cryptococcosis
Coccidiodomycosis
Cryptosporiosis
Non hodgkin’s lymphoma

CD4 under...

200

20

Antibody testing:
-ELISA/Western Blot antibody test
-Rapid blood/oral test
-Home HIV test kit

Viral detection:
-Culture
-RNA PCR (viral load)

Ways to diagnose HIV

21

Orasure:
The only FDA approved HIV antibody.
As accurate as blood testing
Draws blood-derived fluids from the gum tissue.
NOT A SALIVA TEST!

Oral testing for HIV

22

4th generation (HIV1 and HIV2 IgG and IgM plus HIV1 p24 Ag)

initial test for HIV!!!!!!!

(more accurate, faster and less expensive)

23

What is the confirmatory test (after 4th gen HIV-1 and HIV-2 IgG and IgM plus HIV-1 p24 Ag)?

Multispot test!

24

If multi-spot test is positive for HIV-1, order....

QUANTITATIVE HIV-1 PCR

25

Regimens must consists of ___ or more active agents from multiple medication classes

3

26

For the greatest chance of success, post-exposure prophylaxis must begin ASAP..at a minimum within _____ of exposure

72 hours