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Medicine II: Infectious Disease > HIV > Flashcards

Flashcards in HIV Deck (43):
1

Most likely cells affected by HIV

primary targets for HIV are dendritic cells in the mucosa of the genital tract, use receptor DC-sign to attach

2

What are the receptors for HIV?

CD4 moleucles on the surface of a subpopulation of t-lymphocytes (a coreceptor is needed for infection)

3

Pathogenesis of HIV

Newly infected lymphocytes flood the blood and are transported to all tissues with in days; there is a progressive annual loss of CD4 cells

4

How is HIV transmitted?

predominantly through heterosexual intercourse (0.1-1% chance), can be transmitted through HIV infected blood transfusion (100%), child of mother with out tx (30%), needle prick (1/300)

5

Signs and symptoms of primary HIV infection (acute retroviral syndrome)

incubation period of 2-4 weeks; fever, painful ulcers/lesions, nonexudative pharyngitis and swollen LN (diffuse lymphadenopathy), GI complaints, skin rash (upper body)-2-3 days after fever, HEADACHE

6

What is the hallmark of HIV infection?

progressive reduction in CD4 T cells (rarely returns to normal)

7

HIV testing

Diagnosed by the detection of HIV specific antibodies in the plasma or serum. (ELISA) Antibodies appear a few weeks afer infection, shortly before or after symptoms of acute retroviral syndrome. There is a WINDOW PERIOD where patient is infected but its not detected. These antibodies remain positive for LIFE. Do not use PCR.

8

How do we confirm a dx of HIV

second blood sample, if indeterminate do a western blot to confirm

9

AIDS defining illness

When the number of CD4 cells declines below a critical level of 200 or they have an AIDs associated syndrome (candidiasis, ____, ____). Patients CD4 count indicates the degree of immune deficiency and predicts short term risk of oppurtunistic disease. In long term- prognosis is also determines by viral load.

10

When do we consider HAART therapy?

if CD4 is between 350-500

11

Indications for starting tx

atients CD4 count indicates the degree of immune deficiency and predicts short term risk of oppurtunistic disease. Viral load = more rapid progression. Need to account for speed of progression, patients acceptance of tx, likelihood of compliance and possible side effects.

12

Tx of HIV

combo therapy: 4 different classes of drugs to tx AIDs: Nucleoside reverse transcriptase (NRTI), Non-nucleoside reverse transcriptase (NNRTI), Protease inhibitors, Fusion inhibitor enfurvitide.

13

How do we pick the Tx

2 NRTI's and one of the others

14

Occupational blood exposure risks

percutaneous injury (needle stick, cut) OR contact of mucous membrane or nonintact skin. Recommendations: Gloves handwashing, etc. Post exposure prophylaxis (w/in hrs) and follow up testing.

15

Efficacy of Tx monitoring

monitored by decline in viral load and rise in CD4 count (get this done every 3 mo)

16

What predicts the duration of viral supression?

Nadir- lowest point of viral load reached during tx; time to optimal supression depends on initial viral load.

17

When to initiate prophylaxis with PCP

CD4 <400 or after episode of PCP

18

What to give as prophylaxis for PCP

trimethoprim-sulfamehoxazole

19

When to initiate prophylaxis with Toxoplasma

if CD4 <100

20

What to give as prophylaxis for Toxoplasma

trimethoprim-sulfamehoxazole

21

When to initiate prophylaxis of Mycobacterium avian intracellulare

primary prophylaxis if CD4 <100

22

What to give as prophylaxis of Mycobacterium avian intracellulare

Azithromycin

23

When to initiate prophylaxis of Cryptococcus

CD4 <50; only in regions of high incidence

24

What to give as prophylaxis for Cryptococcus

Fluconazole

25

When to initiate prophylaxis of Candida

?

26

What to give as prophylaxis of Candida

?

27

When to initiate prophylaxis of Cytomegalovirus

CD4 <50, secondary if after retinitis

28

What to give for prophylaxis of CMV

valganiciclovir

29

Toxoplasma encephalitis

reactivation of latent toxoplasma infection. Starts with focal deficit (hemiplegia), convulsions, headaches, fever or confusion. CD4 IS BELOW 200

30

Dx of Toxoplasma encephalitis

Toxoplasma IgG antibody will be positive. CT or MRI (w/ gadolinium/contrast) will show abscesses that are usually multiple and preferentially located in the basal ganglia and corticomedullary junction. USUALLY HAS MARKED EDEMA

31

Tx of Toxoplasma encephalitis

combo of otal sulfadiazine and oral pyrimethamine w/folic acid to prevent bone marrow toxicity (also prevents PCP). Tx is not well tolerated

32

Pneumocysitis Jiroveci Pneumonia

PCP, subacute disease that develops in HIV infected patients with CD4 below 200.

33

Symptoms of PCP

fever, dyspnea on exertion, dry cough, weight loss and fatigue. Pulm exam is normal

34

Dx of PCP

CXR- usually shows interstitial butterfly pattern. Lactate dehydrogenase is usually elevated and PaO2 depressed.

35

Tx of PCP

trimethoprim-sulfamethoxazole

36

Cryptococcal Meningitis

fever, head ache, +/- meningeal signs, NO NECK STIFFNESS

37

Cryptococcal Meningitis Dx

on CD4 <100; blood and LCR are positive

38

Tx of cryptococcal meningitis

amphotericin B

39

CMV retinitis

Before advent of HAART, 35-30% of AIDS pts developed this infection. Visual symptoms—blurred vision, scotomas, floaters, or flashing lights— subacute onset.

40

Retinal findings of CMV retinitis

Mix of exudates, hemorrhages, and atrophy; Vascular 
sheathing

41

Tx of CMV retinitis

Tx is required to prevent progression to
retinal detachment and blindness. Ganciclovir is drug of choice; causes
bone marrow toxicity, and dosing must be corrected for renal dysfunction.

42

Candida

most frequent opportunistic pathogen in all HIV positive patients with severe immunosuppression. Yellow white plaques (thrush). Often accompanied by esophagitis

43

Tx for Candida

fluconazole