Infections In IC Patients (Guest Dr Yu)

Question 1

HIV
What is a normal CD4 count?
When is AIDS advanced? 2

Answer 1

Impacts CD4 mainly
Normal is >500
AIDS is advanced when CD4 <200 or
has an AIDS defining illness such as Kaposi sarcoma, lymphoma

IC status if they are undiagnosed
Lacking adherence to meds
HIV resistance to anti-viral meds

Question 2

HIV prevention
What do you prophylaxis for? 3 pathogens based on CD4 count…

Answer 2

Prophylaxis:
Based on CD4 count:
—Pneumocystitis jiroveci (TMP/SMX)
—Toxoplasma gondii (TMP/SMX)
—MAC (Azithromycin)

Prior infection: coccidioidal meningitis

On meds for life

routine antibiotic prophylaxis is NOT recommended for bacterial infections because patients are at a higher risk of the infections above

Question 3

HIV: approach to infection

Answer 3

—Complete medical history
—thorough PE
—DDX for fever, malignancies, IRIS, drug rxn
—routine labs and CD4
—consult with ID/HIV expert

IRIS: immune reconstitution inflammatory syndrome — immune system gets back up and running and starts a fever

Question 4

HIV infections
What are you covering for w/ CD4 count
>500
200-500
<200
<50

Answer 4

—>500 community acquired pneumonia
—UTI

200-500
—TB

<200 have to cover for more specific organisms, usually fungal : candida, cryptosporidium, pneumocystis jiroveci

<50
CMV
MAC

Question 5

SOT — solid organ transplant
Discuss immunosuppression medicine

Answer 5

Balance their immunosuppression

Might have to ease up on their immunosuppressive to let them fight their infection, whether it’s viral/fungal or bacterial

High immunosuppressant immediately after transplantation. Then taper as body gets used to the foreign organ.

Peri-operative, give antibacterial prophylaxis to prevent opportunistic infections

Kidneys need more immunosuppression than the liver for example

Prophylaxis depend on servo status (abs present or not)
pneumocystis
candida & aspergillus
HSV and CMV

Check serostatus to see if recipient has Abs or not against something the donor has

Question 6

Cancer & infection

Answer 6

Hematologic cancers — these pts more likely to be immunosuppressed.

Solid tumours are not as immunosuppressive — but the chemo might immunosuppress the patient. Except nibs/mabs. The cytotoxic ones are though.

Antimicrobial prophylaxis
—enterobacteriacecae and other gram negs, like UTI, e.coli
—PJP
—candida & aspergillus
—viral HSV

Prophylaxis until neutropenia resolves

neutropenia
—ANC <500 cells/mcL
—fever: 101F once or two temps of 100.4F an hour apart
>38.3C once or >38C twice and hour apart

highest risk with ANC <100 for 7 days

Question 7

Neutropenic fever
What test should you order?
Why?
What abx should you start empirically?

Answer 7

Sometimes don’t have symptoms.. because you don’t have an immune system to fight infection, so don’t feel it

So still do a URINE culture!!

Gram negative rods are the major causes of neutropenic fever

Can be the patients own flora

start anti-pseudomonas abx empirically ASAP — preferably a beta lactam — Zosyn

make sure you cover MRSA as well

Continue ABX until ANC is above 500 for 2 days. Make sure the fever is coming down.

If fever is persistent, you need to consider viral or fungal.

Question 8

What do you screen for before initiating biologics 2

Answer 8

Prior to initiating therapy with biologics, screening for TB and hepatitis is required

Question 9

1st line treatment for PJP
Duration
SFX?

Answer 9

TMP/SMX
Weight based
3 weeks

SFX: nephrotoxicity

Also prophylax with TMP/SMX for at least 3 months if CD4 >200

Question 10

Mycobacterium Avium complex (MAC)
What is the CD4?
Presents like?
Treatment (3) & duration?

Answer 10

End stage HIV
CD4 <50

Presents as pneumonia: cough, SOB, cough, night sweats, fever

Acid fast positive, like TB

Slow growing, develops resistance so have to give multiple drugs:

Macrolides (azithromycin, clarithromycin)

Rifamycins
Ethambutol

Question 11

CMV
Symptoms?
Dx?
Tx 2

Answer 11

Can affect almost every organ of the body: GI, lungs, eyes, liver

Constitutional symptoms: fever, fatigue, LAD

DX:
—histopathology, biopsy enlarged cell with viral inclusion bodies
—CMV culture
—CMV viral load

TX:
ganciclovir IV or valganciclovir PO
7-14 days or 14-21 days

Question 12

Summary of opportunistic infections
Pneumocystis jiroveci
Toxoplasma gondii
Mycobacterium avium complex
Candida
Aspergillus
HSV/VZV
CMV

Answer 12

Question 13

Prevention strategies for IC patients
Asplenia considerations — when do you vaccinate?

Answer 13

VACCINATIONS!!
—vaccinate either 14 before or 14 days after splenectomy