25. Infectious Diseases IV: Opportunistic Infections

Question 1

What are immunocompromised states?

Answer 1

Diseases that destroy key components of immune response (HIV with CD4 count < 200 cells/mm3 - defining criteria for AIDS)

Systemic steroids for 14 days or longer at prednisone dose ≥20mg/day or ≥2mg/kg/day

Asplenia (lack of functioning spleen) d/t sickle cell disease or splenectomy

Use of immunosuppressants for autoimmune conditions or post-transplant (e.g. TNF-alpha inhibitors)

Use of cancer cehmotherapy taht destroy WBC, particularly severe neutropenia (ANC<500)

Question 2

Immunocompromised state examples: Diseases that destroy key components of immune response (HIV with CD4 count < ___ cells/mm3 - defining criteria for AIDS)

Answer 2

<200

Question 3

Immunocompromised state examples: Systemic steroids for ___ days or longer at prednisone dose ≥ ___/day or ≥___/kg/day

Answer 3

14 days
≥20mg/day
≥2mg/kg/day

Question 4

Immunocompromised state examples: Use of cancer cehmotherapy taht destroy WBC, particularly severe neutropenia (ANC<__)

Answer 4

ANC < 500

Question 5

What are common opportunistic infections requiring primary ppx?

Answer 5

Pneumocystis jirovecii penumonia (PJP or PCP)
Toxoplasmosis gondii encephalitis
Mycobacteriam avium complex (MAC)

Question 6

T/F: Thrush is more likely in immunocompromised states but ppx is usually not recommended

Answer 6

True

Question 7

Criteria for starting primary ppx: PJP/PCP infection

Answer 7

CD4 count <200 or AIDS-defining illness

Question 8

Criteria for starting primary ppx: Toxoplasma gondii encephalitis

Answer 8

Toxoplasma IgG positive and CD4 count <100

Question 9

Criteria for starting primary ppx: MAC

Answer 9

If NOT taking ART and CD4 count <50

Note: Not recommended if ART is started immediately, must rule out active disseminated MAC disease

Question 10

Patient has a sulfa allergy. What are primary ppx options for PCP

Answer 10

Atovaquone, dapsone, and pentamidine

Question 11

Patient has G5PD deficiency. What are primary ppx options for PCP

Answer 11

Atovaquone and pentamidine

Question 12

Leucovorin is added to all pyrimethamine-containing regimens as rescue therapy to reduce risk of ____

Answer 12

pyrimethamine-induced myelosuppression

Question 13

Preferred primary ppx regimen for PJP/PCP

Answer 13

SMX/TMP DS or SS daily

Question 14

Alternative primary ppx regimen for PJP/PCP

Answer 14

SMX/TMP DS 3x/week
Dapsone
Dapsone + pyrimethamine + leucovorin
Atovaquone
Atovaquone + pyrimethamine + leucovorin
Inhaled pentamidine

Question 15

Criteria for d/c primary ppx for PJP/PCP

Answer 15

CD4 count > 200 for > 3 months on ART

Can consider when CD4 count i 100-200 and viral load has been undetectable for 3-6 months

Question 16

Preferred primary ppx for Toxoplasma gondii encephalitis

Answer 16

SMX/TMP DS daily

Question 17

Alternative primary ppx fot Toxoplasma gondii encephalitis

Answer 17

SMX/TMP DS 3x/week or SS daily
Dapsone + pyrimethamine + leucovorin
Atovaquone
Atovaquone + pyrimethamine + leucovorin

Question 18

Preferred primary ppx for MAC

Answer 18

Azithromycin 1200mg weekly

Question 19

Alternative primary ppx for MAC

Answer 19

Azithromycin 600mg twice weekly
Clarithromycin 500mg BID

Question 20

Criteria for d/c primary ppx for MAC

Answer 20

Taking fully suppressive ART

Question 21

Preferred treatment regimen for candidiasis (thrush)

Answer 21

Fluconazole

Question 22

Alternative treatment regimen for candidiasis (thrush)

Answer 22

Oropharyngeal: Itraconazole
Others: posaconazole, topicals (e.g. clotrimazole troche, nystatin)

Esophageal: voriconazole, isavuconazonium, or an echinocandin (e.g. caspofungin)

Question 23

Secondary ppx regimen for candidaisis (thrush)

Answer 23

Not usually recommended

Question 24

Preferred treatment regimen for cryptococcal meningitis

Answer 24

Amphotericin B (deoxycholate or liposomal) + flucytosine

Question 25

Alternative treatment regimen for cryptococcal meningitis

Answer 25

Fluconazole + flucytosine
Amphotericin B + fluconazole

Question 26

Secondary ppx regimen for cryptococcal meningitis

Answer 26

Fluconazole (low doses)

Question 27

Preferred treatment regimen for cytomegalovirus (CMV)

Answer 27

Valganciclovir
Ganciclovir

Question 28

Alternative treatment regimen for cytomegalovirus (CMV)

Answer 28

If toxicities to ganciclovir or resistant strains: foscarnet or cidofovir

Question 29

Secondary ppx regimen for cytomegalovirus (CMV)

Answer 29

None; maintain CD4 >100

Question 30

Preferred treatment regimen for Mycobacterium avium complex (MAC)

Answer 30

(Clarithromycin or azithromycin) + ethambutol

Question 31

Alternative treatment regimen for Mycobacterium avium complex (MAC)

Answer 31

Add 3rd or 4th agent using rifabutin, amikacin, streptomycin, moxifloxacin, or levofloxacin

Question 32

Secondary ppx regimen for Mycobacterium avium complex (MAC)

Answer 32

Same as treatment regimen

Question 33

Preferred treatment regimen for PJP or PCP

Answer 33

SMX/TMP (high dose) ± prednisone or methylprednisolone
Duration 21 days

Question 34

Alternative treatment regimen for PJP or PCP

Answer 34

Atovaquone
Pentamidine IV
Clindamycin + primaquine
Dapsone + trimethoprim

Question 35

Secondary ppx regimen for PJP or PCP

Answer 35

Same as primary ppx

Question 36

Preferred treatment regimen for Toxoplasmosis gondii encephalitis

Answer 36

Pyrimethamine + leucovorin + sulfadiazine

Question 37

Alternative treatment regimen for Toxoplasmosis gondii encephalitis

Answer 37

SMX/TMP
Clindamycin + pyrimethamine + leucovorin
Atovaquone
Atovaquone + sulfadiazine
Atovaquone + pyrimethamine + leucovorin

Question 38

Secondary ppx regimen for Toxoplasmosis gondii encephalitis

Answer 38

Same as treatment (Reduced doses)