Infectious Diseases IV Flashcards
What do opportunistic infections occur?
Immunocompromised patients are predisposed to opportunistic infections, which occur when the immune system is weak and unable to respond normally to invading bacteria, fungi, viruses and protozoa
What do immunocompromised states include?
- Diseases that destroy key components of the immune response, primarily HIV with a CD4 T lymphocyte count < 200 cells/mm3 (which is a defining criteria for AIDS)
- Use of systemic steroids for 14 days or longer at a prednisone dose (or prednisone equivalent dose (> 20 mg/day) or > 2 mg/kg/day
- Asplenia (lack of a functioning spleen), as with sickle cell disease or following a splenectomy
- Use of immunosuppressants for autoimmune conditions or transplant
- Use of cancer chemotherapy agents that destroy white blood cells, particularly with severe neutropenia (ANC < 500 cells/mm3
What are some common opportunistic infections requiring primary prophylaxis?
Pneumocystis jirovecci pneumonia (PJP or PCP), Toxoplasmosis gondii encephalitis, Mycobacterium avium complex (MAC)
What is an opportunistic infection that does not required prophylaxis?
Candida infections in the mouth/esophagus (e.g. thrush) are a higher risk in immunocompromised states, but prophylaxis is not usually recommended
How can opportunistic infections be prevented?
OIs can be prevented with antibodies, antifungals and/or antivirals which is referred to as chemoprophylaxis or simply prophylaxis
What is the selection of alternatives based on?
Selection of primary or alternative regimens (for prophylaxis or treatment) depends on patient-specific factors
What are some examples of alternative regimens and why they are used?
- Atovaquone, dapsone and pentamidine are options for PCP in the setting of a sulfa allergy
- Atovaquone and pentamidine are options in the setting of a G6PD deficiency
- Leucovorin is added to all pyrimethamine-containing regimens as rescue therapy to reduce the risk of pyrimethamine-induced myelosuppression
What is the criteria for starting prophylaxis treatment of Pneumocystis jiroveccii?
CD4 count < 200 cells/mm or AIDS-defining illness
What is the preferred prophylaxis regimen for pneumocystis jiroveccii?
SMX/TMP or SS daily
What is an alternative prophylaxis regimen for pneumocystis jiroveccii?
SMX/TMP DS 3x/week or Dapsone or Dapsone + pyrimethamine + leucovorin or Atovaquone or inhaled pentamidine
What is the criteria for discontinuing prophylaxis regimen for pneumocystis jiroveccii?
- CD4 count > 200 cells/mm3 for > 3 months on ART
- Can consider when CD4 count is 100-200 cells/mm3 and viral load has been undetectable for > 3-6 months
What is the criteria for starting a prophylaxis regimen for Toxoplasma gondii encephalitis?
Toxoplasma IgG positive and CD4 count < 100 cells/mm3
What is the preferred primary prophylaxis regimen for Toxopasma gondii encephalitis?
SMX/TMP DS tab PO daily
What is an alternative primary prophylaxis regimen for Toxopasma gondii encephalitis?
SMX/TMP DS tab PO daily, SMX/TMP 3x/week or 1 SS PO daily or Dapsone + pyrimethamine + leucovorin or Atovaquone or Atovaquone + pyrimethamine + leucovorin
What is the criteria for discontinuing primary prophylaxis regimen for Toxopasma gondii encephalitis?
- CD4 count > 200 cells/mm3 for > 3 months on ART
- Can consider when CD4 count is 100-200 cells/mm3 and viral load has been undetectable for > 3-6 months
What is the criteria for starting prophylaxis regimen for Mycobacterium avium complex?
- Not recommended if ART is started immediately
- Initiate if not taking ART and CD4 count < 50 cells/mm3
- Must rule out active disseminated MAC disease
What is the preferred primary prophylaxis regimen for Mycobacterium avium complex?
Azithromycin 1,200 mg PO weekly
What is the alternative primary prophylaxis regimen for Mycobacterium avium complex?
Azithromycin 600 mg PO twice weekly or Clarithromycin 500 mg PO BID
What is the criteria for discontinuing prophylaxis regimen for Mycobacterium avium complex?
Taking fully suppressive ART
When is secondary prophylaxis for opportunistic infections given?
After completing initial treatment, secondary prophylaxis is given to prevent recurrence of the infection in patients who continue to be at risk
What is the recommendation for treating thrush in patients with HIV?
Even with mild disease, systemic treatment is preferred (rather than localized treatment with agents such as clotrimazole, miconazole or nystatin)
What is the preferred regimen for the treatment of Candidiasis (thrush)?
Fluconazole
What is an alternative regimen for the treatment of Candidiasis?
- Itraconazole, posaconazole
- Esophageal: voriconazole, isavuconazonium or an echinocandin (e.g. caspofungin)
What is the secondary prophylaxis regimen for Candidiasis?
Not usually recommended
What is the preferred regimen for the treatment of Cryptococcal meningitis?
Amphotericin B (deoxycholate or liposomal) + flucytosine
What is the alternative regimen for the treatment of Cryptococcal meningitis?
Fluconazole +/- flucytosine
What is the secondary prophylaxis for the treatment of Cryptococcal meningitis?
Fluconazole (low dose)
What is the preferred regimen for the treatment of Cytomegalovirus?
Valganciclovir or Ganciclovir
What is the alternative regimen for the treatment of Cryptococcal meningitis?
If toxicities to ganciclovir or resistant strains: foscarnet, cidofovir
What is the secondary prophylaxis regimen for the treatment of Cryptococcal meningitis?
None; maintain CD4 count > 100 cells/mm3
What is the preferred regimen for the treatment of Mycobacterium avium complex?
(Clarithromycin or azithromycin) + ethambutamol
What is the alternative regimen for the treatment of Mycobacterium avium complex?
Add a 3rd or 4th agent using rifabutin, amikacin or streptomycin, moxifloxacin or levofloxacin
What is the secondary prophylaxis regimen for the treatment of Mycobacterium avium complex?
Same as treatment regimen
What is the preferred regimen for the treatment of Pneumocystis jiroveccii pneumonia?
SMX/TMP (high-dose) +/- prednisone or methylprednisolone
*Duration: 21 days
What is the alternative regimen for the treatment of Pneumocystis jiroveccii pneumonia?
Atovaquone or Pentamidine IV or Clindamycin + primaquine or Dapsone + trimethoprim
What is the secondary prophylaxis regimen for the treatment of Pneumocystis jiroveccii pneumonia?
Same as primary prophylaxis
What is the preferred regimen for the treatment of Toxoplasmosis gondii encephalitis?
Pyrrimethamine + leucovorin + sulfadiazine
What is the alternative regimen for the treatment of Toxoplasmosis gondii encephalitis?
SMX/TMP or Clindamycin + pyrimethamine + leucovorin or Atovaquone or Atovaquone + sulfadiazine or Atovaquone + pyrimethamine + leucovorin
What is the secondary prophylaxis regimen for the treatment of Toxoplasmosis gondii encephalitis?
Same as treatment (but with reduced doses)
