Opportunistic Infections 2024 PDF

OPPORTUNISTIC INFECTIONS What Are Opportunistic Infections (OI’s)? Infections that occur more frequently and are more severe in people with a weakened immune system (immunocompromised) Who is immunocompromised?  HIV with a CD4 < 200  Asplenia  Immunomodulators  Chemotherapy  High dose steroids...

OPPORTUNISTIC INFECTIONS What Are Opportunistic Infections (OI’s)? Infections that occur more frequently and are more severe in people with a weakened immune system (immunocompromised) Who is immunocompromised?  HIV with a CD4 < 200  Asplenia  Immunomodulators  Chemotherapy  High dose steroids Opportunistic Infections Bacteria Virus Fungus Mycobacteriu m avium complex TB Cytomegalovi rus Herpes simplex virus Varicella Pneumocystis jiroveci Cryptococcus Histoplasmosi s Blastomycosi s Parasite Toxoplasmosi s Giardia Mycobacterium Avium Complex (MAC) Bacteria: Mycobacterium avium  Nontuberculous mycobacterium  Found in soil, household dust, and both fresh and salt water  Not transmitted person-to-person Clinical Presentation  Immunocompromised: disseminated, multi-organ infection (liver, spleen, bone marrow) o Fever, night sweats, weight loss, fatigue, diarrhea, abdominal pain  Immunocompetent: pulmonary infection Risk Factor:  CD4 < 50 MAC Prophylaxis Primary Prophylaxis:  Not routinely recommended  Consider if o Not on fully suppressive ART, and o CD4 < 50  Preferred Therapy: o Azithromycin 1200 mg 1x weekly o Clarithromycin 500 mg BID MAC Treatment Disseminated Treatment:  At least 2 drugs o Clarithromycin 500 mg BID + ethambutol 15 mg/kg daily o Azithromycin 500 mg + ethambutol 15 mg/kg daily  3rd or 4th drug options o Rifabutin, FQs (levofloxacin, moxifloxacin), aminoglycoside  Duration: o Complete at least 12 months therapy, and o No s/sx of MAC disease o Sustained (>6 months) CD4 > 100 in response to ART What is one side effect of ethambutol that must be monitored for? Cytomegalovirus (CMV) Virus  Common virus that most are exposed to during lifetime, but usually produces mild to no symptoms in otherwise healthy  Spread by saliva, urine, respiratory droplets, sexual contact, and blood transfusions  Commonly seen as re-activation of latent infection Clinical Presentation  Most commonly causes retinitis, colitis, esophagitis, pneumonitis, and encephalitis Risk Factor:  Cytomegalovirus Treatment Prophylaxis is NOT recommended  Regular eye exams Treatment Initial  Ganciclovir IV 5 mg/kg every 12 hrs  Valganciclovir 900mg PO BID  Duration: 14-21 days o Until symptoms resolve o No evidence of CMV viremia in 2 blood PCRs 2 wks apart o GI dx usually requires longer tx durations Suppression  Valganciclovir 900mg qD  Duration: 1-3 mo Pneumocystis Pneumonia (PJP) Fungus: Pneumocystis jirovecii  Person to person spread via airborne route  Disease can be due to either new infection or reactivation of latent infection Clinical Presentation  Fungal infection of the lung  Subacute onset of progressive dyspnea, fever, non-productive cough, chest discomfort  Fever usually present, and oral flush is common co-infection  CT imaging: ground glass that may be patch Most common opportunistic infection in HIV+ patients in the US Risk Factor: PJP Prophylaxis Indication:  CD4 < 200 Discontinue:  CD4 > 200 for > 3 months with antiretroviral therapy Preferred Therapy Bactrim 1 DS daily Bactrim 1 SS daily Alternative Therapy Bactrim 1 DS three times weekly Dapsone 50 mg BID or 100 mg daily Atovaquone 1500 mg daily Aerosolized pentamidine 300 mg monthly PJP Treatment Treatment duration: 21 days Consider adjunctive steroids:  Adjunctive therapy for moderate to severe PCP  Prednisone or methylprednisolone Preferred Therapy Bactrim 15-20 mg/kg/day IV or PO divided 3-4x per day Alternative Therapy Dapsone100 mg daily + Bactrim 5 mg/kg TID Primaquine 30 mg daily + clindamycin (IV 600 mg every 6 hours or 900 mg every 8 hours or PO 450 mg every 6 hours or 600 mg every 8 hours) Atovaquone suspension 750 mg BID Pentamidine 4 mg/kg IV daily Cryptococcus Fungus: Cryptococcus neoformans  Found in the soil and associated with pigeons  Non-contagious, systemic infection after inhalation Clinical Presentation  Primarily lungs- cough, shortness of breath, rales  CNS- headache, fever, altered mental status Risk Factor  CD4 < 100 Cryptococcus Treatment Prophylaxis is NOT recommended HIV / Transplant CNS Infection:  Induction therapy: Amphotericin B + flucytosine x2 weeksWhat are some side effects of  Consolidation therapy: fluconazole 400 mg daily x8 weeks amphotericin B?  Maintenance: fluconazole 200 mg daily x6-12 months Histoplasmosis Fungus: Histoplasma capsulatum  Budding, encapsulated dimorphic fungus  Found in the Mississippi and Ohio river valleys o Soil, rotting areas, feces of chickens, bats, and other birds Clinical presentation  Pulmonary infection: non-productive cough, chest pain, fever, chills, headache, myalgia  Disseminated: fever, weight loss, lymphadenopathy, diarrhea, sepsis-like syndrome o Can affect the CNS, GI tract, and skin Risk Factor Histoplasmosis Treatment Prophylaxis is NOT usually recommended  Itraconazole 200 mg daily o Consider if CD4 200 for > 3 months with antiretroviral therapy Preferred Therapy Bactrim 1 DS daily Alternative Therapy Bactrim 1 SS daily Bactrim 1 DS three times weekly Dapsone 50 mg BID or 100 mg daily Atovaquone 1500 mg daily Aerosolized pentamidine 300 mg monthly Toxoplasmosis Treatment Duration: 6 weeks  Extend duration if extensive disease or slow response ALL patients should receive chronic maintenance therapy after completing acute therapy Preferred Therapy Pyrimethamine 200 mg x1, then dosing based on BW BW < 60 kg: Pyrimethamine 50 mg daily + sulfadiazine 1g q6h + leucovorin 10-25 mg daily BW > 60 kg: Pyrimethamine 75 mg daily + sulfadiazine 1500 mg q6h + leucovorin 10-25 mg daily Maintenance Therapy Pyrimethamine 25-50 mg daily + sulfadiazine 20004000 mg daily + leucovorin 10-25 mg daily OPPORTUNISTIC INFECTIONS