Opportunistic Infection Flashcards
PCP - cause
PneumoCystis Pneumonia
Pneumoncystis Jirovecii
classified as fungus, however, not grow on fungal culture
and have cholesterol in their cell wall instead of ergosterol
treat with antibiotic and anti parasitis agents
Opportunistic infection
HIV Pt with low CD 4 count
PCP risk
HIV CD4 <200, oral thrush, recurrent bacterial pneumonia, unintentional weight loss, higher plasma HIV RNA levels
Hematopoietic stem cell and sold organ transplant
Cancer
Immunosuppressive medication, glucocorticoids, chemotherapy
PCP clinical presentation
gradual onset
fever, nonproductive cough, dyspnea progressing over days to weeks
fatigue with usual activities, chill, weight loss or chest pain
most common adventitial sounds are crackles and rhonchi
Oral thrush is a common co-infection
PCP lab & Imaging
CD4 <14%
Hypoxia: wide alveolar- arterial O2 gradient, O2 Desaturation with exercise
Elevated LDH
Elevated plasma 1-3-beta-D-glucan
CXR: Diffuse, bilateral, interstital, or alveolar infiltrates
Lobar or segmental infiltrate, cysts, nodules, and pleural effusions less common
CT: High sensitive
Gallium-67 citrate scanning
PCP - diagnosis
Advanced immunosuppression (CD4 < 200)
Cough, fever, dyspnea, hypoxemia (especially with exercise)
CXR (interstitial, or alveolar infiltrates) or CT (patchy or nodular ground-glass attenuation) findings consistent with PCP
Elevated 1-3-beta-D-glucan level (> 80 pg/mL)
Of note, the occurrence of PCP in patients who are compliant with TMP-SMX PCP prophylaxis is highly unusual.
Breakthrough PCP in patients previously on dapsone, atovaquone, or aerosolized pentamidine prophylaxis is relatively more common.
PCP treatment
DOC: bactrim IV/PO
DOT: 21 days in HIV; 14-21 days in non-HIV Pt
Pt should start show improvement at 5th day of therapy
Start ART within 2 week of PCP treatment if not on
Drugs:
Trimethoprim-sulfamethoxazole (TMP-SMX): IV or PO
o Dosing: 15-20 mg/kg of TMP component in divided doses q6-8 hours, needs renal adjustment for CrCl < 30 ml/min
o Note dosing is based on TMP componen
o ADRs: rash, fever, GI intolerance, hyperkalemia, hepatotoxicity, neutropenia
o Preferred in pregnancy
TMP-dapsone: PO
o ADRs: GI upset, rash, hemolytic anemia, methemoglobinemia
o Test for G6PD deficiency when starting dapsone
o Ok in pregnancy
Clindamycin-primaquine: PO, clindamycin component may be IV
o ADR: rash, hemolytic anemia, neutropenia, methemoglobinemia, diarrhea, C.diff colitis
o Test for G6PD deficiency when starting primaquine
Atovaquone: PO
o ADRs: GI distress, rash
Pentamidine: IV
o Greater toxicity than other regimens reserved for severe infections / intolerant to other options
o ADRs: nausea, taste disturbance, cardiac arrhythmias, hyper/hypokalemia, nephrotoxicity (cumulative), pancreatitis, hypocalcemia, hyper/hypoglycemia, hypotension (life-threatening)
o Give while patient is supine, adequately hydrated, over at least 60 minutes (usually in hospital setting)
Corticosteroids: adjunctive for more severe illness
o Decreases mortality and respiratory failure associated with severe PCP
MAC - cause
Mycobacterium avium complex
M. avium, M. intracellulare
a recent acquisition
no latent phase
MAC prophylaxis
CD4 count < 50
clarithromycin 500mg PO daily
azithromycin 1200 mg PO weekly
D/C three months after attaining CD 4 >100
MAC risk
CD4 <50
MAC persentation
disseminated or localized
fever, night sweats, abdominal pain, diarrhea, weight loss
leukocytosis, focal inflammation in a lymph node
MAC diagnosis
Blood culture, Aspiration of local lymph node
anemia, elevated alkaline phosphatase and lactate dehydrogenase
MAC treatment
combination therapy (at least 2 drugs) is necessary Preferred first line regimen includes clarithromycin + ethambutol + rifabutin if patient is not on a protease inhibitor.
DOT: at least 12 month, life long w/o immune reconstitution 1st DRUG – Clarithromycin (preferred 1st agent) o ADR: increased LFTs Azithromycin (instead of clarithromycin if clarithromycin is not tolerated or concerns for DDIs) o ADR: increased LFTs 2nd DRUG – Ethambutol o ADR: optic neuritis 3rd DRUG (optional) – for patients with high mycobacterial loads or absence of ART Rifabutin Fluoroquinolones Amikacin
Symptom should be improve 2-4 weeks after treatment
CMV (Cytomegalovirus)
risk
Solid organ transplant: seropositive donor to seronegative recipient
Hematopoetic stem cell transplant: seronegative donor stem cells to seropositive recipient
Immunosupression: T lymphocyte depleting therapies used in transplant
Advanced HIV infection (CD4 < 12) and severe immunodeficiency
o CMV as a sole cause of pneumonia is not common until the late stages of HIV disease
CMV prophylaxis
Ganciclovir IV
Valganciclovir PO
alternative: High dose acyclovir and valacyclovir
CMV Clinical presentation
rarely detected before 2nd week after transplant
fever, malaise, weakness, myalgias, and arthalgias
leukopenia, thrombocytopenia that occur in the setting of viremia
Pneumonitis (low-grade fever, shortness of breath, nonproductive cough, and changes in measured pulmonary function)
CMV has also been associated with acute rejection of transplant.
CMV pneumonitis is associated with radiographic evidence of bilateral, symmetrical, peribronchovascular, and alveolar process predominantly affecting the lower lobes.
CMV- INFECTION VS. DISEASE
CMV infection is defined as evidence of CMV replication regardless of symptoms or signs. CMV disease is defined as evidence of CMV infection with attributable symptoms or signs. CMV disease may manifest as a viral syndrome (fever, malaise, leukopenia, thrombocytopenia) or as tissue invasive disease.
CMV diagnosis
If CMV is suspected, test the blood for CMV replication. The test will vary by transplant center but a common option is viral load testing using quantitative polymerase chain reaction (PCR).
Serology should NOT be used to diagnose active CMV infection or disease in transplant recipients.
CMV treatment decision
Treatment of CMV is recommended in the presence of symptomatic pulmonary disease, evidence of CMV in the lung, and the absence of other treatable pulmonary infections
Treatment if CMV is considered for lung transplant recipients with asymptomatic CMV viremia to prevent development of invasive disease and to prevent potential indirect effects of CMV viremia (rejection)
Treatment of asymptomatic patient with evidence of pulmonary CMV is not recommended
Treatment of CMV when concomitant pathogens are present is not recommended
CMV treatment
Ganciclovir - DOC for children and adults with severe disease, and CMV pneumonitis (regardless of severity)
o ADR: hematologic suppression (neutropenia, thrombocytopenia)
o Requires renal adjustments
Valganciclovir
o Highly bioavailable prodrug of ganciclovir
o Oral option for non-severe CMV disease
o ADR: hematologic suppression (neutropenia, thrombocytopenia)
o Requires renal adjustments
Cytomegalovirus immune globulin (CytoGam)
o In addition to antiviral therapy in patients with severe disease
Foscarnet
o Alternative if suspected or confirmed ganciclovir-resistant CMV
ADR: nephrotoxicity (especially when given with cyclosporine or tacrolimus), electrolyte disturbances
o Requires renal adjustments
DOT: minimal of 2 weeks
Nocardiosis cause
Norcardia spp (gram + bacterial ) 2 distinguishing characteristics: 1) Nocardiosis is able to disseminate to virtually any organ, especially the CNS, and 2) has a tendency to relapse or progress despite appropriate therapy, making it difficult to treat.
Nocardiosis Risk
Immunocompermise:
Solid organ or hematopoietic stem cell transplant
Glucocorticoid therapy
HIV infection (especially if CD4 < 100)
Malignancy (especially after recent chemo or glucocorticoid therapy)
Diabetes
Norcardiosis presentation
Lungs: Primary site of nocardial infection in > 2/3 of cases. Fever, night sweats, fatigue, anorexia, weight loss, dyspnea, cough, hemoptysis, and pleuritic chest pain. ~50% of pulmonary cases disseminate to sites outside the lungs, most commonly to the brain
CNS: Parenchymal abscess that can occur in any region of the brain. Fever, headache, meningismus, seizures, and/or focal neurologic deficits.
Cutaneous: Usually from direct inoculation of organisms into the skin during gardening, farming, trauma, surgery, or animal scratch/bite. Ulcerations, pyoderma, cellulitis, nodules, and subcutaneous abscesses.
Norcardiosis diagnosis
Blood culture hold for 4 weeks (acid fast)
sputum culture - indicative
susceptibility test
CT/MRI for Pt with evidence of CNS disease to assess for abscess
