Opportunistic Infections Test 1 Flashcards
Factors that increase risk of Fungal infection
Severity of impairment if cell-mediated immunity
Recent or current use of antifungal meds
Risk of exposure
Neutropenia (invasive candidiasis and aspergillosis)
Criptococcus
Usually but not always a consequence of underlying immune compromise - Transmitted via air droplets/bird droppings - Spores inhaled, lodge into lung alveoli, distributed systemically by blood causing infection - Most common manifestation is Meningitis (full ears/stiff neck/vision changes/headache/light sensitivity etc)
Insidious
Malaise (76%), HA (73%), Fever (65%), NV (42%), Cough/SOB (31%), AMS (28%), Papilledema (eye issues 33%), Meningeal signs (27%)
Studies = Cryptococcal antigen in CSF (Sen 93%-100%; Spec 93%)
Tx = Amphotericin B (80%), Fluconazole (50%)
Histoplasmosis
Endemic in MW US, Infection occurs by inhalation, exposure to chicken coops, Progressive and disseminated 95% - 1 to 3 months after exposure.
Main Char = Fever/Weight loss/Skin Ulcers/Hepato-splenomegaly/lymphadenopathy
Dx = Urine: H.Capsulatum antigen sens 95%
Tx = Amphiotericin B and or Itraconazole 12 Weeks
Candidiasis
Oropharyngeal Candidiasis (OPC) more common if CD4 < 300, Esophagitis if CD4 <100 - In most cases strain causing disease is derivated from PT’s resident GI flora - 4 types of OPC (Erythematous/Hyperplastic/Angular/Pseudomembranous)
Tx for OPC = Itraconazole 200mg/d x 14 d (97%) or Fluconazole 100mg/d x14 d (87%)
Avoid Topicals (lower cure rates and higher relapse rates)
Esophageal Candidiasis is most common cause of dysphagia/odynophagia in AIDS - Most PTs with OPC and oesophageal symptoms have Esophageal Candidiasis, but not all PTs with esophageal candidiasis have OPC.
Studies = EGD
Tx = Fluconazole is DoC 200mg/d first day, 100mg/d other 13 days, if unable to swallow use Fluconazole IV
Pneumocystis Jirovecii
Pneumocystis is a fungus not a parasite with unique tropism for the lung, rarely invade the host, attaches to the alveolar epithelium causing inflammation, interstitial edema and diffuse alveolar damage - PCP occur often via environmental exposure, less often via reaction to latent infection
Clin Pres = Gradual onset and progression of fever/dry cough/dyspnea - Average 1 month before medical consult
Best imaging - HRCT chest - if normal no PCP
Best Lab - Bal+ immunofluorescence
Tx = TMT-SMX (Bactrim) - IV 15-20 mg/kg/day for 21 days - PO 2 DS tab Q8 hrs x 21 Days - Adjuctive steroids if PO2 <70 mm Hg
Cytomegalovirus
Worldwide about 90% of people > 18 are seropositive for CMV, in USA and Canada 50% - Once infected lifelong carrier - CMV mainly affects the Retina (Most important Form), CNS, and GI tract. Rare in lung.
CMV Retinitis: No Pain, but flashers, blurry vision, decrease in peripheral vision. - Light flashes ot sudden vision loss - Usually start in one eye but often involves both - Blindness due to retina detachment 2-6 months if untreated
Dx = Perivascular fluffy yellow-white retinal infiltrate +/- hemorrhage
Tx = IV ganciclovir, lifelong
Toxoplasmosis
30% in the US seropositive for IgG T.gondii - Annual risk of developing Toxo if seropositive and CD4<100 is 30% and <50 is 75% if not receiving prophylaxis
Clin Si = Focal sign (69%), Fever (47%), AMS (42%), Psycomotor retardation (38%), Menignismus (10%)
Clin Sx= HA (55%), Confusion (52%), Fever (47%), Lethargy (43%), Seizures (29%)
Dx = MRI brain (CNS Lymphoma mat look similar) - Obtain IgG serology T. gondii - Order MRI brain look for more than 1 lesion - If LP was done order Cytology for malignant cells and EBV PCR - Order PCR for T. gondii
Tx = Pyrimethamine+Sulfadiazine+Leucovorin
Brain Biopsy if no clin or radiological improvement after 14 days of anti-Toxo therapy
