HIV and Opportunistic - Fungal Flashcards
What is the most common fungal infection to get a hold of the immunocompromised?
Candida
Discuss the lab findings for Candida
Catalase Positive, so those with chronic granulomatous infection are at risk for infection
extracellular pathogen (on epithelial surfaces) that DOES NOT change the pH
When do we see candidiasis thrush in patients?
Candidal esophagitis- AIDS defining illness (CD4+ less than 100)
Other presentations of Cancida besides scraping white plaques?
Cutaneous: Kids& Diaper rash
IV drug user- Endocarditis and Tricuspid valve damage
Eyes - Retinitis
Bones: Vertebral osteomyelitis
mucosal - can wipe away, underlying red, painful
Two histology features for candida
KOH prep= hyphae, germ tubes
necrotic squamous epithelium w yeast overlying inflamed submucosa
Cold vs. warm candida and general structure we will look for
Cold temp = pseudohyphae = yeast form
Warm = germ tubes = mold form
Structure: Budding yeasts and pseudohyphae
Who is at risk besides AIDS patients for getting Candida?
Diabetes, Antibiotics (kill micro-flora in the gut, so Candida can take over), Birth Control
How do we treat Candida?
Azoles for minor infection like diaper rash
Amphotericin or Capsofungin (echinocandin) (if resistant to ampho) for severe disseminated infection in immunocompromised
oral/esophageal candidiasis = Nystatin
What count do we think of for PCP?
Less than 200
PCP symptoms in compromised vs normal health
Asymptomatic in healthy people.
Immune compromised = PCP Pneumonia (CD4+
Chest X ray for PCP
CXR: Ground glass appearance (diffuse interstitial infiltrates, bilateral, perihilar)
Discuss the lab findings of PCP
microscopy= trophozoites/cysts in sputum or bronchoalveolar Lavage.
Anemia with nonspecific increase in LDH.
Histology for PCP
Histo: methamine silver stain= Disc shaped yeast. Foamy exudate with “dented ball” alveolar damage. No inflammatory response.
Direct fluorescent antibody test (DFA) shows antibodies, sensitive, better than giemsa stains
PCP treatment
Bactrim (TMP/SMX, Trimethoprine and sulfamethaxazole), active sx and prophylaxis (CD435)
Leading cause of AIDS death?
Respiratory illness! Never forget PCP!
Discuss the structure of Cryptococcus Neoformans
HEAVILY encapsulated with repeating polysaccharide antigens (antiphagocytic), urease positive
Where do we get cryptococcus from? Discuss transmission and where it goes INSIDE OF YOU
CD4Lung –> Blood –> CNS
patho: Latency in macrophages of lung granulomas like TB, then acute infection in the lungs
Symptoms of cryptococcus infection
Lungs- Cough, dyspnea, pneumonia
CNS: common* fungal meningitis (spread via CSF): visible exudate unlike viral, AMS, diplopia, ataxia/palsy, Sz, meningismus, CN palsies, acute memory loss
Const: Fever, Headache, malaise
other: skin lesions, eye, prostate
Discuss lab stuff for cryptococcus
Sensitivity: culture>antigen>microscopy
- Blood Culture can grow c. neoformans
- (+) cryptococcal antigen test:( CRAG) = latex agglutination= cryptococcal polysaccharide antigen: done on blood/ CSF* (most sensitive)
- direct microscopy of any body fluid
Discuss the histology for crypto
histo: india ink stain= large clear capsules around budding yeast (cryptococcal halos), background is dark
meningeal tissue shows fibrosis, expanded virchow-robin space with organism aggregates, no reactive gliosis, reactive CT can lead to obstruction and hydrocephalus,
other stains: red mucicarmine or silver methanamine
Discuss imaging for crypto
Imaging: Soap bubble lesions in gray matter, basilar meningitis
Discuss treatment and prognosis for crypto
Tx: Amphotericin B and flucytosine followed by maintenance with fluconazole (which we also use if there is only mild disease)
repeated LP’s to decrease ICP
prognosis: severe, death >60%
Discuss the structure and transmission of coccidiomycosis
Trans: Inhalation of spore dust - widespread fevers with earthquakes and dust clouds.
Structure: Cocci forms spherules filled with endospores inside lungs in the warm body, mold form in the cold
These spherules are larger than RBCs
location: SW US, california valley
Discuss the symptoms of coccidio
sx: chronic pneumonia, lung granulomas, meninges, valley fever (rash,joint pain, fever, cough), erythema nodosum on shins in healthy people due to exaggerated immune response
Discuss the histology of coccidio
histo: Cx which takes a while, KOH prep, IgM titers, eosinophilia
Discuss the imaging for coccidio
Imaging: Radiography shows either nothing or cavities or nodules
Discuss the treatment for coccidio
Tx: Azole drugs (ketoconazole) for lung infections.
Amphotericin B in systemic infection
Discuss the treatment for histoplasmosis
Structure: Smaller than RBCs. Dimorphic: Cold/Soil = Mold form, Body/heat = yeast form
Discuss transmission of histoplasmosis
Trans: Bird/Bat droppings (recently in a cave) or chicken coops, transmit via respiratory spores being ingested by macrophages
Histology for Histoplasmosis
Histo: Macrophages with intracellular ovoid bodies often in coin lesion produced by granulomatous inflammatory process, KOH prep, Rapid Histoplasma blood or urine antigen test
Where do we find histoplasmosis
Location: Midwestern and Central U.S. along the Mississippi and Ohio River valleys
What happens to a person with histoplasmosis?
Sx:Pneumonia if granulomas present, Chronic pulmonary issues if granulomas calcify and fibrose
Can mimic TB!
Erythema nodosum on shins due to exaggerated immune response
Immune Compromised - Disseminated = hepatosplenomegaly with calcifications due to targeting macrophages
Treatment for Histoplasmosis
Tx: Local/mild = Fluconazole, Ketoconazole. Systemic = Amphotericin B (lots of side effects)
What dos this Aspergillus thing look like and what do our labs show us?
Structure: Hyphae at acute angles with septations (tree like). Make conidiaphores with fruiting bodies that bud off and are inhaled
Lab: Catalase positive
Diagnose: Serum galactomannan for early screening
Symptoms of Aspergillus (4 main pathways. Don’t kill me, yes this card is long but it’s basic explanations. You’ll be fiiiiiiiiiiiiiiiiiiiiiiiiiine)
Sx: spectrum based on immune response
1) Allergic bronchopulmonary aspergillosis= allergic sinusitis (Type 1 hypersensitivity rxn= elevated IgE; wheezing, fever, recurrent asthma, pulmonary infiltrates)
2) Aspergilloma- solid balls of fungus in lower lungs (especially in pre-existing fibrocavitary lung disease, TB and cancers)
3) angioinvasive aspergillosis- immunocompromised, (invades blood vessels and disseminates) which presents with hemoptysis
4) invasive aspergillosis- systemic involvement ( kidney failure, endocarditis, ring enhancing lesions in brain on CT, necrosis of nose)
What toxin do we see with Aspergillus
toxin: aflatoxin - Very carcinogenic especially for hepatic carcinoma in aspergillus flavus
Histology for Aspergillus
histo: fungal septa hyphae branch at 45*
What do we associate with Aspergillus?
a/w: peanut crops and wheat crops, african liver cancer, neutropenic patients
Treatment for Aspergillus
Tx: Less serious use Voriconazole, systemic use amphotericin. Aspergilloma = surgical resection. ABPA = corticosteroids with antifungals (itraconazole)
Structure of mucormycosis
Structure: broad, nonseptated hyphae (ribbon like), right angle (90 degrees) branching unlike Aspergillus (45 degrees)
Discuss the transmission of Mucormycosis and who is at risk
Risk: Diabetics and immunocompromised. Found in bread (rhizopus)
Transmission: Spore inhalation, proliferate in blood vessel wall where there is high glucose and ketones (think DKA). Breaks through the cribriform plate to get to the brain
Symptoms we see with mucormycosis
Sx: Rhinocerebromucormycoses (black eschar around nose and eyes = very bad prognosis = extensive necrosis)
disseminated disease (basal ganglia, cutaneous tissue, kidney, respiratory tract, etc.)
Treatment of Mucormycosis
Tx: surgical debridement, liposomal amphotericin B (usually doesn’t matter, prognosis dismal - 67%), posaconazole
