ID-Fungal Infections Flashcards
Risk factors for candidemia?
Neutropenia, malignancies, organ transplantation, broad-spectrum antimicrobial agents, intravascular catheters, hemodialysis, parenteral nutrition, major abdominal surgery
How is systemic candidiasis usually diagnosed?
By a positive blood culture or a positive culture from a normally sterile site
When disseminated candidiasis is suspected what consults should you get?
Ophthalmology! You get these white exudate splotches on the retina
What are common focal infections in systemic candidiasis?
UTIs, peritonitis, bone and joint infections, CNS infections
For disseminated candidiasis which anti fungal do you start ASAP?
An echinocandin: anidulafungin, caspofungin, micafungin
What candida infections at specific sites do you not treat with an echinocandin?
Do not treat meningitis, UTI, endopthalmitis because echinocandins have poor organ penetration!
What do you do for C. glabrata?
You have to do susceptibility testing to see if it is susceptible to an -azole
What antifungal is recommended for C. parapsilosis?
An azole!
Because it is not susceptible to an echinocandin
Treatment duration for uncomplicated candidemia?
14 days after first negative cultures
Treatment duration of candidiasis focal organ infection?
For several weeks to months… based on resolution of signs and symptoms
When is treatment of asymptomatic candiduria indicated?
ONLY treat in neutropenic patients and those undergoing urological procedures
With positive blood culture for candida what can’t you forget?
to remove central lines!!!
Risk factors for invasive or disseminated aspergillosis?
profound and prolonged neutropenia and immunosuppression associated with chemo or organ transplantation… now being reported in ppl who are critically ill in the ICU and are exposed to glucocorticoids
Radiographic signs of aspergillus infection?
wedge shaped densities that look like infarcts, target lesion with a necrotic center surrounded by a ring of hemorrhage (halo sign)
What is the best way to diagnose disseminated aspergillus disease?
Galactomannan antigen assay, blood cultures are rarely positive
What is the most common way that mucormycosis presents?
Rhinocerebral infection with headache, epistaxis, ocular findings (proptosis periorbital edema, decreased vision)
How can cryptococcal infection be diagnosed?
suggestive histopathology or by the detection of cryptococcal antigen in the serum or CSF
Diagnosis is confirmed by culture
What is the most sensitive and specific assay for the diagnosis of cryptococcal meningitis?
Latex agglutination assay for cryptococcal antigen
How good is the serum assay for cryptococcal infection?
Not as good, it’s sensitivity is lower so a negative test cannot be used to exclude meningitis
CSF profile of cryptococcal meningitis?
Lymphocyte pleocytosis
High opening pressure
Treatment of cryptococcal infection in AIDS patients
Maintenance therapy required until they have responded to antiretroviral therapy (CD 4 count greater than 100 for more than 3 months) and have been receiving antifungal therapy for at least a years
Treatment of cryptococcal infection in those without AIDS
maintenance therapy for 6-12 months
What happens if a patient has received appropriate antifungal therapy and other measures to reduce elevated ICP have failed? In crypto infection…
give frequent lumbar punctures and removal of CSF or placement of a VP shunt is required
What happens to organ transplant patients with cryptococcus on high dose immunosuppressive therapy?
They may require life-long antifungal therapy
Where is blasto endemic?
It is endemic to the Ohio and Mississippi River valleys , great lakes and st. Lawrence river
How does blasto infection occur?
Inhalation of spores!
What sites can blasto infect?
Bones, joints, prostate, skin, lungs
How is blasto diagnosis made?
Diagnosis made based on characteristic yeast forms with broad based buds on histopathologic samples, definitive diagnosis by culture
If disseminated blasto is expected, what should be done in addition to antifungal therapy?
Bone scan to detect occult osteoarticular involvement
Obtain urine to screen for prostate involvement
How is histo diagnosed?
It is small yeast forms within neutrophils… growth takes 6+ weeks
What are some complications of histo infection?
Acute and chronic pulmonary disease, granulomatous mediastinitis, fibrosing mediastinitis, broncholithiasis, pulmonary nodules (histoplasmosis), and acute/chronic disseminated disease may occur
Cocci–where endemic?
SW US, Texas, California Central Valley and parts of central/South America
How does cocci infection usually present?
It usually presents as a community acquired pneumonia 1-3 weeks after infection
What is Valley Fever?
Valley Fever is a subacute infection with respiratory symptoms, fever, and erythema nodosum, joint athralgias also common
Where does cocci most commonly disseminate too?
It most commonly disseminates to skin, bones, joints, and meninges
How is cocci best diagnosed?
Serological tests and also useful for monitoring therapy–repeat tests may be needed to improve sensitivity
What is the antifungal of choice for sporotrichosis?
itraconazole
What is first choice antifungal for aspergillus infection?
Voriconazole
Treatment of choice for mucormycosis?
Liposomal amphoteracin B
Treatment of crypto?
Induction: Ampho or flucytosine for two weeks
Consolidation/maintenance: Fluconazole
Treatment of blasto?
Ampho B followed by itraconazole?
Treatment of cocci pulmonary infection?
Itraconazole, *fluconazole
Treatment of cocci meningitis?
Fluconazole
