Flashcards in export_cns fungi Deck (44):
Which fungi can cause CNS infections?
Systemic fungi - Histoplasma, Blastomyces, Paracoccidioides, Coccidioides, Cryptococcus
What is the leading cause of fungal meningitis?
Coccidioides immitis important feature
Dimorphic; molds in environment, yeast in tissues
Cryptococcus neoformans important feature
Encapsulated yeast in both environment and man
Coccidioides immitis life cycle
Mold spores inhaled, then converts into a spherule, which produces hundreds of single nucleated spores
Headache, fever, stiff neck, other neurological signs
Treatment for C. immitis
Cryptococcus is commonly found where?
In soil contaminated with bird droppings
Cryptococcal meningitis symptoms
Bouts of headaches, irritability, dizziness, other CNS
May present over weeks or months
India Ink stain
Treatment for Cryptococcal meningitis
Long term treatment of Amphotericin B and fluconazole
Relapse in AIDS patients is common, may require suppressive therapy
Rhinocerebral zygomycosis most commonly affects?
Primarily diabetic patients
Symptoms of rhinocerebral zygomycosis
Nasal congestion, blood-tinged rhinorhhea, tender sinuses, headache, fever
Can progress to altered mental status, coma, and death
Hyphal elements (broad, aseptate, branching at right angles) in clinical material
Treatment for zygomycoses
Main parasitic infections
What does entamoeba histolytica cause in the CNS?
What does Trypanosoma brucei cause in the CNS?
African sleeping sickness
What does Plasmodium falciparum cause in the CNS?
What do protozoa's cause in the CNS
What do helminths cause in the CNS?
Free-living amoeba that can affect the CNS
What does Naegleria cause?
Primary amebic meningoencephalitis (PAM)
Symptoms of PAM
Fever, headache, vomiting, confusion
Rapidly progress to coma and death
Diagnose Naegleria fowleri
Observation of trophozoites in biopsy material or CSF
Treatment of Naegleria fowleri
Infection is usually fatal
Can treat with Amphotericin B, some success is found
What do Acanthamoeba and Balamuthia cause?
Granulomatous amoebic encephalitis (GAE)
Symptoms of GAE
Amoeba invade brain and cause a slow-developing ulcerative lesion
Slower course of disease than PAM
Chronic infection of the cornea, associated with contact lens usage
Toxoplasma gondii symptoms
Majority of people are asymptomatic
Encephalitis in immunocompromised
Congenital Toxoplasma gondii
Can result in miscarriage or stillbirth
Blindness, mental retardation, neurological disorders if baby makes it to term
Most are asymptomatic
"Flu like" - fever, headache, chills, lymphadenopathy
Toxoplasma gondii life cycle
Parasite infects, then differentiates/disseminates to the muscle, brain, etc.
Immune system "walls off" bradyzoite-filled cyst
Immune weakness can result in reactivation
Diagnose Toxoplasma gondii
PCR of amniotic fluid
Maternal IgM or rising IgG (acute)
IgM positive in newborn indicates congential, however not all affected are IgM positive
Taenia solium disease
Taenia solium dissemination
Larvae hatch in intestines and enter circulation
Travel to various body sites where they encyst
Creates a space filling lesion, inducing local inflammation
Seizure and neurological defects
Diagnose Taenia solium
CT scan, MRI, serology
What disease does Ascaris lumbricoides cause in the CNS?
Visceral larval migrans (VLM)
What kind of disease is VLM?
Zoonotic; infection by worms that normally infect dogs and cats
Ingestion of eggs
VLM life cycle
Humans ingest eggs, larvae hatch and enter bloodstream, can't develop in humans so granulomatous lesions develop (commonly in liver, lung, and eye)
Symptoms of VLM
Fever and eosinophilia