Fungal and Parasitic Infections of the CNS Flashcards
Systemic fungi (all acquired by inhalation-potential to spread systemically) can cause CNS infection
histoplasma, blastomyces, paracoccidioides, coccidioides, cryptococcus
Leading cause of fungal meningitis
cryptococcal meningitis
Dimorphic fungi that causes systemic mycoses (molds in environment; yeast in tissues)
histoplasma capsulatum, blastomyces dermatitidis, paracoccidioides brasiliensis, coccidioides immitis
Systemic mycoses agent that is not dimorphic and has a worldwide distribution
cryptococcus neoformans
found throughout the western hemisphere-causes valley fever-found in San Joaquin Valley of California and in Southern Arizona
coccidioidomycosis
occurs when you see drought-rain-drought pattern, large numbers of fungal elements present in blowing dust
coccidioidomycosis
converts to spherules
coccidioidomycosis
develops slowly with increasing headache, fever, stiff neck, and other neurological signs, if untreated is frequently fatal
coccidial meningitis
encapsulated yeast, not dimorphic, identified by india ink
Crytpococcus neoformans
abundant in soil contaminated with bird (mostly pigeon) droppings
cryptococcus neoformans
cryptococcosis acute meningitis in
AIDS/immunosuppressed
Fungal agents that are not causative agents of systemic mycoses
candida albicans, zygomycetes
causes amoebic dysentery and can cause brain abscesses (and liver abscesses)
Entamoeba histolytica
can cause sleeping sickness
Trypanosoma brucei (african trypanosome)
causes complication of malaria-cerebral malaria
plasmodium falciparum
opportunistic amoeba genera-very rare-normally reside in fresh water
acanthamoeba, naegleria, and balamuthia
caused by Naegleria
Primary amebic meningoencephalitis (PAM)
acquired during swimming in warm water-hot springs, heated pools, hot tubs- intranasal inoculation-majority of cases are fatal within one week
Primary amebic meningoencephalitis (PAM)
symptoms of PAM
fever, headache, vomiting, confusion, and death
Dx: PAM
observation of trophozoites in biopsy or cerebrospinal fluid
Tx:
infection is usually fatal, some success following treatment with Amphotericin B
caused by Acanthamoeba and Balamuthia
Granulomatous amoebic encephalitis (GAE)
amoeba invade the brain, resulting in a slowly developing ulcerative lesion (slow progression than PAM)
Granulomatous amoebic encephalitis (GAE)
GAE can be disseminated in
AIDS patients
more common presentation of acanthamoeba infection
Acanthamoeba keratitis (chronic infection of cornea)
corneal ulceration and ocular pain can accompany
Acanthamoeba keratitis
Tx: Acanthamoeba keratitis
topical treatment, corneal transplantation/Eye enucleation
toxoplasmosis is caused by
toxoplasma gondii
sources of toxoplasma gondii
cat (oocysts in feces), food (livestock contaminated w/ cysts)
majority of infected individuals in toxoplasma gondii are
asymptomatic
congenitally acquired infection that can lead to miscarriage or stillbirth or blindness, mental retardation, neurological disorders
Congenital Toxoplasmosis
causes encephalitis in the immunocompromised (HIV/AIDS)
toxoplasma gondii
pregnant women are advised to avoid this task in order to reduce exposure to toxoplasma gondii
changing cat litter
If it occurs in this trimester there is a greater chance of infection but it will be less severe or asymptomatic
toxoplasmosis-3rd trimester
If it occurs in this trimester there is a slimmer chance of fetal infection, but with severe disease
toxoplasmosis-1st trimester
toxoplasmosis symptomatic disease is
“flu-like”
timmu system walls off bradyzoite filled cyst in this infection
toxoplasmosis
toxoplasmosis encephalitis is due to
reactivation of existing infection (at time of severe immunosuppression)
Dx: of toxoplasma gondii
serological testing-congenital may do PCR analysis of amniotic fluid
Maternal testing of toxoplasma gondii
IgM or rising IgG titer indicates acute infection
Children with toxoplasmosis should be treated for
the first year
Visceral Lavarl migrans
granulomatous lesions in liver, spleen, lung, eye, brain
Diagnoses of visceral larval migrans
eosinophilia, clinical presentation, serology, history (pets)
Tx: of visceral larval migrans
steroids (no organisms to kill)
Are eggs passed in the feces in individuals with visceral larval migrans?
No