Fungal and parasites of the CNS Flashcards by tcarlso 3

What are the systemic fungal infections that can cause CNS infections? (5)

Histoplasma
Blastomyces
Paracoccidioides
Coccidioides
Cryptococcus

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What is the most common fungal cause of meningitis? Second most common?

Cryptococcal

2. Coccidiodies

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Are the fungi that cause systemic diseases opportunistic?

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How are fungi infections started?

Through inhalation

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What is the form that coccidioides immitis infects?

Yeast

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What is the only encapsulated yeast?

Cryptococcus neoformans

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Where is coccidioides immitis found in the world? Why?

Desert southwest d/t drought-rain-drought pattern

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What is the morphology of coccidioides immitis?

Spherules

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What are the symptoms of coccidioidomycosis?

Usually asymptomatic

Mild to moderate pulmonary disease

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How does coccidial meningitis present, relative to bacterial meningitis?

Same symptoms, but much slower onset

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How do you diagnose coccidioidomycosis meningitis?

Antigen detection

Serology

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What is the treatment for coccidioidomycosis meningitis?

Amp B

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Can you cultivate coccidioidomycosis

rarely

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Which fungus is NOT dimorphic? Why?

Cryptococcus neoformans b/c it is encapsulated

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India ink stain?

Cryptococcus neoformans

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Where is Cryptococcus neoformans found?

Bird droppings, soil

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What are the symptoms of infx with Cryptococcus neoformans usually? What about for meningeal infections?

Mild pulmonary disease (or none)

Slow meningitis symptoms

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What population are we concerned about with Cryptococcus neoformans infections (cryptococcosis)?

AIDS/ immunosuppressed

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How do you diagnose Cryptococcus neoformans? How sensitive is this?

India ink stain
Serology

Only 50%

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What is the treatment for Cryptococcus neoformans infections of the CNS?

Long term Amp B and 5-fluorocytosine

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What causes rhinocerebral mucormycosis? Who is usually infected with this?

Zygomycetes

DM pts usually get these

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What are the symptoms of rhinocerebral mucormycosis?

Rhinitis

CNS symptoms

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What are the three molds that cause zygomycosis?

Rhizopus
Absidia
Mucor

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Are zygomycetes septate? Broad or narrow?

Broad, aseptate

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How do you diagnose zygomycosis?

Culture confirmation

What is the treatment for zygomycosis?

Amp B

What is the parasite that causes GI symptoms, and can also cause CNS infections?

Entamoeba histolytica

What do entamoeba histolytica cause in the brain?

Abscesses

What does trypanosoma brucei cause?

Sleeping sickness

What does plasmodium falciparum cause?

Cerebral malaria

What causes cerebral malaria?

Plasmodium falciparum

What causes sleeping sickness?

Trypanosoma brucei

What causes neurocysticercosis?

Pork tapeworm | Tenia solium

What are the three genera of amoeba that cause infections in man?

Acanthamoeba Naegleria Balamuthia

Where are the opportunistic amoebas found in the environment?

Fresh water

What is primary cause of primary amebic meningoencephalitis (PAM)?

Naegleria

How is Naegleria acquired?

Snorting water while swimming

What are the symptoms of Naegleria infections?

Fever, HA, CNS, death

What are the amoebas associated with Neti Pot use?

Naegleria fowleri

How do you diagnose naegleria fowleri?

Trophozoites in CSF

True or false: Infection with naegleria fowleri is usually fatal

True

How do you treat naegleria fowleri infections?

Amp B... maybe

What causes granulomatous amoebic encephalitis (GAE)?

Acanthamoeba and balamunthia

What is the pathology of acanthamoeba and balamunthia?

Amoebas invade the brain, resulting in slow CNS involvement and ulcerative lesions

What is acanthamoeba keratitis? What are infections associated with?

Chronic infection of the cornea, associated with contact lenses

What are the symptoms of acanthamoeba keratitis?

Corneal ulceration and ocular pain

How does acanhamoeba appear under a microscope?

Stop-sign appearance

How does toxoplasma gondii move about?

Sporozoan (tank tread)

Where are toxoplasma cysts found?

Cat litter | Garden vegetables

What does the TORCH test used on pregnant women screen for?

``` Toxopalsma Other Rubella CMV Herpes ```

True or false: infections with toxoplasma gondii are usually fatal?

False- usually asymptomatic

What can toxoplasma lead to if a pt becomes immunosuppressed?

Encephalitis

What are the congenital symptoms of toxoplasmosis gondii?

Blindness MR Neuro disorders

What are the ocular signs of toxoplasmosis?

Small, asymptomatic scarring

What do the toxoplasma lesions look like on a CT?

Ring enhanced lesion

How does transmission of toxoplasma gondii occur? (2)

Ingestion of cysts through meats Cat litter

What are the definitive hosts for toxoplasma gondii?

cats

How are cats infected with toxoplasma?

Infected rodents

When are congential transmission of toxoplasma concerning?

When **primary** infection occurs during pregnancy--later the better

What are the symptoms of toxoplasmosis, if it is symptomatic at all?

Flu-like

When, besides pregnancy, it toxoplasmosis concerning? What can it cause?

Immunosuppression Encephalitis

How do you diagnose toxoplasmosis? (3)

1. PCR testing 2. IgM or rising IgG in mother 3. IgM in newborn

How do you prevent toxoplasmosis?

Cook meat | Avoid cat feces

What is the treatment for toxoplasmosis? When?

Treat mothers

What causes neurocysticercosis?

Tenia solium

What are the GI symptoms of tenia solium?

Diarrhea

What is the main pathology with cystercercosis?

Lesions in vital organs

What are the symptoms of neurocysticercosis?

Szs, neuro stuff

What population gets neurocysticercosis?

immigrants

How do you diagnose neurocysticercosis?

Serology | MRI

What is the main disease that is associated with ascaris lumbricoides?

Intestinal disease

What causes visceral larval migrans?

Ascarid worms (similar to Lumbricoides) from dogs/cats Toxocara canis/cati

What is the mech of transmission of visceral larval migrans?

Ingestion of eggs via dog/cat poop contamination

What happens in infections with visceral larval migrans?

Granulomatous lesions in vital organs d/t larval death

What are the symptoms of visceral larval migrans?

Depend on location of granuloma development

How do you diagnose visceral larval migrans?

Eosinophilia | Serology

Can you diagnose viceral larval migrans via fecal cysts?

No, because there are no cysts

What is the treatment for visceral larval migrans?

Symptomatic (steroids)

Sphereules = ?

Coccidioides immitis

Broad, aseptate hyphae, branching at 90 degree angles = ?

Zygomycoses

Septate hyphae, branching at 45 degree angles = ?

Aspergillus

What two places in the body does acanthamoeba infect?

Eye (acanthamoeba keratitis) and brain (GAE)

Stop-sign appearing amoeba = ?

acanthamoeba