Final Exam Review- Fungi and Parasites

Question 0

Treatment for C. albicans

Answer 0

Fluconazole, amphotericin, echinocandins.

Question 1

Candida albicans type and key concepts

Answer 1

Opportunistic infection. Found in indwelling catheters and parenteral nutrition. Mucocutaneous, esophageal (AIDS), vaginal, cutaneous.

Question 2

Cryptococcus neoformans

Answer 2

Opportunistic infection. Leading cause of fungal meningitis. Found in bird droppings. Causes halo shape when stained with India ink. Virulence factors include melanin and phenotypic switching (changes in capsule/cell wall).

Question 3

Treatment for C. neoformans

Answer 3

Amphotericin, followed by fluconazole

Question 4

Histoplasma capsulatum

Answer 4

Systemic dimorphic endemic fungus that hides in macrophages. Can be inhaled when spelunking or around bats. Causes necrotizing granulomas, diagnosed with a urine antigen test. Found in Ohio River Valley. Treat with amphotericin or itraconazole.

Question 5

Treatment for histoplasma capsulatum?

Answer 5

Amphotericin or itraconazole

Question 6

Blastomyces dermatitidis

Answer 6

Systemic dimorphic endemic fungus. Broad based budding. Also found in Ohio River Valley. Causes lung disease. Treat with amphotericin, itraconazole, fluconazole.

Question 7

Coccidioides immitis

Answer 7

Systemic dimorphic endemic fungus. Crowds in southwestern US, spheroid is diagnostic, causes flu-like illness.

Question 8

Paracoccidioides Brasiliensis

Answer 8

Mariner’s wheel appearance. Male predominance, causes a cough and necrotizing granulomas. Treat with itraconazole.

Question 9

Penicillium Marneffei

Answer 9

Opportunistic and dimorphic. In asia causes umbilicated skin lesions. Treat with amphotericin and 5FC.

Question 10

Mucor

Answer 10

Opportunistic infection, common in diabetes, treatment with iron chelators, causes black necrotic lesions. Has wide hyphae with right angle branching. Treat with posaconazole

Question 11

Treatment for mucormycosis?

Answer 11

Posaconazole - stops angioinvasion and tissue death

and tissue debridement.

Question 12

Aspergillus

Answer 12

Opportunistic fungus with narrow hyphae that branch at acute angles. Has fruiting body. Causes Allergic BP aspergellosis (ABPA) and aspergillomas. Treat by reinstating the immune system, but if severe, try voriconazole.

Question 13

How to treat aspergillosis?

Answer 13

Voriconazole or immune system reinstatement.

Question 14

PCP

Answer 14

Caused by pneumocystic jiroveci, treat with TMP-SMZ. Common when CD4 <200.

Question 15

Malassezia furfur

Answer 15

Dermatophyte that causes hypopigmentation (Pityriasis versicolor) and has a spaghetti and meatballs look with KOH stain.

Question 16

Eumycetoma

Answer 16

Swollen foot with fungal granules

Question 18

Sporothrix schenckii

Answer 18

Rose gardener’s disease, lymphangitic spread. Treat with itraconazole.

Question 19

Plasmodium falciparum

Answer 19

Apicompexa protozoan. Causes malaria. Fever, shivering, arthralgias, vomiting, end-organ failure, brain damage (infarct). Worst type. This form does not have a hypnozoite form, so primaquine is not useful. Multiply infected RBC’s and heavy parasitemia. Transmitted by anopheles mosquitos.

Question 20

Plasmodium Vivax

Answer 20

Has hypnozoite form. Can treat with primaquine, will relapse because schizonts will enter bloodstream. Enlarged erythrocytes. Every 48 hours

Question 21

Plasmodium ovale

Answer 21

Trophozoite ring form is oval shaped. Causes malaria, also has hypnozoite form. Treat with primaquine. Every 48 hours

Question 22

Plasmodium malariae

Answer 22

Affects aging RBCs, no hypnozoite form. Band like on peripheral blood smear. Every 72 hours.

Question 23

Babesia microti

Answer 23

Apicomplexa protozoan that is transmitted by ixodes. Commonly affects people from cape cod and hamptons. Impossible to distinguish on PBC from plasmodia Causes wide range of clinical manifestations, mostly flu like, but really affects immunosuppressed and asplenics. Treat with atovaquone and azithromycin.

Question 24

Entamoeba Histolytica

Answer 24

Fecal-oral transmission (analingus, contaminated water), causes amoebic dysentary (bloody diarrhea). Most asymptomatic though. Has two life forms: multiplying trophozoite and infective cyst. Treat with metronidazole and ionoquinol to kill cysts.

Question 25

Naeglaria fowleri/ balamuthia mandrillaris/ acanthamoeba

Answer 25

Infect in fresh water, no host-host transmission, usually kill host. Cause meningoencephalitis (innoculate nasopharynx and move to CNS).

Question 26

Giardia lamblia

Answer 26

Fecal-oral transmission, causes putrid smelling diarrhea that lasts weeks, sulfur burps. Treat with metronidazole. Loss of brush border and inhibition of sucrase and maltase.

Question 27

Trichomonas Vaginalis

Answer 27

Treat with metronidazole, causes green weeping cervical discharge, sexually transmitted.

Question 28

Spore forming protozoa

Answer 28

Cause watery diarrhea, treat by restoring immune system.

Question 29

Leishmania

Answer 29

Kinetoplastid protozoan. South America. Multiply in macrophages Transmitted via the sandfly, reservoir is dogs. Can be cutaneous (painless ulcer, think of the vet on vacation), mucocutaneous (spreads to mucous membranes of oropharynx), and visceral (hepatosplenomegaly, AKA DUM DUM FEVER). Treat with pentavalent antimony

Question 30

Trypanosoma cruzi

Answer 30

Kinetoplastid protozoan. Causes Chagas disease and transmitted by the Reduviid bug. Causes Romana sign (edema of the eye where inoculated), chronic phase marked by megacolon, megaesophagus, cardiomegaly. Treated with Benznidazole and nifurtimox.

Question 31

Trypanosoma brucei

Answer 31

Kinetoplastid protozoan (bar-like) transmitted by tse tse fly that causes sleeping sickness. Can be gambiense or rhodiense, but east african is worse. Initially causes winterbottom's sign (inflammation at inoculation site). Then causes personality changes, daytime somnolence, cns penetration. Antigenic variation and replication in bloodstream. Treat with suramin/melarsoprol for rhod. Pentamidine/melarsoprol for gamb.

Question 32

Toxoplasma gondii

Answer 32

Kinetoplastid protozoan. Transmitted by cats, can cause congenital infection marked by retardation, choreoretinitis. Ring enhancing lesions in AIDS patients. Treatment with TMP-SMZ

Question 33

Ascaris lumbricoides

Answer 33

Egg consumption leads to migration through wall up to lungs, causes Loeffler's Syndrome (allergic response to worms in alveoli), then swallowed to gut where they cause obstructions (esp in children) and malnutrition. Treat w/ albendazole and mebendazole

Question 34

Necatur americanus/ancylostoma duodenale

Answer 34

Hookworms, have 2 pairs of cutting plates, penetrate intact skin, migrate through venous system up to lungs. Swallowed to gut. Important cause of childhood anemia (microcytic), also dog tapeworm (ancylostoma braziliense) causes creeping eruption. Albendazole/mebendazole

Question 35

Strongyloides Stercoralis

Answer 35

Penetrates intact skin, causes superinfection with klebsiella and other gut flora by migrating around walls. Ivermectin, albendazole, mebendazole.

Question 36

Enterobius vermicularis

Answer 36

Pinworm, causes perianal itching, use scotch tape to diagnose. Autoinnoculation, eggs hatch and move back in.

Question 37

Trichuris trichura

Answer 37

Whipworm, causes tenesmus and rectal prolapse. Has polar plugs, also polyparasitism.

Question 38

Wucheria bancrofti

Answer 38

Transmitted by mosquitos causes filariasis. Destruction of lymphoid organs and causes elephantiasis by backup. Even after treatment, elephantiasis persists.

Question 39

Onchocerca volvulus

Answer 39

Causes river blindness when the worms migrate up to eye. Transmitted by blackfly treat with ivermectin.

Question 40

Taenia solium

Answer 40

Pig tapeworm (cestode), has fewer proglottids but hooked scolex, more uterine branches than beef counterpart. Infects people who eat undercooked pork. Also, neurocysticercosis is cause of adult onset seizures in people who eat food contaminated with feces of people infected. Treat with praziquantel.

Question 41

Diphyllobothrium latum

Answer 41

Fish cestode, causes macrocytic anemia, treat with praziquantel.

Question 42

Echinococcus granulosis

Answer 42

Dog tapeworm transmitted in sheepherders causes hydatid cysts that burst and cause vomica. Treat with albendazole.

Question 43

Schistosoma

Answer 43

Flukes that pass through snails, gotten through freshwater by penetrating intact skin. Have lid like operculum. Cause egg induced granuloma formation --> hepatosplenomegaly, CNS involement, and hematuria. Treat with praziquantel.