parasites and fungi

Question 1

giardia method of spread

Answer 1

contaminated water, or faecal-oral

Question 2

giardia mimics what condition

Answer 2

coeliac! - diarrhoea, malaise, foul smelling fatty stool, abdo cramps, wt loss

Question 3

toxoplasmosis - method of spread

Answer 3

pseudocyst from uncooked meat / cat faeces (cat definite host, livestock intermediate host)
(or via placenta, or transplant/transfusion)

Question 4

classic triad of congenital toxoplasmosis

Answer 4

chorioretinitis, hydrocephalus, cerebral calcifications

Question 5

giardia vs cryptosporidium - types of diarrhoea

Answer 5

giardia = osmotic + secretory diarrhoea
cryptosporidium = secretory diarrhoea

Question 6

Drugs for the following:
• Toxoplasmosis
• Entamoeba histolytica
• Giardia
• Strongyloides
• Tapeworm
• Schistosomiasis

Answer 6

• Toxoplasmosis: pyrimethamine, sulfadiazine

• Entamoeba histolytica: metronidazole, tinidazole
• Giardia: metronidazole, tinidazole
• Strongyloides: ivermectin/ albendazole

• Tapeworm: Praziquantel
• Schistosomiasis: Praziquantel

Question 7

nematodes (roundworms) and flukes/flat/tapeworms:
- name the ones we care about
- how they are spread
- and the animal they are associated with if relevant

Answer 7

nematodes
1. Enterobius vermicularis (pinworm) - FO
2. Ascaris lumbricoides (large intestinal roundworm) - FO
3. Strongyloides stercoralis - skin penetration

other
1. schistosomiasis - skin penetration, snail!
2. Echinococcus granulosus - FO, pig!
3. Taenia solium – cysticercosis - FO, cattle/pig

Question 8

Enterobius vermicularis - causes WHAT key symptom and why?

Answer 8

peri-anal itching worse at night!- develop into adults in intestine, travel to perianal region to lay eggs

Question 9

what is broncho-tracheal migration and which yuckies do this

Answer 9

• eat egg > burrows out of GI to blood > portal system to lungs to cause pneumonitis > swallowed mucous > back to GI!
• ascaris, strongyloides, echinoccus

Question 10

the 4 possible clinical manifestations of schistosomiasis

Answer 10

1. asymptomatic
2. swimmer’s itch
3. acute schisto i.e. Katayama syndrome: serum sickness like syndrome
4. chronic schisto (in all major organs - GI, GU, liver, lungs, brain)

Question 11

fbe findings in schistosomiasis

Answer 11

fbe - anaemia (GI/GU blood loss), low plt (splenomegaly), eosinophilia

Question 12

parasite + seizure, think of WHAT

Answer 12

neurocysticercosis

Question 13

waxing and waning GI / cutaneous / pulmonary symptoms think WHAT yuckie

Answer 13

strongyloides

Question 14

fungal examination under wood light will look like what?

Answer 14

green

Question 15

examples of yeast vs moulds

Answer 15

yeast = candida, cryptococcus
mould = aspergillus, zygometes

Question 16

dimorphic fungi - examples and basically what do we treat them al with

Answer 16

Histoplasma, Blastomyces, Cocciodes - itraconazole / lipo-ampho

Question 17

what causes mucormycoses?

Answer 17

zygometes

Question 18

India ink = what organism

Answer 18

cryptococcus

Question 19

treatment for cryptococcus

Answer 19

acute: ampho + flucytosine for 2/52
longer or mild only: azole for 6-12mo (flucon/itra)
IC: lifelong flucon prophylaxis

Question 20

the four major candidas and their treatment

Answer 20

1. Candida albicans = amphotericin, azoles, + echinocandins
2. Candida glabrata = amphotericin B (most R to azoles)
3. Candida krusei = amphotericin B first line (R-AF to flucon, less for vori)
4. Candida lusitaniae = azoles ok, R to amphotericin

Question 21

Paronychia and onychomycosis: affects toes or fingers more

Answer 21

fingers > toes

Question 22

candida auris - what and why do we care

Answer 22

often MDR, hard to grow/mis-identified, and often spread in healthcare setting

Question 23

chronic mucocutaneous candidiasis - what is it?

Answer 23

genetic condition - primary defect in T cell responsiveness to candida
present with chronic severe candida infections

Question 24

4 presentations of non-invasive aspergillosis

Answer 24

1. aspergilloma
2. chronic pulmonary aspergillosis
3. sinusitis
4. otomycosis

Question 25

invasive aspergillosis most often caused by which subtype

Answer 25

aspergillosis fumigatus

Question 26

classic CT signs of invasive aspergillosis

Answer 26

1. Halo sign – haemorrhagic nodule surrounded by ischaemia
2. reverse halo (central ground glass, with more intense ring around)
3. Air crescent - cavitates during treatment, or with granulocyte activity (count recovery)

Question 27

first line Rx for aspergillosis

Answer 27

voriconazole

Question 28

what stain for PJP

Answer 28

Giemsa and methenamine silver stains

Question 29

first and second line tx for PJP

Answer 29

a. 1st line = IV bactrim
b. 2nd line = pentamidine

Question 30

how do azoles, echinocandin and polyenes work?

Answer 30

all weaken the fungal cell wall:
- azoles: inhibit ergosterol synthesis
- echinocandin e.g. micafungin: inhibit glucan synthase > less beta glycans
- polyenes e.g. ampho: make holes in the membrane

Question 31

azoles, echinocandins, polyenes - main side effects

Answer 31

azoles = hepatotoxic
echinocandin = nephrotoxic
polyenes = nephrotoxic

Question 32

caspofungin: shit for what

Answer 32

can’t penetrate CSF / urine

Question 33

which azole is bad for aspergillus

Answer 33

good - vori (first line invasive), itra
bad - flucon

Question 34

posa must take with what

Answer 34

high fat diet