DTM&H - Helminth Spotter UPDATED ACTUAL Exam Questions and CORRECT Answers

DTM&H - Helminth Spotter UPDATED
ACTUAL Exam Questions and CORRECT
Answers
x10 - CORRECT ANSWER - What magnification do you need to scan on to look for
helminth eggs?


Ascaris lumbricoides (giant worm) - CORRECT ANSWER - What species has both
infective and non-infective eggs down a microscope?


Fertile = approx 60um; condensed nuclear material with double notched membrane
Infertile = 75-90um; wooly nuclear material that fills cells; single thick notched membrane -
CORRECT ANSWER - How do you tell the difference between fertile and infertile ascaris
eggs?


- Looks like a tea tray
- Bipolar plugs at either end (like handle)
- Barrel shaped

- 50-60um - CORRECT ANSWER - What are the features of the trichuris trichuria egg?


- Looks like a bunch of grapes inside
- Very thin walled
- Glassy apperance

- 40-60um in size - CORRECT ANSWER - What are the features of the hookworm egg?



Vental teeth - CORRECT ANSWER - What are the features that allow identification of the
adult hookworm?


- Strongyloides (most commonly)

,- Hookworm (if after 24h as eggs hatch within 24-48h into larvae) - CORRECT
ANSWER - Which cestode worm larvae might you see in faeces? (2)


L1 stages of strongyioides

Can get L1 stages of hookworm too - CORRECT ANSWER - What stage of larvae are
commonly seen in faeces?


Likely means you have hyper infection - CORRECT ANSWER - What does it mean if you
see L3 stage strongyloides faeces in larva?


If L1 should fit nicely into x40 field

If L3 won't fit into x40 field - CORRECT ANSWER - What size magnification is
appropriate to see an L1 larvae in the stool?


Hookworm = long buccal cavity; club shaped oesophagus
Strongyloides = no real buccal cavity; double bulbed oesophagus - CORRECT
ANSWER - How do you differentiate an L1 hookworm from an L1 strongyloides larva?
(2)


Strongyloides - oesophagus is half body length; tip of tail looks like its been cut off, NO
SHEATH
Hookworm - outside sheath, tip of tail pointed, oesophagus is < half length of body - CORRECT
ANSWER - How do you differentiate an L3 hookworm from an L3 strongyloides larva?
(2)


- Necator americanus = 2 cutting blades

- Ancylostoma duodenale = cutting teeth - CORRECT ANSWER - How do you tell the
difference between the two adult species of hookworm?


Small intestine (look for undulating villi) - CORRECT ANSWER - If you are looking at
strongyloides, which part of the intestine do you expect to see it in?

, - Would see eggs (look like thin walled cloud of cells) in mucosa
- Larve (look like fragments of pink tubes with blue dots in) (can be in tissue or lumen)
- Adult worms all within mucosa
- Lots of orange eosinophils

- Inflammatory cell infiltration in the lamina propria - CORRECT ANSWER - What
features of strongyloides in the small intestine would you see? (4)


- 55microns in size

- Typically flat on one side - CORRECT ANSWER - What are the features of enterobius
vermicularis eggs?


False - usually get larvae not eggs - CORRECT ANSWER - T or F it is common to see
enterobius vermicualris eggs in faeces?


Lateral aleo

Double bulb oesophagus - CORRECT ANSWER - What are the features of the adult
enterobius vermicularis?


Striated muscle - CORRECT ANSWER - Which tissue will you likely see trichinella in?


- See encysted larvae in striated muscle
- Look for pink round bodies that contain larvae (pink tube with blue dots in)

- Becomes walled off with pink collagen capsule - CORRECT ANSWER - What are the
features of trichinella that allow you to identify it on a tissue slide?


- CORRECT ANSWER -