Parasitology gorgas EXTRAS Flashcards
Soil transmitted helminths pneumonic? Common names of each
A2NTS
Ascaris lumbricoides - Giant roundworm = Ascariasis
Ancylostoma duodenale/Necator americanusHookworms - Hookworm infection
Trichuris trichiura - Whipworm - Trichuriasis
Strongyloides stercoralis - Threadworm - Strongyloidiasis
Which of the soil-transmitted helminths affects large intestine ? All others ar Small intestine
Trichuris trichiura - Whipworm
What magnification for microfilaria
10x
[40x for identifying which nucleus]
Thick or thin which one do you fix?
Thin
When dip in hypotonic stain it would lyse blood cells.
[Need this in thick fil
What are cestodes and trematodes called
Platyhelminthes
Difference between a definitive and intermediate host
Definitive- the parasite reproduces sexually and/or harbors the adult stage
Intermediate - the parasite reproduces asexually and/or harbors the larval stage
Some parasites have 2 intermediate hosts.
Paratenic host?
Paratenic - The parasite lives but can’t develop further, Eg not essential
Functions as a transport or carrier host
What are the diagnostic stage of all filarial bois
L1
What is a rhabditiform vs a filariform larva? How to tell difference in strongy?
rhabditiform - L1/2 - Oesophagus is joined to a terminal oesophageal bulb by a narrow isthmus
filariform - Elongated and cylindrical oesophagus with no terminal bulb
How much blood for thick stain
50uL
What is oviparous? Which organisms are like this?
Eggs take time to hatch in environment
-Most intestinal nematodes (bar strongyloides)
[Dx eggs in stool]
What is viviparous? Which organisms are like this?
Directly give birth to larva Eg no eggs
-Tissue nematodes (filarial, Trichinella, dracunculus)
[Dx larvae in tissue/blood]
What is ovoviviparous? Which organisms are like this?
Females lay eggs which immediately hatch
-Strongyloides
[Dx Larva in stool]
Lifecycle of most nematodes has how many hosts? Which are exceptions
Complete lifecycle with only 1 host [human]
Exemptions:
filarial worms
- Def - Humans
- Intermediate - mosquito/fly
Dracunculus medinensis
- Def Humans
- Intermediate - cyclops flea
Which Todes are segmented
cestodes
Why saginata more motile than solium
Need to get out of poo so cows eat them
Pigs don’t mind eating poo
How to conform an amastigote on microscopy
Has kinetoplast (small dot next to nucleus)
Often both within and outwith macrophage
