Parasites Flashcards
what preservations are good for eggs, larvae, and cysts
refrigeration
10% formalin
MIF
what preservations are good for trophozoites
PVA (best)
SAF
advantages of formalin ethyl acetate sedimentation
indefinite
easy
detects all parasites
disadvantage of formalin ethyl acetate sedimentation
more debris
advantage of zinc sulfate flotation technique
no flammable chemicals
cleaner preparation
disadvantage of zinc sulfate flotation technique
large eggs and operculated eggs missed
general characterisitics of round worms
males smaller
unsegmented
complete digestive tract
largest nematode
ascaris lumbricoides
infection mode of ascaris lumbricoides
infective egg ingested
diagnosis of ascaris lumbricoides
adult worms or eggs in feces
larvae in sputum
most common helminth of humans
enterobius vermicularis (pinworm)
infection mode of enterobius vermicularis
infective eggs ingested
diagnosis of pinworm
scotch tape (eggs and larvae
infection mode of trichuris trichiuria (whipworm)
infective eggs ingested
diagnosis of whipworm
egg in feces
football shaped with mucoid polar plugs egg
tricguris trichuria
smallest nematode
strongyloides stercoralis (threadworm)
noninfective form of threadworm
rhabditiform larva
infective form of threadworm
filariform larva (penetrates skin)
short buccal cavity with notch at end of tail
larva
strongyloides stercoralis
diagnosis of strongyloides stercoralis
rhabditiform larvae / filariform larvae in stool
adult / larva/ eggs in sputum
characteristics of rhabditiform larvae of hookworm
long buccal cavity
infective stage of hookworm
filariform larvae
characteristics of filariform larvae of hookworm
long buccal cavity
pointed tail
diagnosis of hookworm
egg in feces
what organisms are hookworm
necator americanus (new world) ancylostoma duodenale (old world)
how do you differentiate hook worm adults?
necator - cutting plates
duodenale - 2 pair
infective stage of trichinella spiralis
ingestion of encysted larvae in pork
diagnosis of trichinella spiralis
muscle biopsy
encysted larvae in muscle
larval stage:
sheathed
no nuclei in tail
nocturnal periodicity
wuchereria bancrofti
diagnosis of wuchereria bancrofti
larvae in blood smear
what condition does wuchereria bancrofti cause?
elephantiasis
microfilaria:
sheathed
2 terminal nuclei at tip of tail
brugia malayi
diagnosis of brugia malayi
larvae in blood smear
microfilaria:
sheathed
nuclei in tip of tail
diurnal periodicity
loa loa (eye worm)
what organism causes calabar swellings
loa loa
diagnosis of loa loa
larvae in blood smear