Helminth Ova Flashcards
What is this?
Fertile Ascaris (lumbricoides) egg
55-65μm
Oval, brownish
Thick shell
‘developing ovum’
‘mammilated projections/protuberances’
What is this?
Trichuris trichuria egg (whipworm)
45-55μm
‘unembryonated ovum’
‘polar or mucous plugs’
- associated with rectal prolapse
- no intermediate host
- eggs become infective in 15 to 30 days once pooped out into environment
What is this?
Hookworm egg
60-70μm
Oval or ellipsoidal shape.
Morulated, Thin smooth wall,
Space between ovum and wall
What is this?
Taenia egg
35-45 μm
Round with a thick, radially striated dark brown wall
Inside each shell is an embryonated oncosphere with 3 pairs of hooklets
What is this?
Taenia egg
35-45 μm
Round with a thick, radially striated dark brown wall
Inside each shell is an embryonated oncosphere with 3 pairs of hooklets
What is this?
D. Latum egg
60-70μm.
Fish Tapeworm
pale yellow-brown and oval in shape
often has an operculum at one end
‘mass of granulated yolk cell’
What is this?
D. Latum egg
60-70μm. ‘Fish tapeworm’
pale yellow-brown (although sometimes clear) and oval in shape
often has an operculum at one end
‘mass of granulated yolk cell’
What is this?
Hymenolepsis nana egg
35-45μm
- hooklets in the central oncosphere
- polar filaments within the space between the oncosphere and outer shell
What is this?
H.nana egg
35-45μm
- hooklets in the central oncosphere
- polar filaments within the space between the oncosphere and outer shell
Describe this (exam style)
Schistosoma mansoni egg
Light brown, oval shape and with a lateral spine. Contains miracidia.
~150 μm
What is this?
Fertile ascaris egg
55-65 μm
What is this?
Decorticated ascaris egg
55-65 μm
absent outer layer (this indicates it is decorticated)
What is this?
Decorticated ascaris egg
55-65 μm
absent outer layer (this indicates it is decorticated)
What is this?
Infertile ascaris egg
85-90 μm
What is this?
Fertile ascaris egg
55-65 μm
bumpy outer layer = ‘mammilated’
What is this?
Infertile ascaris egg
85-90μm
Decorticated
What is this?
Infertile ascaris egg
85-90μm
What is this?
Ascaris egg with developing embryo
55-65 μm
What is this?
Fertile ascaris egg
55-65 μm
corticated, mammilated
What is this?
Decorticated ascaris egg
55-65 μm
What is this?
D. Latum
60-70μm
contains mass of granulated yolk cell
operculum at one end
is a tapeworm from undercooked infected fish
What is this?
D. Latum
60-70μm
contains mass of granulated yolk cell
operculum at one end
is a tapeworm from undercooked infected fish
What is this?
H. Nana egg
35-45μm
slightly oval in shape
striated outer membrane and a thin inner membrane
oncosphere has six hooklets
is a ‘dwarf tapeworm’, beetles/fleas are infective intermediate host
What is this? (is large)
Fasciola egg
120-140μm
is a liver fluke
intermediate host is freshwater snail
definitive host usually sheep or cattle
metacerciae on vegetation (ie watercress) ingested by host = infection
What is this?
Hookworm egg
60-70μm
filariform larvae found in soil penetrates skin (wear shoes!)
What is this?
Trichuris trichuria egg
45-55μm
‘Whipworm’
simple life cycle, embryonates in soil
Has a ‘polar plug’ on each end
What is this?
Schistosoma mansoni egg
120-140μm
prominent lateral spine
contain mature miracidium
found primarily across sub-Saharan Africa and some South American countries (Brazil, Venezuela, Suriname) and the Caribbean
usually asymptomatic, can cause hepatomegaly. severe infections can cause an ulcerative colitis type presentation
What is this?
Schistosoma haematobium egg
110-140μm
conspicuous terminal spine
contain mature miracidium
S. haematobium is found in Africa and pockets of the Middle East.
causes uro-genital schistosomiasis
What is this?
Schistosoma japonicum egg
80-90μm
small inconspicuous spine
more rounded shape
more likely to cause Katayama fever
similar symptoms to S.Mansoni but even more severe (gut symptoms)
S. japonicum is found in China, the Philippines (NOT Japan!)
What is this?
large
Paragonimus westermanii egg
70-110μm
operculum at one end
unembryonated ovum
occurs by eating inadequately cooked or pickled crab or crayfish
found in S.E Asia and Japan
