HELMINTHS

HELMINTHS CA2

Ascaris Lumbricoides
Female > Male
Male curled ventrally tail, Female straight tapered tail

Ascaris Lumbricoides ova
Left is fertilized (smaller), right is unfertilized (larger, oval)

Bile stained Ascaris Lumbricoides ova

Ascaris Lumbricoides ova

Left is decorticated ova, 2 layers (no albumin layer), Right is corticated 3 layers

Trichuris Trichirua

Head smaller than posterior, male has spicule

Trichuris Trichirua ova

Rugby shaped, polar plug at both ends, bile stained

Hookworm ova

Thin egg shell, not bile stained, cannot differentiate between species

Hookworm filariform larva

Sharp tail end, infective

Hookworm rhabditiform larva

Shorter and stouter than filariform

Strongyloides stercoralis filariform

Elongated, longer than hookwork, notched end, infective

Strongyloides stercoralis filariform

Enterobius vermicularis female adult

Larger than male, tail straight and pointed, cervical alae at head

Enterobius vermicularis cervical alae

Enterobius vermicularis ova

Planoconvex (one side flat the other convex), thin transparent egg shell

Enterobius vermicularis ova with scotch tape technique

Wuchereria bancrofti microfilaria

Body nuclei discrete, no terminal nuclei, sheated, Cephalic space ratio 1:1

Wuchereria bancrofti microfilaria

Giemsa staining

Brugia malayi microfilaria

Cephalic space ratio 2:1, body nuclei overlap, 2 terminal nuclei on each end

Brugia malayi microfilaria terminal nuclei

Feature of the Brugia genus

Brugia malayi nocturnal microfilaria terminal nuclei

Lose their sheath (50-80%)

Onchocerca volvulus microfilaria

Subcutaneous filariasis, unsheathed, bulbous head, not in blood but skin and eye, river blindness

Taenia solium Scolex

4 suckers. dome shaped rostellum, 2 rows of hooks

Taenia saginata scolex

4 suckers with no hooks

Taenia mature proglottid

Male and female organs located centrally, genetial pores on lateral.

Taenia solium gravid proglottid

Branching lateral uterus: 7-10 branches on each side

Taenia saginata gravid proglottid

Longer than solium, 15-30 branches each side

Echinococcus granulosus adult

Scolex (4 suckers, 2 hooks), neck, immature and mature proglotids

Hymenolepis nana scolex and mature proglotid

Scolex: 1 row of hooks, 4 suckers

Hymenolepis nana cysticercoid (larva)

Invaginated scolex, tail points posteriorly

Diphyllidium caninum scolex and gravid proglotid

Scolex: 4 suckers, 3-4 rows of hooks

Diphyllbothrium latum

Scolex: 2 bothria at dorsal and ventral, spatula shaped. Mature proglotid with 2 lobbed ovary, a lot of testis, follicle shaped vitelaria gland, short coiled uterus.

Pleurocercoid of Diphyllidium latum

Not fully differentiated scolex

Cysticercus cellulose, Taenia solium larval stage

Elongated sac with protoscolex and fluid, 2 rows of hooks can be seen at apical rostellum

Hidatid cyst, Echinococcus granulosus larval stage

3 layer wall, germinal, laminated, host tissue

Diphyllidium caninum ova

Capsulated, congregration of eggs in membranous sac capsule

Taenia spp. ova

Round thick shell with radiating striation, cannot differentiate between species

Hymenolepis nana ova

Oval translucent, both poles have papillate and fine filaments

Diphyllobothrium ova

Oval, operculated, small knob on one end

Fasciola hepatica adult

2 suckers

Clonorchis sinesis adult

Fasciolopsis buski adult

Paragonimus westermani adult

Oval, coffee bean shape, thorny integument, caecum unbranched, testes with lobes at posterior, ventral sucker in middle

Schistosoma mansoni male and female adult

Male larger and stouter with 8 testes, female thinner with fine cuticle

Schistosoma japonicum adult and head end

Schistosoma cercaria

Elongated with forked terminal tail, penetrate skin

Cercaria of other trematodes

Unforked tail

Schistosoma mansoni ova

Oval with lateral spine

Schistosoma japonicum ova

Spherical, lateral knob

Schistosoma haematobium ova

Oval, terminal spine

Fasciola hepatica ova

Oval thin shelled, opercullum inapparent

Clonorchis sinensis ova

Anterior operculum with shoulder

Fasciolopsis buski ova

Oval, thin shell, operculated

Paragonimus westermani ova

Brownish, thick shell, operculated

Metacercaria of trematode

Infective, encysted cercaria, round/oval with cercaria inside