Parasitology part 2 Flashcards
Hermaphroditic, or monoecious (no separate sexes). they obtain nutrition through integument, with microtriches
Cestodes or tapeworms
anterior end of the body; muscular organ for attachment
“hold fast”
scolex
projection at the apex of the scolex armed with hooks or spines
Rostellum
Behind the scolex; unsegmented; region of growth where strobilation begins
Neck
chain of segments (proglottids)
Strobila
contains non-fully developed reproductive organs
immature segment
contains at least one set of fully developed reproductive organs
Mature segment
filled with eggs
other reproductive organs have atrophied
uterus remain
Gravid segment
proglottid detaches from the body to release eggs
apolysis
Fish tapeworm or Broad tapeworm
Diphyllobothrium latum
Uterus rosette shape
D. latum
Ova: abundant yolk granules, small knob at abopercular end
D. latum
Pork tapeworm
Taenia solium
Rostellum with double crown of 25-30 hooks
T. solium
Uterus has 7-15 lateral branches
T. solium
Cystic larvae of T. solium
Cysticercus bovis
IH of D. latum
1st: copepods
2nd: fish
IH of T. solium
Swine
Beef tapeworm
Taenia saginata
uterus has 15-30 lateral branches
T. saginata
Cystic larvae of T. saginata
Cysticercus cellulosae
Dwarf tapeworm
Hymenolepis nana
Short, invaginated rostellum with single row of 20 -30 hooks
H. nana
ova has 2 polar thickenings where 4-8 filaments arise
H. nana
IH of H. nana
Grain beetles, rat flea
Rat tapeworm
Hymenolepis diminuta
RUdimentary rostellum without hooks
H. diminuta
ova has 2 polar thickenings where NO filaments arise
H. diminuta
Dog and cat tapeworm
Dipylidium caninum
Scolex is conical refractile with 1-7 circlets of hooks
Dipylidium caninum
Proglottid is vase-, barrel-, cucumber seed-, pumpkin seed- shaped with compartmented egg clusters
D. caninum
Genital pore is bilateral or double pored
D. caninum
ova has 8-12 eggs enclosed in a membranous capsule
D. caninum
hydatid tapeworm
Echinococcus granulosus
Scolex has rostellum with double crown of 30 - 36 hooks
E. granulosus
IH of E. granulosus
Sheep
MOT of D. latum
Ingestion of plerocercoid (sparganum) on flesh of infected fish
Causes megaloblastic anemia (Vit. B12)
D. latum
Eggs confused with Paragonimus eggs
D. latum
1st IH or Spirometra mansoni
Copepods
2nd IH of Spirometra mansoni
Frogs, snakes
Incidental host of Spirometra mansoni
Man
DH of Spirometra mansoni
Dogs and cats
Causes extraintestinal infection in the eyes, thorax, abdomen
Spirometra mansoni
Adult worms are mistaken for adult D. latum
Spirometra mansoni
Beef tapeworm
Taenia saginata
Eggs confused with pollen grains
Taenia eggs
DS of T. saginata
Eggs or proglottid
IS of T. saginata
Larva
Pork tapeworm
Taenia solium
Causes cysticercosis
Taenia solium
Dwarf tapeworm
Hymenolepis nana
Smallest intestinal cestode
H. nana
MOT of H. nana
Ingestion of cysticercoid in infected rat flea
IH of H. nana
Rat flea
DH of H. nana
Man
DS of H. nana
Embryonated egg
IS of H. nana
Larva
IH of H. diminuta
Arthropod
DH of H. diminuta
Rat
Gravid proglottids resemble rice grains (dry) or cucumber seeds (moist)
Dipylidium caninum
MOT of E.granulosus
Ingestion of egg
Filled with fluid containing brood capsules and protoscolices
Hydatid cyst
Diagnosis for E. granulosus
Casoni’s intradermal test
IS of E. granulosus
Ingestion of eggs
Most commonly organ affected by E. granulosus
Liver
IH of Echinococcus multiocularis
Rodents (mice, voles)
DH of Echinococcus multiocularis
Foxes, wolves
Fluid-filled cyst which contains multiple scolices arising from germinal layer
Coenurus
Extraintestinal infection commonly in the brain, spinal cord, eyes
Multiceps spp
Unsegmented, leaf-like appearance
Trematodes
“Pierced with holes”
Trematos
Oral sucker
Acetabulum
Genital sucker
Gonotyl
No body cavity
Acoelomate
IH of heteroxenous trematodes
Snail
Excretory system of Trematodes has branching tubules ending up in ___
Flame cells
Functional unit for osmoregulation
Flame cells
Egg stages of flukes are operculated except
Blood flukes
Free swimming cilliated larval stage, pyriform in shape, has secretory glands–> enzymes for penetration of snail tissue
Miracidium
Saclike, serves as brood sac for the development and production of redia
Sporocysts
Daughter sporocysts
Redia
Free-swimming larval stage with a tail
Cercaria
Encysted cercaria
Metacercaria
Capable of producing operculated eggs
Adult
Habitat of liver flukes
Intrahepatic bile duct
MOT of liver flukes
Ingestion of encysted metacercaria in infected secondary host
Sheep liver fluke
Temperature fluke
Fasciola hepatica
Hen’s egg with flat operculum
Fasciola hepatica
Adult: leaf-shaped with branched ceca, with shoulder
Fasciola hepatica
Tropical liver fluke
Fasciola gigantica
Oriental liver fluke
Chinese liver fluke
Clonorchis sinensis
E: old-fashioned electric bulb
Clonorchis sinensis
A: bottle-neck appearance
Clonorchis sinensis
Inflammation of the bile duct
Cholangitis
Inflammation of the gallbladder
Cholecystitis
Cancer of the bile duct
Cholangiocarcinoma
Car liver fluke
Southeast Asian liver fluke
Opisthorchis felineus and viverrini
Resembles Clonorchis sinensis but narrow and smaller. Egg is practically similar
Opisthorchis felineus and viverrini
Lancet liver fluke
Dicrocoelium dendriticum
E: asymmetrically ovoid with broad convex opeculum
Dicrocoelium dendriticum
A: lancet shaped
Testes obliquely anterior to ovary
Dicrocoelium dendriticum
Causes liver for
Halzoun
Fasciola hepatica
Causes hyperplasia of biliary epithelium
Dicrocoelium dendriticum
Habitat of intestinal flukes
Small intestine
Giant intestinal fluke
Largest fluke of man
Fasciolopsis buski
E: identical to F. hepatica but larger and with slightly convex operculum
A: elongate-ovoid with unbranched ceca, no shoulder
Fasciolopsis buski
Garrison’s fluke
Echinostoma ilocanum
E: ovoid, straw colored with small operculum
A: attenuated at both ends; circumoral disk with horseshoe - shaped crown of 49-51 hooks
Echinostoma ilocanum
Von Seibold fluke
Dwarf intestinal fluke
Heterophyes heterophyes
Deadliest
Smallest fluke in man
Heterophyes heterophyes
E: indistinguishable with Metagonimus
A: pyriform, with fine, scaly spines
Heterophyes heterophyes
Yokogawai fluke
Metagonimus yokogawai
Oriental lung fluke
Paragonimus westermani
1st IH of P. westermani
Snail (Antemalania spp)
2nd IH of P. westermani
Crustaceans (Sundathelphusa philippina mountain crab)
Egg: asymmetrical with abopercular end which is generally thicker than the sides
A: when fresh, spoon-shaped. When preserved, coffee-bean shaped
Paragonimus westermani
Causes pulmonary granuloma formation, fibrosis.
Usually misdiagnosed as pulmonary tuberculosis and cerebral paragonimiasis
Paragonimus westermani
Fluke that penetrates skin lipids
Schistosoma spp
Cercaria without a tail
Schistosomule
Causes Bilharziasus
Schistosoma spp
Causes swimmer’s itch, clam digger’s itch, water itch
Schistosoma spp
Causes Katayama disease
Schistosoma spp
Causes ectopic granulomas (colon, liver, spleen, lungs)
Schistosoma spp
Causes urinary bladder cancer
Schistosoma haematobium
Most pathogenic and virulent Schistosoma spp
Schistosoma japonicum
Massive egg output (3000eggs/day)
Cerebral schistosomiasis
Schistosoma japonicum
Method of choice for definitive diagnosis of schistomiasis in PH
Circumoval precipitin test (COPT)
Oriental blood fluke
Schistosoma japonicum
Habitat of Schistosoma japonicum
Superior mesenteric venules (drains the SI)
Egg lateral knob (70-105 x 50-80um)
50- 100 eggs in uterus
Schistosoma japonicum
Adult female: central ovary
Male: smooth tegument, 6-8 testes
Schistosoma japonicum
Manson’s blood fluke
Schistosoma mansoni
Habitat of Schistosoma mansoni
Inferior mesenteric venules (drains the LI)
Egg: lateral spine (140-180 x 45-70um)
1-4 eggs in uterus
Schistosoma mansoni
F: ovary in anterior half
M: coarsely tuberculated, 8-9 testes
Schistosoma mansoni
Vesical blood fluke
Schistosoma haematobium
Habitat of Schistosoma haematobium
Vesical plexus
Egg: terminal spine (112-170 x 40-70 um)
20-30 eggs in uterus
Schistosoma haematobium
F: ovary in posterior half
M: slightly tuberculated tegument, 4-5 testes
Schistosoma haematobium
Egg: oval, minute lateral spine or knob
Ova is smaller than japonicum
Schistosoma mekongi
Egg: elongate, terminal spine
Ova is larger than haematobium
Occurs primarily in the feces
Schistosoma intercalatum