tapeworms Flashcards
Diphyllobothrium latum or Dibothriocephalus latus
COMMON NAME
Broad or Fish Tapeworm
Diphyllobothrium latum or Dibothriocephalus latus
FH
Man (Dogs-resorvoir)
Diphyllobothrium latum or Dibothriocephalus latus
HABITAT
Small Intestine (Ileum)
Diphyllobothrium latum or Dibothriocephalus latus
1ST IH
Copepods
Diphyllobothrium latum or Dibothriocephalus latus
2ND IH
Freshwater fish (salmon, trout, pike, ruff, etc.)
Larger predator fish (paratenic)
Diphyllobothrium latum or Dibothriocephalus latus
INFECTIVE STAGE
Plerocercoid larva
Diphyllobothrium latum or Dibothriocephalus latus
Scolex
- Almond-shaped
- 2 long prominent sucking grooves/organ
Diphyllobothrium latum or Dibothriocephalus latus
MOT
Ingestion of raw, undercooked or pickled freshwater fish
Diphyllobothrium latum or Dibothriocephalus latus
Proglottids
Wider than long (10-20 mm wide)
Diphyllobothrium latum or Dibothriocephalus latus
Mature proglottid
- “rosette” uterus
- presence of bilobed ovaries
Diphyllobothrium latum or Dibothriocephalus latus
Egg
- Operculated
- The eggs of D. latum are smaller and more symmetrical than P. westermani
Diphyllobothrium latum or Dibothriocephalus latus
Embryonation
8-12 days
Diphyllobothrium latum or Dibothriocephalus latus
Epidemiology
Northern Temperate Areas
Scandinavia, Finland, Japan, Europe, Chile and North America
Diphyllobothrium latum or Dibothriocephalus latus
Treatment
Praziquantel
Taenia solium
COMMON NAME
Pork Tapeworm
Taenia solium
FH
Man
Taenia solium
HABITAT
Small Intestine
Taenia solium
1ST IH
Pigs, Humans (developed Cysticercosis)
Taenia solium
INFECTIVE STAGE
- Cysticercus cellulosae (armed)
- Embryonated egg (if Cysticercosis)
Taenia solium
Scolex
- Globular (4 cup shaped suckers)
- Armed Rostellum (Has 2 rows of approx. 25-30 hooklets)
- Short Neck
- 2-3 meters or up to 8 meters
Taenia solium
MOT
- Consumption of contaminated undercooked pork (Measly Pork)
- Ingestion of Egg (lead to cysticercosis)
Taenia solium
Proglottids
Square-like or squarish
Taenia solium
Mature proglottid
- Trilobe ovary (2 prominent lobes; 1 small central lobe)
- Uterus is connected to the genital pore.
Taenia solium
Gravid Proglottid
- “finger-like” uterine branches (5-13)
- Longer than wide
Taenia solium
Egg
- Indistinguishable from the other Taenia spp. Eggs
- Spherical brown and striated
- Oncosphere with 6 hooklets (contains hexacanth embryo)
- reported as Taenia egg, look for proglottids to identify species
Taenia solium
Embryonation
Embryonated
Taenia solium
Epidemiology
Worldwide distribution
Taenia solium
Treatment
Praziquantel or Niclosamide
Surgery for Cysticercosis
- Praziquantel and Albendazole
Criteria for cure
- Recovery of Scolex
- Negative stool examination 3 months after treatment
Taenia saginata
COMMON NAME
Beef Tapeworm
Taenia saginata
FH
Man
Taenia saginata
HABITAT
Small Intestine
Taenia saginata
1ST IH
Cattle
Taenia saginata
INFECTIVE STAGE
Cysticercus bovis
Taenia saginata
Scolex
- Cuboidal
- no rostellum
- Whitish opaque
- 4-10 meters or up to 25 meters
Taenia saginata
MOT
consumption of contaminated undercooked beef
Taenia saginata
Proglottids
More Proglottids compared to T. solium
Taenia saginata
Mature proglottid
- Bilobed ovary
- Reproductive organs are connected to the genital pore
Taenia saginata
Gravid Proglottid
- Tree-like uterine segments (15-20)
- Longer than wide
Taenia saginata
Egg
- Indistinguishable from the other Taenia spp. Eggs
- Spherical brown and striated
- Oncosphere with 6 hooklets (contains hexacanth embryo)
reported as Taenia egg, look for proglottids to identify species
Taenia saginata
Embryonation
Embryonated
Taenia saginata
Epidemiology
- Worldwide distribution
- more commonly reported here in the country
Taenia saginata
Treatment
Praziquantel or Niclosamide
Surgery for Cysticercosis
- Praziquantel and Albendazole
Criteria for cure
- Recovery of Scolex
- Negative stool examination 3 months after treatment
Hymenolepis nana
Common name
Dwarf tapeworm
Hymenolepis nana
Final Host
Rat
Hymenolepis nana
Accidental Host
Man
Hymenolepis nana
IH
- Rice beetle/Tenebrio spp.
- Fleas
- flour beetles
- rats/house mice (H.nana var. fraternal)
Note:
IH is not required (direct life cycle)
Hymenolepis nana
Infective Stage
Cysticercoid larva (indirect)
Eggs (direct)
Hymenolepis nana
Scolex
- rhomboidal/subglobular
- Short armed rostellum (retractable)
- 1 row of hooks (20-30)
Hymenolepis nana
Proglottid
not recovered in stool because they undergo degeneration
Hymenolepis nana
Mature Proglottid
- broad than long
- 3 ovoid testis and one ovary in between
Hymenolepis nana
Gravid Proglottid
- broad than long
- enlarged uterus containing eggs
Hymenolepis nana
Strobilus
25 to 45mm
Hymenolepis nana
Egg Shape
Spherical or subspherical (30 to 47 µm)
Hymenolepis nana
Egg Color
colorless or clay-colored
Hymenolepis nana
Egg Membrane
- thin outer membrane
- thick inner membrane
- conspicuous bipolar thickenings
Hymenolepis nana
Polar filaments
- 4 to 8
- Hair-like
- embedded in the inner membrane
Hymenolepis nana
Egg Other features
die immediately in environment
Hymenolepis nana
Larva
Mature in 20 to 30 days after ingestion
Hymenolepis nana
Treatment
Praziquantel
Niclosamide
Hymenolepis nana
Epidemiology
Tropical and subtropical climates (most common tapeworm in US)
Hymenolepis diminuta
Common name
Rat tapeworm
Hymenolepis diminuta
Final Host
Rat
Hymenolepis diminuta
Accidental Host
Man
Hymenolepis diminuta
IH
- Grain beetle
- Flea
- Cockroaches
- Mealworms
- earwigs
Hymenolepis diminuta
Infective Stage
Cysticercoid larva
Hymenolepis diminuta
Scolex
- knob-shaped
- Small unarmed rostellum
- protrudes from the anterior end
Hymenolepis diminuta
Proglottid
not recovered in stool because they undergo degeneration
Hymenolepis diminuta
Mature Proglottid
- broad than long
- 3 ovoid testis and one ovary in between
Hymenolepis diminuta
Gravid Proglottid
- broad than long
- enlarged uterus containing eggs
Hymenolepis diminuta
Strobilus
60cm
Hymenolepis diminuta
Egg Shape
Circular (fried egg) (60 to 80 µm)
Hymenolepis diminuta
Egg Color
bile-stained
Hymenolepis diminuta
Egg Membrane
- thin outer membrane
- thick inner membrane
- Not conspicuous bipolar thickenings
- Striated
- larger
Hymenolepis diminuta
Polar filaments
none
Hymenolepis diminuta
Egg Other features
Hooklets have a fan-like arrangement. (3 pairs)
Hymenolepis diminuta
Larva
Mature in 3 weeks after ingestion
Hymenolepis diminuta
Treatment
Praziquantel
Niclosamide
Hymenolepis diminuta
Epidemiology
Worldwide
Dipylidium caninum
Common name
- Dog / Cat tapeworm
- Pumpkin seed tapeworm
- Flea tapeworm
- Double-pored tapeworm
Dipylidium caninum
Final Host
dogs/cats
Dipylidium caninum
Accidental Host
Man
Dipylidium caninum
IH
Dog and cat fleas:
- Ctenocephalides canis: dog
- Ctenocephalides felis: cat
- Pulex irritans: Human
- Trichodectes canis: Dog louse
Dipylidium caninum
Infective Stage
cysticercoid larva
Dipylidium caninum
Scolex
- Small and globular (conical)
- Protrusible armed rostellum
- 1 - 7 rows hooks (thorn-shaped)
- Scolex is also armed
Dipylidium caninum
Proglottid
Pumpkin seed shape
Dipylidium caninum
Mature Proglottid
- 2 genital pores (Bilateral)
- 2 sets of male and female reproductive organs
Dipylidium caninum
Gravid Proglottid
- very large
- pumpkin seed/cucumber shape
Dipylidium caninum
Strobilus
10-70 cm
Dipylidium caninum
Egg Shape
spherical
Dipylidium caninum
Egg Membrane
- Thin-shelled
- In embryonic membrane packets
Dipylidium caninum
Egg Other features
- Egg packets (8-15 eggs)
- Six-hooked oncosphere
Dipylidium caninum
Treatment
- Praziquantel
-Niclosamide and Paromomycin
Dipylidium caninum
Epidemiology
Worldwide
Echinococcus granulosus
Common name
- Dog tapeworm
- Hydatid tapeworm
Echinococcus granulosus
Final Host
Dogs/Wild Canine
Echinococcus granulosus
Accidental Host
Man
Echinococcus granulosus
IH
- Humans (dead end host)
- Sheep
- Goat
- Horse
- Camel
Mechanical vectors - Birds
- arthropods
Echinococcus granulosus
Infective Stage
- Hydatid cyst
- Eggs (in humans)
Echinococcus granulosus
Scolex
- Pyriform (pear-shaped)
- armed rostellum
- 30 to 36 hooks
- short neck
- typically taeniid
- 4 acetabula
Echinococcus granulosus
Proglottid
3 proglottids only
Echinococcus granulosus
Gravid Proglottid
largest proglottod
Echinococcus granulosus
Strobilus
3-6 mm
Composed of layers
Echinococcus granulosus
Egg Shape
Spherical and striated
Echinococcus granulosus
Egg Color
brown
Echinococcus granulosus
Egg Other features
- Indistinguishable from the eggs of Taenia spp.
- may be released inside or outside the host
Echinococcus granulosus
Larva
- Diagnostic stage
- See hydatid cyst table
Echinococcus granulosus
Treatment
Mebendazole, albendazole, and praziquante
Echinococcus granulosus
Epidemiology
Middle East, Iraq
Raillietina garrisoni
Common name
Madagascar worm
Raillietina garrisoni
Final Host
brown rats in PH
Raillietina garrisoni
Accidental Host
Man
Raillietina garrisoni
IH
- Tribolium confosum (Flour beetle)
- arthropods
Raillietina garrisoni
Infective Stage
Cysticercoid larva
Raillietina garrisoni
Scolex
- Subglobular
- armed rostellum
- 2 alternating circular rows
90-140 hooks (hammer-shaped) - 4 acetabula
Raillietina garrisoni
Mature Proglottid
- bilobed ovary surrounded by 36 to 50 ovoid testes
- Genital pore opens on the side
Raillietina garrisoni
Gravid Proglottid
- “grains of rice” appearance
- 200 to 400 egg capsules
Raillietina garrisoni
Strobilus
60 cm
Raillietina garrisoni
Egg Shape
spindle-shaped
Raillietina garrisoni
Egg Membrane
- outer elongated membrane
- inner spherical membrane
Raillietina garrisoni
Egg Other features
egg capsules (1-4 eggs)
Raillietina garrisoni
Treatment
Praziquantel