Cestodes
- Tapeworm; flat and ribbon-like
- Hermaphrodite; lack digestive organs
Body
- Scolex (head)
- Neck (region of growth)
- Proglottids (strobila)
| Taenia spp | ||
| Taenia solium | Taenia saginata | |
| Common name | Pork Tapeworm | Beef tapeworm |
| Intermediate host | Pig; man | Cattle |
| Scolex | w/ rostellum armed with 2 rows of large & small hooklets | No rostellar hooks 4 prominent acetabula |
| Length | <7 meters | <25 meters |
| No. of proglottids | 8000-10,000 | 1000-4000 |
| Gravid proglottids | Finger-like (dendritic) 7-13 lateral branches (less active) w/ accessory ovarian lobe; w/o vaginal sphincter | Tree-like (dichotomous) 15 -20 lateral branches Genitals: irregularly alternate |
| Infective stage | Cysticercus cellulosae Infected meat: “measly pork” | Cysticercus bovis |
| Eggs | Eggs Indistinguishable: spherical, striated inside with oncosphere and 6 hooklets | |
CLINICAL MANIFESTATION (T. solium)
- Intestinal infection
- Cysticercosis
- Neurocysticercosis
- Parenchymal
- Extraparenchymal
DIAGNOSIS
- CAT
- CSF-ELISA
- Electroimmuno transfer blot
- Western blot
- DOT ELISA
TREATMENT
- Praziquantel
- Niclosamide
Taenia asiatica
- 3rd Taenia spp.
- Misidentified as T. saginata
- INFECTIVE STAGE – CYSTICERCUS VISCEROTROPICA
| H. nana | H. diminuta | |
| Common Name | “dwarf tapeworm” | “rat tapeworm” |
| Length | 25-45 mm | 60 cm |
| Scolex | 4 cup-shaped suckers with rostellum & Y shaped hooklets | Rudimentary unarmed rostellum |
| Egg | Spherical/subspherical with thin outer layer and thick inner layer w/ bipolar thinking & 4 hairlike polar filament | w/ bipolar thickening; absent bipolar filaments Hooklets: fan-like arrangement |
| Infective stage | Direct: eggs Indirect: Cysticercoid larvae | Cysticercoid larvae |
| Remarks | ONLY human tapeworm which can complete its entire cycle in 1 host | Requires intermediate host |
Diphyllobothrium latum
- Fish tapeworm; broad tapeworm
- INFECTIVE STAGE – PLEROCERCOID
- Scolex – 2 bothria
- Proglottids – 4000
- Egg – with inspicuous operculum
CLINICAL MANIFESTATION & PATHOGENESIS
- Megaloblastic anemia w/ thrombocytopenia and leukopenia
DIAGNOSIS
- Finding eggs and proglottids in stool
TREATMENT
- Praziquantel
Echinococcus spp.
- Scolex – pyriform w/ 4 acetabula; armed
- Proglottids: 3 (immature, short neck, & 1 gravid proglottid)
- INFECTIVE STAGE – egg
- LARVAL STAGE – HYDATID CYST w/ protolices inside
CLINICAL MANIFESTATION AND PATHOGENESIS
- Human cystic echinococcus
DIAGNOSIS
- Radiographic findings / ultrasonography
- Positive serologic tests
- Indirect hemagglutination
- Indirect fluorescent antibody (IFA)
- Enzyme immunoassay
- GOLD STANDARD – IgE detection hydatid cyst fluid derived native or recombinant antigen B through ELISA or immunoblot
TREATMENT
- Surgical resection
- Albendazole; mebendazole
- Percutaneous aspiration, injection, re-aspiration
Diphylidium caninum
- Dog tapeworm; double-pored dog tapeworm
- Mature and gravid proglottid “pumpkin seed” shaped
- Infective stage – cysticercoid larvae
