Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Tapeworm
SGU Parasitology
| Question | Answer |
|---|---|
| DH – Canids and wild carnivores – the most common taeniid tapeworm of dogs in US. | T. pisiformis |
| IH - rabbits and hares - Cysticercus pisiformis (pea-like) – found in the liver and peritoneal cavity. | T. pisiformis |
| DH – Canids and wild carnivores. The adult = 2.0 m long | T. ovis |
| IH – sheep - Cysticercus ovis infects the cardiac and skeletal muscles and represents the most important pathological lesion found by US inspectors in imported Australian mutton | T. ovis |
| DH – Canids and wild carnivores. The adult – large tapeworm (up to 5.0 m) | T. hydatigena |
| IH - cattle, sheep, swine, and certain wild ungulates - Cysticercus tenuicolis (long, attenuated neck) | T. hydatigena |
| (8.0 cm diameter) migrates through the liver tissue and encysts on the peritoneal membranes of IH. | Cysticercus tenuicolis |
| Prevalent in sheep, but only detected at meat inspection | Cysticercus tenuicolis |
| sometimes large numbers of developing cysticerci migrate in the liver of sheep or pig producing | hepatitis cysticercosa |
| a condition resembling acute fasciolosis pathology, often fatal. | hepatitis cysticercosa |
| Even small numbers of migrating larvae are capable of inducing “black disease” in the presence of C. novyi. | Cysticercus tenuicolis |
| the subcapsular surface of the liver is studded with greenish nodules of around 1 cm in diameter. | Cysticercus tenuicolis |
| Control: based only on excluding dogs and other canids from sheep pastures, but this is next to impossible; praziquantel (dog). | Cysticercus tenuicolis |
| Cysticercus tenuicolis | T. hydatigena |
| DH – cat. The adult = 60 cm long; treatment: Profender®; praziquantel | T. taeniaeformis |
| IH - mice and other rodents - Cysticercus fasciolaris – strobilocerci found within pea-sized nodules partially embedded in the liver parenchyma | T. taeniaeformis |
| DH – domestic dog and wild canids. The adult = 10.0 m long. | T. multiceps |
| ID - sheep, goats, and sometimes cattle - Coenurus cerebralis in the cranial cavity | T. multiceps |
| mature cyst is a large fluid-filled cyst (~ 5.0 cm or more in diameter), bearing clusters of scolices on its internal wall. | Coenurus cerebralis |
| As the cyst grows over a period of 6 or 8 months, neurological signs of progressive space occupation slowly develop | Coenurus cerebralis |
| There may be: blindness, incoordination, walking in circles, peculiarities in gait, hyperaesthesia or paraplegia and pressing the head against the walls, tree trunks, etc | Coenurus cerebralis |
| If the cyst is located superficially – local softening of the skull; death | The clinical syndrome – True Gid |
| Differential diagnostic with: bacterial encephalitis (listeriosis) and parelaphostrongylosis | The clinical syndrome – True Gid |
| Control – similar with the one for T. hydatigena | T. multiceps |
| DH: humans. Adult tapeworms = 5-15m in length. The scolex has no rostellum or hooks | Taenia saginata |
| The uterus of gravid segment has 15-30 lateral branches on each side of the central stem | Taenia saginata |
| IH: cattle - Cysticercus bovis | Taenia saginata |
| encysts in the striated muscles of heart, tongue, masseter and intercostal muscles | bovine cysticercosis |
| infected humans pass millions of eggs daily, either free in the feces or as intact segments each containing 250,000 eggs | Taenia saginata |
| In the pasture the eggs can survive for several months. | Taenia saginata |
| The bovine get infected by ingesting the oncospheres which travels via the blood to striated muscles | Taenia saginata |
| Humans become infected by ingesting raw or inadequately cooked meat. PPP = 2-3 month | Taenia saginata |
| adult tapeworm may induce diarrhea and hunger pains, but the infection is usually asymptomatic. | Taenia saginata |
| Public Health Concern | Cysticercus bovis |
| is first visible in about 2 weeks after ingestion of the oncospheres, as a pale, semi-transparent spot, of about 1.0 mm diameter | Cysticercus bovis |
| It is only infective to humans after 12 weeks, when it reaches its full size of 1.0 cm, usually enclosed (by the host) in a thin fibrous capsule. | Cysticercus bovis |
| unarmed scolex, lacking the typical hooks of other taeniids is visible | Cysticercus bovis |
| grayish white. Its longevity ranges from weeks to years | The cysticercus |
| The dead ones are usually replaced by a caseous, crumbly mass which may become calcified | The cysticercus |
| the masseter muscle, tongue and heart are examined and the intercostal muscles and diaphragm are inspected | Cysticercus bovis |
| is not a common parasite in US | Taenia saginata |
| DH – humans. The adult tapeworm is similar to T. saginata although the scolex has a rostellum armed with 2 rows of hooks | T. solium |
| Uterus of the gravid segment has only 7-12 lateral branches | T. solium |
| IH – pigs and humans - Cysticercus cellulosae | T. solium |
| Clinical signs insignificant in humans with the adult tapeworms | T. solium |
| Cysticercosis with Cysticercus cellulosae | Public health hazard |
| Humans may become infected with cysticerci after ingestion of eggs on vegetables, other foods contaminated with human feces, handled by infected person, or due to lapse in personal hygiene (autoinfection). | Cysticercosis with Cysticercus cellulosae |
| When the eggs reach the stomach, the oncospheres hatch out, enter the gut wall and wander far and wide in the body, slowly developing into cysticerci | Cysticercosis with Cysticercus cellulosae |
| pigs – inapparent. | T. solium |
| humas - the signs depend on the localization of the cysticerci, usually in the eye (loss of vision), or CNS (neurocysticercosis: mental disturbances, clinical signs of epilepsy or intracranial hypertension may occur) | T. solium |
| 2 species of veterinary importance | Echinococcus granulosus and E. multilocularis |
| Unilocular hydatid disease | E. granulosus |
| DH: dogs, wolves, coyotes. Adults located in the small intestine | E. granulosus |
| IH: domestic ruminants, man, pig and wild ruminants | E. granulosus |
| Hydatid cysts – mainly in the liver and lungs. | E. granulosus |
| 2 life cycles: pastoral and sylvatic | E. granulosus |
| DH (dog & wild canids); IH – sheep (the natural IH), camel (Middle East), reindeer (Northern Europe). | pastoral cycle: |
| DH- wild canids, ID – wild ruminants. Based on predation or carrion feeding. | sylvatic cycle: |
| most common in Europe. The strain is highly specific for the horse and the eggs do not develop in the sheep | E.g. equinus |
| DH: dog and the red fox. | E.g. equinus |
| IH: horse and donkey | E.g. equinus |
| one of the smallest cestodes of domestic animals (2-8 mm long) | E. granulosus |
| adults have only 4-5 segments | E. granulosus |
| terminal segment is gravid, occupying about half the length of the complete tapeworm | E. granulosus |
| 45-65 testes are generally distributed | E. granulosus |
| the genital pore is located at or the posterior the middle of the segment. | E. granulosus |
| oncosheres – very resistant on the ground (may be viable for ~ 2 years) | E. granulosus |
| PPP (DH) – 40-50 days, after which only one gravid segment is shed per week | E. granulosus |
| the adult tapeworm– non-pathogenic (thousands may be present in a dog without clinical signs) | E. granulosus |
| adult worms – very difficult because the segments are small and only sparsely shed | E. granulosus |
| When found – identified by their size (2-3 mm), ovoid shape and single genital pore; eggs resemble Taenia spp eggs | E. granulosus |
| do not infiltrate, in contrast to alveolar hydatid cysts. | unilocular hydatid cysts |
| grows very slowly and infrequently exceeds more than a few centimeters in diameter in slaughtered sheep and cattle. | Unilocular hydatid cyst of E.granulosus |
| The hydatid membrane is surrounded by an inflammatory connective tissue capsule. Brood capsules, each containing many scolices, develop from the germinal epithelium lining the | laminated hydatid membrane |
| Brood capsules, each containing many scolices, develop from the germinal epithelium lining the laminated hydatid membrane. Some of these rupture, releasing | scolices to form sediment of so-called hydatid sand |
| lack brood capsules, scolices and daughter cysts; their identification in cattle and swine is necessarily somewhat presumptive | Sterile hydatids |
| essentially a parasite of tundra regions, with its greatest prevalence in the subarctic regions of Canada, Alaska and former U.S.S.R | E.multilocularis |
| Adult tapeworm – similar to E. granulosus, but with 4-5 segments and 17-26 testes are found posterior to the genital pore | E.multilocularis |
| Alveolar hydatid cyst | E.multilocularis |
| characterized by a diffuse growth with many compartments containing a gelatinous matrix into which the scolices are budded off. | Alveolar hydatid cyst |
| Exogenous budding is not contained within the reactive connective tissue capsule but continuously proliferates and infiltrates surrounding tissues like a malignant neoplasm | Alveolar hydatid cyst |
| DH: wild canids, domestic dog and cat | E.multilocularis |
| Sled-dogs, domestic dogs and cats – potential carriers of infection for humans. Adults – in the intestine | E.multilocularis |
| IH: mainly microtine rodents (voles and lemmings) | E.multilocularis |
| Some of the larger mammals, including humans are also susceptible | E.multilocularis |
| develop in voles, lemmings, cattle, horses, swine and humans, mainly in the liver | Alveolar hydatid cysts of E. multilocularis |
| DH: asymptomatic | E.multilocularis |
| H: alveolar hydatid infection proves invariably fatal in a few years | E.multilocularis |
| Tapeworm of dogs, cats (and birds) | Family: Dipylidiidae |
| Scolex with 4 suckers and an retractile rostellum armed with several rows of thornlike hooks | Family: Dipylidiidae |
| The intermediate stage: cysticercoid | Family: Dipylidiidae |
| the most common tapeworm of the domestic dog and cat, with a worldwide distribution | Dipylidium caninum |
| much shorter than Taenia spp. (up to 50 cm long) | Dipylidium caninum |
| segments are cucumber seed-like and have 2 sets of genital organs and bilateral genital pores | Dipylidium caninum |
| genital apparatus lie slightly behind the middle of the segment, and each egg capsule may contain from 5 to 30 eggs | Dipylidium caninum |
| eggs are clustered in packets (formed by outpocketing of the uterine wall) | Dipylidium caninum |
| DH: dog, cat; rarely humans (usually children). Adults in small intestine. | Dipylidium caninum |
| IH: fleas (Ctenocephalides canis, C. felis and Pulex irritans) and lice (Trichodectes canis), containing cysticercoids | Dipylidium caninum |
| newly passed segments are active and can crawl about on the tail region of the animal. | Dipylidium caninum |
| Dog or cat acquires this tapeworm while ingesting infected insects (e.g., fleas & lice) | Dipylidium caninum |
| PPP = 2-3 weeks | Dipylidium caninum |
| non-pathogenic, but the crawling segments may cause some discomfort (pruritus ani), and a useful sign of infections excessive grooming of the perineum. Rubbing the anus along the floor | Dipylidium caninum |
| presence of a segment(s) on the coat around the perineum or in the pet’s environment | Dipylidium caninum |
| anthelmintics (nitroscanate, niclosamide bunamidine and praziquantel) should be accompanied by the use of insecticides on the animal, bedding and resting places, to eliminate the immature stages of the fleas | Dipylidium caninum |
| multiply asexually in the intestine of dogs and if not totally eliminated by anthelmintics, will repopulate the intestine even without further exposure (tetrathyridium). | Mesocestoides corti |
| Adults - up to 40 cm in length | Mesocestoides corti |
| scolex has 4 suckers but no hooks (or rostellum) | Mesocestoides corti |
| mature segments have a mediodorsal genital pore | Mesocestoides corti |
| eggs accumulate in a thick-walled parauterine organ as the segments mature | Mesocestoides corti |
| gravid segments detach from the strobila and carry their relatively small burden of oncospheres to the exterior | Mesocestoides corti |
| DH: dogs, cats and wild carnivores. Adults found in the small intestine. | Mesocestoides corti |
| IH: (requires 2) | Mesocestoides corti |
| 1st: insects or mites, bearing the cysticercoids | Mesocestoides corti |
| 2nd: mammals and reptiles, bearing the tetrathyridia in their peritoneal cavity, or birds, bearing the tetrathyridia in their lungs. | Mesocestoides corti |
| Dogs and cats get infected by predation of snakes, birds and small mammals. | Mesocestoides corti |
| PPP=2 weeks | Mesocestoides corti |
| Scolex without rostellum or hooks; lappets present | Anoplocephala |
| Gravid segments are wide | Anoplocephala |
| DH: horses | Anoplocephala |
| IH: Soil (orbatid) mites. The larval stage is a cysticercoid (a small and solid cysticercus with an inverted scolex) | Anoplocephala |
| Grazing animals get infected by the incidental ingestion of these infected arthropods | Anoplocephala |
| specific treatment for adult tapeworms – Praziquantel | Anoplocephala |
| Control – difficult since the forage mites are widespread on pasture. Administer the anthelmintic treatment before the grazing period | Anoplocephala |
| the most common species in horses of all ages, but clinical signs are mainly reported in the animals up to 3-4 years of age | Anoplocephala perfoliata |
| the lowest prevalence in the spring and highest in the winter | Anoplocephala perfoliata |
| large white tapeworm up to 20 cm in length, with a rounded scolex having a lappet behind each of the 4 suckers. Very short neck. Strobila widens rapidly. | Anoplocephala perfoliata |
| eggs – irregularly spherical or triangular, with a diameter of 50-80 um ; the oncosphere is supported by a pair of projections (pyriform apparatus) | Anoplocephala perfoliata |
| DH: horses and donkeys. Adults found in the small and large intestine | Anoplocephala perfoliata |
| IH: various forage mites in the soil and pasture | Anoplocephala perfoliata |
| Mature segments are passed in the feces and disintegrate, releasing the eggs. The forage mites ingest the eggs which develop into the cysticercoid in 2-4 month. The DHs get infected by ingestion of the infected mites | Anoplocephala perfoliata |
| The adult tapeworm develops in the intestine of horses in about 1-2 month | Anoplocephala perfoliata |
| considered to be relatively non-pathogenic, but heavy infection may cause severe clinical signs, and may even be fatal | Anoplocephala perfoliata |
| Found mainly in the cecum, but also tends to cluster in the ileum near the ileocecal valve, where it is associated with ulceration and reactive inflammation of the ileal wall, ileocecal colic in horses. These pathological changes probably account for some | Anoplocephala perfoliata |
| Intestinal obstruction and perforation of the intestinal wall are fatal | Anoplocephala perfoliata |
| Diagnostic– based on clinical signs (colic); serological ELISA (IgG); Multiplex fecal PCR | Anoplocephala perfoliata |
| eggs and segments frequently cannot be demonstrated, either by flotation or sedimentation techniques, in the feces of horses known to be heavily infected with the parasite | Anoplocephala perfoliata |
| common in ruminants; eggs resemble Anoplocephala (pyriform apparatus) | Monezia |
| DH: ruminants. Infection affects mainly lambs, kids and calves during their first year of life. | Monezia |
| More prevalent during the summer associated with the active periods of the forage mite vectors. | Monezia |
| Adult worms found in the small intestine | Monezia |
| long tapeworms (> 2m) | Monezia |
| unarmed scolices with four large suckers | Monezia |
| very wide segments containing 2 sets of genital organs visible along the lateral margins of segments with bilateral genitalia | Monezia |
| interproglottidal glands at the posterior margins of each segment extend the full width of M.expansa but occupy only the midzone of the M. benedeni segment. | Monezia |
| squared eggs, with the pyriform apparatus | Monezia |
| IH: forage (orbatid) mites. The cysticercoids may overwinter in the mites. | Monezia |
| Diagnosis – based on the presence of mature proglottids in the feces and eggs with characteristic pyriform apparatus. | Monezia |
| Mature segments are broader than long. | Family: Diphyllobothriidae |
| The genital organs are concentrated at the centers of the segments. | Family: Diphyllobothriidae |
| The uterus consists of a spiral tube with four to eight loops on each side and opens to the outside through a midventral uterine pore behind the genital pore. | Family: Diphyllobothriidae |
| Operculated eggs are discharged through the uterine pore. | Family: Diphyllobothriidae |
| Tapeworms of dogs, cats and wild carnivores in North and South America, Australia and the Far East | Spirometra |
| DH: natural definitive host is probably the bobcat Lynx rufus. Other definitive hosts: domestic cats, and dogs and the raccoon. | S. mansonoides |
| 1st IH = copepods (Cyclops) containing procercoids | S. mansonoides |
| 2nd IH = any class of vertebrates except fishes (bearing the pleurocercoids = spargana); even kittens fed procercoids support development of pleurocercoids, which appear in the flat muscles of the body wall and subcutaneous fascia. The natural IH is prob | S. mansonoides |
| Treatment and Control: praziquantel (dogs and cats); prevent pets from predating infected intermediate hosts. | S. mansonoides |
| Important tapeworm of the small intestine of humans in northern climates (Scandinavia, former USSR and North America) acquired by eating uncooked predatory freshwater fish. | Diphyllobothrium latum |
| Very long tapeworm (broadfish tapeworm); up to 20 m in length | Diphyllobothrium latum |
| Unarmed scolex with 2 bothria | Diphyllobothrium latum |
| Mature and gravid segments are square-shaped with a central genital pore | Diphyllobothrium latum |
| Eggs resemble F. hepatica eggs (yellow and operculate, but smaller). | Diphyllobothrium latum |
| DH: humans and fish-eating mammals (dog, cat, pig, polar bear, mongoose, walrus, seals, sea lions, bears, foxes and mink) | Diphyllobothrium latum |
| IH: 1st = an aquatic copepod crustacean (Cyclops) – procercoid | Diphyllobothrium latum |
| 2nd = a freshwater fish. The pleurocercoid (5 mm long, already has the scolex) is able to parasitize a series of predatory paratenic hosts until a suitable DH is found. PPP = 4-6 weeks | Diphyllobothrium latum |
| The tapeworm causes a macrocytic, hypochromic (megaloblastic) anemia, due to its uptake of vitamin B12 from the intestine. | Diphyllobothrium latum |
| Diagnosis: Detection of the characteristic eggs in the feces; clinical signs of anemia | Diphyllobothrium latum |
| In areas where infection is common, domestic animals should be fed only thoroughly cooked or deep-frozen fish products | Diphyllobothrium latum |
| are obligate endoparasites of vertebrates with an indirect life cycle | (Phylum: Platyhelminthes) (Class: Cestoda) |
| Adults are GI parasites and the metacestodes (or larval) stages are extra-intestinally located in the intermediate hosts | (Phylum: Platyhelminthes) (Class: Cestoda) |
| The adults are dorsoventrally flattened, segmented with variable length (4mm to > 10 m). | (Phylum: Platyhelminthes) (Class: Cestoda) |
| No alimentary canal – all nutrients are absorbed through the integument | (Phylum: Platyhelminthes) (Class: Cestoda) |
| body divided in 3 parts: scolex, neck and strobila | (Phylum: Platyhelminthes) (Class: Cestoda) |
| the anterior part, holding the attachment organs to the host; 4 suckers with or without a rostellum (Cyclophyllidea) or 2 bothria = longitudinal grooves which become flattened to form organs of attachment (Pseudophyllidea) | scolex |
| the body part of undifferentiated tissue where the segments start to develop | neck |
| a chain of independent, progressively maturing reproductive units (proglottids). Each mature segment is hermaphroditic containing one or two sets of male and female reproductive organs. Gravid segments are full of eggs (onchospheres) | strobila |
| When an infective tapeworm metacestode (larva) first arrives in the intestine of definitive host (DH), most of its body is digested away, leaving only the scolex and the neck. The scolex attaches to the intestinal wall, and the neck begins to bud off segm | life cycle 1 |
| These segments remain attached to one another to form the strobila. The reproductive organs (both female and male) gradually begin to mature, eggs and sperm are formed and fertilization occurs. Only the gravid proglottids are eliminated throughout the fec | life cycle 2 |
Created by:
alljacks
Popular Veterinary sets