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175 Cards in this Set
- Front
- Back
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Describe the nervous sytem of the platyhelminthes
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they have a "head end" with a concentration of nerve elements at the anterior end, ladder shaped nervous network
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Describe the general body plan of platyhelminthes
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aceoelamate, bilateria, flatworms
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Describe the muscular system of the platyhelminthes
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longitudinal, circular, and transverse muscles
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describe the excretory system of the platyhelminthes
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flame cells (pronephridia)
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describe the circulatory and respiratory system of the platyhelminthes
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no circulatory or respiratory system, thin body plan allows for diffusion of gases/ nutrients
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describe the digestive system of platyhelminthes
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may or may not have a digestive system, if they do it is incomplete with only one opening
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What is the tegument
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The unique outer covering of the platyhelminthes. The subtegumental cells share cytoplasm under the outer layer forming one continuous cell. There is ornimentation to increase the surface area like a "reverse intestine", the suface also acts with the host immune system and prevents the parasite from being digested
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Describe platyhelminthes reproduction
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they are "egg laying machines" with very complex life cycles, the majority are monoecious (hermaphroditic) the are also triploblastic (endo, ecto and mesoderm)
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What are the 3 classes of platyhelminthes
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Monogenoidea
Trematoda Cestoidean |
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What are the two subclasses of the platyhelminthes class trematoda
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1. aspidoblothria
2. digenea (flukes) |
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Give a general description of the Platyhelminthes class trematoda subclass digenea
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the flukes, all are parasitic, most have 3 host cycles that invovle snails
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Give a general description of the Platyhelminthes class cestoidean
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The tapeworms, no digestive tract, totally committed to reproduction, usually benign infections, pathology associated with developmental stage
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Give a general description of the Platyhelminthes class monogenoidea
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ectoparasites (some inside mouth), primarily parasites of cold blooded aquatic animals, Oculotrema can live on the hippo, direct life cycle
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A haptor is a unique feature of the monogenoidea class of the platyhelminthes. What does it do?
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It is a posterior structure that can have suckers or hooks, it is designed for adhesion to the host (gills of fish etc)
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Describe the life cycle of platyhelminthes class monogenoidea
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they are hermaphroditic and produce eggs. The larval stage called an oncomiracidium, is a free swiming cilliated form.
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What is the larval stage of platyhelminthes class monogenoidea called
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oncomiracidium
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Describe platyhelminthes class trematoda, subclass aspidobothria
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parasite of bivalve clams, large ventral disk with loculi (adhesive disk), produce eggs that hatch to the cilliated larval stage call "cotylocidium", no economic significance but may give insight into parasite transition from free living form to parasitic form
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What is the larval stage of platyhelminthes class trematoda subclass aspidobothria called?
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cotylocidium
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Describe the diastome body plan of Platylhelminthes calss trematoda subclass dignea (flukes)
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oral sucker (connected to digestive system via pharynx, dead end gut)
ventral sucker (acetabulum) at midpoint |
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Describe the monostome body plan of Platylhelminthes calss trematoda subclass dignea (flukes)
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-oral sucker
-no acetabulum |
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Describe the amphistome body plan of Platylhelminthes calss trematoda subclass dignea (flukes)
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-oral sucker
-large, posterior sucker |
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Describe the Echinostome body plan of Platylhelminthes calss trematoda subclass dignea (flukes)
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-oral sucker with spines
-acetabulum in the middle (pnemonic: Echinodermata are the starfish which are pointy just like spines) |
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Describe the schistosome body plan of Platylhelminthes calss trematoda subclass dignea (flukes)
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male with gynecopheral canal where female can lie
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Describe the strigeoid body plan of Platylhelminthes calss trematoda subclass dignea (flukes)
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peanut shaped/ divided into forebody and hindbody with oral sucker, and median sucker
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Describe the male reproductive anatomy of the platyhelminthes class trematoda subclass digenea
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pair of testes attached via vas efferentia to the vas deferens. Joins to cirrus sac which contains the prostate gland, seminal vesicle (internal or external, and cirrus (analogous to the penis)
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Describe the female reproductive anatomy of the platyhelminthes class trematoda subclass digenea
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single ovary with ooduct, oocapt squeezes egg into ootype which is surroned by the mehils glands, the eggs are held in the uterus where they develop an eggshell, yolk glands (vittelaria) deliver yolk to the eggs (the degree of egg maturity upon release depends on the species)
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What trematode body form is this?
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This is the gasterostome, note the oral sucker in the middle of the body
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What trematode body form is this?
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This is the monostome, note that there is no acetabulum present (hence mono)
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What trematode body form is this?
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This is the amphistome. Note the acetabulum at the posterior extremity
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What trematode body form is this?
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This is the distome. The acetabulum is never at the posterior of the body
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What trematode body form is this?
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This is the echinostome, not ethe collar of spines around the oral sucker
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What trematode body form is this?
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This is the stigeoid, note that the body is divided into the forebody and the hindbody
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What trematode body form is this?
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This is the schistosome, note the split body, found in blood flukes, usually dioecious (not hermaphroditic)
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What is significant about trematode reprodutive development.
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protandry- male develops first
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what is an operculum
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"trap door" structure on diagenean egg where the free living ciliated larval stage exits
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Describe the free living larval stage of diageneans
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called a miracidium, it is ciliated and swins around to find a new host, they can modify their behavior to find a new host (geotaxsis)
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What is unqiue about the first intermediate host specificity of digenean mericidium
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very host specific
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How can the digenean mericidium get into its first intermediate host (usually a snail or gastropod mollusk)
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burrows into head foot or is ingested, parasite has enzymes to get into tissues
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What happens to diagenean mericidium after they enter the first intermediate host
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they transform into a mother sporocyst and asexual reproduction occurs producing two types of offspring (daughter sporocyst, Redia)
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One type of offspring of diagenean mother sporocysts is the daughter sporocyst. What stage occurs after this
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The daugher sporocyst forms and moves into other tissues (reproductive or hepatopancreatic) and more asexual reproduction occurs. Cercaria are produce and move to a second intermediate host (except for schistosomes)
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Describe what happens after a diagenean cercaria leaves the 1st intermediate host (this is not true for schistosomes)
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They burrow into the 2nd intermediate host and lose their tail .they ball up and become cystic forming a metacercaria. If a 2nd intermediate host isn't available, the can do this on vegitation instead. New infections occur via ingestion of the metacercaria
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A second type of offspring of diagenean mother sporocysts is the Redia. Describe what stage comes after this
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Redia have a mouth, sucker, and gut and they can eat IH tissue. The redia produce daughter redia which then produce cercariae
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What is the infective stage to the definitive host of digeneans
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cercaria (schistosomes) or metacercaria (all others)
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Describe the pathology asscoiated with digenean infection of its 1st and 2nd intermediate hosts
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Snails can be parasitically castrated and stop produce eggs
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Which is the only free living class of the platyhelminthes?
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dugesia
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Describe the pathology associated with Fasicola hepatica
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dependent on intensity, much occurs before parasite is mature, causes liver rot in sheep, liver destruction (problems for farmers because decrease in animal size)
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describe the life cycle of Fasicola hepatica
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eggs are produced and move into the bile, they are excreted into the intestines and voided with the feces. Need to get to water, eggs hatch and mericidum enters the snail. The mericdium becomes a sporocyst then mother redia, daughter redia the cercariae. The cerariae leave the snail and attach to vegetation where they become metacercariae. The DH becomes infected by ingesting the metacercariae on the vegetation
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describe fasicola hepatica infection in humans
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eating liver with parasites can lead t ofalse positives because eggs appear in feces but there is no infectioin, infection in france due to watercress consumption
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Describe Fasciolodies magna
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parasite of deer, not much pathology, life cycle similar to F. hepatica, deer pick up metacercariae from eating vegetation, doesn't settle in biliary system but stays in perencum, big problems in sheet, cattle do not function as a host
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What is unique about the intermediate host of Dicrocoelium dendriticum
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infects land snails, does not require aquatic habitat
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describe dicrocoelium dendriticum
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"lancet fluke" liver parasite of sheep and cattle
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Describe the life cycle of Dicrocoelium dendriticum
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Eggs are produce and move into bile, voided in feces, eggs are ingested by land snail and hatch into mercidium, transition to cercariae, exit the snail via mantel cavity and cause an irritation leading to more slime, cercariae wrap up in slime ball which is eaten by ants. Metacercariae near circumesophageal ganglion mess with ant make make them clamp on vegetation. Sheep graze on the vegetation and get infected
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Describe Chlonorchis sinensis
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aka chineese liver fluke, infection can occur by eating raw fish, nightsoil fertilization
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describe the life cycle of chlonorchis sinensis
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lives in billiary system eggs are in bile, voided with feces, aquatic snails ingest mericidia, cercaria get into fish
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T/F the schistosoma are moneciuos
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false, the females live in a grove formed by the folding of the male body
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What are the 4 main species of schistosoma
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haematobium, japonicum, mekongi, mansoni
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Which specices of the schistosoma is the most important to human pathogenesis? Where does it live and what disease does it cause?
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S. mansoni, it lives in the mesenteric veins and causes hepatosplenic schistomiasis
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Describe how schistosome eggs move from the capilary beds to the lumen of the intestine or urinary bladder to be excreted.
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the eggs filter through capilary beds and release enzymes/ use their spines to ruptuer the capilary and move into the lumen
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What are the larval stage of the schistosomes called?
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miracidia
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What is the infective stage (to humans) of schistosomes
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cercariae (there are no metacercariae)
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What strategies do cercariae use to find their host
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orient phototrophically
riotaxsis (move towards disturbances in the water) |
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What causes the pathology associated with schistosome infection
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Eggs enter the liver via the hepatic portal system this leads to severe inflammation, fibrosis, hepato/spleno magaly
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What is unique about the duration of Schistosome infection
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they can last up to 40 years
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Why are children more suceptible to acute schistomiasis
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they are more suceptible to infection, the parasites produce more eggs in children (possibly due to naive immune response)
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What are the symptoms of schistomiasis infection
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Fibrosis- imparised circuation and portal hypertension leading to ascites (fluid build up)
liver dysfunction and failure hemorrhage in children0 delayed or retarded growth/ mental development |
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list the strategies used to control schistomiasis infection
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- vaccines (little progress)
- chemotherapeutics -sanitation -snail control |
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T/F Those who have been infecte4d with schistomiasis can have sterile immunity
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false, reinfection is possible
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What are some chemotherapeutic methods used to treat infection with schistomiasis
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praziquantel (drug of choice), oxamniquine (limited efficacy) , aretemisnins (anti malaria drug)
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Besides vaccines and chemotherapeutics, how else might schistosomes be controlled
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sanitation- prevent transmission through proper sanitation
snail control- prevent transmission by removing intermediate host, however mollusciciadal chemicals are very toxic to ecosystems as a whole |
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T/F intestinal trematodeas are highly pathogenic
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flase, they are generally not pathogenic because they are a ceolozoic parasite
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Describe Fasciolopsis buski
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a very large trematode, pig and human parasite, life cycle similar to fasciola hepatica, long lived infeciton, ~10-20 million people infected
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How does human infection with Fasciolopsis buski occur?
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ingestion of aquatic vegetation that has cercariae on it including water chestnuts, bamboo, lotus, caltrop, night soil fertilization
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Describe Paramphistomum cerui and its pathology
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paraiste of cattle, pathogenicity is due to life cycle where metacercaria that are ingested enter the duodenum and excist. they then penetrate to the true stomach and migrate to the rumen and lay eggs. Migration through the tissue creates lesions where secondary bacterial infections can occur
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Describe the intestinal trematode nanophyetus salmincola, its transmission and pathology
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parasite of dogs and skunks (and other things that eat salmon), tipical digenean life cycle, cercaria leave the snail and penetraet salmonid fish, restricted to North west, salmon common feed for sled dogs. Pathogenicity is due to a pathogen carried by the parasite called neorickettsia helmoenthica. When the dog eats the salmon it becomes infected with both the parasite and the pathogen
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What is the significance of neorickettsia helmoenthica?
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It is the pathogen associated with Nanophyetus salmincola that leads to pathology in sled dogs etc.
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Describe the intestinal trematode Echinostoma
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not vertebrate host specific, humans infected by eating snails, cercariae can become metacercariae in another snail or within the same snail
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Describe Paragonimus westermani
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human parasite, lives in the lungs, many reservior hosts, adults live paired in the lungs and produceeggs that move through the itssue into the alveoli, eggs are released by being swallowed and voided in the feces or spit out, once in the water cercariae infect fresh water crabs, infections are common in people who prepare crbas or eat picked or marinated (uncooked) crab, the metacercariae hatch in the intestine and burrow through the diaphragm to the lungs
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What parasite would be suspected in someone who prepares crab or eats raw crab?
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Paragonimus westermani
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What is the host for and in what species does infeciton occur for P. kelliccoti
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host is crawdads/ crayfish, infection occurs in cats and dogs
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What are 4 methods that can be used to control trematodes
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1. chemotherapy and vaccine development (vaccines to eukaryotes are nonexsistent at this point)
2.sanitation to prevent release of eggs into the environment 3. prevention by cooking food 4. snail control |
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What class makes up the tapeworms?
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cestoidea
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Describe the cestoidea class (tapeworms)
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no digestive tract, live in intestines of vertebrates (ceolozoic)
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Describe the tegument of the tapeworms (class cestoidea)
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like an inside otu intestine, microtriches increase the surface area for absportion, macromolecules to protect from digestion
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T/F Tape worm infections are highly pathogenic at all stages
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False, adult tape worm infections are usually benign, pathology is associated with the larval stage
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Describe the body plan of the tapeworms (class cestoidea)
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polyzoic- multiple body segements (proglottids)
scolex with 4 suckers and hooks to help move through tissue - neck has germinal layers that give rise to new proglottids |
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Describe the proglottid development of tapeworms
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Arise from the germinal tissue of the neck and get older as you move back, new proglottids are immature and lack reproductive organs, protandry (male first) occurs and the mature proglottids are hermaphroditic, they produce eggs galled gravid. the entire string of proglottids is refered to as the strobila
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Describe the scolex of Class Cestoidea (tapeworms) order pseudophyllidea
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the scolex lacks armorment or suckers but they do have groves called bothria
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Describe the proglottid reproductive structures of Class Cestoidea (tapeworms) order pseudophyllidea
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the ovary is located at the base with the uterus moving up to the birth pore, there is a separate vaginal opening that connects to the uterus. Testies are connected to the cirrus pouch via the vas deferens,
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How would you diganose and infection with Cestoidea class Pseudophyllidea
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look for eggs in fecal sample
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Describe the 3 host life cycle of Cestoidea order Pseudophyllidea
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eggs containing an oncosphere are released and ingested by a copepod where they change into a procercoid. The procercoid is ingested by a second intermediate host, usually a fish where it develops into a plerocercoid (there are many paratenic hosts because bigger fish eat the little fish)
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Describe the egg anatomy of Cestoidea Order pseudophyllidea
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The egg has an operculum and a layer of ciliated cells called coracidium the embryo also called an oncosphere or hexacauth has 6 hooks
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Describe the scolex of Cestoidea order Cyclophyllidea
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scolex has 4 suckers and can be armed or unarmed, hooks can be associated with a structure called a rostellum, a point a the anterior of the scolex
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How do the scolexes of the two classes of cestoidea differe?
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Pseudophyllidea-scolex lacks armorment or suckers, has groves called bothria
cyclophyllidea- scolex has 4 suckers can be armed or unarmed, hooks can be associate with rostellum at the anterior of the scolex |
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Describe the proglottid reproductive anatomy of Cestoidea order Cyclophyllidea
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no birth pore, ovary and vittelaria are distinct units at the base of the proglottid, the uterus is a blind sac, the eggs are not release but rather the uterus expands and fills the proglottid until proglottid is shed at maturity, there is a vagina, the testes are scattered around and there is a cirrus
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How does the reproductive anatomy of the two Cestoidean orders differ?
Consider location of uterine anatomy, egg release, location of vittlelaria |
uterine anatomy-Pseudophyllidea uterus is located at the base of the proglottid moving ending in a birth pore, the cyclophyllidea have a blind sac uterus
egg release- pseudophyllidea have a birth pore, cyclophyllidea uterus fills with eggs which are release when proglottid is shed at maturity |
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How to the pseudophyllidea and cyclophyllidea differ in terms of the number of hosts in their life cycles
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pseudophyllidea have a 3 host life cycle (DH, copepod, fish) cyclophyllidea have a 2 host life cycle
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Describe the eggs of Cestoidea order cyclophyllidea
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egg contains oncosphere which does not hatch but rather must be digested
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Describe the caryophyllidea
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the third order of the cestoideans, they are unsegmented and infect bottom feeding fish
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Describe the life cycle of a cyclophyllidea if the egg is injested by a definitive host
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the oncosphere hatches and enters the intestinal villus where it becomes a cysticercoid the cysticercoid re-enters the lumen of the intestine and develops into a mature worm
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Describe the life cycle of a cyclophyllidea if egg is ingested by an invertebrate host
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the oncosphere hatches and penetreates to the coelom or tissues and becomes a cysticercoid, the cysticercoid is ingested by a vertebraet host and develops into a mature worm
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Describe the life cycle of a cylcophyllidea if the egg is ingested by a vertebrate (not definitive) host
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the oncosphere hatches and passes via the blood stream to variuos parts of the body to form cysticercus, coenurus, strobilocercus, or hydatid cyst, a vertegrate ingestes the intermediate host and the tapeworms develop to maturity
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Describe the life cycle of the pseudophyllidea begining with the adult cestode releasing eggs in the intesting
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the eggs hatch in water and the free swiming coracidium is released, the coracidium is ingested by a crustacean and the oncosphere is released, the oncosphere develops itno a procercoid in the body cacity of the 1st intermediate host, a vertebrate feeds on the infected crustacean and the procercoid migrates to various body regions and becomes the plerocercoid, the 2nd intermediate host containing the plerocercoid is ingested by the definitive host (a vertebrate) and the cestode develops to maturity in the intestine
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How is a parasite defined ecologically?
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the parasite establishes a prolonged, close association with the host where the parasite benefits at the expense of the host
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Contrast micro and macroparasites
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micro- viruses, bacteria, protozoa, asexual amplificaiton
macro- metazoans, sexual reproduction, complex life cycles |
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What are the 5 basic rules of parasite ecology
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1. parasties are smaller than their hoss
2. parasites are more primative than their hosts 3. host always act as a habitat 4. as the rate of transmission increases the virulence also increases 5. parasits aggregate (many parasites in few hosts) |
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The third rule of parasitoloty states that hosts always act as a habitat and that all parasites want the same thing in the same order. What are these 4 things?
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1. contact with suceptible host
2. sucessful establishment 3. exploitation of host resources 4. successful reproduction and transmission to the next host |
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Describe the linear relationship between parasites and the species of their environment
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Pasites are related to species stability and configuration of trophic interactions, as stability increase so do parasites
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What species do parasites infect in relationship to trophic interactions
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parasites infect the super generalists
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What is the habitat of Schistosoma haematobium
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Africa and Middle East
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what is the habitat of S. mansoni
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Africa, Middle East, South America (Venezuela, Brazil), Caribbean
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What is the habitat of S. japonicum
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China, Philippines, Indonesia
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What is the habitat of S. intercalatum
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Africa
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Which species of schistosomes cause the majority of human infections
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S. haematobium, S. mansoni, S. japonicum, S. mekongi
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What is the location of infeciton, diease, and snail host of S. haematobium
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location-pelvic veins
disease- urinary schistosomiasis snail host- Bulinus spp. |
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What is the location of infeciton, diease, and snail host of S. mansoni
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location-mesenteric veins
disease- intesntinal (hepatosplenic) schistosomiasis snail host- Biomphalaria spp. |
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What is the location of infeciton, diease, and snail host of S. japonicum, S. mekongi, and S. intercalatum
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location-mesenteric veins
disease- intestinal (hepatosplenic) schistosomiasis snail host- Oncomelania (japonicum) note that diesase and location are similar to S. mansoni |
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Describe the basic schistosome life cycle begining with the egg
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the egg containing the miracidium (infective stage) hatches in freshwater and directly infects the snail intermeidate host, asexual development occurs via sporocysts and cercariae are produced. The cercariae (infective stage) are released into the water and directly infect mammalian host where sexual development occurs and adult worms are present
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What are three unique features of schistosomes?
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1. live in blood vascular system
2. adult worms are dioecious (separately sexed) 3. cercariae directly infect the definitive host (no metacercarial stage) |
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describe the body plan of caryophyllidea
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monozoic (unsegmented) tapeworms
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Descibe the scolex of the caryophyllidea
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suckers or groves
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Describe the life cycle of caryophyllidea
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bottom feeding fish ingests oligochaete worm, adult develops and produces eggs, eggs are ingested by annelid, the oncosphere hatches and moves into the body cavity where it develops into a procercoid with a tail called a cercomer, the procercoid is ingested by the fish where it becomes a sexually mature plerocercoid
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What structure can be used to differentiate between the procercoid and plerocercoid of caryophyllidea
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the cercomer (the tail on the procercoid)
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What is unique about C. archigetes
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The procercoid can become sexually mature as a larval stage, "neoteny" within an invertebrate host
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Diphyllobothrium latum is also known as
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the human fish tapeworm
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Describe the life cycle of Diphyllobothrium latum
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tape worm lives in gut of human or reservior host, eggs released from birth pore, need to get to water, ingested by copepod and penetrate through gut into body cavity, develop into procercoid, small fish feeds on copepod, development into plerocercoid, big fish eats little fish (paratenic hosts)
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What fish is Diphyllobothrium common in
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pike
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Describe the pathology associated with Diphyllobothrium latum infection
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usually benign but intestinal blockage can oocur, parasite can outcompete host for vitamin B12 leading to pernicious anemia (no longer common because of fortified foods), infection was common in Scandinavinas (lutefisk consumption) and Jews (gafiltafish), treat infection with praziquatel but resistance is upcoming, can treat by removing parasite
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What life cycle stage is difficult to differentiate to a particular species?
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Plerocercoids, plerocercoid infections in humans are refered to as sparganum infections, molecular markers can be used to pin down the species
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How can D. latum infection occur?
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infection can occur by drinking water that has copepods that have procercoids which move to subcutaneous tissue and develop into the plerocercoid
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What is the general term for infection with a pseudophyllidean?
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sparanosis
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How can a D. latum infection become serious?
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if the plerocercoids start to multiply
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What cultural practices can be associated with D. latum infection
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eating raw snake, poltising (using raw frogs to treat inflamation of the eye, vagina, etc)
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What is the most important order of tapeworms
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Cyclophyllidea, the larval stage is pathogenic, 14 distinct families
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Descrive the Taenia genus of the tape worm order Cyclophyllidea
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large and robust
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Descrive Taenia saginata (tapeworm order CYclophyllidea)
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aka Human Beef Tapeworm, can be found anywhere (not just tropics) with a breakdown in sanitation, humans are the one and only definitive host
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Describe the distinct morphology of Taenia saginata
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the body can grow to 30ft or more at maturity, the scolex is unarmed, there are 4 suckers and no spines, the gravid proglottid has 15-35 lateral branches of the uterus (per side)
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T/F Cyclophyllidea genus Taenia can be differentiated based on their eggs
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false, they all loot the same
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Describe the life cycle of Taenia saginata
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Egg exits the human via the feces, the gravid proglottid contains eggs with contain the oncosphere, the eggs/ oncoshpere are ingested by cattle and hatch, they move into the intestine and the oncosphere goes throug hthe venules and is swept away in the resipratory system to muscles, in the muscle they develop as cysticerci (bladder worm), a human can become infected by ingesting a bladder worm from infected beef
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What stage of T. saginata occus in bovine muscle
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cysticerci (cysticercus)
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What is the cause of measly beef at beef inspection
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infection with tania saginata
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What is another term for Taenia saginata
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Cysticercosis bovis
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Why was infection with T. saginata common in older days
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cattle herders would defecate in their fields and the cows selectively ate the human feces
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What are the symptoms of infection with Taenia saginata
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"Verminous intoxication" general ill feeing, upset stomach from waste products of parasite, rare intestinal blockage, loss of appetite
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How can T. saginata infection be treated?
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quaziquantel, must kill the scolex!
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How can infection with T. saginata be treated
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find gravid proglottids in the feces, if you get eggs you can Dx taenia but you can't narrow down the species
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Describe Taenia solium
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aka Human pork Tapeworm, the only definitive host is human, infection occurs by ingesting undercooked pork, human can also funciton as intermediate host (problem)
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Describe the morphology of Taenia solium
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armed scolex with a rostellum, two rows of hooks, 4 suckers, 7-14 lateral branches of the uterus, not as big as saginata
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Describe the life cyel of T. solium
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adult in humans, GP releasedin feces, ingested by pigs, cysticerci get into gut then veins then muscle, results in bladder worms
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How can infection with T. solium become pathogenic
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oncosphere can go through intestine and get into veins, it can be swept into eye, brain or spinal cord, neuronal cysticercosis can occur- swiss cheese brain
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How can infection with T. solium be treated
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adult stage can be treated with praziquantel butcysticerci are hard to treat in musle and brain
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describe Taenia pisiformis
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dog tapeworm, large proglottid that can be seen in feces, creamy and white
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What is the larval stage of T. pisiformis
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cysticercus
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What is the intermediate host of T. pisiformis
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rabbits (cysticercus in mesenteary viscera)
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Describe T. taeniiformis
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cat tapeworm
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What is the intermediate host of T. taeniiformis
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rats (strobilocercus) T. taeniiformis is the only tape worm with a strobilocercus larval stage
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describe Dipulidium caninum
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"dobule pored tapeworm of dogs", two complete sets of reproductive systems per proglotid, cucumber shapped proglottid
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What is the intermediate host of dipulidium caninum
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flea (ctenocephalides)
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What is the larval stage of D. caninum
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cysticercoid (because the intermediate host is the flea which is an invertebrate)
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Describe the lifecycle of D. caninum
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the adult flea lays eggs off of its host. The larval stage of the flea picks up the tapeworm. The dog gets infected by eating the flea. Children can also get infected by "mouthing" a dog
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Describe T. multiceps
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a parasite of canines bu tyhey are not affected. Sheep are the IH and they get "gid" or staggers when they are infected. Humans can get infected with eggs, pathogenic in nervous tissue.
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describe Hymenolepis nana
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the dwarf tapeworm of humans, another DH is mice. very small but very heavy infection. Leads to intestinal discomfortn and mild pathology , auto infection can lead to heavy infection
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Describe the lifecycle of H. nana
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Humans or mice ingest the eggs which hatch in the intestine and release the oncosphere. In the villi the oncosphere develops into a cysticercoid which breaks into the gut lumen.
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Describe Hymenolepis diminuta
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Often studied in the lab, IH is the beetle, DH is the rat, the cysticercoids from the beetle can get into grain products ingested by humans, about 90 species of beetles can support cysticercoids
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Describe Echinococcus granulosus
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small tape worm, DH is a carnovore but not humans, IH is an herbivore
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Describe the lifecycle of Echinococcus granulosus
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Dogs have the adults that lay eggs, eggs in the feces get into the soil and plants which are ingested by herbicore. The egg hatches and the oncosphere burrows into the gut and moves into capillaries to liver then lungs, develops into a bladder worm . A laminate layer with an inner germinal layer develops which gives rise to proscoleces (unilocular hydatid) and internal daughter cysts with little protoscoleces. The dog ingests the hydatid by eating infected sheep
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What is hydatid sand
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the fluid in the hydatid cyst that has a grainy texture because of all the protoscoleces
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T/F you can diagnosis E. granulosus infection based on the eggs
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false the eggs cannot be differntiated similar to taenia
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Describe the epidemiology of E. granulosus
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common in trappers because of skinning (slyvatic cycle), domestic cycle with use of dog feces in tanning solution, consumption of dog intestines
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Describe the pathology of E. granulosus
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highly dependent on location, breaking of cyst in body vacity can lead to anaphylatic shock, cystic echinococcosis, hydatid disease, hydatidosis
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How can E. granulosus be treated
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surgical removal of the cyst but must avoid rupture (fill with formalin first)
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how can E. granulosus be diagnosed
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some immunodiagnostic techniques but not great, can cross react with other taenia, best Dx is by ultrasound or MRI
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Describe E. multilocularis
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restriced to boreal regions, DH is red fox, cats (can be dogs or coyotes also) IH is rodents like voles
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Describe the life cycle of E. multilocularis
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same as E. granulosus, the carnivore has eggs which are ingested by the herbivore
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How is the multilocular cyst different than the unilocular
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lacks the laminate layer, continues to grow and infiltrate the tissue
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what disease is caused by E. multilocularis
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alveolar echinococcosis, alvealor hydatid disease, in humans the cysts infiltrates to the lungs and liver, similar to cancerous growth
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