Parasitology Helinthes

Question 1

What are platyhelminths? What are trematodes? What are cestodes ?

Answer 1

Platyhelminths - flatworms

Trematodes - flukes

Cestodes - tapeworms

Question 2

What is schistosomiasis? What are the 3 species that cause it?

Answer 2

Neglected Tropical Diseases , Parasitic disease

Schistosoma mansoni
S. haematobium
S. japonicum

Question 3

What causes swimmer’s itch? What vector is it?

Answer 3

cerarial dermatitis

water transmits, from birds and mammals

Question 4

What is the life cycle of Schistosomiasis?

Answer 4

Eggs in urine/feces > hatch and infect snails > release CERCARIAE (fluke) > penetrate swimmer’s skin and become SCHISTOMULAE > liver and mature into adult worms > pass in feces/urine or get stuck in organs (GRANULOMA)

Question 5

Adult Schistosomiasis in veins draining to large intestine are what?

Veins draining to small intestine?

Veins of bladder/rectum?

Answer 5

Large intestine -> s. mansoni

small intestine -> s. japonicum

bladder/rectum -> s. haematobium

Question 6

What are the infective/diagnosis stage of Schistosomiasis?

Answer 6

Infective stage- > ceracariae (the fluke)

Diagnosis -> eggs

Question 7

What are the symptoms of an acute infection of schistosomiasis? What about after 1-2 months?

Answer 7

Rash/itchy skin within a few days

1-2 months worms become lodged in intestines/bladder causing inflammation
Fever, cough, chips, muscle aches -> Katayama fever

Question 8

What are the symptoms of a chronic schistomiasis infection?

Answer 8

Blood in stool/urine, enlarged liver, diarrhea, bladder stones -> fibrotic damage

Children -> anemia, malnutrition, learning difficulties

S. HAEMATOBIUM -> Cancer

Brain/spinal cord -> seizures, paralysis, spinal cord inflammation

Question 9

To diagnose light infections of Schistosomiasis, what is used?

Answer 9

Serologic tests

Question 10

What is the clinical presentation of cerarial dermatitis? Treatment?

Answer 10

Tingling,burning, itching w/ red pimples after swimming (1 week)

Treat w/ antihistamines + topical corticosteroids

Question 11

What are scolex? What is the significance of segmented body? What is each segment called and where are the segments produced?

Answer 11

scolex -anteria end bearing suckers and hooks

Segmented body absorb nutrients thru skin

Proglottid is segments w/ separate GI/reproductive tract -> segments produced by neckpiece

Question 12

Segments of cestodes at the end only contain what? What are they called

Answer 12

At end, only reproductive tract left (Gravid proglottids)

Sack of eggs separates and carries tapeworm eggs out of host

Question 13

Name the tapeworm
Pork
Beef
Fish
Dwarf 
Hydatid

Answer 13

Pork - taenia solium
Beef- taenia saginata
Fish - diphyllobothrium latum
Dwarf- hymenolepis nana
Hyatid- echinococcus granulosus

Question 14

What is the life cycle of taeniasis?

Answer 14

Cattle/pigs consume gravid proglottis > eggs form cysticerci (fluid + larva) > humans ingest cyst( CYSTICERCUS) > larvae attached by SCOLEX suckers to small intestine > PROGLOTTIDS > GRAVID PROGLOTTIDS pass

Question 15

What is infective/diagnosis stage of taeniasis?

Answer 15

Infective -> cysticerci in muscle

Diagnosis ->eggs, gravid proglottids

Question 16

What are the clinical symptoms of taeniasis?

Answer 16

Usually no symptoms (carriers)
Abdominal discomfort

Pork tapeworms -> CYSTICERCOIDS-> move out of intestines and damage tissues

Question 17

What is neurocysticercosis?

Answer 17

taeniasis infect brain, seizures, MAIN CAUSE OF ACQUIRED epilepsy in developing countries

Question 18

What is the largest tapeworm infestation? What species does it come from?

Answer 18

Diphyllobathrium latum (fish tapeworm)
Salmon, trout, lightly salted, smoked, pickled fish

Question 19

What is the life cycle of diphyllobothrium?

Answer 19

Eggs into water from feces >hatch into CORACIDIA into LARVAE into fish flesh > trout feed on small fish > into predator fish musculature human eat undercooked fish > larvae into adult tapeworm in small intestine > intestinal mucosa > proglottids filled w/ eggs into feces

Question 20

What is the infective/diagnosis phase of diphyllobothrium?

Answer 20

Infective -> larvae

Diagnositic -> eggs in stool

Question 21

What is clinical presentation of diphylobothrium?

Answer 21

Asymptomatic

Intestinal obstruction and gallbladder disease bc proglottids migrate

Question 22

What is the life cycle of hymenolepiasis?

Answer 22

Similar to teanea except eggs ingested by arthropods (fleas beetles) and develop into cysticercoids >adult tapeworm matures in intestine > segments break off into stool >auto infection ?

Eating beetle/mealworm in food

Question 23

What size do dwarf tapeworms grow to?

Answer 23

2 cm, very small in comparison to other tapeworms

Question 24

What are the clinical symptoms of hymenolepiasis?

Answer 24

Asymptomatic, often misdiagnosed as pinworm

Headache, itchy bottom, difficult sleeping

Question 25

What is echinococcosis?

Answer 25

echinocactus granulosus -> tiny tapeworm in dog (DEFINITIVE host, sheep, cattle, goats intermediate hosts)

Question 26

What is the life cycle of echinococcosis?

Answer 26

Adult worms in dog( DEF. host) > grave proglottids release eggs into stool > sheep/goats/cattle (intermediate hosts) ingest eggs> eggs hatch into LARVAE w/ scolex that penetrate intestinal wall> migrates thru circulatory system into liver/lungs> HYDATID (fluid cysts w/ larvae)

Question 27

What is the clinical presentation of echinococcosis?

Answer 27

Cystic Echinoccosis - hydatid disease
Hydatid cysts - liver, lung organs

Cyst rupture, trauma -> anaphylactic reactions

Surgical removal leads to complete cure