Flatworms

Question 1

This flatworm - trematode is found in southeast asia and india; ingestion of encysted larval form by husking water chestnuts with one’s teeth. It is ID’d by large golden, bile-stained operculated eggs in fecal smears.

Answer 1

Fasciolospis buski - Giant intestinal fluke

Question 2

What disease does Fasciolospis buski cause?

Answer 2

resembles giardiasis (malabsorption syndrome)

Question 3

This flatworm - trematode is found in sheep-raising areas; ingestion of vegetation growing in fecally contaminated water leads to infection; flukes invade liver and release operculated eggs via the bile duct; It is ID’d by large golden, bile-stained operculated eggs in fecal smears.

Answer 3

Fasciola hepatica - sheep liver fluke

Question 4

What disease does Fasciola hepatica - sheep liver fluke cause?

Answer 4

hepatitis and cirrhosis

Question 5

This flatworm - trematode is frequent in Asian immigrants; reservoirs = dogs, fish-eating mammals, cats; ingestion of raw or improperly processed fresh-water fish containing viable metacercaria -> infection; snails eat eggs -> hatch to yield free swimming form -> attaches to fresh water fish -> encystation in muscle. It is ID’d by shouldered, operculated eggs with a small knob at the apopercular end

Answer 5

Opisthorchis sinesis - Chinese liver fluke

Question 6

What disease does Opisthorchis sinesis - chinese liver fluke cause?

Answer 6

asymptomatic mild hepatitis

sever cases: biliary obstruction and adenocarcinoma

Question 7

This organisms is found in mostly tropical countries; ingestion of improperly cooked crabs and crayfish, or infected flesh of shore-feeding animals -> infection; eggs are produced in the lung and leave the body via rusty sputum and feces.

Answer 7

Paragonimus westermani

Question 8

What disease does Paragonimus westermani cause?

Answer 8

paragonimiasis - inflammatory disease of the lung, liver, or CNS

Question 9

These flatworms are obligate intracellular parasites, two sexes, non-operculated eggs; confined to tropical areas; penetration of human skin by free-swimming cercaria -> infection; flukes develop in the hepatic portal, the bladder, or other well-vascularized tissues; 1000 eggs/day are made in the blood; tissue destruction allows non-operculated eggs to enter feces or urine and be eliminated -> hatch in water->free swimming form infects snails -> cercaria are released.

Answer 9

Schistosomes (S. mansoni, S. japoncium - oriental, S. haematobium - bladder)

Question 10

How are schistosomes ID’d?

Answer 10

non-operculated eggs with a sharp lateral spine (mansoni) or with a small spine (japonicum), or urine samples with a sharp terminal spine (haematobium)

Question 11

What diseases do Schistosomes cause?

Answer 11

1. Schistosomiasis - cercarial itch in the skin and a severe inflammatory reaction with granuloma formation in the liver, spleen, intestine, lung, bladder, or CNS
2. Katayama Syndrome - severe life-threatening disease: fever, chills, cough associated with egg-laying

Question 12

This Flatworm - chested is found in countries with poor sanitation; ingestion of undercooked pork containing “bladder worm” larvae -> infection; non-operculated eggs are passed in the feces; humans are the only definitive host. It is ID’d by proglottids in the feces; calcified cysticerci pockets are identified with x-rays, CT. IT IS THE MOST COMMON CAUSE OF CNS PARASITIC DISEASE.

Answer 12

Taenia solium - pork tapeworm

Question 13

What disease does Tania solium cause?

Answer 13

Asymptomatic to mild diarrhea
Cysticercosis - ingestion of eggs or proglottids from fecally contaminated water; eggs hatch and invade tissue - severe inflammatory reaction in heart, muscle, brain, and eyes

Question 14

This flatworm - cestode is found worldwide; one of the most common cestode infections in the US; transmission similar to T. solium except it involves beef instead of pork.

Answer 14

Taenia saginata - beef tapeworm

Question 15

This flatworm - cestode is found worldwide; cool-lake regions; ingestion of poorly-cooked or pickled fish containing a ribbon-like larval worm (sparganum) -> infection; storable can be up to 10m long; produces fluke-like operculated eggs. It’s ID’d by fecal smears with thin-walled operculated eggs with an apopercular knob

Answer 15

Diphyllo-bothrium latum - fish tapeworm

Question 16

What diseases does Diphyllo-bothrium latum - fish tapeworm cause?

Answer 16

1. pernicious anemia
2. sparganosis - when humans drink pond water or eat raw frogs -> ingestion of a sparganum form of chested closely related to D. latum - invades tissues (esp eyes) - painful inflammation

Question 17

These flatworms - cestodes are found worldwide; ingestion of tapeworm eggs passed in canine or feline feces -> infection, cyst formation, and tissue damage. It’s ID’d by clinical and radiographic picture and the Casoni test - intradermal injection of hydatid fluid -> immediate inflammatory reaction

Answer 17

Echinococcus (E. granulosis - sheep areas, E. multilocularis - rural areas with mice)

Question 18

What disease does Echinoccus cause?

Answer 18

Echinococcosis - organ destruction due to growing cysts and severe inflammatory reaction when the cysts split open and release contents

Question 19

This flatworm - cestode is found worldwide; MOST COMMON TAPEWORM INFECTION IN US; ingestion of eggs from mouse, cat, or human feces, or bugs in flour or cereal -> infection. It’s ID’d by fecal smears with embyronated eggs

Answer 19

Hymenolopsis nana

Question 20

What disease does Hymenolopsis nana cause?

Answer 20

diarrheal symptoms

Question 21

This flatworm - cestode is found worldwide, especially in kids; ingestion of fleas (crushed, found on dogs tongue) which possess larval from having eaten tapeworm eggs present about the dog’s anus -> infection. It is ID’d by fecal smear with large egg packets containing 8-15 eggs.

Answer 21

Diphylidium caninum - pumpkin seed tapeworm

Question 22

What disease does Diphylidium caninum - pumpkin seed tapeworm cause?

Answer 22

mild diarrhea

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