Lesson 3 - Trematodes

Question 1

Oriental fluke; Blood flukes.

Reside in the mesentric and portal veins.

Adult schistosomes exist as separate sexes (others are hermaphrodites)

Can cause schistosomiasis (aka bilharzias, bilharziasis, or snail fever).

Answer 1

Schistosoma japonicum / S. mansoni / S. haematobium

Question 2

Snail: Oncomelania hupensis quadrasi

Answer 2

Schistosoma japonicum

Question 3

Affects veins of small intestine, liver

Answer 3

Schistosoma japonicum

Question 4

Diagnostic feature of eggs: Small lateral spine (‘knob’)

Answer 4

Schistosoma japonicum

Question 5

Snail: Biomphlaria glabrata

Answer 5

S. mansoni

Question 6

Affects veins of colon

Answer 6

S. mansoni

Question 7

Diagnostic feature of eggs: Large, prominent lateral spine

Answer 7

S. mansoni

Question 8

Snail: Bulinus truncatus

Answer 8

S. haematobium

Question 9

Affects veins of Urinary Bladder

Answer 9

S. haematobium

Question 10

Chronic Schistosomiasis:
Painless hematuria and fibrosis of the bladder. Hydronephrosis. Associated with squamous cell carcinoma of the bladder.

Answer 10

S. haematobium

Question 11

Diagnostic feature of eggs: large terminal spine

Answer 11

S. haematobium

Question 12

Intestinal Schistosomiasis

Acute schistosomiasis:
- Cercarial dermatitis (swimmer’s itch)
- Katayama fever

Answer 12

Schistosoma japonicum / S. mansoni / S. haematobium

Question 13

Chronic Schistosomiasis:
- Pseudopolyps in colon
- Liver granulomas leading to presinusoidal obstruction, hepatomegaly, and portal hypertension.
- Gastrointestinal hemorrhage, massive splenomegaly

Answer 13

Schistosoma japonicum / S. mansoni

Question 14

Liver UTZ: clay pipestem fibrosis with lacelike pattern.
MCC of death: exsanguination from ruptured esophageal varices.

Answer 14

Schistosoma japonicum / S. mansoni

Question 15

Diagnostic Test:
- Fecalsys (kato-katz)
- Circumoval precipitin test (COPT)
- Rectal imprint

Answer 15

Schistosoma japonicum / S. mansoni / S. haematobium

Question 16

Adult flukes living in mesentric or bladder veins la eggs that cause granulomas

Answer 16

Schistosoma japonicum / S. mansoni / S. haematobium

Question 17

Japanese Lung fluke, Hermaphrodite

Answer 17

Paragonimus westermani

Question 18

Snail: Antemelania asperata
Mountain crab: Sundathelphusa philippina

Answer 18

Paragonimus westermani

Question 19

Infective stage - Larvae (metacercariae)

Transmitted by ingestion of raw crabmeat/crayfish

Answer 19

Paragonimus westermani

Question 20

Affects the Lungs. Adult flukes live in the lungs.

Answer 20

Paragonimus westermani

Question 21

Paragonimiasis

Within the lung, the worm exists in a fibrous capsule communicating with a bronchiole - granulomatous reaction. Secondary bacterial infection frequently occurs.

Answer 21

Paragonimus westermani

Question 22

Main symptom: chronic cough with blood sputum

CXR: ring shadow opacity

Closely resembles tuberculosis

Answer 22

Paragonimus westermani

Question 23

Diagnostic test: 3% NaOH preparation

Answer 23

Paragonimus westermani

Question 24

Diagnostic feature of eggs: Operculated / unembryonated egg in sputum or feces

Answer 24

Paragonimus westermani

Question 25

Chinese Liver fluke / Oriental liver fluke, Hermaphrodite

Answer 25

Clonorchis sinensis

Question 26

Snail: Parafossarulus Fish: Cyprinidae

Answer 26

Clonorchis sinensis

Question 27

Infective stage: Larvae (metacercariae) Transmitted by ingestion of undercooked fish.

Answer 27

Clonorchis sinensis

Question 28

Affects the Liver, especially the common bile duct. Adult flukes live in the liver.

Answer 28

Clonorchis sinensis

Question 29

Inflammatory response can cause hyperplasia and fibrosis of the biliary tract.

Answer 29

Clonorchis sinensis

Question 30

Acute disease: - Fever, eosinophilia, lymphadenopathy, tender hepatomegaly. Chronic disease: - Hepatobiliary disease - Pancreatitis - Cholangiocarcinoma (Klatskin tumor) - Neurocirculatory dystonia

Answer 30

Clonorchis sinensis

Question 31

Diagnostic Test: - Direct fecal smear - Potassium permanganate stain (showing melon-like ridges with abopercular protuberance)

Answer 31

Clonorchis sinensis

Question 32

Treatment of Choice: PRAZIQUANTEL

Answer 32

Schistosoma japonicum, S. mansoni, S. haematobium, Paragonimus westermani, Clonorchis sinensis

Question 33

Sheep liver fluke - Humans are infected by eating watercress (or other aquatic plants) - Symptoms are due primarily to the presence of the adult worm in the biliary tract.

Answer 33

Fasciola hepatica

Question 34

In early infection, RUQ pain, fever, and hepatomegaly can occur but most infections are asymptomatic. Months or years later, obstructive jaundice can occur. Halzuon is a painful pharyngitis caused by the presence of adult flukes on the posterior pharyngeal wall.

Answer 34

Fasciola hepatica

Question 35

Drug of choice is TRICLABENDAZOLE

Answer 35

Fasciola hepatica

Question 36

Giant Intestinal fluke Intestinal parasites of humans and pigs that is endemic to Asia and India. Humans are infected by eating aquatic vegetation that carries the cysts. Pathologic findings are due to damage of the intestinal mucosa by the adult fluke.

Answer 36

Fasciola buski

Question 37

Most infections are asymptomatic, but ulceration, abscess, formation, and hemorrhage can occur. Worm intoxication: anasarca and coma resulting from accumulation of toxins.

Answer 37

Fasciolopsis buski

Question 38

Intestinal parasite of people living in Africa, the Middle East, and Asia, who are infected by eating raw fish containing cysts. Pathologic findings are due to inflammation of the intestinal epithelium as a result of the presence of the adult flukes.

Answer 38

Heterophyes heterophyes

Question 39

Mimics peptic ulcer disease.

Answer 39

Heterophyes heterophyes

Question 40

PRAZIQUANTEL is the treatment of choice.

Answer 40

Fasciolopsis buski / Heterophyes heterophyes