TREMATODES (DIOECIOUS FLUKES)

Question 1

• Oriental blood fluke

Answer 1

Schistosoma japonicum

Question 2

• Visceral blood fluke

Answer 2

Schistosoma japonicum

Question 3

• Vesical blood fluke

Answer 3

Schistosoma haematobium

Question 4

• Bladder fluke

Answer 4

Schistosoma haematobium

Question 5

Manson’s blood fluke

Answer 5

Schistosoma mansoni

Question 6

Superior mesenteric veins

Answer 6

Schistosoma japonicum

Question 7

Veins of the urinary bladder

Answer 7

Schistosoma haematobium

Question 8

Inferior mesenteric veins

Answer 8

Schistosoma mansoni

Question 9

China, Japan, Indonesia, Thailand, Cambodia, Philippines

Answer 9

Schistosoma japonicum

Question 10

Intermediate hosts: Snails
- Oncomelania quadrasi (Philippines)
- Oncomelania nocophara (Japan)
- Oncomelania formosana (Taiwan)

Answer 10

Schistosoma japonicum

Question 11

Intermediate hosts: Snails
- Biomphalaria (Africa)
- Bulimus (Middle east)

Answer 11

Schistosoma haematobium

Question 12

Intermediate hosts:
- Biomphalaria (Africa)
- Tropicorbis (South America)
- Austrolarbis

Answer 12

Schistosoma mansoni

Question 13

Ova/Eggs ➢ Measuring about 50-85 um by 38-60 um;

Answer 13

Schistosoma japonicum

Question 14

Ova/Eggs ➢ Oval to sub-spherical with minute lateral spines/knob

Answer 14

Schistosoma japonicum

Question 15

✓ Females ➢ More delicate than males

Answer 15

Schistosoma japonicum

Question 16

✓ Females ➢ Longer and slender

Answer 16

Schistosoma japonicum

Question 17

✓ Females ➢ With pyramid ovary located at the center of the body (containing 50-100 eggs)

Answer 17

Schistosoma japonicum

Question 18

✓ Males ➢ shorter but sturdier; measuring about 12-20 mm by 0.4-0.5 mm

Answer 18

Schistosoma japonicum

Question 19

✓ Males ➢ with 7 ovoidal testes arranged in single row behind acetabulum

Answer 19

Schistosoma japonicum

Question 20

✓ Males ➢ union of ceca and testes is posterior to the middle half of the body

Answer 20

Schistosoma japonicum

Question 21

Ova/Eggs ➢ Ellipsoidal with prominent terminal spines measuring about 110-170 um by 38-70 um

Answer 21

Schistosoma haematobium

Question 22

Adult ➢ The ovary is located at the posterior to middle of the body containing 20-30 eggs

Answer 22

Schistosoma haematobium

Question 23

Ova/Eggs ➢ Ellipsoidal with prominent lateral spines

Answer 23

Schistosoma mansoni

Question 24

Ova/Eggs ➢ Measures 112-182 um by 40-75 um

Answer 24

Schistosoma mansoni

Question 25

Ova/Eggs ➢ Appear in the feces 30-40 days after infection

Answer 25

Schistosoma mansoni

Question 26

✓ Females➢ Considered as the smallest schistosome

Answer 26

Schistosoma mansoni

Question 27

✓ Females ➢ Ovary is at the anterior to the middle half of the body containing 1-4 eggs

Answer 27

Schistosoma mansoni

Question 28

✓ Males ➢ Union of ceca is at the middle half of the body containing 8-9 testes

Answer 28

Schistosoma mansoni

Question 29

- Katayama disease

Answer 29

Schistosoma japonicum

Question 30

- Oriental schistosomiasis/Visceral schistosomiasis

Answer 30

Schistosoma japonicum

Question 31

- Vesical/Urinary schistosomiasis

Answer 31

Schistosoma haematobium

Question 32

- Schistosoma hematuria

Answer 32

Schistosoma haematobium

Question 33

- Intestinal Bilharziasis

Answer 33

Schistosoma mansoni

Question 34

- Schistosomal dysentery

Answer 34

Schistosoma mansoni

Question 35

There are three (3) progressive stages in the pathologic processes of Schistosomiasis:

Answer 35

1. Pre-patent/Developmental stage 2. Acute stage 3. Chronic stage

Question 36

➢ Starts from the penetration of the skin to the arrival of the mature worm to the venules of the intestines or urinary bladder where female adults are ready to oviposit

Answer 36

1. Pre-patent/Developmental stage

Question 37

✓ Negligible to mild cutaneous lesions at the side of cervical entry

Answer 37

1. Pre-patent/Developmental stage

Question 38

✓ Tissue reactions to the immature worms inside and outside the blood vessels

Answer 38

1. Pre-patent/Developmental stage

Question 39

✓ Some associated toxic and allergic reactions

Answer 39

1. Pre-patent/Developmental stage

Question 40

:➢ There is active egg deposition and extrusion

Answer 40

2. Acute stage

Question 41

➢ Symptoms include: Loss of weight and relapse of pain

Answer 41

2. Acute stage

Question 42

➢ Stable egg output and tissue proliferation

Answer 42

3. Chronic stage

Question 43

➢ Invasion of the tissues by the migrating larva

Answer 43

3. Chronic stage

Question 44

✓ Petechial hemorrhage

Answer 44

3. Chronic stage

Question 45

✓ Small foci of eosinophilic and neutrophilic infiltration in the lungs with cough and hemoptysis

Answer 45

3. Chronic stage

Question 46

✓ Acute inflammation reactions in the liver with fever and urticaria

Answer 46

3. Chronic stage

Question 47

1. Demonstration of eggs in stool sample is diagnostic of Schistosomiasis

Question 48

2. Concentration techniques – useful in chronic and light infections

Question 49

3. Liver biopsy/Proctoscopic aspiration

Question 50

➢ Demonstration of eggs in feces

Answer 50

4. Diagnosis of S. japonicum and S. mansoni

Question 51

➢ Rectal biopsy

Answer 51

4. Diagnosis of S. japonicum and S. mansoni

Question 52

➢ Demonstration of eggs in urine or recovery of eggs through bladder biopsy

Answer 52

5. Diagnosis of Urinary schistosomiasis

Question 53

➢ Accompanied with dysuria and hematuria

Answer 53

5. Diagnosis of Urinary schistosomiasis

Question 54

6. Immunodiagnostic Tests:

Answer 54

a. COPT (Circumoval Precipitin Test) b. ELISA – highly sensitive test

Question 55

➢ Principle: it is based on patient serum precipitation with lyophilized eggs identified under microscope

Question 56

➢ Uses lyophilized eggs to detect antibodies in patient serum

Question 57

➢ Gold standard test for diagnosis of Schistosomiasis

Question 58

➢ Method of choice and is routinely used in the Philippines as diagnostic test for schistosomiasis

Question 59

➢ DISADVANTAGE: Cross-reactivity with other helminths (affects specificity)

Question 60

➢ Procedure: a. One drop (?) of the suspension containing larvae, eggs, or immature adults are put into the well of a slide and 3 drops (?) of serum is added b. A [?] is placed over the well c. Incubated at [?] d. After incubation, the slide is examined under the [?] e. Positive result: appearance of [?] attached to the worms or eggs

Answer 60

0.025 mL; 0.075 mL cover slip 34°C for 24 hours microscope precipitates/bleb formation

Question 61

Prevention and Control

Answer 61

✓ Snail control ✓ Sanitary disposal of human excreta ✓ Treatment of infected individual

Question 62

Treatment

Answer 62

✓ Praziquantel ✓ Oxamniquine ✓ Metrifonate ✓ Niridazole

Question 63

The schistosomes of man are similar in their basic [?]and in their pathologic effects on mammalian host tissues, yet they differ in [?] of the adults, the [?] of their eggs and larvae, in the groups of snails that they utilize as an [?], and in [?].

Answer 63

life cycles morphology shape intermediate host host susceptibility

Question 64

The most significant species of Schistosoma that causes disease to humans are

Answer 64

S. japonicum, S. mansoni, and S. haematobium