BLOOD FLUKES

Question 1

Species which inhabit the portal
bloodstream of vertebrates

Answer 1

(Blood Flukes)

Question 2

Oriental blood fluke

Answer 2

Schistosoma japonicum

Question 3

Visceral blood fluke

Answer 3

Schistosoma haematobium:

Question 4

Manson’s blood fluke

Answer 4

Schistosoma mansoni:

Question 5

___________ are dioecous (individuals of
separate sexes)

Answer 5

Schistosoma spp.

Question 6

___________is more frequently found in the
________________draining the
small intestine

Answer 6

S. japonicum
SUPERIOR MESENTERIC VEINS

Question 7

_____________occurs more often in the _________________ draining the large
intestine

Answer 7

S. Mansinoni
INFERIOR
MESENTERIC VEINS

Question 8

_______________most often inhabits in the
____________, but it can also be found in the
RECTAL VENULES

Answer 8

S. haematobium
VESICULAR AND PELVIC VENOUS PLEXUS OF
THE BLADDER

Question 9

______________also inhabit
the INFERIOR MESENTERIC PLEXUS but lower
in the bowel than S. mansoni.

Answer 9

S. intercalatum and S. guineensis

Question 10

The eggs are moved progressively toward the
lumen of the intestine
and of the bladder
and ureters (__________), and are
eliminated with feces or urine, respectively.

Answer 10

(S. mansoni,
S.japonicum,
S. mekongi,
S. intercalatum/guineensis)

S. haematobium

Question 11

Parasitizes portal vein
and its branches

Answer 11

Schistosoma japonicum

Question 12

Each female fluke
deposits _______
immature eggs/day

Answer 12

500-2000

Question 12

Each female fluke
deposits _______
immature eggs/day

Answer 12

500-2000

Question 13

Adult worms are 10 to 20 mm long

schistosomes have separate sexes

the male has a canal in which the slender worms enter

Answer 13

Schistosoma Japonicum

Question 14

Males have a
gynecophoral canal
which receives the
female during
copulation

Answer 14

Schistosoma
japonicum in
eternal copula

Question 15

Ova

Ovoidal, rounded or
pear-shaped
 Thin shell
 Pale yellow
 Curved hook / spine
or lateral knob
 Laid in the
multicellular stage
and embryonate
within _________

Answer 15

Schistosoma japonicum
10-12 days

Question 16

Hatches from the egg in
slightly alkaline clean
water with a temp.
between __________
 Free swimming ciliated
embryo liberated from
the egg
 Phototactic
 Infect snails

Answer 16

Miracidium
Schistosome Miracidium
25 0C to 310C

Question 17

______________
develop from miracidium within
the snail

Answer 17

Mother
sporocysts

Question 18

___________ develops from
mother sporocyst

Answer 18

Daughter
sporocyst

Question 19

___________ develop from daughter
sporocyst

Answer 19

Cercariae

Question 20

Emerges from
daughter sporocysts
 Escapes from the snail
 Has a body and a
bifurcate tail
 Infects man by skin
penetration

Answer 20

Cercaria

Question 21

Develops from cercaria after skin
penetration
 Adapted to survive in serum or
physiologic saline at _______
 Enter the pleural cavity—diaphragm—
peritoneal space—penetrate the liver to
reach the intrahepatic portions of the
portal vein

Answer 21

Schistosomulae
37 0C

Question 22

______nside the
gynecophoral canal
of male

Answer 22

female

Question 23

▪ Ova
With Lateral spine

Answer 23

Schistosoma mansoni

Question 24

terminal spine Eliminated with urine

Answer 24

Schistosoma haematobium

Question 25

___________is one of the symptoms of schistosomiasis

Answer 25

Distended belly

Question 26

-a pruritic papular
rash that develops 24
hrs after exposure)

Answer 26

Cercarial
Dermatitis/
Swimmer’s Itch -
local cutaneous
hypersensitivity

Evasive Stage

Question 27

-cough, fever,
asthma-like
symptoms and
may have
lymphadenopathy ,
hepatic, and splenic
enlargement due to
the migration of the
worms through the
circulation (occurs 5-
10 weeks after
infection)

Answer 27

Katayama fever -
systemic
hypersensitivity

Acute Stage

Question 28

Gastrointestinal
involvement in which
more and more eggs
enter the portal
circulation, resulting
to enlargement of
the liver, spleen,
anemia, ascites,
sometimes CNS
involvement

Answer 28

Chronic Stage

Question 29

Sensitive for moderate and heavy infections
 Not adequate for light infections (less than 10
eggs/gram of stool)

Answer 29

Merthiolate-Iodine Formalin Concentration
Technique (MIFC)

Question 30

For enumeration of eggs
 Most commonly used for evaluating epidemiology,
effect of control measures, drug trials

Answer 30

Kato Katz Technique

Question 31

Blood Flukes: Diagnosis

▪ Schistosomiasis

Answer 31

 Rectal biopsy
 Stool Examination Techniques

Question 32

Intradermal tests for immediate cutaneous
hypersensitivity using adult worm extracts
Cercarian Hullen Reaction (CHR)
 Indirect hemagglutination using adult worm and egg
antigens
 Circumoval precipitin test (COPT)
 Enzyme-Linked Immunosorbent Assay using soluble
antigens of adults and eggs

Answer 32

Schistosomiasis
 Immunodiagnosis