Phylum:
Platyhelminthes
class: Trematoda
Schistosoma
By
Assist. lecturer Maytham A. Alwan
Trematodes
Schistosomes: Blood flukes
Family: Schistosomatidae
Genus: Schistosoma
Spp. : Schistosoma haematobium, Schistosoma mansoni,
Schistosoma japonicum,
For animals(ruminant & horses) : Sch. bovis, sch. Mattheei, sch.
Spindale, sch. nasalis, Sch. margrebowiei
Disease : Bilharziasis or Schistosomiasis
Schistosomes: Blood flukes
Morphology: The male is broader than the female, and its lateral
borders are rolled ventrally into a cylinderical shape , producing
along groove or tough called the gynaecophoric canal, in which the
female is held. lack the mascular pharynx, intestinal seca reunite
after bifurcation to form a single canal.
Lifecycle: Schistosomes are dioecious trematodes in which the sexes
are separate .
Life span : may live for 30 years in the human host.
non operculate eggs, they have no redia, no metacercariae stages in
larval development, the cercaria have forked tail and infect by
penetrating un broken skin or ingestion .
Schistosomiasis is a water borne disease .
Spp.
Sch. haematobium
Sch.mansoni
Sch. japonicum
Name of disease
Urinary bilharziasis
(Vesical
schistosomiasis),
endemic haematuria
Intestinal bilharziasis
(schistosomiasis
dysentery)
Oriental bilharziasis
Katayama
disease(fever)
Final host
human
Human& monkeys&
rodents
Human&domestic
animals&wild rodent
Clinical signs
Hyperplasia &
calcification of
bladder
Liver fibrosis , bloody Lung fibrosis,
diarrohea
spleenomegally
Table
Morphological differentiation between the species of schistosomes of man
Male adult worm :
S. haematobium
S. mansoni
Length
10 – 15 mm
6 – 10 mm
Integument
finely tuberculated
coarsely tuberculated
No of testes
3–5(4)
Ceca
reunite late
reunite early
15 – 20 mm
10 – 14 mm
S. japonicum
12 – 20 mm
smooth
6 – 9 ( 7 ) in (cluster)
7 – 9 ( 7 ) (in column)
reunite very late
Female adult worm :
Length
15 – 30 mm
Position of the ovary
posterior half
anterior half
middle
Length of the uterus
long
short
long
No. of ova in the uterus
20 – 50
1–4
50 – 300
Ova :
Spine
Present
terminal spine
in urine, less, frequenitly in stool
lateral spine
short lateral spine (rudimntary)
in stool rarely in urine
in stool
Habitat in human :
Body
vesical plexus of urinary bladder
inferior mesentric vein,
less frequently superior
superior mesentric vein, less
frequently interior
Snails :
(intermediate host)
Bulinus truncatus
Biomphalaria spp.
Oncomelani spp.
Differential Features of Shistosoma spp.
Saline s.
Iodine s.
( in stool )
Schistosoma japonicum Egg
Schistosoma haematobium Egg
Schistosoma mansoni Egg
( in urine )
Figure : Ova of Schistosoma spp.
( in stool )
4/12/2020
8
4/12/2020
9
Female
Oral sucker
Male
Ventral
sucker
Schistosoma mansoni Male-Female Copula
Figure : Schistosoma mansoni male and
female in copula
4/12/2020
11
Figure 3: Schistosoma mansoni male and female in copula
Fig. 4 : S. mansoni, female and male
In Saline
R. B. C
Iodine stain
Fig. 5: Schistosoma mansoni Egg
Man
egg
Snail
Diagram 2: life cycle of schistosoma mansoni
Methylene blue s.
Fig. 8: Schistosoma japonicum female and male
Saline s.
Fig. 9: Schistosoma japonicum Egg
Fig. 11 : Schistosoma haematobium female and male
Eosin s.
Eggs
Saline s.
Iodine s.
Saline s.
R. B. C
Fig. 12 : S. haematobium eggs
Schistosoma spp- Cercaria
Schistosoma spp- Miracidium
Fig. 15: stages from the life cycle of the schistosoma spp.
Oncomelania
Biomphalaria
Fig. 16: the intermediate hosts of schistosoma spp.
Diagram 1 : life cycle of Schistosoma spp.