Studied by 3 people
Schistosomes
Blood Trematodes, Blood Flukes
How many species of schistosomes parasitize humans?
3
What is significant about schistosomes
They are dioecious
dioecious
Having male and female reproductive organs in separate plants or animals
What are the male schistosomes sizes?
.6 - 2.2 cm flat
What are the female schistosomes sizes?
1.2 cm - 2.6 cm cylinder
Explain the schistosomes sex?
Males have a gynecephoral canal, female slides in and lays eggs, and the male will continuously enseminate
Where do schistosomes live?
In blood vessels
Where do females lay eggs?
In the intestine and liver lumen
What happens to blood vessels during the egg laying process?
The vessel dilates and then tightens around the egg
What are the eggs like in schistosomes?
They are sharp but not operculated; hatch by freshwater rupture
Lifecycle?
The egg hatches and the miracidian looks for the snail host
How does the egg hatch?
An enzyme in the egg diffuses through and dissolves surrounding tissue. The egg is released into the lumen
How can one be infected with the blood fluke?
Getting in water with the fluke; it can get through the skin. The cerceria has glands that produce an enzyme capable of breaking the skin and the tail will be lost. They change from aerobic to anaerobic.
Schistosomulum
the form which develps after skin penetration by schistosome cercariae, when the cercariae lose their tails
How long does the immature fluke stay in the sub-cutaneous skin?
2 days before entering the blood vessel, lungs, liver, and eventually the liver lumen, mesenteric or vesicular veins
Schistosoma mansoni
blood fluke (Western Hemisphere)
African slave trade- Brazil, Venezuela, Caribbean, Peurto Rico, and eventually the US.
Can the S. mansoni stay in America?
No, we don't have the snail vector.
Where do adult S. mansoni reside?
In the small branches of the mesenteric vein and region of the lower colon
Does S. mansoni have a reservoir?
No
What is the egg of S. mansoni like?
Light brown, elongated, large spine like a rose thorn. They are found in the rectal biopsy
Schistosomes japanicum
Oriental blood fluke
Found in ALL mammals exposed to infected water.
Where does S. japanicum reside?
In the SUPERIOR mesenteric vein adjacent to S. mansoni
What is significant about S. Japanicum
They lay a lot of eggs and they are neurally spherical
What are some sever symptoms attached to s japanicum
Hepatic and pulmonary cirrhosis
CNS lodgment and problems
What is significant about s japanicum eggs?
Can have a spine and found in the stool for diagnosis
Schistosoma haematobium
Which trematode is associated with bladder carcinoma in Egypt and Africa?
Urinary Schistosomiasis
Schistosoma haematobium lodges in to the blood vessels of the bladder •May or may not result in symptoms •If symptoms occur: itchiness in the area where the worm enters the body, fever, chills, diarrhea, and cough •Urinary tract symptoms occur later which may include blood in the urine and bladder obstruction
Where do you get s haematobium
From the Nile
Life cycle of S. Haematobium
Liver, then Vesical, prostetic, and then the uterine plexuses via hemmorhodical veins
Where are SH BLOOD FLUKES eggs layed?
They are deposited in the bladder uterus vaginal and prostate walls
How can diagnosis occur for SH?
Contrifugation or sedimentation
Contrifugation
Urine samples taken and spun down
Schistosoma mekongi & schistosoma intercalatum
Blood flukes very alike
Symptoms include reaction penetration of the metacecaria, lung inflammation
Once in the liver cause hepatitis
1-3 months in they will reside in the mesocentric vein or the vesicle venules
Symptoms of s mekongi and s inter
Diarrhea and peeing blood
How long do S mekongi and s inter last?
4 days
How does s japanicum affect the body early on if bad?
Very severely
Katiguma fever
Katayama fever
acute schistosomiasis
Schistosomiasis
Helminth infection acquired from contact with water containing infected snails.
How do japanicum eggs affect the body?
They cause abcesses and may dislodge and get in the circulation
What severe condition is characteristic of japanicum and mansoni
Hepatosplenic schistosomiasis and portal hypertension
portal hypertension
the elevation of blood pressure within the portal venous system
What does hepatosplenic schistosomiasis lead to
Liver disease and an enlarged spleen
What does liver disease and an enlarged spleen lead to?
Esophageal varices and eventual internal bleeding
What intestinal problems can japanicum and mansoni cause?
Intestinal schistosomiasis
Intestinal schistosomiasis
mansoni and japonicum (cramps, bloody stool, mucous, protein loss, weight loss, anemia, eggs block things in the intestine)
T/F japanicum and mansoni affect the spleen and intestines simultaneously often?
F
Male menarche
Another name for urinary schistosomiasis
Why is urinary schistosomiasis ignored?
Culture; religion; Jewish boys don't go to water; Muslim boys do.
obstructive uropathy
anatomic changes in the urinary system caused by obstruction
What does SH usually cause?
Pulmonary issues
Japanicum and mansoni cause neurological problems but what parts?
Japanicum affects the cerebral and mansoni the spinal
What are the symptoms of japanicum and mansoni neurological problems
Lethargy, confusion, focal seizures, optical field affects, transverse myolitis
Speech
Transverse Myelitis
inflammation of the spinal cord
What is the immunology of japanicum and mansoni
Slight immunity if you've had it
However adult worms don't affect but can't be protected against "immunological camouflage"
What is significant about mansoni very early on
Schistosomal dysentery
What unfortunate thing can happen to the eggs of mansoni?
They can be swept back into the liver and cause fibrosis of the portal vessel Although granular build up can stop this
What happens if a mansoni infection is heavy enough?
Fibrosis can occur
colateral circulation
This carries eggs from mansoni to capillaries
What does fibrosis lead to
New vessels and more mansoni widespread
Where do the eggs of SH , japanicum, and mansoni end up
Lungs SH
superior mesenteric - japanicum
Inferior mesinteric - mansoni
How long do urninary schistosomiasis symptoms last?
3 months to a year and can turn into a uti
In which blood fluke is neurological symptoms common?
Japanicum
amastomosis
Vein formation in spinal and pelvic
What does the epidemiology of mansoni look like?
Widely distributed; humans only important host
Migration still occurs because of snail agriculture expansion
What is significant about the epidemiology of SH
Humans are the only good host!
What is the vector temp range for mansoni snail?
Mid
What is the vector temp range for SH snail?
Wide lots of Africa
What can snails do?
Estivate in dry temps and during wet the cerceria come out
What is significant about the japanicum vector?
Many animals are a good hosts
Why is it hard to prevent japanicum?
The snail vector only comes to water for laying eggs
Molluscasides
Only apply to water
What is the estimate of japanicum infections
70,000,000
What is the drug of choice for japanicum
Praziquantel and is FDA approved
How does severity increase in a SH
Bladder wall thickens or cerebral schistosomiasis and eventual schistosomial demylelation that doesn't respond to praziquantel
laminectomy
the surgical removal of a lamina, or posterior portion, of a vertebra
How do we control blood flukes?
Education molluscicides, biological control draining swamps and proper disposal of urine of feces and the end of human fertilizer
How much of the world still doesn't have clean drinking water?
50%
What can be used as a control measure on peoe
Niclosamide as lotion Ali though toxic
What happens to schistosomes not meant for humans
Schistosomal dermatitis - swimmers itch/ worms looking for a way out
What is the issue with biological comtrol
It can introduce new problems
Note 
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