Test 1 Medical Helminthology: blood flukes

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