schistosomoiasis ( balahaziaris )

Question 1

what are 2 types of parasites?

Answer 1

Protozoa

Helminths

Question 2

Describe protozoa ?

Answer 2

Single celled

their life cycle : Cyst —> protozoa

Question 3

describe helminths?

Answer 3

Multicellular

their life cycle :

eggs —> larvae —> adult

Sometimes the eggs themselves can cause disease or the larvae stage can cause disease depending on the parasite ( no need to grow )

Question 4

what are 2 types of helminth ?

Answer 4

Round worms ( nematodes ) : Elongated, cylindrical , unsegmented

Flat worms :

Trematodes : leaf like, unsegmented ( tree = leaf )

Cestodes : Tape like , segmented ( CES, connect each segment with tape )

Question 5

What is schistosomiasis ?

Answer 5

Aka bilharziasis

acute and chronic parasitic disease caused by blood flukes ( trematode worms ) of the genus schistosoma

its helminths

Question 6

compare schistosoma to other trematodes ?

Answer 6

we have 2 trematodes which are hermaphroditic

schistosoma spp are DIOCESES ( individuals of separate sexes )

Question 7

Where do schistosomiasis liv?

Answer 7

certain types of freshwater snails

human become infected when the skin comes in contact with contaminated freshwater

Question 8

what are 3 mains species infecting humans ?

Answer 8

Schistosoma haematobium : africa, areas of the middle east , cause disease in urinary and genital areas

S. mansoni : Africa ( sudan and egypt ), south america, caribbean

S. Japonicum : Parts of china and southeast asia

the 3 above most common

S. mekongi : cambodia and laos

S. guineesis : Central africa

These cause disease in bowel and liver

Question 9

describe the life cycle of schistosom?

Answer 9

Schistosoma eggs are eliminated with feces or urine ( eggs need water )

Eggs hatch and release larvae ( MIRACIDIA )

Swim and penetrate specific ( SNAIL INTERMEDIATE HOSTS ) ( it needs water to survive thats why snails in water )

Produces CERCARIAE ( INFECTIVE FORM ) and penetrate the skin of the human host ( definitive host )

After we get infected by cercaria they turn into adult worms then they produce eggs in feces or urine and cycle repeats

Question 10

in which form of schistosoma we get infected?

Answer 10

ONLY CERCARIAE

we dont get infected by eggs or larvae

we get infected by skin peentration

Question 11

describe life cycle in human?

Answer 11

1- Cercariae ( forked tail ) in fresh water penetrate the skin of the human lost ( skin become infected first )

2- Go to the lung (affect them ) then to the heart Then to the LIVER ( matures in the liver ) and exist the liver when matures

3- males and females adult worms copulate and reside in the mesenteric venules , the location vary depending on the species

Question 11

Where does S. japonicum residue ?

Answer 11

Superior mesenteric vein draining SMALL INTESTINE

Question 12

Where does S. mansoni residue ?

Answer 12

Superior mesenteric vein draining LARGE INTESTINE

Question 13

Where does S. haematobium residue ?

Answer 13

Bladder

Question 14

what is the fate of eggs?

Answer 14

Eggs germinate as they pass through the vessel wall into intestine or bladder

S. japonicum –> small intestine= feces

S. Mansoni —> large intestine = feces

S. hematobium —-> bladder = urine

Question 15

what is the shape of egg of S. hematobium ?

Answer 15

Oval egg in urine ( cuz residue in bladder)

Terminal spine

Question 16

what is the shape of egg of S. mansoni?

Answer 16

Oval eggs in feces ( large intestine )

LATERAL SPINE

Question 17

what is the shape of egg of S. japonicum ?

Answer 17

More round eggs in feces ( small intestine )

RUDIMENTARY SPINE ( almost no spine )

Question 18

what causes the acute and chronic symptoms of schistosomiasis ?

Answer 18

Eggs migration through tissue and the human immune response to the eggs

Host response to toxic or antigenic substances produced by developmental stages

Question 19

describe cercarial dermatitis ? ( symptom )

Answer 19

Swimmers itch or fishman itch

Occur in all types cuz they all have to penetrate skin

happen following the penetration of the skin by schistosomal cercariae larvae

the rash is itchy , maculopapular ( small red bumps )

may be come vesicular ( small fluid filled blisters )

Question 20

describe acute schistosomiasis ?

Answer 20

aka katayama fever

this is a systemic ( whole body ) hypersensitivity reaction

Develops 4-6 weeks after infection

Symptoms include : Fever , muscle , joint aches, cough , diarrhea, headache

usually resolve on their own

caused by all types

Question 21

describe chronic schistosomiasis ?

Answer 21

world wide chronic schistosomiasis

more serious and common than the acute illness

chronic symptoms arise months to years after exposure

chronic symptoms are due to an intense immune response against the eggs

Question 22

what happens when bowel is affected?

Answer 22

bowel involvement causes bloody diarrhea

chronic pain

iron deficiency anemia

Question 23

what happens when liver is affected?

Answer 23

Granuloma formation in liver

Question 24

what happens when bladder is affected?

Answer 24

bloody urine pain when urinating kidney damage increased risk of bladder cancer usually by hematobium subtype

Question 25

what happens when skin is affected?

Answer 25

eggs migrate to skin producing firm red papules

Question 26

what happens when other organs are affected?

Answer 26

Egg can also e producing complication in almost any organ Such as lung , brain , spinal cord , muscles and eyes

Question 27

what causes intestinal schistosomiasis ?

Answer 27

S. mansoni, Japonicum Symptoms include chronic abdominal pain , poor appetite and bloody diarrhea hepatosplenomegaly liver failure JAPONCIUM IS MORE SEVERE cuz : Higher egg output so the clinical manifestation are more severe and liver is most affected

Question 28

describe urogenital schistosomiasis ?

Answer 28

Caused by Hematobium these worms live in blood vessels around bladder and release eggs in persons urine in chronic infection patient may develop : blood in urine , pain and difficulty urinating Chronic cystitis formation of bladder stones tumours near prostate bladder cancer

Question 29

what are the lab diagnosis ?

Answer 29

Stool or urine samples can be examined for eggs S/ hematobium = in urine S. mansoni and S japonicum : bile stained eggs in stool Eggs excretion peaks between noon and 3 pm Biopsy : Demonstration of eggs in the bladder or rectal mucosa the eggs tend to be passed intermittently and in small amounts and may not be detected so it may be necessary to perform a blood serologic test ELISA : Detection of specific schistosome antigen in the serum and urine , helpful for detecting light infection or before eggs appear in the stool or urine

Question 30

what is the treatment of schis?

Answer 30

no vaccine is available for schistosomiasis but treatment can help reduce impact of infection no specific therapy for dermatitis or katayama syndrome Praziquantel is active against all 3 species Metrifonate : may be used for S hematobium Oxamniquine for S. mansori as alterantive drugs no satisfactory alternative for japonicum so you need to use praziquantel