BLOOD FLUKE: GENERAL

Elongated and cylindrical

Adult’s shape

Dioecious - separate sexes

Sex

perpetual copulation

The most romantic parasite due to their ______________

blood vessels

Adult stages are in the _____________

gynecophoral canal

Adult male with ___________________ where the female is held

• Only 1 IH

  • Snail

IH

cercaria (fork-tailed)

Infective stage

Schistosomule

• tail-less cercaria

• It is the stage formed after the cercaria penetrates human skin

• During entry, the cercaria loses its tail

skin penetration

MOT

Blood vessels

Habitat

hemoglobinase;

RBCs

They ingest _____. They also contain ______________, a protein that breaks down hemoglobin.

Miracidium → Sporocyst → Redia → Cercaria

• No redia and metacercaria

Larval Stages:

• Non-operculated

• embryonated

Egg

Pathology of Schistosomes

Pathology of Schistosomes

Swimmer's itch/ Gulf-coast itch/ Cercarial itch/ Clam digger's itch

Pathology of Schistosomes

• Dermatitis with pruritus at the site of cercarial penetration

Katayam disease/Katayama fever/Snail fever

Pathology of Schistosomes

• Systemic hypersensitivity reaction to the schistosomulum migrating through tissue

Intestinal schistosomiasis

Pathology of Schistosomes

• Eggs are deposited in the intestinal mucosa triggering granuloma formation (obstruction of intestinal tract)

Hepatosplenic schistosomiasis

Pathology of Schistosomes

• Most serious consequence of chronic schistosomiasis

• Hepatomegaly, ascites, portal hypertension, and development of collateral circulation

Pulmonary schistosomiasis

Pathology of Schistosomes

• Wheezing and coughing

• Can lead to cor pulmonale (right-sided heart enlargement)

Cerebral schistosomiasis

Pathology of Schistosomes

• Motor and sensory disturbances

1. Direct fecal smear, Kato-Katz, FECT

2. Urinalysis using 24-hour unpreserved urine (centrifugation) for S. haematobium

3. Circumoval Precipitin test (COPT)

Laboratory Diagnosis for Schistosomiasis

Laboratory Diagnosis for Schistosomiasis

Laboratory Diagnosis for Schistosomiasis

Laboratory Diagnosis for Schistosomiasis

COPT (Circumoval Precipitin test)

A confirmatory serologic test for schistosomiasis.

Oliver and Gonzales

COPT

• By who?

• Lyophilized eggs of S. japonicum

• Obtained from rabbit (reservoir host)

• Eggs act as the antigen

COPT

• Reagent:

• Patient serum
  👉 Contains antibodies (if infected)

COPT

• Specimen

Bleb formation

COPT:

• Positive result

Comparison between FECT and COPT

Pathology of S. haematobiumPathology of S. haematobium

Urinary schistosomiasis

Pathology of S. haematobium

• Sandy patches in the lower urinary tract

Female genital schistosomiasis

Pathology of S. haematobium

• Associated with presence of eggs in the cervix, vagina and/or vulva

Obstructive uropathy

Pathology of S. haematobium

• Due to deposition of eggs in the ureter wall causing obstruction in urinary flow

Bladder calcification

Pathology of S. haematobium

• Calcium deposition around schistosome eggs in the urinary bladder

• "Fetal head" sign in abdominal X ray

Bladder carcinoma

Pathology of S. haematobium

• Most prevalent among Egyptians

• May be due to continuous exposure to carcinogens secondary to bacterial infections (bacteria that metabolizes to form N-nitroso compounds)

• Stool examination

• Rectal biopsy

• Sedimentation techniques

• Faust Meleney's egg hatching technique

• Circumoval Precipitin Test (COPT)

• Cercarial Hullen Reaction

Diagnosis for S. japonicum and S. mansoni

Cercarial Hullen Reaction

Diagnosis that demonstrates shrinking of cercaria

serum

Cercarial Hullen Reaction

• Specimen

Lyophilized cercaria

Cercarial Hullen Reaction

• Reagent

Cercaria shrinks

Cercarial Hullen Reaction

• Positive result

• Urine examination

  • Preferred specimen: 24-hour unpreserved urine (all urine within 24 hours)

  • Optimized recovery in urine: Between noon and 2PM

Diagnosis for S. japonicum and S. mansoni