Schistosomiasis

SCHISTOSOMIASIS/

BILHARZIOSISBY:

INUSAH ADAMS

4th yr med. Student

TDMU, Ukraine

DEC, 1ST, 2012

TDMU

Bilhazia in Ghana

PLAN OF PRESENTATIONDEFINITION

EPIDEMIOLOGY

ETIOLOGY

MODE OF TRANSMISSION/LIFE CYCLE

PATHOGENESIS

SIGNS &SYMPTOMS

DIAGNOSIS

DIFFERENTIALS

TREATMENT

COMPLICATIONS

PROGNOSIS

DEFINITION

• Schistosomiasis is a chronic, parasitic

disease caused by blood flukes

(trematode worms) of the genus

Schistosoma

• Also, called snail fever

EPIDEMEOLOGYThe disease is found in Africa, South

America, East Asia and Middle East

Over 230 million people require treatment for schistosomiasis yearly

90% of those requiring treatment for schistosomiasis live in Africa.

More than 200,000 deaths per year are due to schistosomiasis in sub-Saharan Africa

ETIOLOGY• Parasitic worms of schistosoma species

Main species are;

a. Schistosoma haematobium

b. Schistosoma mansoni

c. S. japonicum

d. S. mekongi and

e. S intercalatum

Two forms of schistosomiasis exist

1. Intestinal schistosomiasis and

2. Urogenital schistosomiasis

SCHISTOSOMA MANSONI (lateral spine)

SCHISTOSOMA HAEMATOBIUM(terminal spine)

• TT

RISK FACTORS• wading or swimming in lakes, ponds and

other bodies of water which are infested

with the snails

• Fishing (both men and women)

• Women washing clothes in infested water

are at risk

• People with STIs

LIFE CYCLE• : parasite eggs are released(by way of urination

or defecation) into the environment from infected

individuals.

• The eggs hatch on contact with fresh water to

release the free-swimming miracidium

• Miracidium penetrates a water snail tissue where

it develops into cercaria

• Cercaria is release into the water from the snail

• cercaria penetrates the skin of human (definitive

host), circulate to organs (GIT, urinary tract)

LIFE CYCLE

LIFE CYCL con’t

Schistosoma dermatitis or “swimmers itch”

PATHOGENESIS1. People become infected when larval forms of the

parasite – released by freshwater snails – penetrate

their skin during contact with infested water.

2. the larvae develop into adult schistosomes

3. Adult schistosomes live in the blood vessels where

the females release eggs

4. Some of the eggs are passed out of the body in the

faeces or urine to continue the parasite life-cycle

5. Others become trapped in body tissues (intestinal

and urinary system), causing an immune reaction

and progressive damage to organs.

SIGNS & SYMPTOMS• Clinical picture: low grade fever. Fatigue, weight loss and

anemia

• INTESTINAL SCHISTOSOMIASIS

1. Abdominal pain

2. Diarrhea

3. Blood in stool, fresh or melena

4. Hematemesis

5. Liver enlargement

UROGENITAL SCHISTOSOMIASIS

1. Hematuria (terminal)

2. dysuria

3. Frequent need to urinate (polykauria)

4. In females; genital lesions, vaginal bleeding, pain during sexual intercourse and nodules on the vulva, irregular menstruation

DIFFERENTIAL DIAGNOSISUROGENITAL SCHISTOSOMIASIS

• Renal tuberculosis ("golf-hole" (gaping) ureteral orifice is seen during cystoscopy, Yellow raised nodules) surrounded by a halo of hyperemia in bladder)

• Urogenital tract cancer ( total hematuria, hematuria may stop and recur in a week, month or year time)

• Urolithiasis (colicky pain)

INTESTINAL SCHISTOSOMIASIS

• Peptic ulcer disease (heartburns, GERD,

endoscopically, ulcer in GIT)

• Pancreatitis (H-like pain, vomiting that is worsened with eating, high diastase level, etc.)

• cutaneous leishmaniasis (non-healing raised, scaling lesions on the skin)

DIAGNOSTIC PLAN

1. stool examination for S. mansoni and ova

2. Urinalysis and urine for S. hematobium and ova

3. General blood analysis:

4. Serological: hemagglutination test; reaction is positive @ a dilution of 1: 16 or more

5. BUN and creatinine level

6. Ureterocystoscopy

7. Biopsy of rectum or urinary bladder

8. Plain abdominal X-ray: chronic cases may show calcification and fibrosis of ureters, urinary bladder, ascites

9. Intravenous urography: may show the level of ureter stricture

10. Ultrasound of abdomen: hepatosplenomegaly, bilharzial hepatic fibrosis, ascites

clusters of the parasite eggs with

intense eosinophilia

Calcification of the urinary bladder

Yellow raised nodules surrounded by a

halo of hyperemia (TB of bladder)

Cystoscopy in tumor of kidney

(gross hematuria)

TREATMENT

• Drug: Prazequnatel

Dose: 40mg/kg single oral dose

60mg/kg in 2 divided doses if

quantity of ova is high

Review in 2 weeks

COMPLICATIONS

Urogenital schistosomiasis

1. cystitis

2. Urinary bladder cancer

3. Polyps, ulcers of urinary bladder

4. Hemospermia

5. Infertility

6. Spontaneous abortion

7. Renal failure

8. anemia

Intestinal schistosomiasis

1. Liver fibrosis

2. Intestinal cancer

3. Portal hypertension/Pulmonary hypertension/ Cor pulmonale

4. Ascites

5. Esophageal varices

6. Malnutrition

PROGNOSIS

• Always good especially with prompt

diagnosis and treatment

PREVENTION

Education

Eliminating the water-borne snails which are natural reservoirs for the disease

Annual dose of prazequantel

adding niclosamide, acrolein, copper sulfate, etc., to the water sources in order to kill the snails.

Avoid swimming and contact with fresh water in endemic areas

Boiling water for 1 minute will kill the parasite. (Filtration of drinking water )

• GHANA AND BILHARZIA