Schistosomiasis

Schistosomiasis By Mohammed Mahmoud, MD Lecturer of tropical Medicine Cairo university

Specices & Distribution • S. Mansoni : Nile valley, Sudan, Brazil and Venzezuella • S. Haematobium: Upper Egypt, Africa, Western Asia • S. Japonicum: Far East

Life Cycle

Basic pathology • Cercaria  Allergic dermatitis • Adults  No harm • Eggs  granulomas  Fibrosis  egg antigens  immune complexes  Katayama fever

Clinical picture • Cercarial dermatitis: pruritic rash occurs within 24 h of cercarial penetration • Katayama fever: - Usually with S. japonicum (???) - Heavy infection with mansoni - Occur in non-immune persons - 4-6 weeks after primary infection (time of egg deposition) - Fever, rigors, HSM, LN, ulticarial rash, marked eosionophilia

Urogenital schistosomiasis: - S.haematobium - affect UB, ureter, genital organs - Dysuria, terminal haematuria Complications: 1- Obstructive uropathy 2- Cancer bladder (squamous cell)

Intestinal schistosomiasis: - caused by mansoni - affect large bowel (rectum and sigmoid) - due to submucosal egg deposition granumona fibrosis- Clinically: 1- Bilharzial dysentery dysentery, tensmus, mucus in stools, crampy abdominal pain 2- Colonic polyposis Bloody diarrhea, anemia, hypoprotinemia, clubbing of fingers (never turn malig) 3- Bilharzioma: Tender palpable mass in Lt iliac fossa Never turn malignant

Hepatic schisosomiasis • Caused by S. Mansoni, S. Japonicum • Stages: 1- Stage of hepatomegly: ovideposition and granuloma formation liver is enlarged, smooth, firm, rounded edge. 2- Stage of HSM (Mainly due RES) 3- Stage of Huge splenomegly (PH) and shrunken liver (periportal fibrosis) and PS collaterals. 4- Stage of ascites (PH and hypoprotinemia, late due to malnutrition, loss of proteins by colonic polyposis and haematemesis) 5- Terminal hepatic failure concomitant viral hepatitis Reversal of the blood flow away from the liver (PS)

Periportal fibrosis

Paraumbilical vein

Oesophageal varices

Cardiopulmonary Schistosomiasis • Larval Pneumonitis: allery to schistosomulae migrations low grade fever, cough, haemoptysis, wheezes, eosionophilia • Core pulmonale: due to eggs of S. mansoni (reach through PS collaterals), S. haemtobium pulmonary arterioles granuloma fibrosis endertaritis oblitrans  pulmonary HT  RVH RVF X-ray  dilatation of main pulmonary arteries (Dumble shape masses at the hilum)

Schistosomal corepulmonale

Ectopic Schistosomiasis • Due to aberrant migration of the eggs • Mainly affect brain (seizures), spinal cord (paraplegia), eye (visual field defects), skin.

Chronic salmonellosis • Salmonella behave atypical in cases of schistosomiasis following a rather chronic course unlike the usual acute illness • Due to proliferation of salmonella in the gut of the adult schistosomes, shedding salmonella into blood  chronic bacteraemia  prolonged fever • Ttt by antityphoid to eradicate salmonella and prevent relapse by antischistosomal therapy.

Diagnosis • Stool and urine examination • Rectal snip (gold standard) • Liver biopsy • Serological tests: • Ab detection donot differentiate between active and past infection, did not decrease after ttt • Ag detection  indicate active infection and decrease after successful ttt

Treatment • Praziquantel (Drug of choice) for both mansoni and haematobium, 40 mg/kg, can be repreated 2 or 3 times in moderate and severe infections • Metrifonate: for S.haematobium 10 mg/kg in 3 repeated doses at 2 weeks interval • Oxamniquine: for mansoni 20 mg/kg daily for 3 days

Thank you

Schistosomiasis