IaD [018-019] Schistosoma species (Schistosomiasis) 2024-2025 PDF

 IaD [018-019] Schistosoma species Parasite affecting human blood and tissues Schistosomiasis Prof. Dr. Azza El-Adawy Professor of Medical Parasitology 2024-2025 Key groups of parasites affecting man Schistosoma belongs to which key group of parasites? I- Met...

 IaD [018-019] Schistosoma species Parasite affecting human blood and tissues Schistosomiasis Prof. Dr. Azza El-Adawy Professor of Medical Parasitology 2024-2025 Key groups of parasites affecting man Schistosoma belongs to which key group of parasites? I- Metazoan Parasites II- Protozoan Parasites termed Helminths termed Protozoa Body is composed of one cell Body is composed of organs and systems 11/17/2024 Infection & Defence Module 3 Key groups of Helminths affecting man Schistosoma belongs to which key group of Helminths? Group I Group II Group III Have flat & unsegmented Have flat & segmented Have cylindrical body body body Trematoda Cestoda Nematoda (flukes) (tape worms) (Cylindrical worms) Developmental stages of Schistosoma include adult lays egg larva adult egg 11/17/2024 Parasitology for MSc IND 4 Schistosoma species that infect man Schistosoma haematobium Schistosoma species infect mainly Schistosoma mansoni farmers who are exposed to contaminated canal water Schistosoma japonicum 11/17/2024 Infection & Defence Module 6 Ecology that facilitate Schistosoma infection Englishmobaser.info pbase.com dailynewsegypt.com iwmi.cigar.org 11/17/2024 Infection & Defence Module 7 Geographical distribution of Human Schistosomiasis web.stanford.edu web.stanford.edu Schistosoma mansoni Distribution Schistosoma haematobium Distribution 11/17/2024 Infection & Defence Module 8 Geographical distribution of Human Schistosomiasis (continued) South East Asia Schistosoma japonicum infection Distribution web.stanford.edu 11/17/2024 Infection & Defence Module 9  How does Schistosoma transmission occur? Englishmobaser.info Definitive host Infected man Mode of infection Schistosoma Schistosoma Cercaria penetrate haematobium mansoni human skin Eggs pass in urine Eggs pass in stool Diagnostic stage Fresh canal water Eggs hatch Infective stage forked tail Furco-cercus cercaria Intermediate host miracidium Biomphalaria alexandrina Bulinus truncatus For Schistosoma mansoni For Schistosoma haematobium 11/17/2024 Infection & Defence Module 10  Pathway of Schistosoma in the body of infected patient Aorta II- Migration stage Left Right side side of the of the heart heart Systemic circulation Venous circulation Schistosomula Liver Vesical plexus in S.haematobium Portal vein I- Invasion stage Mesenteric plexus in S.mansoni Cercariae penetrates human skin IV-Eggs trapped III- Egg extrusion Direction of venous blood flow In urine or stool 11/17/2024 Infection & Defence Module 11 Pathogenesis & Clinical Picture of Schistosoma infection I- Invasion stage Skin lesion (1- 4 days following cercarial penetration) Local dermatitis, irritation & Papular rash 11/17/2024 Infection & Defence Module 12  Pathogenesis & Clinical Picture of Schistosoma infection II- Migration stage (3 - 4 weeks following infection) From right To left side of the side of heart the heart By schistosomula Metabolic products: toxic and allergic manifestations urticaria, fever, headache, muscle pain. In the lung: verminous pneumonitis, minute haemorrhage cough, haemoptysis. In the liver: liver becomes enlarged and tender 11/17/2024 Infection & Defence Module 13  Pathogenesis & Clinical Picture of Schistosoma infection III- Stage of egg deposition & extrusion Acute stage (1-2 months) Soluble egg antigens The patient may complain of: Fever, rigors, urticaria Generalized malaise Abdominal pain Liver tenderness Urticaria Generalized malaise 11/17/2024 Infection & Defence Module 14 Egg deposition by female Schistosoma japonicum Schistosoma japonicum lays large number of eggs that release excess soluble egg antigens Immune system is strongly stimulated and produce antibodies & finally immune complexes immune complex Circulate Blood vessel Deposit in the tissues The patient suffers from: Fever, chills, diarrhoea, generalized lymphadenopathy Tissue damage This is called acute toxemic schistosomiasis or Katayama syndrome 11/17/2024 Infection & Defence Module 15  Pathogenesis & Clinical Picture of Schistosoma infection Schistosoma haematobium Schistosoma mansoni & Schistosoma japonicum In vesical & pelvic plexus of veins In mesenteric plexus of veins Eggs fail to Eggs fail to 3 pass out 3 pass out Eggs remain Eggs remain 2 trapped 2 trapped Bladder Intestinal en.wikipedia.org wall 1 wall en.wikipedia.org 1 III- Egg extrusion Eggs extruded in urine Eggs extruded in stool Terminal haematuria, frequency of Dysentery with blood and mucus in stool micturition, burning pain 11/17/2024 Infection & Defence Module 16 Pathogenesis of Schistosoma infection Shell & miracidial antigens IV- Stage of tissue reaction Chronic stage (takes months to years) 2 Schistosoma eggs trapped in bladder Bladder wall Intestinal wall or intestinal wall cause tissue Attract reaction occurs around them inflammatory Granuloma develops cells Deposition of fibrous tissue Delayed-type hypersensitivity Damage & fibrosis of affected organ Loss of its function 11/17/2024 Infection & Defence Module 17  Pathogenesis & Clinical Picture of Schistosoma infection In normal condition In S.haematobium infection kidney my.cleveandclinic.org Normal colonic mucosa hydronephrosis Ureter hydroureter Fibrous tissue sciencedirect.com Bladder Egg trapped in bladder wall Polyps & sandy patches in the colon in Schistosoma mansoni infection Stone formation 11/17/2024 Cancer bladder may occur Infection & Defence Module 18  Pathogenesis & Clinical Picture of Schistosoma infection 3- Eggs fail to fix to venule wall are swept by blood & cause embolic lesions Portal hypertension medvin2u.net Ascites edurston.wordpress.com Hepatosplenomegaly saravanahospital.com 11/17/2024 Infection & Defence Module 19 Clinical Picture of Patients with Embolic Lesion in the Lung Schistosoma eggs that fail to fix to venules wall are swept by blood to reach pulmonary capillaries Pulmonary hypertension Trapped eggs Enlargement of right side of the heart Congestive heart failure = Cor-pulmonale Enlarged right ventricle Bilharzial Cor-pulmonale 11/17/2024 Infection & Defence Module 20 Diagnosis of Schistosomiasis Clinically (suggestive) 1- History of contact with contaminated water. 2- Clinical picture according to stage of infection. Laboratory Methods Radiological Imaging Endoscopy 11/17/2024 Infection & Defence Module 21  Laboratory Diagnosis of Schistosomiasis 1- Detection of Schistosoma eggs: - Detection of S.haematobium eggs in urine - Detection of S.mansoni eggs in stool - Test for viability (click here) - Test for viability - Kato thick smear: for egg counting (click here) to assess the intensity of infection - Rectal swab or rectal snip haematobium 11/17/2024 Infection & Defence Module 22 Laboratory Diagnosis of Schistosomiasis 2- Serological Tests: Detection of anti-Schistosoma antibodies or antigen in patient’s serum 3- Complete Blood Count: 1- Egg extrusion accompanied by blood loss Anaemia Iron deficiency anemia 2- Hypersplenism Haemolytic anemia Eosinophilia, leukocytosis 11/17/2024 Infection & Defence Module 24 Diagnosis of Schistosomiasis using radiological imaging Schistosoma haematobium infection Schistosoma mansoni infection Calcified bladder Stenosed ureters and Intestinal affection with hydroureter hydronephrosis 11/17/2024 Infection & Defence Module 25 Diagnosis of Schistosomiasis using endoscopy Cystoscopy Colonoscopy, sigmoidoscopy for urinary Schistosomal affection for intestinal Schistosomal affection quantifiedhealth.blogspot.com quantifiedhealth.blogspot.com Done in chronic cases to detect lesions and take biopsies 11/17/2024 Infection & Defence Module 26  Treatment of Schistosomiasis Praziquantel (Distocide / Epiquantel) Ca²+ Increases the permeability of the cell membrane of Ca²+ Ca²+ Schistosoma worms to Ca ions Ca²+ Ca²+ Ca²+ Ca²+ Ca²+ Ca²+ Ca²+ Ca²+ Contraction & paralysis of Schistosoma worms Ca²+ Ca²+ so they lose their grip on veins wall & die Ca²+ 11/17/2024 Infection & Defence Module 27 Prevention & Control of Schistosomiasis - Mass treatment X - Health Education naturepl.com - Snail control X X pbase.com 11/17/2024 Infection & Defence Module 28 Quiz A 20-year-old woman from Kafr El-Sheikh (Egypt) has abnormally rapid heart beats & gets tired easily. She recalls passing mucus tinged with blood in stool. She is used to wash dishes in the village canal. The village doctor requests lab investigations that reveal iron deficiency anemia and parasitic stage with observable blood drops in stool. Where does thestage What parasitic adultdoes stagethe reside in the farmer’s lab doctor body? see in stool? a) Vesical plexus The cercaria of veins stage b) Mesenteric Trophozoitevenous stage plexus c) The Capillaries around lung alveoli egg stages flickr.com d) In liver parynchymal Oocyst stages tissue e) The In mucosa of intestinal wall cyst stages  Quiz A 30-year-old farmer has has difficulty in voiding urine. Occasionally drops of blood pass out at the end of micturition. He is a resident in a rural village in Upper Egypt. He is used to wash his farm animals in the village canal after finishing his work. If he isisleft What theuntreated, whatresponsible parasitic stage is the most likely complication for passage he is at of the blood in risk? the boy’s urine? a) Cancer kidney Schistosomula b) Acute renal Adult S. failure mansoni c) Stone in ureterstage The Cercaria d) Nephrotic syndrome The extruded eggs e) Adult CancerS.bladder mansoni 11/17/2024 Infection & Defence Module 30 Suggested Textbooks & Websites Paniker’s Textbook of Medical Parasitology https://www.cdc.gov/dpdx/az.html Best Wishes