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Parasites causing this clinical presentation How did the parasite produce this presentation (Pathogenesis) Mode of infection. Common Clinical Presentations of Parasitic Infections. Jaundice. Bronchial asthma. Diarrhoea. Appendicitis. Jaundice.
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Parasites causing this clinical presentation How did the parasite produce this presentation (Pathogenesis) Mode of infection Common Clinical Presentations of Parasitic Infections • Jaundice • Bronchial asthma • Diarrhoea • Appendicitis
Jaundice Yellowish coloration of skin and sclera with high bilirubin level in blood • Fascioliasis • Schistosomiasis. • Hydatid disease. • Ascariasis. • Amoebiasis. • Toxoplasma. • Falciparum malaria Cell damage
How can P.falciparum infection cause jaundice? Blood Vessel of the infected patient Auto-antibodies Normal RBCs Infected RBCs The produced (autoantibodies)will cross-react with hostRBCs Haemolysis of RBCs haemolytic anaemia The patient suffers from jaundice & Haemoglobinuria
Mode of Infection with Toxoplasma 1- Oral route (ingestion): Contaminated food or drink Handling cat excreta Sporulated oocyst Infected undercooked meat Tissue cyst Pseudocyst 2- Organ transplantation Tachyzoites 3- Blood transfusion 4- Transplacental route
Mode of Infection 5- Contamination of mucous membrane & skin abrasion (in research workers & butchers) Tachyzoites
Bronchial asthma Means: difficulty in breathing Parasitic infections that may be associated with bronchial asthma: 1- Fascioliasis. 2- Ascariasis. 3- Ancylostomiasis. 4- Visceral larva migrans. 5- Bodies of living and dead mites and their excreta. Cause of bronchial asthma: An allergic reaction to parasite antigens and metabolites Mediated by IgE
Allergic dermatitis ? Eosinophilic pneumonia How can Parasites Produce Bronchial asthma? Helminths antigens & metabolic byproducts Fab IgE is produced Fc Receptor for IgE Eosinophil Become activated Receptor for IgE Mast cell Produce Broncho-spasm Pneumonitis Urticaria Mediators (substances) Become activated
Appendicitis Means: inflammation of appendix Parasitic infection that may be associated with appendicitis: Helminthic infections: 1- Taenia saginata infection. 2- Enterobius vermicularis infection. 3- Ascaris lumbricoides infection. 4- Trichuris trichiura infection. Protozoal infections: 1- Entamoeba histolytica infection. 2- Balantidium coli infection. Gravid segment Trophozoite stage
Diarrhoea Increase in frequency, fluidity or volume of bowel motions - Heterophyiasis • All tape worm infections • Ancylostomiasis • Ascariasis • Strongyloidiasis • Trichinosis • Capillariasis • Giardiasis • Cryptosporidiosis, Cylosporiasis, Isosporiasis. Parasitic infections associated with diarrhoea:
Mode of Infection Insufficiently salted and grilled fish (encysted metacercaria) Ancylostoma and Strongyloides Heterophyes heterophyes T.Spiralis (encysted larva) C. philippinensis (infective larva in fish intestine) Ascaris, Giardia, Cryptosporidium
Mode of Infection of Tape worms Beef (cysticercus bovis) Pork (cysticercus cellulosae) T.saginata Salmon (plerocercoid larva) T.solium D.latum Rat flea (cysticercoid nana, diminuta) D.caninum H.nana, H.diminuta Dog flea(cysticercoid caninum)
Stool Examination for helminths causing diarrhoea reveals Heterophyes egg Capillaria egg Ancylostoma egg Fetilized & unfertilized Ascaris egg H.nana egg H.diminuta egg Taenia egg or segment Strongyloides larva
Stool Examination for Protozoa causing diarrhoea By MZN stain G.Lamblia cyst By immunofluorescence G.Lamblia trophozoite Cryptosporidium oocysts Unstained Intestinal Microsporidia (1.2x5µ) By MZN stain Cyclospora oocysts Unstained By MZN stain Isospora belli oocyst
Complications • Amoeboma. • Perforation of ulcer. • Haemorrhage. • Stricture of colon. • Appendicitis
Haematogenous spread of Entamoebatrophozoites Brain abscess Trophozoite Lung abscess Histolytic enzymes Skin abscess Liver abscess Blood vessel
Give reason Schistosoma can evade the immune system Patient’s RBCs Schistosoma can evade the immune system by: - antigen disguise. - antigen mimicry. Similar to patient’s antigens - antigen shedding. - Cause inactivation of complement by protease activity. eosinophil Mast cell - Produce blocking antibodies.