1. Common Clinical Presentations of Parasitic Infections
Parasites causing this clinical presentation
How did the parasite produce this presentation (Pathogenesis)
Mode of infection
Jaundice
Bronchial asthma
Diarrhoea
Appendicitis

2. Jaundice
Yellowish coloration of skin and sclera with high bilirubin level in blood
Fascioliasis
Schistosomiasis.
Hydatid disease.
Ascariasis.
Amoebiasis.
Toxoplasma.
Falciparum malaria
Cell damage

3. 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 host RBCs
Haemolysis of RBCs haemolytic anaemia
The patient suffers from jaundice
& Haemoglobinuria

4. 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

5. Mode of Infection
5- Contamination of mucous membrane & skin abrasion (in research workers & butchers)
Tachyzoites

6. Means: difficulty in breathing
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

7. How can Parasites Produce Bronchial asthma?
Eosinophilic pneumonia
Allergic dermatitis ?
Helminths antigens & metabolic byproducts
Fab
IgE is produced Fc
Receptor for IgE
Eosinophil
Become activated
Receptor for IgE
Mast cell
Produce
Mediators (substances)
Broncho-spasm
Pneumonitis
Urticaria
Become activated

8. Means: inflammation of appendix
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

9. Increase in frequency, fluidity or volume of bowel motions
Diarrhoea
Increase in frequency, fluidity or volume of bowel motions
Parasitic infections associated with diarrhoea:
- Heterophyiasis
All tape worm infections
Ancylostomiasis
Ascariasis
Strongyloidiasis
Trichinosis
Capillariasis
Giardiasis
Cryptosporidiosis, Cylosporiasis, Isosporiasis.

10. 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

11. 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)

12. 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

13. 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

14. Complications Amoeboma. Perforation of ulcer. Haemorrhage.
Stricture of colon.
Appendicitis

15. Haematogenous spread of Entamoeba trophozoites
Brain abscess
Trophozoite
Lung abscess
Histolytic enzymes
Skin abscess
Liver abscess
Blood vessel

16. 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.