Revision
Give reasons for
• Detection of Fasciola egg in the stool is not always diagnostic for fascioliasis
• Control of Heterophyes heterophyes is difficult
• Taenia solium infection is more dangerous than T. saginata.
• H. nana infection is common in children.
• Anaemia usually complicates D. latum infection.
• Ingestion of undercooked pork meat is dangerous.
• Ascariasis should be treated before surgical operations.
• Eggs of E. vermicularis may be detected in urine samples.
• Anaemia in trichuriasis.
• Heterophyes heterophyes is common in North Delta, Egypt.
• The hazards of eating undercooked fish.
• Chronicity of Strongyloides stercoralis infection.
• Hyperinfection in capillariasis.
• Accidental ingestion of fleas is potentially dangerous.
• Puncture and aspiration of hydatid cyst fluid is a risky procedure.
• Stool examination is usually not sufficient for the diagnosis of enterobiasis.
• Halzoun syndrome.
Case
An Egyptian farmer complained of general weakness and recurrent fainting attacks. Clinically, there was severe pallor. Blood examination revealed severe anaemia (Hb level: 6 gm/dl.) and eosinophilia. Stool examination showed immature, colorless, oval eggs with blunt poles.
• What is the expected causative parasite? • What is the infective stage and mode of
infection?• What is the drug treatment?• What is the type and cause of anaemia in this
case?
A male patient aged 30 years came complaining of chronic headache and recurrent epileptic fits. Blood examination revealed eosinophilia. CT imaging of the brain showed multiple lesions (1.5- 2 cm). On routine stool exam., there were spheroid mature eggs (30- 40 µ).
• What is your provisional diagnosis?• How would you confirm the diagnosis?• What is the treatment of this case?• How was this patient infected with the cerebral
lesions?
Enterotest• Fasciola• Strongyloides stercoralis• Capillaria philipinensis
Parasites transmitted by autoinfection
• T. solium• H. nana• S. stercoralis• E. vermicularis• C. philipinensis
Parasites transmitted by fish
• Heterophyes• Paragonimus• D. latum• Capillaria philipinensis
Parasites transmitted by meat
Beef meat:
T. saginata
Pork meat:
T. solium
T. spiralis
Parasites transmitted by eating raw vegetables
• Fasciola (encysted metacercaria).• Hymenoleis nana (eggs).• Cysticercosis (eggs).• Hydatid cyst (eggs).• Coenurus cerebralis (eggs).• Enterobius vermicularis (eggs).• Ascaris lumbricoides (eggs).• Visceral larva migrans(eggs) • Trichuris trichiura (eggs).• Trichostrongylus colubriformis (Larvae).
Parasites transmitted by oral route
Parasites transmitted by skin penetration
• Schistosoma• Hook worms• Strongyloides stercoralis• Filariae
Parasites transmitted by walking bare foot
Hook wormsStrongyloides stercoralis
Parasites causing diarrhea• Heterophyes heterophyes• T. solium, saginata.• H. nana, H. diminuta, D. caninum• D. latum• Trichinella spiralis• Strongyloides stercoralis.• Trichostongylus cloubriformis• Capillaria philipinensis• Ascaris lumbricoides• Hook worms
Parasites causing dysentery
• Schistosoma mansoni• Trichuris trichura
Charcot−leyden crystals
• In sputum:
Paragonimus• In stool:
Trichuris trichura
Parasites causing cutaneous manifestations
• Schistosoma• Paragonimus• Cysticercosis• Sparganosis• Hook worms• Strongyloides ( larva currens)• Enterobius• CLM.• Lymphatic filariasis.• Onchoerca volvulus.• Loa loa• Draculculus medinensis
Parasites causing itching
• Cercarial dermatitis & Swimmer’s itch• Ground itch• CLM
Parasites causing perianal itching
Enterobius vermicularisTaenia saginata
Parasites causing anaemia
• Hookworms .• Diphyllobothrium latum.• Trichuris trichiura.• Schistosoma species.• Fasciola
Parasites causing eosinophilia
• High (30-80%)Trichinella
Toxocara
Fasciola
• Moderate (10-30%)Hookworms
Strongyloides
Filariasis.
Parasites causing intestinal obstruction
• Taenia• D. latum• Ascaris
Parasites causing appendicitis
• Taenia saginata• Ascaris lumbricoides• Enterobius vermicularis• Trichuris trichura
Parasites causing jaundice
• Fasciola• Ascaris lumbricoides• Strongyloides stercoralis• Hydatid cyst
Parasites affecting small intestine
• Heterophyes heterophyes• T. solium, T. saginata.• H. nana, H. diminuta, D. caninum• D. latum• Ascaris lumbricoides• Trichinella spiralis.• Hook worms• Stongyloides stercoralis.• Trichostongylus cloubriformis• Capillaria philipinensis
Parasites affecting large intestine
• Schistosoma mansoni• Trichuris trichura• Enterobius vermicularis
Parasites affecting Heart• Heterophyes heterophyes (Egg emboli)• Schistosoma (egg emboli)• Cysticercosis• Hydatid cyst.• Trichinella spiralis• Lymphatic filariasis in chylopericardium• Mansonella perstans & Mansonella ozzardi
(in the pericardium).
Parasites affecting brain
• Schistosoma (egg emboli)• Heterophyes heterophyes (egg emboli)• Cysticercosis• Hydatid disease• Coenurus cerebralis
Parasites affecting eye
• Cysticercosis• Sparganosis• Ocular larva migrans• Loa loa• Onchocerca volvulus
Parasites affecting liver
• Fasciola• Schistosoma• Hydatid cyst• Cysticercus cellulosae• VLM
Parsites affecting muscles
• Trichinella spiralis• Cysticercosis• Sparganosis
Parasites affecting lung
• Paragonimus westermani• Hydatid cyst• Cysticercus cellulosae• Lymphatic filariasis in chylothorax• Migrating nematode larvae e.g.
Ascaris, hook worms, Strongyloides• Schistosomula
Role of dogs in transmission of parasitic infections
• Ecchinococcus granulosus• Dipylidium caninum• CLM• VLM• Reservoir host for: Heterophyes
Paragonimus
D. latum
Capillaria philipinensis
Role of pigs in transmission of parasitic infections
• Taenia solium• Trichinella spiralis
Role of rats in transmission of parasitic infections
• Hymenolepis nana• Hymenolepis diminuta
Parasites require two I.H.
• Heterophyes heterophyes• Paragonimus westermani• Diphyllobothrium latum• Diphyllobothrium mansoni
Man act as I.H. in:
• Hydatid disease• Cysticercosis• Coenurus cerebralis• Sparganosis• Hymenolepis nana• Trichinella spiralis
Eggs immediately infective to man
• Taenia solium• Hymenolepis nana• Echinococcus granulosus• Multiceps multiceps• Enterobius vermicularis
Transparent eggs
Schistosoma eggs
Hymenolepis nana. Trichostrongylus colubriformis.Strongyloides stercoralis.Hookworms.Enterobius vermicularis.
Mature eggs
• Heterophyes heterophyes.• Shistosoma mansoni,japonicum& haematobium.• All cestode eggs except D.latum.• Enterobius vermicularis.• Strongyloides stercoralis.
Operculated eggs
• Fasciola • Heterophyes heterophyes .• Paragonimus westermani. • Diphyllobothrium latum .
Eggs with thin shell
• Fasciola• Schistosoma• Hookworms.• Strongyloides stercoralis.• Trichostrongylus colubriformis
Eggs with thick shell
• Heterophyes heterophyes.• Paragonimus westermani• Diphyllobothrium latum• Trichuris trichura .• Capillaria philippinensis.
Parasites detected in stool
• Eggs of most helminthes.• Scolices & segments of most
cestodes.• Larvae of some nematodes.• Adults of some nematodes.
Parasites detected in sputum
• Eggs of Paragonimus.• Hydatid sand• Migrating larva stages of :-
A. lumbricoides.
Hookworms.
S. stercoralis .
Parasites detected in urine
• Eggs of Schistosoma haematobium.• Hydatid sand.• Entrobius vermicularis (In females).• Larva of S. stercoralis .• Microfilaria of W.bancrofti.• Larvae of Dracunulus medinensis