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