Presentation on theme: "Parasitology is classified into three main groups Protozology (proto = primitive) Study of protozoa Helminthology (Helminth = Worm ) Study of helminth."— Presentation transcript:
Parasitology is classified into three main groups Protozology (proto = primitive) Study of protozoa Helminthology (Helminth = Worm ) Study of helminth Entomology Study of arthropods
Helminthology Helminths Helminths (worms) are multicellular parasites. They are divided into: 1- Round Worms 2- Flat Worms (Nemathelminths) (Platyhelminths) Class Nematoda (Flukes) (Tape worms) Class Trematoda Class Cestoda
General characters Flat worms (no cavity), not segmented, bilaterally flattened (except Schistosoma is cylindrical) Hermaphrodite (except Schistosoma) Body has 2 suckers for attachment : oral, ventral, (except Heterophyes has a 3 rd genital sucker.
General characters Life cycle show sexual phase (defenitive host) and asexual phase (intermediate host) Require one or more intermediate host 1 st intermediate host is a snail. Eggs have an operculum. Infective stage is encysted metacercaria. (except Schistosoma: cercariae)
Location of adult: Small intestine Intermediate host: Primary: Pirenella conica. Secondary: Bolti and Bouri fish. Infective stage: Encysted metacercaria. Mode of transmission: Ingestion of raw fish containing encysted metacercaria. Diagnosis: Eggs in stool. Disease: Heterophiasis.
Location of adult: Bile duct. Intermediate host : Primary : Snail Lymnaea truncatula for F.hepatica and Lymnaea. Cailliaudi for F. gigantica. Secondary: leaves of fresh-water plants. Mode of transmission: Ingestion of raw water-cress containing encysted metacercariae. Infective stage: Encysted metacercaria. Diagnosis: Eggs in stool. Disease: Fascioliasis. Fasciola sp. cont.
a. Schistosoma mansoni Schistosoma mansoni male: 8-10 mm, has gynacophoric canal, dorsal surface covered with tubercle (4X) Schistosoma mansoni female: 14 mm, taller and thinner,vitelline glands occupy 2/3 of the body( 4X) Schistosoma sp.
Schistosoma mansoni snail Biomphlaria alexandrina Cercaria of Schistosoma mansoni : elongated head, biforked tail (H.P) Schistosoma mansoni egg: oval with lateral spine (H.P) a. Schistosoma mansoni cont.
b. Schistosoma hematobium Egg: oval with terminal spine (H.P) Snail: Bulinus truncatus
Schistosoma mansoniSchistosoma hematobium Location Veins of large intestine, colon (lower mesentric vein Veins of urinary bladder (venous plexus of urinary bladder Interm. host Biomphalaria alexandrina Bulinus truncatus DiagnosisEggs in stoolEggs in urine Infective stageCercariae Mode of transmission Direct skin penetration of cercariae during swimming Disease:Intestinal BilharziasisUrinary Bilharziasis
Helminthology Questions form: Name and sex of the parasite Class to which the parasite belongs Location in the host Intermediate host Definitive host Infective stage Mode of transmission Lab diagnosis Disease