Lab 11: Trematodes

* Schistosoma japonicum
* Schistosoma mansoni
* Schistosoma haematobium

Blood flukes

Schistosomiasis or Bilharziasis

Schistosoma spp: Disease

IH: Freshwater snail

Schistosoma spp: Intermediate host

Mammalian host

Schistosoma spp: Definitive host

Skin penetration of cercariae

Schistosoma spp: MOT

Miracidium

Schistosoma spp: Infective stage to snail

Forked tail cercariae

Schistosoma spp: Infective stage to man

Embryonated egg

Schistosoma spp: Diagnostic stage

230

Schistosoma spp:

Total no of cercariae shed in whole infection: Single infection

280

Schistosoma spp:

Total no of cercariae shed in whole infection: Multiple infection

Manson’s Blood fluke

Schistosoma mansoni common name

Biomphalaria

Schistosoma mansoni IH

Vesical blood fluke

Schistosoma haematobium common name

Bulinus

Schistosoma haematobium IH

Oriental Blood fluke

Schistosoma japonicum common name

Oncomelania

Schistosoma japonicum IH

* Veins of colon
* Stool, Rectal biopsy

Schistosoma mansoni: Habitat & Specimen

* Veins of urinary bladder
* Urine

Schistosoma haematobiumi: Habitat & Specimen

* Veins of small intestine
* Stool, Rectal biopsy

Schistosoma japonicum: Habitat & Specimen

Schistosoma japonicum, egg

* Ovoid, round, pear shaped
* Pale yellow
* Thin shell
* Small lateral spine

Schistosoma japonicum, egg

Schistosoma japonicum, egg

Schistosoma mansoni, egg

* Oblong
* Large lateral spine

Schistosoma mansoni, egg

* Oblong
* Large terminal spine

Schistosoma haematobium, egg

Schistosoma haematobium, egg

500-2000 immature eggs

Schistosoma japonicum, adult

Adult female deposits ________________/ day

gynecophoral canal

\[S. japonicum\]

Adult male has _____________ that receives the adult female in copulation

Swimmer’s itch

dermatitis with pruritis; localized reaction to the cercarial penetration

* Swimmer’s itch
* Katayama fever/ Snail Fever
* Cor pulmonale
* Distended belly

symptoms of schistosomiasis

Katayama fever/ Snail Fever

hypersensitivity reaction to the schistosomula migration

Cor pulmonale

obstruction of the pulmonary vasculature

recovery of eggs in stool or rectal imprint/biopsy spx.

Lab diagnosis for S. japonicum, S. mansoni

eggs are recovered from urine spx.

Lab diagnosis for S. haematobium

* Kato Katz Technique - most suitable for egg quantification
* MIFT
* Immunodiagnostic techniques Intradermal test, ELISA, COPT, Indirect hemagglutination

Lab diagnosis for Schistosomiasis

Paragonimiasis, Pulmonary distomiasis

Paragonimus westermani: Disease

Ingestion of undercooked/raw crabs infected with metacercariae

Paragonimus westermani: MOT

Lung

Paragonimus westermani: Habitat

Antemelania asperata, Antemelania dactylus (snails)

Paragonimus westermani: 1st IH

Sundathelphusa philippina (mountain

Paragonimus westermani: 2nd IH

Human

Paragonimus westermani: DH

Unembryonated egg

Paragonimus westermani: Diagnostic stage

Metacercariae

Paragonimus westermani: Infective stage

Paragonimus westermani, adult

* Reddish brown
* Coffee bean
* Rounded anteriorly
* Slightly tapered posteriorly

Paragonimus westermani, adult

Paragonimus westermani, adult

Paragonimus westermani, egg

* Oval
* Yellowish brown
* Flattened, prominent operculum
* Thickened abopercular portion

Paragonimus westermani, egg

Paragonimus westermani, egg

* Pulmonary Distomiasis /Paragonimiasis
* Cerebral paragonimiasis

Paragonimus westermani: Clinical manifestation

Pulmonary Distomiasis/Paragonimiasis

mimics Pulmonary tuberculosis symptoms

Cerebral paragonimiasis

migration of immature P. westermani leading to serious neurologic condition

Recovery of eggs from sputum/feces (when swallowed)

Paragonimus westermani: Lab diagnosis

T

\[Paragonimus westermani\]

T/F: If initial findings in sputum are negative, repeat examination up to three times on different days provides best sensitivity for microscopic analysis

* CT scan, MRI - characteristic findings of “grape cluster” app (posterior part of the)
* Skull Radiograph - soap bubble calcifications

Lab diagnosis for Cerebral paragonimiasis

* Fasciolopsis buski
* Echinostoma ilocanum
* Artyfechinostomum malayanum

Intestinal flukes

Fasciolopsis buski

Common name: Giant Intestinal fluke

Ingestion of encysted metacercariae from aquatic plants

Fasciolopsis buski: MOT

Duodenum

Fasciolopsis buski: Habitat

Segmentina or Hippeutis (

Fasciolopsis buski: 1st IH

Water caltrop, Water chestnut, Morning glory (kangkong), Lotus

Fasciolopsis buski: 2nd IH

Humans, pigs

Fasciolopsis buski: Definitive host

Unembryonated egg

Fasciolopsis buski: Diagnostic stage

Metacercariae

Fasciolopsis buski: Infective stage

Fasciolopsis buski, adult

* Large, oval
* Unbranched intestinal ceca
* does not have a cephalic cone

Fasciolopsis buski, adult

Fasciolopsis buski, adult

Fasciolopsis buski, egg

* Large
* Operculated
* Unembryonated when first passed

Detection of parasite eggs in stool

Fasciolopsis buski: Lab diagnosis

* Traumatic - inflammation and ulceration
* Obstructive - heavy infection
* Toxic - absorption of worm metabolites by the host

Fasciolopsis buski: Clin. manifestation

Echinostoma ilocanum

Garisson’s fluke

Ingestion of metacercariae encysted in snails

Echinostoma ilocanum: MOT

Duodenum

Echinostoma ilocanum: Habitat

Gyralus, Hippeutis (Snails)

Echinostoma ilocanum: 1st IH

Pila luzonica and Vivipara angularis

Echinostoma ilocanum: 2nd IH

Miracidium

Echinostoma ilocanum: IS to 1st IH

Cercariae

Echinostoma ilocanum: IS to 2nd IH

Metacercariae

Echinostoma ilocanum: IS to DH

Humans

Echinostoma ilocanum: DH

Unembryonated eggs

Echinostoma ilocanum: DS

Echinostoma ilocanum, adult

* Reddish gray
* Tapered posterior end with 49-51 collar spines surrounding the oral sucker
* Simple intestinal ceca

Echinostoma ilocanum, adult

Echinostoma ilocanum, adult

Echinostoma ilocanum, adult

Echinostoma ilocanum, egg

* Straw colored
* Ovoid
* Operculated

Echinostoma ilocanum, egg

Echinostoma ilocanum, egg

Detection of parasite eggs in stool

Echinostoma ilocanum: Lab diagnosis

Ingestion of metacercariae encysted in fish

Heterophyid flukes: MOT

Small Intestine

Heterophyid flukes: Habitat

Snail

Heterophyid flukes: 1st IH

Freshwater, Brackish Water Fish

Heterophyid flukes: 2nd IH

Cercariae

Heterophyid flukes: IS to 2nd IH

Humans, other fresh eating mammals

Heterophyid flukes: DH

Embryonated egg

Heterophyid flukes: DS

base of the fin

\[Heterophyid flukes\]

Metacercariae are frequently found in the muscles at the ___________

Heterophyes heterophyes

Von Siebold’s fluke

Heterophyes heterophyes, egg

* Light brown
* With developed miracidium
* Thick shell
* Discrete shoulder

Metagonimus yokogawai

Smallest human fluke

Metagonimus yokogawai, egg

* Light brown
* With developed miracidium
* Thin shell
* Discrete shoulder