trematodes pt.2 Flashcards
Clonorchis sinensis
- aka
- its disease
- endemic areas
Chinese liver fluke
Oriental liver fluke
disease:
Clonorchiasis
Chinese liver fluke infection
endemic areas:
Japan
Korea
Taiwan
China
Vietnam
what are the intermediate host of Clonorchis Sinensis
1st intermediate host:
snails under the genus of
- Parafossarulus
- Bulimus
- Semisulcospira
- Alocinma
- Melanoides tuberculatus
2nd intermediate host:
- fresh water fishes of family Cyprinidae such as Ctenopharyngodon idellus (most common source of infection for Clonorchis sinensis)
morphology of Clonorchis sinensis adult worm
flat, transparent, spatulate body
pointed anteriorly and rounded
posteriorly
briefly explain the diagnosis of Clonorchis sinensis
- macroscopic examination
- detect of eggs in feces or aspirated bile
- identify of adult worm extracted during surgical treatment (rare) - entero test
- collect duodenal aspirates w/o requiring intubation
- patient swallows a gelatin capsule that contains coiled length of yarn and the capsule will dissolve in the stomach and then the free end of the string is attached to the patient’s neck or cheek with tape
- then up for incubation period, after that the yarn is pulled back out of the patient then prepare for staining
briefly explain the treatment and prevention and control of Clonorchis sinensis
★ Treatment
1. Drug of choice is:
- Praziquantel (75 mg/kg/day orally, 3 doses per day for 2 days).
2. Surgical intervention
- in cases of obstructive jaundice
★ Prevention and Control
1. Proper cooking of freshwater fish
2. Proper disposal of faeces
3. Control of snails
4. Treatment of cases
Fasciola hepatica
Disease:
Diagnostic stage:
Infective stage:
1st intermediate host:
2nd intermediate host:
Habitats in adults:
Main route of infection:
Disease:
Fascioliasis
- aka “sheep liver fluke”
- also called fascioliasis hepatica or sheep liver rot
Diagnostic stage:
unembryonated eggs in the feces
Infective stage:
metacercariae on aquatic plants
1st intermediate host:
snails
2nd intermediate host:
freshwater or aquatic plants
Habitats in adults:
liver
Main route of infection:
ingestion of contaminated or raw plants
Fasciola hepatica, mode of infection
humans, sheep, or cattle become infected when consume:
contaminated or uncooked water plants carrying the metacercariae
what happens when Fasciola hepatica enters the body
- metacercariae go to the duodenum (first part of the small intestine).
- break out of their cysts, penetrate the intestinal wall, and travel through the peritoneal cavity.
- eventually reach the bile ducts in the liver.
damage they caused:
- adult flukes live in the bile ducts :
Cause chronic inflammation
Lead to bile duct blockage
Result in liver damage
morphology of Fasciola hepatica egg
Large, oval, and operculated (has a lid-like cap)
Size: 140 µm × 80 µm
Unembryonated when passed in feces
Note: The eggs of Fasciola hepatica and Fasciolopsis buski look identical under the microscope.
hosts of Fasciola hepatica
1st Intermediate Host (Snail):
Lymnaea philippinensis
2nd Intermediate Host (Plant):
Nasturtium officinale
(commonly known as watercress)
what parasite causes Fasciola hepatica
Caused by the Fasciola hepatica worm
Adult worms live in the bile ducts of the liver
- they appear rolled like a mat in the liver’s bile passages
briefly explain the diagnosis of Fascioliasis
- Microscopic examination
- detect unembryonated eggs in feces or aspirated bile. - Imaging
- ultrasound and CT abdomen.
treatment and prevention and control of Fascioliasis
★ Treatment
● Triclabendazole
- (single oral dose of 10 mg/kg)
- the treatment of choice.
● Bithionol
- alternative drug
★ Prevention and Control
1. Prevent pollution of water courses with sheep and cattle feces
2. Proper sanitation
3. Wash watercresses and other water vegetations, preferably in hot water or cook well before consumption
Opisthorchis viverrini, common disease name
Opisthorchis viverrini
- Often asymptomatic, but symptoms (if any) may look like Clonorchiasis
- common in thailand
- linked to caner: can cause cholangiocarcinoma (bile duct cancer)
*e life cycle and other features of Opisthorchis are similar to Clonorchis.
morphology of Opisthorchis viverrini
- adult worms
- eggs
Adult worm:
- lobe-shaped testes
Egg:
- similar in morphology to that of
Clonorchis
treatment for Opisthorchis viverrini
Praziquantel (75 mg/kg/day orally, 3 doses per day for 2 days)
- drug of choice
what are the 2 intestinal flukes
- Fasciolopsis buski
- Echinostoma ilocanum
Fasciolopsis buski
Diagnostic stage:
Infective stage:
1st intermediate host:
2nd intermediate host:
Habitat of the adult:
Sporocysts:
Diagnostic stage:
unembryonated eggs that are passed in the feces into the freshwater
Infective stage:
metacercariae
1st intermediate host:
freshwater snails
- Segmentina hemisphaerula
- Hippeutis cantori
2nd intermediate host:
water plants
- Water caltrop (Trapa natans, Trapa bicornis)
- Water chestnut (Eliocaris tuberosa)
- Lotus
- Water bamboo
- Other edible water plants
Habitat of the adult:
small intestines
Sporocysts:
asexual reproduction
Fasciolopsis buski
common disease name:
epidemiology:
how infection happens:
common disease name:
Fasciolopsiasis
epidemiology:
Central and south China
Taiwan
Vietnam
Thailand
Borneo
Sumatra
Bengal
nearby areas
*can infect humans, pigs, and even some dogs in China
how infection happens:
People or pigs become infected by eating raw or undercooked aquatic plants with metacercariae (infective stage)
The larvae develop into adult flukes in the small intestine
diagnosis of Fasciolopsis buski
in feces:
- unembryonated eggs
- adult worms
treatment and prevention and control of Fasciolopsis buski
★ Treatment
Praziquantel (75 mg/kg/day orally in 3 divided doses for 1day)
- treatment of choice
Hexylresorcinol
Tetrachlorethylene
★ Prevention and Control
1. Treatment of infected cases
2. Wash water vegetations, preferably in hot water or cook well before consumption
3. Prevent contamination of ponds and other water sources with pig or human excreta
4. Control of snails
Echinostoma ilocanum
disease name:
aka:
1st intermediate host:
2nd intermediate host:
disease name:
Echinostomiasis
Also known as:
“Garrison’s Fluke”
1st intermediate host:
- Planorbid snails such as
Gyraulus convexiusculus
Hippeutis umbilicalis
2nd intermediate host:
- large snails such as
Pila conica
Pila luzonica (kuhol)
Viviparus javanicus
diagnosis of Echinostoma ilocanum
microscopic examination
- detect unembryonated eggs in feces
treatment and prevention and control of Echinostoma ilocanum
★ Treatment
Praziquantel
- drug of choice
★ Prevention and Control
1. Refrain from eating raw or inadequately cooked snails
2. Molluscicides to kill snail hosts.
3. Proper and sanitary procedures of human waste disposal
4. Public education
