The body is long and narrow, dorsally and ventrally flat, the front end is slightly narrow, and the rear end is blunt, shaped like a sunflower seed, without spines on the body surface, androgynous.

See overview

Shaped like sesame, light yellowish brown

One end is narrower and has an egg cover

Acromion (thickening of the egg shell around the egg cover)

Eggs containing miracidia

Parasitizes the liver and bile ducts of humans (definitive hosts) and cats, dogs and pigs (parasitoid hosts), and is occasionally found in the pancreatic ducts

The bile is excreted in the feces and enters the water, where it is swallowed by freshwater snails (the first intermediate host) and hatches into miracidia.

Cercariae escape from the snail and enter the water

When encountering freshwater fish in the water, shrimps (the second intermediate host) invade their muscles and develop into metacercariae.

Fish and shrimp are swallowed by the definitive host and develop into adult worms in the liver and bile ducts

Liver damage (major)

No obvious clinical symptoms

Acute phase - allergic reaction (not obvious in most patients)

Chronic - various symptoms of the digestive tract, hepatosplenomegaly (the patient gradually appears after several years)

Dizziness, weight loss, edema, anemia, cirrhosis, death

Detection rate: duodenal bile drainage > egg collection method > modified Kato thick smear method

Huge oblong shape, flat dorsoventrally, narrow front and wide back, fleshy red, rich and thick muscles

See overview

Long oval, light yellow

The largest worm egg among human parasites

There is an inconspicuous egg cover at one end

Parasitizes in the upper part of the small intestine of humans (definitive host) and pigs (insect-protecting host), and the eggs enter the water with the feces

The miracidia hatch out and invade the snail (intermediate host)

Cercariae enter the water

develop into metacercariae in water

Devoured by final host

Mechanical injury, hypersensitivity reaction

Abdominal pain, diarrhea, intestinal obstruction

saline smear method

sedimentation egg collection method

Thick soybean size, red flesh

Overview

golden yellow, oval

The front end is wide and the back end is narrow, with a flat egg cover.

Parasitizes in the lungs of humans (definitive host) and carnivorous mammals (parasitized host) (ectopic parasitism: liver, brain, subcutaneous and muscle), and the eggs enter the water with sputum/feces

Milcariae hatch and invade freshwater snails (the first intermediate host)

Cercariae are ingested by river crabs and mantis crickets (second intermediate hosts) and develop into metacercariae

When crabs and crickets are ingested by humans, the metacercariae mature into larvae in the upper part of the small intestine and begin to migrate.

Mild - general symptoms

Severe case - systemic allergic reaction

thoracopulmonary type

Sodium hydroxide centrifugal sedimentation microscopy

sedimentation egg collection method

Dioecious, the female is located in the gynecomastia groove and mates with the male

The insect body is cylindrical and looks like a nematode

The oral and abdominal suckers are located at the front of the insect body

Oval, light yellow

There is no egg cover, and there are small comma-shaped spines on one side of the egg shell.

Contains mature miracidia, and oily drop-like miracarial secretions can be seen between the miracidia and egg cases.

Forked tail type

Parasitizes the portal-mesenteric venous system of humans (definitive hosts), buffalo and other mammals (insect-protecting hosts), and egg deposition can occur

Mature eggs are in the blood and cannot hatch in the intestines. They can only hatch under certain conditions when they enter the water with feces and hatch out miracidia.

Invades Hubei snails (intermediate host) and reproduces asexually to produce giant polycercariae

It invades through contact with human skin in water (mode of infection). It becomes a child worm when it invades and matures.

Migration: skin → lung → liver → mesenteric vein

cercarial dermatitis

pneumonia

Hot flashes, back pain, cough, loss of appetite, diarrhea

Endophlebitis

Deposited in small veins of liver and intestinal wall, forming granulomas