Liver flukes, also known as Fasciola hepatica, are parasites that cause the liver fluke disease known as Fascioliasis in the liver of human beings. The liver fluke parasite falls under the phylum Platyhelminthes. The liver fluke disease is caused when immature liver fluke parasites migrate through the liver and are sometimes caused by the presence of bile ducts, or sometimes both. Liver fluke infects all grazing animals like sheep, cattle and mammals like human beings. Liver fluke parasites occur in regions around water bodies like river banks, slow streaming rivers, irrigation channels, as all these areas are suitable for hatching eggs of the liver fluke. The infestation of these parasites in animals like sheep, cattle has caused great descent in agricultural industry production.
Let’s look at the life cycle of liver fluke to get a better understanding.
Life Cycle of Liver Fluke
1) The Egg – Stage 1 –
After fertilization, the adult female live fluke parasite passes immature eggs in the bile duct and comes out into the environment through the feces. If and when the eggs come in contact with water, the eggs become embryonated and form into a larvae called miracidia.
2) The Intermediate Host – Stage 2 –
A miracidia larvae infects a snail and the miracidia larva transforms into cercaria larvae. Here, the snail acts as an intermediate host and the cercaria larvae has a long tail that helps them swim in water. The cercaria larvae grows, leaves the snail host and looks for vegetation, where it forms cysts called metacercariae. Metacercariae states the infective stage in animals like sheep and cattle and in human beings. Metacercariae have a rigid hard outer layer, which helps them live for long periods of time. When and if human beings consume the raw freshwater plant or fish contaminated with the cysts, the cysts release immature eggs into the small intestine of the human host.
3) The Young Fluke – Stage 3 –
The fluke parasite penetrates the small intestinal wall and enters the peritoneal cavity. After this, it finds the liver and the parasite starts feeding on liver cells. This occurs a few days after the host comes in contact with the parasite. After eating plenty of liver cells, the young flukes migrate to the bile duct and transform into adult liver flukes.
4) The Adult – Stage 4 –
The metacercariae transforms into an adult liver fluke parasite after around three months. An adult liver fluke measures up to 3 cm in length. A gravid adult female liver fluke can produce 20,000 to 25,000 eggs per day.
Liver flukes are primarily large, flat parasitic worms that are found in the liver, causing a disease known as fascioliasis. Liver fluke parasites are most prominent in parts of Australia as well as in regions with several water bodies like irrigation channels, slow-streaming rivers and so on.
Frequently Asked Questions on Liver Fluke Life Cycle
How does one know they have liver fluke?
At first, the ingestion of the parasite will not show any symptoms, depending upon the species. However, later when the parasite becomes infective, it shows symptoms like fever, chills, abdominal pain, liver inflammation, nausea and so on.
Are liver flukes contagious?
Liver flukes are not contagious and cannot transfer from one person to the other. They spread from contaminated fish or water that humans consume.
How big are liver flukes?
The liver fluke measures up to 15mm in length and 0.1 mm in width, in size.
Can one see liver fluke in stool?
Eggs of Clonorchis, Opisthorchis or Fasciola are seen in the feces of the human host. It can also be found in the small intestine.
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