[Biology Class Notes] on Liver Fluke Life Cycle Pdf for EXAM

Numerous parasites that live in the human body can lead to a number of diseases, which may range from mild to very life-threatening. Liver fluke, scientifically known as Fasciola hepatica are parasites that can live in the liver of living beings and can lead to liver fluke disease. This condition is also called Fascioliasis. 

What do We Understand by Liver Fluke?

These are parasites that can be present in the livers of most mammals and they can lead to liver fluke disease. The parasite falls into the phylum Platyhelminthes. They can cause the disease by entering the liver and the bile duct. These parasites are usually seen around watery areas since the environmental conditions are ripe for them to lay eggs. 

What are the Various Life Stages for Liver Fluke?

The liver fluke parasite goes through certain life stages. It is important to know this to understand the stage at which the infection can occur.

Stage 1- The Egg

Immature eggs are laid by the parasites in the bile duct and they are excreted out with the waste produced. Once they come into contact with water, these eggs can hatch and form larvae, which is known as miracidia.

Stage 2- Intermediate Host

In this stage, the parasite first infects a host that it uses only as an intermediary to get to its final host. For example, it can infect a snail and grow into bigger larvae, and once this is done they abandon the host’s body and move around independently. These develop and become bigger and then they are ready to move on to bigger hosts such as animals and human beings.

Step 3- Young Fluke

After stage 2 the small intestine wall is penetrated by the fluke parasite and it enters into the peritoneal cavity. Next, it directly comes in contact with the liver and it begins feeding on liver cells. The above phenomenon happens a few days after the host comes in contact with the parasite. The young flukes enter into the bile duct and transform into adult liver flukes after eating numerous liver cells.

Stage 4- Adult

It takes approximately three months for the transformation of the metacercariae into the adult liver fluke. The approximate length of an adult liver fluke is around 3 cm. An adult female liver fluke can lay 20,000 to 25,000 eggs per day in her last stage of pregnancy. 

What are the Symptoms of Liver Fluke Infection?

There are various symptoms of liver fluke disease which are:

• Acute abdominal pain

• Fever

• Vomiting

• Nausea

• Diarrhea

• Hives

• Malaise

Apart from the above-mentioned symptoms, there may be some other rare complications associated with heavy liver fluke infections which include the formation of stone, recurrent infections of the biliary system, and cholangiocarcinoma (bile duct cancer).

What are the Treatment Options for Liver Fluke Infection?

Medication or Surgery:

Liver flukes can be cured completely with the help of medication. The most common medication to treat liver fluke is triclabendazole. Generally, the drug is given in one or two doses orally and most people soundly respond to this treatment. Sometimes doctors prescribe a short course of corticosteroids for severe phases with acute symptoms. In very rare cases surgery is required for related long-term complications such as cholangitis (infection of the bile duct).

Alternative Treatments:

There are some alternative and unusual therapies for parasite infection. It is recommended to take goldenseal for parasitic infections, parasite cleanses, and colonic irrigation. 

How to Get Relief from Liver Fluke Symptoms?

Acetaminophen (Tylenol) can be taken to get relief from abdominal pain and to reduce fever. Nausea and vomiting can be reduced by anti-nausea medications. But the root of the disease cannot be treated by these medications. Hence, diagnosing the liver fluke infection and commencing the treatment as early as possible is always suggested.

Are there Risk Factors for Liver Fluke Disease?

Yes, certain parts of the world see a greater occurrence of this disease compared to others. Usually, unsanitary and unhygienic conditions can cause this problem. While it may not be directly a communicable disease, family members of the patient can also get affected. 

How is this Disease Diagnosed?

A stool sample is taken and eggs can be identified from that. This would mean that the parasite has moved to the bile duct. The enzyme-linked immunosorbent assay (ELISA) test can diagnose this disease very accurately.

Prevention:

For every disease, it is universally true that ‘prevention is better than cure. Everyone must be aware of the fact that liver fluke infection can easily be cured. The most effective and proper way to prevent a liver fluke infection is to ensure that freshwater fish and watercress are properly cooked before consuming them. People must avoid food and water that could potentially be contaminated with the parasites while traveling to areas with the least sanitation.

Presently there is no vaccine available to prevent liver fluke infections. Liver flukes are initially big, flat parasitic worms that are found in the liver, resulting in a disease known as fascioliasis. The parasites are mostly found in parts of Australia and the regions with several water bodies such as irrigation channels, slow-streaming rivers, and so on. It is quite a natural infection and can be cured completely with the help of medications. Generally, complications don’t arise due to liver fluke infection.