Liver Fluke Life Cycle – An Overview of Various Stages
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.
FAQs on Liver Fluke Life Cycle
1. What is fasciolosis?
Liver fluke disease affects the sheep in three different clinical forms – acute, subacute and chronic fasciolosis. The type of clinical forms depends upon the numbers of infective metacercariae ingested and the actual time frame at which they are ingested. According to a recent report, milder winters and wetter summers have experienced changing patterns in parasite epidemiology and reported disease with earlier seasonal reports in severe disease.
2. What is fluke quarantine?
At the time of buying sheep, fluke quarantine treatment strategies must be taken into consideration on the basis of risk posed by the sheep and the risk status of the farm. The strategies must be expedited by the consultation with a vet or animal health advisor. The three main reasons behind the fluke quarantine are:
1. There is a possibility of the introduction of sheep onto a farm with no known snail habitat. Hence, there might not be any history of fluke infection. The risk factor behind the introduced fluke on the farm is very minimal and treatment should be done accordingly.
2. The farm may have regions identified as a favourable habitat for snails but no history of fluke infection. The risk of introduced fluke establishing on the farm is considered to be prominent. Therefore to remove all the treatment is necessary.
3. It is a high possibility that the liver fluke will become endemic. So, introducing small numbers of fluke will not be a serious issue.
3. How do snails get infected in the warm seasons?
Snails act as intermediate hosts for liver fluke parasites. Snails can get infected all year round due to the hatching cycles of the parasites as well as the life cycle of snails themselves. Between May and July, a number of parasites hatch and latch onto snails for their survival. If these months are cold and dry then the likelihood of this happening is quite low. Between this time and late autumn, the parasites keep clinging to the snail and derive nutrition from them.
4. Do snails get infected in the winter season as well?
This does not usually happen, however, it is possible that the infection can persist well beyond winter too. In these cases, however, the parasites are likely to hibernate through the cold season. Their growth in the snails can become dormant. They only start growing again once the weather warms up and spring arrives. In this case, it can then affect the animals that start grazing pastures again in spring and then get passed onto humans, and keep the infection going.
5. Is this disease contagious?
Liver fluke disease is not directly contagious, no. It cannot pass on from skin contact, it must be ingested. The only way the parasites can enter the body is through food. Usually, unhygienic and unsanitary conditions can lead to this. Therefore, simply being in contact with an affected person will not communicate the disease, however, not maintaining sanitary conditions or eating from the same plate as them, or not cleaning up after them can certainly cause this disease in others too.
6. How can liver fluke disease affect human beings?
In human beings, liver fluke disease can affect the liver, bile duct, and intestines. In fact, it can affect the entire gastrointestinal duct. A lot of times, symptoms do not manifest immediately, rather, the parasites fester on, and only after a considerable time has passed, the person shows symptoms. The life span of the parasite can range p to 25-30 years, and in case the person remains undiagnosed and/or untreated, the parasite can live in their system for that long.
7. How to be certain that the parasites in the body are dying?
Once the person has been diagnosed, he/she can start treatment. In this case, the results can be seen soon in the form of headaches, fainting spells, nausea, dizziness, frequent bowel movement, and vomiting. This might seem like the infection is getting worse, but these are actually signs that the disease is recuperating and the parasites are being flushed from the system. These are called die-off symptoms and they are exhibited when parasites tend to die or leave the host’s body.
