Hookworm and Liver Fluke Life Cycle

Hookworm and Liver Fluke are parasites that live in the human body and cause contagious and infectious diseases. Hookworms are found in the small intestine whereas Liver Fluke, as the name suggests, is mainly found in the liver of various mammals. Both the creatures are known to cause mild to high threatening diseases, namely, Helminthiasis and Fascioliasis respectively. The two most common hookworms which are found in the human body are Ancylostoma duodenale and Necator americanus. The average size of an adult hookworm is 11 mm in size whereas the size of liver fluke ranges from 8 mm to 15 mm.

Read Also: Human Health and Diseases

Key Terms: Life Cycle, Parasites, Blood, Digestive System, Diseases, Lungs, Symptoms

---

What is a Hookworm?

[Click Here for Sample Questions]

Hookworms are a kind of parasite which feeds on blood and resides in the small intestine of the human body. They are harmful for the human digestive system and can cause diseases like Helminthiasis, which affects the human lungs, skin and digestive system. Hookworms belong to the class Secernentea and order Strongylida. Itching, rash, nausea, abdominal pain, intestinal cramps and blood in stool are a few symptoms of Hookworm infection in the human body.

Hookworm

---

Life Cycle of Hookworm

[Click Here for Sample Questions]

Life Cycle of a Hookworm is completed in 4 stages, namely, egg stage, larval stage and adult stage. Mentioned below are the details:

• Egg Stage: Female hookworms lay around 30,000 eggs per day in the small intestine. The eggs contain two to eight sectioned embryos that pass to the soil via human stool. It hatches in about 24-48 hours and transforms to larvae, which is the second stage of its development. 
• Larvae Stage: In this second stage, larvaes are hatched in the deposited faeces. They are initially non-infective and they feed on soil microorganisms. The larva grows in four stages where the first and second stage is called the rhabditiform stage. After feeding for a week, they transform into the third stage which is a filariform stage. In this form, they survive up to a week. They are extremely motile and keep moving to higher ground in order to find a host easily. These larvae can only infect by penetration through the skin. A common route for these larvae to enter is through the feet of barefoot walkers. Once the larvae enter the host, they travel in the circulatory system to the lungs and then enter the alveoli. They travel to the trachea from where they are swallowed into the small intestine. In the small intestine, the larvae goes to its fourth stage to become an adult hookworm. It takes almost five to nine weeks from entering the host to becoming an adult. 
• Adult Stage: The adult hookworms can cause infection which may last from 1 year to 5 years in which some worms might die within a year. Some hookworms are also found to have lived up to 15 years. The larvae remain dormant in tissues and can be recruited after some adult worms die. The worms mate inside the host, in which the females lay eggs. They are passed out with the host’s faeces to start the cycle again. The hookworms can lay up to nine to ten thousand eggs per day. 

Life Cycle of Hookworm in Human Body

---

Symptoms of Hookworm Infection

[Click Here for Sample Questions]

Most commonly seen symptoms of Hookworm infections in human body are:

• Rash on the skin (feet mainly) from where the larvae entered the body
• Fever
• Coughing or Wheezing
• Abdominal pain
• Loss of appetite
• Diarrhoea
• Weight loss
• Anaemia

---

What is Liver Fluke?

[Click Here for Sample Questions]

Liver Flukes are parasites which reside in the liver and cause diseases, called liver fluke disease. The scientific name of liver fluke is Fasciola hepatica. They belong to the phylum Platyhelminthes. Liver flukes are mobile and can travel through bile ducts. They are normally found in moist environments and as they prefer watery habitats to lay eggs. Liver Fluke possesses the capability to move with the blood circulation.

Liver Fluke

---

Life Cycle of Liver Fluke

[Click Here for Sample Questions]

The life cycle of a liver fluke is completed in 4 stages, as mentioned below:

• Egg Stage: The adult female liver fluke lays immature eggs in the bile duct of the host and passes outside through defecation. The eggs get embryonated when they come in contact with water and take the form of larva which is called miracidia.
• Intermediate Host Stage: The eggs infect different species of snails in which they grow into larvae called cercaria larvae. The cercaria larvae grow and leave the host. Snails are intermediate hosts for the liver fluke and it leaves the host to look for vegetation. Cercaria larvae are capable of swimming in the water. Metacercariae have a rigid outer body which allows them to live for a longer time. If humans consume water that is contaminated with the cysts, the cysts will release immature eggs in the small intestine.
• Young Fluke Stage: After the intermediate stage, now the fluke parasite enters the human body through the peritoneal cavity. Then it enters the liver and starts feeding on liver cells. All of it starts happening within a few days of coming in contact with the parasite. After eating a good amount of liver cells, it then travels to the bile duct and starts transforming into an adult liver fluke.
• Adult Stage: Metacercaria finally gets transformed into adult liver fluke. It takes approximately 3 months for it to become mature. An adult liver fluke can be as long as 3 cm. Adult female liver fluke lays approximately 20,000 to 25,000 eggs per day in its last state of pregnancy. 

Life Cycle of Liver Fluke in Human Body

---

Symptoms of Liver Fluke Infection

[Click Here for Sample Questions]

Signs and symptoms of hookworm infection may vary from host to species. The common symptoms of liver fluke infection are:

• Abdominal pain
• Fever
• Vomiting
• Nausea
• Hives
• Diarrhoea
• Malaise
• Decreased appetite 
• Weight loss

If the infection is more severe then the person can even get stones or bile duct cancer.

Also Read:

---

Things to Remember

[Click Here for Sample Questions]

• Hookworms are parasites that feed on blood which are found in the small intestine of the human body.
• The hookworm larvae can only infect by penetration through the skin.
• The hookworm larvae take almost five to nine weeks from entering the host to become an adult. 
• Liver flukes are hermaphrodites, which means they have both sets of male and female reproductive organs.
• Liver fluke infections also cause serious medical issues and veterinary diseases. 
• The digestive system of liver flukes is simple and they primarily feed on blood. 
• The adult female liver fluke lays immature eggs in the bile duct of the host and passes outside through defecation

Also Check:

---