The Life Cycle Of Worms

1. The Phylum of Platyhelminthes Platyhelminthes derived from Greek word, Platy means flat and helminthes means worm. Platyhelminthes is triploblastic acelomates organism. This phylum is classified into three main classes; cestoda, trematoda, and tubellarian. A. The Life Cycle of Fasciola hepatica Fasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic flatworm of the class trematoda, phylum Platyhelminthes that infects liver of a various mammals, including man. The disease caused by the fluke is called fascioliasis (also known as fasciolosis). F. hepatica is world-

wide distributed and causes great economic losses in sheep. Scientific classification Kingdom: Animalia Phylum:

Platyhelminthes

Class:

Trematoda

Subclass: Digenea Order:

Echinostomida

Family:

Fasciolidae

Genus:

Fasciola

Species:

F. hepatica

Binomial name Fasciola hepatica (Linnaeus, 1758)

The life cycle of liver fluke can be described as the picture above. The adult worm, who live in the bile duct produce egg that will be emitted through the feces. As the egg released from the host, they will hatch, releasing the miracidia (larva I). The miracidia penetrated the snails then develop and multiply as sporocyst, rediae and cercariae. The cercariae leave the snails and swim until they adhere on vegetation, forming metacercariae (young fluke) which are the infective stage of the liver fluke. The entire cycle takes about 2-3 months.

If the grass eated by sheep or other hosts (including human) the metacercariae enter the small intestine and penetrate the intestinal wall and enter the abdominal cavity. The young fluke penetrated into the liver and move to the bile duct for releasing eggs. B. The Life Cycle of Clonorchis sinensis The Clonorchis sinensis is a human liver fluke in the class Trematoda, Phylum Platyhelminthes. This parasite lives in the liver of humans, and is found mainly in the common bile duct and gall bladder, feeding on bile. These animals, which are believed to be the third most prevalent worm parasite in the world, are endemic to Japan, China, Taiwan, and Southeast Asia, currently infecting an estimated 30,000,000 humans.

Scientific classification Kingdom: Animalia Phylum:

Platyhelminthes

Class:

Trematoda

Order:

Opisthorchiida

Family:

Opisthorchiidae

Genus:

Clonorchis

Species: sinensis Binomial name Clonorchis sinensis Looss, 1907

The life cycle of Clonorchis sinensis is almost the same with Fasciola hepatica. The adult worm, which live in the bile duct, produce egg that will be emitted through the faeces. The egg then floating in the fresh water until it’s eaten by snails as miracidia. Miracidia penetrated the snails then develops and multiplies as sporocyst, rediae and cercariae. The cercariae leave the snails and swim until they adhere parasitically on fish, forming metacercariae. The animal or human who eats those fish without good sanitation can be infected.

C. The Life Cycle of Taenia solium and Taenia saginata

Scientific classification

Scientific classification

Kingdom: Animalia

Kingdom: Animalia

Phylum:

Platyhelminthes

Phylum:

Platyhelminthes

Class:

Cestoda

Class:

Cestoda

Order:

Cyclophyllidea

Order:

Cyclophyllidea

Family:

Taeniidae

Family:

Taeniidae

Genus:

Taenia

Genus:

Taenia

Species: solium

Species: saginata

Binomial name

Binomial name

Taenia solium

Taenia saginata

Linnaeus, 1758

Goeze, 1782

The life cycle started when the egg (gravid prologtid) of T. solium or T. saginata in human feces released in the environment. These eggs then adhere in the grass. The grass then eaten by cow (for T. saginata) saginata or pig (for T. solium). The eggs hatches become oncospheres and move to the animal’s flesh. There, oncospheres develop become cycsticerci. The human who eats the infected animal in raw condition will be infected too. Cysts attach to the small intestine by their scolex. Adult tapeworms develop, up to 2 to 7 m in length and produce prod less than 1000 proglottids, each with approximately 50,000 eggs and reside in the small intestine for years. One thing that differentiate T. solium and T. saginata is their hook. T. saginata don’t have chitin hook while T. solium have. 2. The Phylum of Nemathelminthes

Nemathelminthes derived from Greek word, nema means thread and helminthes means worm. Nemathelminthes is triploblastic pseudocelomates organism. This phylum is classified into two main classes; Nematoda and Nematophora. A. The Life Cycle of Ancylostoma duodenalis (Hookworm) The hookworm is a parasitic nematode worm that lives in the small intestine of its host, which may be a mammal such as a dog, cat, or human. u

Scientific classification Kingdom: Animalia Phylum:

Nemathelminthes

Class:

Nematoda

Order:

Strongiloidae

Family:

Ancylostomatidae

Genus:

Ancylostoma

Species: duodenale Binomial name

The life cycle of A. duodenale started when the feces containing the egg released to the environment. The egg hatches into rhabditiform larva. The rhabditiform larve growth becomes filariform larva. This larva can penetrate the skin and enter the blood circulation. The larva flows to cardiac and lungs. In the lung, larva penetrates the lung’s wall to the trachea and pharynx. From here, the larva swallowed back and enters the small intestine. Here it grows become an adult worm. The female can produce up to 1000 eggs per days and distributed via feces.

Ancylostoma duodenale

B. The Life Cycle of Oxyuris vermicularis Oxyuris vermicularis (pinworm) is 9-15 mm long worm. When the female want to release the egg, it moves to the anus. This movement caused itchiness. The egg can be easily transferred by hands to the other object. The human who eats the contaminated food can be infected. Also, the same human can be infected again.

This phenomenon called autoinfection. In a human being, the worm can be discovered up to 5000 worms because of autoinfection. This worm classified in secernentea class, Rhabditida order, Oxyuridae familia, and the genus of Oxyuris C. The Life Cycle of Fillaria bancrofti (Wuchereria bancrofti) Wuchereria bancrofti is a parasitic filarial nematode worm spread by a mosquito vector. It is one of the three parasites that cause lymphatic filariasis. Named for Otto Wucherer and Joseph Bancroft, it infects over 120 million people, especially in Africa, South America, and other tropical and subtropical countries. Elephantiasis can occur if the infection is untreated. v

W. bancrofti carry out their life cycle in two hosts. Human beings as the definitive host and mosquitoes as their intermediate hosts. The adult parasites reside in the lymphatics. They are viviparous. The first stage larvae are known as microfilariae. The microfilaria are present in the circulation. The microfilaria migrate between the deep and the peripheral circulation. During the day they are present in the deep veins and during the night the migrate to the peripheral circulation. Next, the worm is transferred into a vector; the most common vectors are the mosquito species: Culex, Anopheles and Aedes. Inside their second host, it matures into motile larvae. When its current host feeds, and it is egested into the blood stream of its new human host. The larvae moves to the lymph nodes, predominantly in the legs and genital area, and develops into adult worm over the course of a year. By this time, an adult female can produce microfilariae itself.