The development cycle of the hepatic trematode consists of many stages. If you familiarize yourself with the habitat of all intermediate forms of this parasite, you can avoid accidental infection. It is possible to protect yourself from a fluke only by following the rules of hygiene. It is necessary to monitor the habitat of livestock, as well as check the status of ponds and lakes located near residential buildings.
What is a parasite?
The development cycle of the hepatic trematode includes the following stages:
- An egg secreted with feces from the previous host into the aquatic environment.
- Larva wandering in search of mollusks living in the water.
- Transformation into a sac with embryos (sporocyst) inside mollusks.
- Larva with a tail (cercaria), which has left the mollusk and freely floating in the expanses of a reservoir.
- Adolescaria is a larva that has been selected on land and covered with a protective shell. She is waiting for her main owner - a sheep, a pig, a horse, a cow, etc. Often, such a master is a person.
- The adult is the hepatic trematode itself, which develops inside the liver of the new host and lays eggs.
All intermediate stages are non-hazardous in relation to human infection. Only adolescaria can be the beginning of the development of a parasite in the liver.
A sexually mature individual grows up to 3 mm in length, and it becomes the cause of devastating consequences for the internal organs of a person. The cycle of development of the hepatic trematode in the animalās body does not differ from the growth of individuals inside the liver in humans. There is only one difference, in humans this process is more unnatural.
Diseases of the internal organs occur from mechanical damage to the walls of the liver. And since the development cycle of the hepatic trematode includes egg throwing, this also increases the risks of acquiring pathologies of internal tissues. The eggs of the parasite are so small that they can penetrate the blood and wander for a long time with its current. At their high concentrations, blockage of small vessels may occur.
Where does the parasite live?
Biologists have found that the life of the parasite follows a certain pattern - the development cycle of the hepatic trematode can occur only under favorable conditions. These include warm weather, the presence of a carrier of infection, in addition, fluke also requires the presence of mollusks in a pond. Without them, the life pattern established by nature will be violated. The development cycle of the hepatic trematode includes the formation of cysts. They are a protective shell for living microorganisms, which can withstand frost, heat, lack of moisture.
Often helminths even experience a short boiling process. Therefore, it is recommended to boil pond water for more than 5 minutes over high heat in order to avoid infection. Parasites that do not always get into the liver begin to develop, most of them die.
Parasite carrier
The development cycle of the hepatic trematode and bovine tapeworm is the same in terms of the possibility of infection. The cysts of both parasites live on plants near ponds or drift freely in the water. Where livestock dwells, goes to a watering place, parasite eggs also exist. So, it is much more likely to become infected by swimming in such a pond or relaxing on its shore.
If we consider separately the development cycle of the hepatic trematode, a brief description of its sequence can be as follows:
- domestic animal (not necessarily only cattle) ;
- water;
- clam;
- cyst;
- mammal.
That is, if one of the conditions is thrown out of the chain, the parasite dies. If there is a mollusk in the pond called a pond, it is safe to judge that the plants in the area are infected.
In the literature there are many variations that describe the development cycle of the hepatic trematode. Pictures depicting people affected by the parasite are terrifying. For the liver, the action of the tapeworm is destructive. In the event of a case, the body must be replaced, and not everyone can afford this expensive procedure.
If the parasite is detected in time for certain symptoms, then disability can be prevented. Treatment ends positively and is carried out in a hospital. One tablet of the parasite can not be removed from the body. However, often, with the exception of factors negative for health, the parasite can die under the influence of immunity.
How can I get infected?
If we understand the whole cycle of development of the hepatic trematode, the ways of infection of a person will be more clear, and they can be excluded. So, consuming raw water, especially from a reservoir, is dangerous. It is not recommended to have a picnic on the beach, in the place of walking of pets. Dirty hands after bathing in a pond can cause cysts to enter the body.
You can get infected from pets. Cysts can cling to the wool of cattle, birds, dogs that are waiting on plants near a reservoir. A person can also be a carrier, but he is not dangerous to others.
Development process
The development cycle of the hepatic trematode occurs primarily due to mollusks. The reason for the parasite to live in water is the warm temperature of stagnant water. However, the larvae can also find a new intermediate host. So, in Australia, they live inside the mollusk L. Tomentosa, which indicates a high survival rate of the parasite.
Water is a necessary element of development, as well as plants on which cysts are fixed. By nature, the parasite is intended to enter the body of cattle, eating plants around a reservoir. Man and other animals are occasional carriers of fluke.
Cysts are revealed only in favorable conditions. More often this happens in the internal cavity of the intestine. It may happen that a person at that moment consumed antibiotics, then the cyst may not open and will come out naturally without infecting it. But most likely the larvae penetrate through the walls of the intestine and enter the bloodstream. They will linger only in the liver, where they will be fixed with their suction cups to the walls of the organ.
The parasite can live in the liver for several years, causing microscopic damage daily. Which ultimately leads to the formation of fibrous tissues that impair the functioning of the organ.
Comparison with an equally dangerous parasite
A huge parasite - bovine tapeworm - is known for its unpleasant suckers and hooks with which it clings to the intestinal wall of a person. The body of the parasite can reach 3 m. When it is removed, they try to extend the head, since if it remains inside, the worm will continue to grow again.
You can catch a bullās tapeworm from livestock, caring for it. But meat is also hazardous to health, as parasite cysts live in muscle fibers. They get here in the process of eating infected grass by cows. The eggs of the parasite open, and the larvae penetrate the muscles of the animal through the blood ducts.
The next stage in the development of helminth is a condition called Finnish. Finn is a small, pea-sized, bubble with a small hole in which there are undeveloped suction cups and hooks. This is the head of the future tapeworm. Her parasite is attached to the intestinal wall, after which it begins to build up its body.
How do they become infected with tapeworm?
Similar to the previous parasite, bovine tapeworm can be infected through food. However, the Finn is much larger and so easy not to swallow. Therefore, cases of infection are quite rare and occur with absolute disorder of a person. Raw meat is the main cause of infection.
Unnoticed, the parasite can penetrate only with food. Lovers of meat with blood risk getting for many years an unpleasant parasite. The parasite draws out all the beneficial substances from food, preventing the body from getting what it needs. And when the tapeworm reaches enormous size, shock conditions can occur, the intestines become blocked.
Ways to prevent and control parasites
The feces of humans and animals are carriers of tapeworm or fluke eggs. Therefore, isolation of latrines with their subsequent processing can stop the spread of infection. Also, periodic cleaning of the bottom of ponds from silt and mollusks is used. Livestock should be grazed exclusively in uninhabited places.
The meat must undergo a lengthy heat treatment. And the safest cooking method is boiling. Livestock should be constantly checked for parasites and treated. Along with this, personal hygiene is also required.