What are roundworms?
Roundworms are a type of biohazard organisms causing threats to humans and some other organisms. Some types of roundworms such as filaria, rishta, whipworm, are dangerous to human health causing serious illnesses like diarrhea or fever.
The classification of roundworms links several types of organisms. There are parasitic and free-living worms. The sizes of roundworms are most often microscopic. They got their name because of the round transverse incision on the body. They mastered almost all habitats from soil to life at the expense of another representative. There are about 20,000 species.
Structure of roundworms
Body length varies up to 8m. They have bilateral symmetry. Females are in most cases larger than males. The body is usually spindle-shaped. They don’t have segmentation. The cavity fluid acts as excretory organs. The circulatory and respiratory systems are missing. Nerve cells represent muscle rollers. Inside the body there is a reproductive, digestive and excretory system.
Free-living worms live at the bottom of oceans and seas. Same with soil and freshwater. Roundworms also live in the decaying remains of plants and animals. Worms also live in other organisms (roundworms). Settling in the human body, roundworms have mastered almost all organ systems: the brain, blood vessels, eye environment, heart, intestines, tendons, lungs. Roundworms also include the smallest multicellular animal – rotifers. The body length is only 2mm. They can crawl and swim.
Almost all representatives of this species are dioecious organisms, but there are also hermaphrodites. The reproductive system is represented by a tubular structure. Males have only one unpaired tube, while females have 2. The development of the parasite is possible only when it enters the human body. Conditions for good maturation of the larvae: temperature 20-25 degrees, humidity, maturation time 2-3 weeks. The eggs of the larvae are covered with a thin shell. (In some cases, there is also a thick shell). Roundworms also have the ability to live birth.
Roundworms are very prolific. One roundworm female is capable of laying up to 200,000 eggs per day.
In the external environment in oxygen – aerobic conditions, the development of eggs occurs within 21 days. Eggs become invasive, that is, capable of parasitic infection. They form a larva.
In the human intestine, the larva that has emerged from the shell is introduced into its walls and enters the blood capillaries. With the blood flow, the larva then enters the liver, and then into the lungs. From the lungs, the larva reaches the oral cavity through the respiratory tract. From the oral cavity, with saliva, it enters the intestines, where it reaches puberty.
Parasitic worms cause great harm to health, as they poison the host organism and disrupt the digestion process.
Unlike flat parasitic worms, there is no change of hosts in the roundworm breeding cycle: intermediate and main; Oxygen is necessary for the development of roundworm larvae.
Roundworms as parasitic biohazard
Some types of roundworms are dangerous to human health. For example: filaria, rishta, whipworm. These parasites destroy the organs of their host.
Rishta enters the body when drinking unpurified water. They migrate into the subcutaneous tissue. To remove their larvae from the body of the host, they make holes in the skin with the help of a secret. These areas are inflamed.
Vladislav lives in the large intestine. The body length is about 5.5cm. You can distinguish them by the tail: the female has the shape of a tail similar to an arc, and in the male it is twisted in a spiral. The worm feeds on blood. The coloring is mostly gray. The main host of the worm is man.
There are many ways of infection with roundworms:
- Eating raw, poorly washed vegetables.
- Transfer of roundworm eggs by flies.
- Dirty hands – a source of infection, ingestion of eggs into the body.
- Raw water from reservoirs
To prevent infection, you must: wash your hands before eating, pour boiling water over raw vegetables before eating. Do not leave food on the table. To prevent the appearance of flies, you can use aerosols and special adhesive tapes.
Dangerous for humans and other parasitic roundworms – Trichinella. The female of this parasite is about 3 mm, and the male is 2 times smaller. Trichinella larvae enter the body by eating infected meat. With the blood flow, they enter the muscles, where they are covered with a calcareous capsule and can remain in this form for several years.
Rats are the main host of Trichinella. Dead rats can be eaten by pigs and become a source of infection for humans.
Let’s name the distinguishing features of the external and internal structure of roundworms compared to flatworms:
- non-segmented body;
- sexual dimorphism – the external difference between the female and the male;
- musculature is represented only by a longitudinal group of muscles;
- the presence of a primary body cavity – pseudo-goals;
- division of the digestive tube into 3 sections: anterior, middle and hindgut.
- the appearance of the anus;
- presence of phagocytic cells in the excretory system.