Roundworms are human parasites. Ascaris human. Ascaris human Presentation of human ascaris
Presentation on the topic: "Ascarids" Completed by: student 214 (3), Biryukova K. V. Checked by: Eliseeva N. V.
Ascaris is one of the most common types of roundworms. The length of the male roundworm reaches 25 cm, and the female - 40 cm. Roundworms do not have attachment organs, they move towards food and are thus retained in the intestines. It causes ascariasis.
The source of infection with ascariasis are our pets: cats and dogs. Domestic animals disperse eggs through wet breath: dogs up to 5 meters and cats up to 3 meters.
A person becomes infected with ascariasis when swallowing a mature egg containing an infective larva, mainly together with contaminated vegetables, berries, fruits; as well as from pets.
A few hours after a mature roundworm egg enters the human body, larvae appear in the small intestine from them, which actively penetrate through the intestinal membranes into the blood. With the blood flow, roundworm larvae enter the liver and lungs, from there into the bronchi, trachea, and then, when coughing, with sputum, into the throat, and finally into the gastrointestinal tract. The entire period of migration of roundworm larvae lasts about two weeks.
The end point of roundworms is the small intestine, where they develop into adults. Attaching to the intestinal wall with its head end, which has a mouth opening, the helminth absorbs nutrients. The existence and development of ascaris in the intestine lasts about 1 year. After which they die.
Roundworms reach sexual maturity 2-3 months after their penetration into the human body and begin to lay eggs. The release of eggs continues for several months. One individual allocates up to 240 thousand eggs per day.
Damage to blood vessels occurs with the development of hemorrhages, pain in the chest, cough (often with bloody sputum), body temperature rises. In the intestinal stage (2 months after the onset of ascariasis), sudden abdominal pain occurs; appetite decreases (up to disgust for food); there is nausea, vomiting, increased salivation; loose stools or constipation occurs; sometimes helminths, outwardly similar to white worms, or their fragments, depart with feces. Affecting the bile ducts and liver, roundworms cause the development of jaundice, liver abscess. There are frequent colds and infectious diseases, intestinal infections; allergic reactions appear, as roundworms secrete their metabolic products into the intestines, which are strong allergens and have a toxic effect on the body.
Ascariasis (Latin ascaridosis) is a helminthiasis from the group of intestinal nematodes caused by roundworms (usually Ascaris lumbricoides), characterized at an early stage by allergy phenomena, and at a later stage by dyspeptic symptoms and complications when helminths penetrate into other organs, as well as as a result of blockage or spasm intestines. Codes according to ICD-10 B77.0. Ascariasis with intestinal complications Ascariasis with other complications Ascariasis, unspecified.
Epidemiology of ascariasis Ascariasis refers to geohelminthiasis. The source of environmental contamination is only a person with ascariasis. Transmission factors are contaminated vegetables, berries, other foods, water, and hands. In the temperate zone, the infection season lasts up to 7 months. - from April to October, in a warm humid climate - all year round.
Epidemiology of ascariasis Human infection occurs through direct contact with soil containing invasive eggs. If the rules of personal hygiene are not observed, eggs from the soil with unwashed hands fall into the human mouth. Eggs can get into living quarters with dust, they can be brought on the soles of shoes. Susceptibility to ascariasis is high. In highly epidemic areas, up to 90% of children are sick with ascariasis. This is due to the fact that ascariasis does not leave a pronounced immunity.
Epidemiology of ascariasis Ascariasis is the most common helminthiasis in the world. According to WHO, more than 1.2 billion people are infected with ascariasis worldwide. Of these, about 100 thousand people die from this invasion every year. Ascariasis is common in 153 out of 218 countries of the world located in temperate, subtropical and tropical climate zones. More than 50% of the surveyed population is infected with ascariasis in Nigeria, Congo, Brazil, Ecuador, Iraq, Malaysia, Afghanistan, Indonesia. In the zones of deserts, semi-deserts and permafrost, ascariasis is very rare.
Pathogenesis The infective roundworm larva is released from the membranes in the upper gastrointestinal tract due to the action of enzymes. The larva from the small intestine penetrates into the blood vessels. Ascaris larvae "pass" through the portal vein through the liver, getting into the right heart, and through the pulmonary circulation into the lungs. From the capillaries, the larvae penetrate into the alveoli, then gradually rise through the bronchial tree to the larynx, enter the pharynx, are swallowed with saliva and again enter the small intestine. The migration process described above lasts from 2 to 3 weeks. Larvae mature to adults within 2 months. Edema, hyperemia, proliferation of macrophage elements, lymphoid, eosinophilic reaction (local and general) occur in the small intestine. With ascariasis, indigestion is caused not only by an inflammatory reaction with hypersecretion of intestinal enzymes, but also by a violation of the production and mutual regulation of peptide hormones.
Symptoms of the early (migratory) phase In severe forms of the disease, the following syndromes are characteristic: 1) acute infectious-toxic syndrome (high temperature up to 39-40 ° for 1-8 days, malaise, weakness, sweating, fatigue, decreased performance) in the first weeks after infection; 2) allergic syndrome (the appearance of a blistering rash on the trunk or only on the hands and feet, accompanied by severe itching); 3) some patients may develop hepatic syndrome (moderate pain in the right hypochondrium, discomfort in the abdomen, enlargement of the liver, there may be changes in the biochemical blood test - an increase in the level of liver enzymes ALT, AST, bilirubin);
Symptoms of the early (migratory) phase The most characteristic of the early phase is bronchopulmonary syndrome or the so-called transient pneumonitis (Löffler's syndrome). The patient develops a cough dry or with sputum, which may have streaks of blood, complaints of shortness of breath, chest pains, dry or wet coarse rales are heard on examination, shortening of the percussion sound when the lungs are tapped; exudative pleurisy may develop - in the exudate: erythrocytes and eosinophils, in isolated cases, larvae. On a chest radiograph: areas of infiltration (inflammation) 2-4 cm in size are eosinophilic infiltration. These foci change their location as the larva moves, in connection with which they received the name "flying infiltrates of Loeffler". The lesions may disappear after 3-5 days, but sometimes they can last up to days. During this period, ascariasis must be distinguished from pneumonia, tuberculosis, and oncology.
Late phase symptoms The process of transformation from larvae to adults determines the onset of late (intestinal) phase symptoms. The patient has 2 syndromes: gastrointestinal (intestinal) and nervous. Gastrointestinal syndrome is characterized by a decrease in appetite, stool. nausea in the morning, vomiting, abdominal pain, disorder Nervous syndrome is characterized by poor health, sleep disturbance, headaches, decreased performance, fatigue. In children, psychomotor development is delayed, epileptiform seizures, meningism phenomena (severe headaches, nausea, vomiting, pain in the neck) are sometimes recorded. In all patients, even in cases that occur without symptoms of the disease, weight loss is observed, sometimes even significantly.
Complications of ascariasis Complications of this disease are due to the fact that ascaris larvae are carried by blood throughout the body, damaging organs and tissues, and adults are actively moving inside the intestines, causing disruption of the digestive system. The most common complications of ascariasis include the following diseases: intestinal obstruction; perforative peritonitis; acute pancreatitis; acute appendicitis; liver abscesses; acute cholecystitis and inflammation of the bile ducts; suffocation when ascaris enters the respiratory tract; purulent pleurisy, pneumonia; sepsis; complications during pregnancy and childbirth; more severe course of other ailments; occasionally inflammatory processes in the kidneys and reproductive system.
Differential diagnosis of ascariasis Differential diagnosis of ascariasis in the migration stage is carried out with toxocariasis, an early phase of other helminthiases, characterized by allergic manifestations, acute bronchitis, pneumonia. In the intestinal stage, according to clinical symptoms, it is almost impossible to differentiate ascariasis from chronic gastrointestinal diseases. If complications occur, depending on their nature, differential diagnosis of ascariasis is carried out with intestinal obstruction, cholangitis, liver abscess, pancreatitis of another etiology. In these cases, additional instrumental studies (ultrasound of the abdominal organs) and a surgeon's consultation are necessary.
Treatment of ascariasis Organizational and regime measures: 1) ascariasis is treated at home or at a day hospital; patients with are subject to hospitalization; 2) diet therapy - table 13 (according to Pevzner) - is prescribed for the entire period of treatment and recovery. Diet - 4-5 times a day in small portions. General characteristics: - a diet with energy value, reduced to a large extent due to fats and carbohydrates, with a high content of vitamins Chemical composition and energy value (daily diet): - g proteins (60-70% animals); - g fats; - carbohydrates g; - energy value kcal Recommended products and dishes: dried wheat bread; fat-free meat and fish broths, soups on vegetable broth, mucous broths from cereals; lean meats, poultry, fish; lactic acid drinks, cottage cheese; mashed rice porridge, semolina and buckwheat; potatoes, carrots, beets, cauliflower, ripe tomatoes; ripe soft fruits and berries, rosehip broth; sugar, honey, jam, jam, marmalade. Excluded foods and dishes: rye and any fresh bread, muffin; fatty broths, cabbage soup, borscht; fatty meats, poultry, fish, sausage, smoked meats, salted fish, canned food; whole milk and cream, fat sour cream, cheeses; millet, barley and barley groats, pasta; white cabbage, radish, radish, onion, garlic, cucumbers, legumes; fruits rich in fiber; chocolate, cakes, cocoa
Prevention of ascariasis Prevention of ascariasis is aimed at detecting the infected and treating them, protecting the soil from fecal contamination, and educating the population. It includes the following measures: observance of hygiene rules: regular hand washing, the use of only thoroughly washed vegetables, fruits and herbs; giving up the habit of biting nails and licking fingers; prevention of contamination of yards and playgrounds with animal and human feces (regular cleaning of yard toilets, refusal to use feces as fertilizer); playgrounds must be placed in sunny places, as roundworm eggs die under the influence of direct sunlight; refusal to use raw water.
Ascaris human.
The full development of the roundworm takes place without a host at all: the eggs perfectly reach maturity in the soil. The larvae appear on the 16-17th day. They, unlike adults, need oxygen. Eggs enter the human intestines from the soil, through water, dirty vegetables and fruits. There, the larvae pass through the intestinal wall and enter the blood vessels, and then migrate through the body. Together with the blood flow, they can penetrate into the liver, right atrium, into the ventricle of the heart, and from there into the pulmonary artery and capillaries of the pulmonary alveoli. Actively moving, they literally drill into the walls of the capillaries and enter the cavity of the alveoli, into the bronchi and trachea. As a result, a person develops a cough. And when coughing, the larvae fall into the throat. When re-swallowed by the host, they enter the small intestine, where they reach sexual maturity. The entire process takes two weeks. And the roundworm turns into an adult individual in 70-75 days. In total, adults live 10-12 months.
Roundworm development cycle As a rule, this stage of roundworm development ends on the 16-17th day, when a mature larva is formed in the egg and it becomes invasive, that is, dangerous to humans. As soon as the invasive egg enters the human body (with food, through unwashed hands, contaminated water, etc.), under the influence of the chemical environment of the human gastrointestinal tract, the shells of the egg dissolve and the larva enters the intestine, its favorite habitat. Sometimes the microscopic larva does not remain in the intestine, but migrates through the circulatory system. It is not uncommon for ascaris to be found in large quantities in the ventricle of the patient's heart, in the alveoli, bronchi and trachea, in the liver and even in the brain. Since the human roundworm, like all nematodes, does not have an intermediate host, the development of the larva occurs directly in the external environment. All she needs is access to oxygen, sufficient humidity and a temperature close to room temperature.
Pinworm The female pinworm. 1 mouth; 2 esophagus; 36 parts of the reproductive system; 7 anus. Pinworm: adult and eggs
At the anterior end of the body of pinworms is a swelling that surrounds the mouth opening and is called the "vesicle".
Enterobiasis
Pinworm life cycle
Vlasoglav and female vlasoglav; b male whipworm; 1 front end of the body; 2 back end. adults and eggs
Vlasoglav.
Whipworm development cycle
Trichinella A) female B) male Trichinella larva encapsulated in muscle fiber
Trichinella
Trichinella.
Trichinella. Trichinella larvae in muscle cells.
life cycle of trichinella
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to form knowledge about the structure, life processes, lifestyle and adaptability of roundworms to the environment; develop the ability to highlight the main thing, compare, work independently with a textbook; carry out hygiene education. Tasks:
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Life cycle of the liver fluke The liver fluke lives in the ducts of the liver of cattle. Its development includes a change of owners and alternation of generations. Fluke eggs exit the liver into the intestines of the host and then, with feces, out. At the same time, for their development, they must certainly fall into the water, which, obviously, does not always happen. In the water, a larva with cilia emerges from the egg, which, for further development, must penetrate the body of the pond snail mollusk. Here the larva not only grows, but also multiplies, giving a few more larvae of the next generation. These second generation larvae emerge from the pond snail's body into the water. They can actively swim with the help of their tail. Settling in a reservoir, they eventually attach to the leaves of aquatic plants, become covered with a shell and become immobile, that is, they turn into a cyst. In this state, they can remain for a long time. Cattle become infected with liver fluke by drinking water or eating grass with its cysts. In the intestine, the cyst bursts, the young fluke comes out and enters the liver. Thus, the development of the fluke depends on many accidents. Therefore, the fluke produces a huge amount of eggs. It also reproduces in the larval stage.
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Habitat and external structure of roundworm. Roundworms This white or yellowish worm that lives in the small intestine of the human body is roundworms. The body of the female reaches: (20–40 cm) males (15–20 cm), the anterior and posterior ends are pointed. With them, roundworm rests against the walls of the intestine and is held in it. They do not have special attachment organs like flatworms. At the front end of the body is the mouth, and at the rear end is the anus. The integument of the roundworm is devoid of cilia, its body is covered with a dense cuticle. It protects against mechanical damage and prevents its digestion in the human intestine.
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Internal structure of roundworms 1 - ectoderm 2 - longitudinal muscles 3 - ovary 4 - endoderm 5 - intestinal lumen 6 - body cavity 1 2 3 4 5 6
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