Human Ascaris

The human ascaris is a parasite that affects people of any age, mostly children, with the localization of the pathological process in the intestine and the corresponding symptoms. This parasite is the representative of Nematode - this is the class of roundworms. It is necessary to know some features of the life cycle of this worm in order to predict complications and conduct effective treatment.

[1], [2], [3], [4]

Features of the structure of the human roundworm

All types of worms are divided into classes, which corresponds to the peculiarities of their structure, digestion and life cycle. Ascaris is a heterozygous organism that has differences in structure between males and females. These parasites have an elongated shape, rounded. The size of the female is significant - about forty centimeters long, while the male is half as small as twenty-twenty-five centimeters. The male also has a pointed portion at the end of his body, which allows him to identify.

The outer layer of the roundworm is made up of a hypodermis, which in its structure resembles epithelial cells, of which a considerable number are ten layers, which play a protective role and prevent damage to the individual and digestion by intestinal enzymes. Under the hypoderm is a layer of muscle fibers that allow the ascarid to actively move. Further under the muscle fibers is a cavity, which is filled with liquid. This structure allows worms to maintain a constant body shape and elasticity.

The digestive system of the parasite is represented by the oral cavity, which is surrounded by the lips. Next comes the gullet, represented by several layers of muscle - this structure helps to promote food by reducing the transverse muscle fibers. After the pharynx, the food enters the gut, which looks like a closed bag - there is a digestion of food and a final absorption of nutrients. Ascarid human lives in the small intestine and feeds on nutrients that come there in the form of food. Therefore, all foods that enter the human intestine are the substrate for feeding the worm. Mostly worms prefer sweet foods.

Excretory system ascarids is represented by two lateral canals that run along the body and correspond to the length of the ascarid body. Harmful undigested substances after the intestine fall into the cavity filled with liquid, and then into these channels. Near the initial end of the body of the ascaris, the excretory openings are opened, which correspond to the excretory organs.   

The nervous system of the human roundworm is represented by nerve tubes that are located on the sides of the body, they have connecting elements. So the innervation of the senses and other internal organs passes. The sensory organs are very poorly developed - they are represented by setae, which are organs of touch.

The types of human ascarids that cause ascariasis are Ascaris lumbricoides, there may be differences only in the length of the individual between males and females.

[5], [6], [7],

The life cycle of a human roundworm

Ascaris has a very long life cycle, a feature of which is the change in the location of the individual in the human body. Ways of infection with worms from the Nematode class are a fecal-oral route. The human Ascaris belongs to geogelmints, because one of the cycles of its development is in the earth. Thus, infection occurs during ingestion of ascaris eggs. Ways of infection can be the following:

1. dirty hands - children are at greater risk due to the fact that they constantly play in the sandbox and eggs can be kept under the fingernails;
2. dirty unwashed vegetables and fruits - during ripening eggs from the ground can fall on vegetables and berries;
3. after animals that have ascarids on their wool - they can be the bearer;
4. with unboiled water, which has ascaris eggs;
5. poorly thermally processed food, which does not allow you to kill eggs or larvae ascarids.

The life cycle of a human roundworm has its own characteristics. The development of the human roundworm is without a change of owners, so the final owner of the human roundworm is only a man. Eggs of the roundworm fall through the mouth into the small intestine of a person. Further, the parasite undergoes developmental stages in the form of a young larva, an adult larva and an adult worm. After the egg enters the intestine, a young larva emerges, which hooks into the intestinal wall with hooks. So the young larva penetrates through the wall into the veins and enters the bloodstream. There, the young larva feeds on blood serum and then erythrocytes, which allows her to grow to a considerable size. In this case, the young larva turns into an adult, which migrates with a blood flow through the portal vein system into the liver, and through the system of the inferior vena cava into the right heart and lungs. Oxygen is needed for ascaride for growth, so it has sensitivity, migrating specifically to the lungs, which are filled with oxygen. Further, the cycle of the roundworm is such that, with a strong cough, the young larva enters the pharynx from where the repeated infection occurs, and the ascarid again enters the intestine. The adult worm lives in the intestines and feeds on the foods that are there. The total cycle time of one individual from the moment it hits to the exit is about one year, but because the roundworms during the migration all the time multiply - the duration of such life cycles can be years.

The reproduction of the human roundworm is very complex, because the parasites are of different sexes. In this case, males have a cloaca in which ejaculation occurs. The female has a complex reproductive system, which is represented by the seminal receptacle, vagina, uterus, ovaries and oviducts. Fertilization occurs in the sperm, after the male is attached to the female with special clothespins. The female allocates a huge number of eggs that can be excreted with human feces, and some of them are simply stored and activated in favorable conditions.

Diagnosis and differential diagnosis of human ascaris

Diagnosis of human roundworm should be aimed at timely detection of the parasite and as soon as possible treatment, because ascaris has the ability to migrate with the occurrence of complications.

Diagnosis should begin with a careful collection of anamnesis. Ascaride, being in the human body for a long time, contributes to the development of symptoms of intoxication, as well as dyspeptic disorders. Therefore, this disease will be accompanied by complaints of poor appetite, rumbling in the abdomen, weight loss, nausea in the morning. If it concerns children, then it is clear that the child is thin, small, pale. Characteristic signs of ascaridosis, like any other helminthiasis, it gnaws at night during sleep. If such symptoms are observed for at least the last few months, then you should think about helminthiasis.

There are also symptoms of intoxication, which are caused by persistent persistence of the parasite. Ascaris feeds on what is in the intestines and at the same time the products of the helminth's vital activity enter the intestinal cavity, which is absorbed and contributes to the development of intoxication.

To timely determine and accurately confirm the diagnosis of ascarid parasitization, it is necessary to identify the causative agent. The simplest method of diagnosis is a koprolological study of feces and the identification of helminth eggs in feces. However, there are some features of such a survey. The analysis of feces should be taken on an empty stomach. Helminth eggs can not be allocated continuously, therefore, as a rule, three repeated analyzes are carried out for diagnosis. If eggs are found in one of the tests that are specific for the ascaris, then the diagnosis can be confirmed. Given that the precise definition of eggs in the stool is not always possible, that is, the need for additional methods. Use light microscopy, in which the stool is stained with a special luminescent paint and when eggs are present they glow under a microscope. It is also possible to detect the presence of eggs and antigenic material in the stool with the help of a polymerase chain reaction (the method is based on the identification of the specific ascarid genome). After the treatment, a repeated examination of the stool is always performed to determine its effectiveness.

To determine the degree of change, a blood test is also performed. In the general analysis of the blood, changes in the form of eosinophilia are determined, and also anemia can be caused by the parasite feeding on erythrocytes.

If the larvae of the human roundworm fall into the liver and lungs during migration, then nonspecific symptoms with violation of intrahepatic outflow of bile may occur. At the same time, an ultrasonic study is used to identify the cause of this pathology. Ultrasound in the liver determines anechogenic foci, which have distinct edges and a rounded shape. Also, such changes can be determined in the lungs, which allows one to suspect the presence of ascarid larvae.

Many of the helminths can cause similar symptoms, which cause ascarids, so it is necessary to conduct differential diagnosis. First of all, it is necessary to differentiate ascaridosis and bovine tapeworm.

Bovine tapeworm is a parasite that is the representative of Flatworms. This worm reaches a length of four to ten meters and is armed with suckers.

Comparative characteristics of bovine tapeworm and human roundworm need to be carried out because they have similar symptoms - a syndrome of intoxication and dyspepsia with loss of weight and appetite. But there are also differences. In the first place, bovine tapeworm is a biohelminth. Therefore, in the bull chain, unlike the roundworm, there is an intermediate host - this is a large cattle. Unlike the human roundworm, infection with a bull chain occurs when eating badly boiled cattle meat, which contains the larva of this parasite. Therefore, in the anamnesis, when parasitizing bovine tapeworm, there are data on the consumption of meat of large cattle. Also, the feature of the chain is that its life cycle in the human body is not characterized by migration, but when it enters the intestine, it simply lives in the lumen and grows to considerable size. This also leads to intoxication and impaired absorption of nutrients. To identify and identify the type of pathogen, it is necessary to detect eggs, which is a specific proof.

Although the principles of treatment for different types of helminthiases are similar, but there are differences, so you need to precisely differentiate the pathogen.

[8], [9], [10], [11]

Treatment and prophylaxis for the invasion of human ascaris

Treatment of any helminthic invasion should only be carried out in conjunction with other agents that prepare the gastrointestinal tract for dehylmensis. Therefore, you need to start with a diet that cleanses the intestines. It is necessary at the time of treatment to completely limit the sweet, flour foods. You need to eat porridge and cooked vegetables, which stimulate the intestinal peristalsis. After this, it is advisable to conduct a course of piercing therapy. To do this, it is necessary to conduct a single course with the use of laxatives. It is better to take herbal preparations with a penetrating effect. These include "Senadexin" - this is a scavenger on the basis of leaves of hay - a plant with laxative effect. After such a course of purification therapy go to the treatment of the most helminthic invasion. Use anthelmintic drugs.

1. Pyrantel is an antihelminthic drug that acts against a human ascaris by depolarizing the membranes of muscle cells of worms, which contributes to the death of mature forms of ascarids. The drug is available in the form of tablets and suspensions. Dosage of the drug for children is 250 milligrams to six years, and over six years - 500 milligrams. For adults, the dose of one gram is recommended in the treatment of ascaris, that is, four tablets per treatment. There are side effects from the digestive system in the form of diarrhea, abdominal pain, nausea, as well as changes in the nervous activity in the form of dizziness, drowsiness, increased excitability, paresthesias.
2. Vormil is an anthelmintic agent, the main active ingredient of which is albendazole. The mechanism of action of the drug is a violation of the metabolism of ascarid cells. The advantage of this remedy is that albendazole acts both on the intestinal form, that is, on the adult individual, and on the larvae and eggs. The drug is available in the form of chewable tablets and suspensions. Dosage of the drug - one tablet at a dose of 400 milligrams once a day, the course of treatment - three days. Possible side effects of the drug in the form of drowsiness, dizziness, decreased performance, as well as dyspepsia.

Prevention of infection with a human ascarid can be specific and nonspecific. Specific prophylaxis is the administration of anthelmintic agents, which have activity against ascarids for prophylactic purposes. For this, it is necessary to take anthelmintic drugs twice a year, for children, half the doses from the treatment can be recommended. You can use any antihelminthic drugs - mebendazole, albendazole, Pirantel.

Nonspecific prevention should be used by all people, especially the need to monitor children. Before eating, you should definitely wash your hands, fruits and vegetables should also be washed before eating. With regard to water and food, it is better for children not to drink water raw, and food to give sufficient heat treatment. For good digestion and a decrease in the possibility of invasion of ascarids, proper nutrition is necessary, which increases local immunity and anthelmintic abilities of the intestine.

The human Ascaris is geogelmint, which parasitizes in the human body in the small intestine. The danger of this worm is that it affects the intestinal mucosa, which reduces the absorption and absorption of nutrients - this leads to weight loss and symptoms of intoxication. Given that ascarids are very difficult to treat, because there are many immature forms in the body, it is necessary to prevent the infection with helminths.