Ascariasis is a parasitic-induced disease that affects people who have ascarids in their bodies (helminthic parasites from the group of nematodes).
The disease is widespread throughout the world, excluding deserts and permafrost areas. The source of infection is the land contaminated by waste products of the human body.
Females of roundworm in vivo lay more than 230 thousand eggs per day, which, along with the feces, fall into the ground. In order for the larva to develop in the soil, a suitable temperature and humidity of the air is necessary. So, at 25-30 ° C the egg matures in 17 days. And at 13-20 ° C, this process will take from four to six weeks.
At a lower temperature, the development of the larva stops, but it does not die. And, if favorable conditions arise in the future, she will still be able to infect a person with ascariasis.
How can you get infected?
How can you get ascariasis, and what is it? The causative agent of ascariasis is the ascaris ascaris lumbricoides, a large, long yellow-white worm belonging to the family of roundworms. A typical parasite lives only at the expense of its owner. In humans, ascarids live in pairs, there are always an even number, females reach 20-30 cm or more, males reach 15-22 cm. The mechanism of ascaris transmission, like most intestinal parasites, is fecal-oral.
Causes of ascariasis is infection by parasites through unwashed hands, poorly washed vegetables (primarily greenery), by transferring ascaris eggs to insects. Directly transferring adult worms from one person to another is impossible. The incidence of ascariasis is more susceptible to children, workers of sewage treatment plants, agricultural workers, gardeners, etc. The season of increased risk of infection lasts from spring to autumn.
The disease occurs due to ingestion of mature parasite eggs, and this happens only after they fall into the soil. Then, by oral route, the eggs enter the small intestine, where the larvae hatch, which are then transferred from the bloodstream throughout the body.
Some people mistakenly believe that they can become infected with ascariasis from domestic animals (cats, dogs, pigs) and recommend prophylactic treatment once a year. This statement is fundamentally wrong. The cause of ascariasis in children and adults is only human ascaris. In the body of domestic animals, it can parasitize, but does not reach puberty and does not release eggs, which means that the animal cannot become a source of infection. But the uncontrolled intake of anthelmintic drugs, especially in overestimated dosage, has a detrimental effect on the liver.
But in some circumstances, communication with pets can lead to infection:
- Helminth eggs from the ground may be on the animal's fur. With wool, they fall on the hands and food, and from there into the mouth.
- The invasive parasite larvae can be in the animal's mouth after it has eaten food from the ground. Therefore, do not kiss the animal and allow him to lick a person's face.
- An animal can carry helminth eggs on its paws, and they will end up on household items.
Given these factors, the owners of animals are more likely to become infected with ascariasis, but if you follow the rules of personal hygiene, this danger is reduced to zero.
What happens after infection?
A person, swallowing mature eggs, becomes infected with ascariasis. 2 weeks after infection, their migration begins in the body. Once in the human body, they undergo several stages of development, and end up in the intestine, where their transformation into larvae occurs.
After which they enter the blood through the intestinal wall, and migrate to the bloodstream. Erythrocytes and blood plasma serve as the basis for feeding the larvae at this time. Then they get into other organs - the heart, liver and others, where ascariasis in humans forms infiltrates with a large number of eosinophils.
The larvae enter the lungs, bronchi and pharynx, where they are spread with sputum and from there return to the small intestine, where the larvae form adult individuals that release toxins and a huge number of eggs excreted in the feces. This is the stage at which there are obvious symptoms of the disease. Eggs get into the soil, infecting everything around, and the person again receives them through food that has not undergone heat treatment.
Symptoms of Ascariasis in Adults
Once in the human body, roundworm causes a number of characteristic symptoms. Early signs of ascariasis in adults begin to occur only at the stage of larval migration:
- low-grade body temperature;
- dry cough, sometimes with scanty mucous or purulent sputum;
- allergic dermatosis;
- rash on hands and feet.
Being in the small intestine, helminths cause such symptoms of ascariasis such as difficulty in moving food, impaired absorption of nutrients. The patient has pain in the abdomen, he is worried about diarrhea or constipation, nausea appears, appetite decreases or disappears, general weakness occurs, susceptibility to colds can increase, body weight decreases. Toxins secreted by parasites can cause allergic rashes on the skin.
In some cases, roundworms cause an obstruction of the intestinal lumen or ducts, through which bile is secreted, causing intestinal obstruction, colic, appendicitis, inflammation of the gallbladder and ducts.
Depending on the general state of health, the listed symptoms can be expressed or more intense, reminding intoxication of the body, or manifest weakly, practically absent.
In the intestinal phase, it is necessary to fear the development of serious complications for the patient's health:
- Intestinal obstruction, which occurs due to the closure of the intestinal lumen with a ball of ascaris. Intestinal obstruction in ascariasis is 3% of the total cases of such complications.
- Peritonitis (as a result of the vital activity of adults, the integrity of the intestinal wall may be disturbed).
- Ascariasis pancreatitis (migration of ascaris to the ducts of the pancreas leads to the development of acute pancreatitis). The patient has severe abdominal pain, vomiting, may be a collapse, an increase in urinary diastase.
- Mechanical blockage of the respiratory tract (roundworm crawling into the stomach, esophagus, oropharynx, respiratory tract, can cause filling of the lumen of the broncho-pulmonary tree, respiratory failure).
- Ascariasis of the liver (crawling of ascaris into the biliary ducts of the liver will lead to the development of obstructive jaundice). The patient has arching boring pains in the right hypochondrium, vomiting, jaundice, enlarged liver. Purulent cholangitis or inflammation of the bile ducts may develop (due to the addition of bacterial flora), which can lead to multiple liver abscesses.
Due to the fact that at the early stages of development of ascariasis the clinical picture is characterized by a multiplicity of various symptoms, it is often difficult to make a correct and accurate diagnosis. Diagnosis of this parasitosis is carried out, resorting both to the help of clinical and laboratory data, and taking into account the data of the epidemiological study.
The main methods of diagnosis of the parasite:
- Feces on helminth eggs - in the laboratory, a microscopic examination of feces is carried out, in which, when parasitizing an adult roundworm in the body, you can see eggs - round (barrel-shaped) formations. To obtain a reliable result, it is recommended to conduct this study several times (usually 3 times) with an interval of several days.
- Laboratory microscopic examination of sputum - is carried out to identify the larvae in it during their migration from the alveoli to the upper respiratory tract.
- A blood test - allows you to determine the presence of an allergic reaction by increasing the number of eosinophils. The degree of anemia is also determined by the level of decrease in hemoglobin and red blood cells.
- Radiography of the intestine with a contrast agent helps to visualize adult roundworm in it during the intestinal stage of pathology.
- Immunological study of blood plasma in order to determine specific antibodies to ascarid larvae.
- Radiography of the lungs is an additional method of instrumental investigation, which makes it possible to identify characteristic infiltrates (darkening area) in the area of the exit of the larvae of the roundworm from the bloodstream to the alveoli.
Treatment of ascariasis
Taking into account the results of all tests, and taking into account the symptoms of ascariasis, the doctor prescribes appropriate treatment. The process of expulsion from the body of worms of this type includes the use of modern antihistamine drugs (see the best worms tablets). Treatment of ascariasis is accompanied by iron supplements and multivitamins. It is also recommended to adhere to a diet containing an increased amount of protein foods.
At the same time, doctors forbid self-treatment of ascariasis at home, as an incorrectly calculated dose of the drug can result in serious body intoxication. Short-term side effects from the use of drugs are so diverse that they can lead to negative consequences for the patient.
How to treat ascariasis? In the early stages of the treatment of ascariasis, adult patients are prescribed desensitization therapy: Mintezol (50 mg / kg body weight twice a day during the week) or Mebendazole (taken 100 mg 2 times a day for 3 to 4 days). Treatment of ascariasis in children and adults is carried out with the help of anthelmintic drugs: Decaris (after dinner), Kombantrina (during meals), Vermox (in cases of polyinvasion). Continuous improvement of these drugs and increase their effectiveness have led to the fact that today antihelminthics are able to cope with the treatment of ascariasis in 85-100% of cases.
When ascariasis is in the migration phase, preparations for nematodes of universal action are used to treat invasions in children and adults:
- Mebendazole - Vormin, Mebex, Vermox (from 90 to 130 rubles), Termox, Vero-Mebendazole, Vermacar;
- Levamisole - Dekaris (from 70 to 90 rubles);
- Tiabendazole - Mintezol, Mertekt, Arbotect, Tresaderm, Mintezol, Tekto.
Additionally, bronchodilators are prescribed for obstructive bronchitis and pneumonia, as well as corticosteroids. Antihistamines (Claritin, Zirtek, Zodak, Erius, Suprastin, Tavegil) are prescribed in a short course at the same time as antiparasitic drugs in order to avoid allergization during the destruction of helminth.
The intestinal stage of ascariasis is relieved by the following medications:
- Pyrantel pamoat - Gelmintoks (from 90 to 120 rubles), Pyrantel (from 30 to 50 rubles), Kombantrin, Nemotsid, all drugs are designed for a single use;
- Dekaris - taken in accordance with the instructions, focusing on the age and weight of the patient.
- Mebendazole - Vormin, Mebex, Vermox, Termox, Vero-Mebendazole, Vermacar.
It is also recommended that people with ascariasis follow a diet according to treatment table No. 5. In the diet should reduce the presence of alcohol and fat, as well as increase the amount of food rich in protein. The rules of hygiene for patients with ascariasis should be strictly observed, they are strongly not recommended to drink raw water, and all food should be thoroughly washed out before use.
A control study of the effectiveness of treatment is recommended 2-3 weeks after treatment for 3 days in a row and again after 2 weeks also 3 days in a row. Clinical observation of patients with ascariasis lasts 3 years with an annual examination of feces from an infectious disease specialist.
In uncomplicated cases, the prognosis is favorable, treatment is effective for 2 weeks, without treatment and self-infection, the worms are removed a maximum of one year.
However, it is forbidden to use anthelmintic drugs for prophylaxis on their own. The drugs are toxic, dosages for children are selected individually by weight, and negative reactions from the liver and nervous system can develop in the process.
The main measure of prevention of infection with ascaris is compliance with certain rules:
- wash products that may have been exposed to the ground thoroughly (vegetables, fruits, or greens);
- wash hands with soap and water after contact or work with the ground;
- not letting the child pull the ground in his mouth and teach him to wash his hands after playing outside;
- place children's sandboxes in the sun and regularly loosen sand;
- prevent children from playing with outdoor shoes;
- weekly wet cleaning of the house.
Despite the adequate sanitary and hygienic standard of living of the population, therapeutic and diagnostic capabilities, the incidence of ascariasis is high. So today about 1 billion cases of ascariasis worldwide are registered annually.