Ankylostomidosis: ankylostomiasis, non-coryza: causes, symptoms, diagnosis, treatment

Ankylostomidosis - geogelmintosis. Adult helminths parasitize the human duodenum and jejunum.

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The cycle of development of ankylostomiasis

A person becomes infected with ankylostomiasis and non-katorosis when invasive (filarial) larvae penetrate through the skin, for example, when walking barefoot. Infection with hookworm infection can occur when ingested larvae with hookworm, found in water or on vegetables and fruits.

With the penetration of the larvae through the skin, their further development occurs with migration. Larvae migrate through the venous system to the right ventricle of the heart, then into the lungs, enter the cavity of the alveoli, move into the pharynx, the oral cavity and are swallowed again. The larvae pass through the esophagus into the stomach and then find themselves in the small intestine. Five to six weeks after the introduction of larvae into the skin, migration and two lines, they become sexually mature helminths. After this period, eggs can be found in feces.

In the northern areas of the distribution of ankylostomiasis with a marked change of seasons there are strains of hookworm, the larvae of which may not develop for 8 months. Then they continue and finish their development. Thanks to this, the eggs go out into the environment at the time most favorable for their development.

When penetrating the larvae with hookworm through the mouth, migration does not occur. The larvae immediately find themselves in the intestine.

Life expectancy of hookworm is 7-8 years, and of a non-killer - up to 15 years.

Epidemiology of ankylostomiasis, hookworm disease, non-carotidosis

About 25% of the world's population is infected with ankylostomiasis. Most often, this disease occurs in areas with a low level of sanitation. Ankylostomidosis - diseases common on all continents within 45 ° N. W. And 30 ° S. W. About 900 million people in the world are affected by ankylostomiasis, and about 450 million new cases are registered each year. Most often, these diseases occur in tropical and subtropical countries. Foci of ankylostomiasis are found in South and Central America, Africa, Hindustan, Indochina and the islands of the Malay Archipelago. Ankylostomosis occurs in the Caucasus, in Turkmenistan, Kyrgyzstan. Nekatorozy registered on the Black Sea coast of the Krasnodar Territory, on the border with Abkhazia. There are mixed foci of non-carotid and ankylostomiasis in Western Georgia and Azerbaijan.

The source of infection is an invasive person who secretes eggs into the environment.

Female hookworm a day allocates 10-25 thousand eggs, and a non-catcher - 5-10 thousand with feces eggs fall into the soil. The development of larvae occurs at a temperature of 14 to 40 ° C. For the development of larvae hookworm needs a moisture content of 85-100%, and for the grower - 70-80%. Larvae require access to free oxygen, at 0 ° C they are able to maintain viability for not more than a week. Under favorable conditions, rhabditic larvae develop in eggs in 1-2 days. They have two bulbuses in the esophagus. These larvae are noninvasive. 7-10 days after molting, the larvae become filariform. They have a esophagus cylindrical. After the second moult, the filariform larvae become invasive. Larvae can freely move in the soil along the vertical and horizontal lines.

The main factor in the transmission of the pathogen is soil contaminated with eggs and larvae of helminths. Infection of a person occurs most often due to the penetration of the filarous larvae through the skin (percutaneously) when walking barefoot. Transplacental and transmammaric modes of infection are also possible. Sometimes the infection occurs orally with the use of meat from rabbits, lambs, calves, pigs, as well as vegetables, fruits and water contaminated with invasive helminth larvae.

Epidemic foci of ankylostomosis are formed in the humid tropics, and noncathorosa in countries with a subtropical climate of wet type. Intensive foci of ankylostomidosis can form in mines, where larvae are able to develop rapidly in conditions of high humidity and high temperatures.

What causes ankylostomidosis?

Ankylostomiasis combines two helminthiasis: ankylostomiasis caused by the duodenal curve of the duodenum - Ancylostoma duodenale, and noncatarosis caused by the nekator - Necator amencanus.

These helminths are similar in morphology, cycles of development and action on the body. Body nematodes are pinkish-yellowish in color, small in size. The female of the curve of the duodenum has a length of 10-13 mm, and the male - 8-10 mm. The length of the female nekatora is 9-10 mm, and the male - 5-8 mm. The anterior end of the hookworm body is bent to the ventral side, and the noncataral to the dorsal. The head end has an oral capsule, with the help of which helminths attach to the wall of the small intestine. In hookworm, the capsule has four ventral and two dorsal incisal teeth, while the non-calcifier has two cutting blades.

The males at the caudal end have a bell-shaped extension of the cuticle (the cirrus sac). Ankylostoma it is larger and wider than that of a nekator.

Eggs hookworm and nekator on the structure are indistinguishable. They are oval in shape, covered with a smooth, thin, colorless shell, measuring 66 x 38 μm. In freshly etched eggs, 4-8 blastomeres are visible.

Pathogenesis of ankylostomiasis, hookworm disease, non-carotidosis

The pathogenesis of ankylostomidosis is different in the early and chronic stages. At an early stage, the larvae migrate to the organs and tissues of the host, cause allergic reactions, and have a sensitizing effect on the body. On the path of migration of larvae, as in ascariasis, respiratory tract tissues are injured, eosinophilic infiltrates are formed, hemorrhages develop. The duration of the early stage is 1-2 weeks. The intestinal (chronic) stage begins after the migration and penetration of the larvae into the duodenum. With the help of cuticular teeth, larvae attach to the mucous membrane, injure vessels, secrete anticoagulants and cause severe bleeding. Hookworms are hematophagi: for one day one specimen of hookworm consumes 0.16-0.34 ml of blood, and the nonacitor takes 0.03-0.05 ml. In places where the hookworm is fixed, ulcers are formed. Intensive invasion with helminths promotes the development of hypochromic anemia.

Symptoms of ankylostomiasis, hookworm disease, non-carotidosis

There are three clinical phases of ankylostomidosis.

The first phase is associated with the penetration of larvae through the skin. This phase is accompanied by the development of dermatitis (papulo-vesicular rash). In the skin there is a neutrophilic infiltration of the connective tissue with the presence of lymphoid and epithelioid cells and fibroblasts. The rash disappears after 10-12 days. With repeated infections develop hives, local edema.

In the second (migratory) phase of the disease, coughing, hoarseness, dyspnea, and fever sometimes appear. In sputum and blood, the number of eosinophils increases, focal pneumonias, bronchitis, tracheitis, and laryngitis occur.

The third, intestinal phase - a long, chronic. The first symptoms of ankylostomiasis are violations of the functions of the gastrointestinal tract, which appear 30-60 days after infection. Symptoms of ankylostomidosis depend on the number of parasites. The mild form is almost asymptomatic.

There may be unpleasant sensations in the epigastric region. By the end of the 12th month, duodenitis develops with nausea, anorexia, and abdominal pain.

The severe form leads to significant blood loss and is accompanied by chronic iron deficiency anemia, shortness of breath, lethargy, developmental delay, swelling, diarrhea with an admixture of blood and mucus in the feces, loss of albumins, leading to myocardial damage and cardiac dysfunction.

In patients of the black race, skin depigmentation occurs due to iron deficiency and hypoalbuminemia.

When infestation with hookworm infestation develops faster and reaches a higher degree than with invasion by a non-agent.

Complications of ankylostomiasis

Ankylostomidosis may have a complication in the form of decompensated anemia.

Diagnosis of ankylostomiasis

Differential diagnosis of ankylostomiasis is carried out with other intestinal helminthiases, with the development of anemia - with anemia of another etiology.

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Laboratory diagnosis of ankylostomiasis

The diagnosis of "ankylostomiasis" is made when eggs are found in faeces or duodenal contents. When studying feces use flotation methods (according to Füllleborn - in 15-20 minutes, for Kalantaryan - in 10-15 minutes). Diagnosis of ankylostomiasis is carried out by a special method of Harada and Mori - by culturing the larvae in a test tube on filter paper. Diagnosis takes into account epidemiological and clinical data.

Treatment of ankylostomiasis, ankylostomiasis, non-carotidosis

Treatment of ankylostomiasis involves the use of the following drugs:

• albendazole (nemozol) - adults and children over 2 years of age 400 mg once;
• mebendazole (vermox, antiox) - adults and children over 2 years of age 100 mg twice a day for 3 days (for a course of 600 mg);
• carbendacim (medamin) - adults and children at the rate of 10 mg / kg / day in three divided doses for 3 days;
• pirantel (helminthox) - 10 mg / kg (maximum 750 mg for adults and children over 12 years) per day once 3 consecutive days.

With the development of anemia, iron and folic acid preparations are prescribed. To monitor the effectiveness of treatment in a month after deworming, 3 studies of faeces are carried out with an interval of 30 days.

How to prevent ankylostomiasis, ankylostomiasis, non-carotidosis?

Ankylostomiasis can be prevented through the identification and treatment of patients, sanitary and hygienic measures aimed at protecting the environment from fecal contamination, neutralizing sewage, wearing shoes in foci of diseases, observing personal hygiene rules, washing fruits and vegetables before eating.