ASCARIDOSIS

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ASCARIDOSIS (ascaridosis; grech, askaris, askaridos + - ösis) — the helminthosis caused by roundworms — ascarids. At the person several species of ascarids from which everything, except Ascaris lumbricoides, are obligate parasites of animals can parasitize and in a puberal stage occur at the person extremely seldom.


Etiology

Fig. 1. Ascarids: 1 — a male, 2 — a female.
Fig. 2. Eggs of an ascarid: 1 — impregnated, covered with a fibrous casing; 2 — unfertilized, covered with a fibrous casing; 3 — impregnated without fibrous casing.

The activator — Ascaris lumbricoides — large diclinous helminths (fig. 1). The size of females is 25 — 40 cm, males — 15 — 25 cm. The head end is supplied with three big kutikulyarny lips surrounding an actinostome. The tail end of a female of a straight line with a conic appendage, a male — will be bent on the belly party. Eggs oval (fig. 2), are supplied with five covers, outside of them thick, scalloped (the proteinaceous nature), is painted over by a pigment of excrements in brown color. Eggs and without fibrous casing meet. Behind proteinaceous the three-layered lustrous cover is located. Both covers protect germinal weight from bruises. The internal (thin) cover — lipidic, semipermeable, detains salts and organic matters, but a pronitsayema for water. The size of eggs is 0,050 — 0,070 X 0,040 — 0,050 mm. Ascarids can produce also the so-called unfertilized eggs (ova) having irregular shape, the large sizes (0,050 — 0,106 X 0,040 — 0,050 mm) and deprived of germinal weight.

Fig. 3. A larva of an ascarid in an alveolus of a lung.

Adult ascarids live in thin department of intestines where they keep, having bent by an arch or having curled up a ring, resting against walls of a gut. Eat the food gruel which is in intestines and surface layers of a mucous membrane of a small bowel. Females after fertilization allocate eggs for stages of one blastomere which all development happens in the environment. Speed of development depends on conditions of temperature, humidity and structure of the soil. Egg becomes infectious after the larva created in it makes a molt and will turn into an invasive larva in a cap. At hit of such egg in intestines of the person the larva is exempted from egg covers, gets into thickness of a mucous membrane and a submucosa and is implemented into intestinal veins, on the Crimea gets into a portal vein. On intra lobular capillaries the larva gets into the central veins of hepatic segments, then into a sublobular vein and through large venous trunks — into the lower vena cava. On the lower vena cava it gets to the right auricle, then a right ventricle and through a pulmonary trunk — to capillaries of alveoluses, and then to a gleam of last (fig. 3). Before eviction in pneumatic ways of a larva can get from pulmonary arteries into veins, then through a left heart in a big circle of blood circulation and a blood flow to be brought in different bodies. The drilling ability of larvae at the same time is lost, and they cannot return to a circulatory bed, are gradually encapsulated and perish.

The larvae which are in pneumatic ways are fond of the movement of cilia of the ciliary epithelium covering bronchial tubes in an oral cavity and mix up with saliva. Being a zaglotana, they get into intestines where develop in adult parasites. In development of a larva of an ascarid make four molts. The first of them occurs between the fifth and sixth day during stay in a liver, the second — in 10 days when larvae are in lungs, the third — for the 15th day (the term of hit in intestines) and the fourth — on 25 — the 29th day in intestines then larvae develop in adult parasites. All development cycle of ascarids (from the moment of hit of egg in an organism of the owner before emergence in its excrements of eggs of new generation of parasites) proceeds 2V2 — 3 month from which 14 — 15 days migration on a circulatory bed and internals continues. Longevity of ascarids does not exceed years.

Epidemiology

Fig. 4. An area of an ascaridosis in the world (according to natural premises). (x) The level of a prevalence depends on social factors and the held hygienic and anti-epidemic events. (xx) Isohyets — the lines on the map connecting points to identical annual quantity of an atmospheric precipitation.

And. has a wide spread occurance in zones of a tropical, subtropical and temperate climate (fig. 4) with sufficient humidity. It is absent in a zone of permafrost and deserts; seldom meets in dry steppes. Perhaps, however, formation of the microcenters And. in the area, in general adverse for their existence. Prevalence And. is higher than children, than adults, as a result of insufficient observance of measures of personal hygiene by them and, perhaps, owing to development in adults of relative immunity to And. as a result of repeated infections. And. treats geohelminthoses. The only source of an invasion is the patient A. the person, in intestines to-rogo males and females of ascarids parasitize. The female in days lays over 200 000 impregnated unripe eggs which with a stake of the patient are allocated outside. Maturing of eggs happens, as a rule, in the soil, at a temperature from 10 — 12 ° (lower limit) to 36 ° (upper limit) and relative humidity of the soil not less than 8%.

Optimum temperature for development of eggs of ascarids apprx. 24 °; at it the invasive larva is created in egg in 14 days. In a temperate climate at temperature variations process of maturing of larvae usually comes to the end only in 40 — 60 days. Clay, chernozem and oozy soils are more favorable for development of eggs of ascarids, than the sandy and sandy soils which are quickly giving moisture and intensively warmed up by the sun.

Eggs of ascarids differ in considerable firmness and remain viable under snow at t ° — 30 ° and it is not lower than 4% of relative humidity. In a zone of a temperate climate, in the soils poor in organic matters, they remain live at a depth of 20 cm up to 5 — 7 years. The eggs which did not finish development by fall winter, and larvae in them become invasive in the spring. Infection And. happens at a proglatyvaniye of eggs of ascarids to an invasive larva. It occurs at consumption in the raw of the vegetables, berries and fruit contaminated by particles of excrements with eggs of ascarids is more rare than other food stuffs, at drink of not boiled water etc.

Season of infection And. in the .zena of a temperate climate lasts up to 7 months — from April to October; in more northern regions of 2 — 3 months, in the conditions of warm climate — all the year round. In a zone of a temperate climate infection And. in the winter perhaps through greenhouse vegetables, at a drift of eggs on footwear to dwellings etc. Prevalence And. it is especially high in areas where the soil of kitchen gardens is fertilized not neutralized excrements of the person.

Pathogeny

Fig. 5. A micronecrosis of a parenchyma of a liver (in the center of drug) as a result of migration of larvae of ascarids.

In an early, migratory phase A. there is a sensitization of an organism of exchange of a parasite sick with products, and sometimes and disintegration of larvae of ascarids that leads to emergence of eosinophilic and lympho-histiocytic infiltrates, an endarteritis and micronecroses in a wall of intestines, liver (fig. 5) and lungs. The sensitization of the patient proceeds, but to a lesser extent, and during an intestinal phase A. Larvae put damages to fabrics during migration, napr, break off the capillaries changed as a result of an allergy in lungs, causing hemorrhages. Adult ascarids injure and sometimes perforate a wall of intestines the ends of the body. Balls of ascarids can cause mechanical Ilheus, and the irritation of nerve terminations of intestines sometimes results it in spastic impassability. Leads penetration of ascarids into a liver, a pancreas, a respiratory organs to very serious consequences. Pilot model of an early migratory phase A. the Guinea pig whom feed invasive eggs of ascarids is. Larvae migrate in a body of a Guinea pig, but never reach puberty here. These experiments showed that at repeated infections the number of the migrating larvae in comparison with primary infection considerably is reduced, decreases their size and term of stay in an organism of the owner; pathoanatomical changes in bodies at repeated infection are expressed more weakly, than at primary. At repeated infection of a larva perish at the earliest stage of development, without reaching lungs. All this speaks about development in animals of immunity which has the cellular and humoral nature. In 5 — 10 days after infection And. in blood of the owner there are antibodies found within 80 — 90 days by a precipitation test. The last is positive and to blood serum of the people who transferred a migratory phase A.; it becomes at them negative in 3 months after infection. In the large centers And. at people immunity to a superinvasion is created — apprx. 25% of infections comes to an end at an early stage of development of helminths. Intensity of an invasion at visitors from areas, where And. has no wide spread occurance, through a nek-swarm time becomes higher, than at natives.

A clinical picture

the Incubation interval at And. — 2 — 3 days. In a clinical current And. there are two phases — early, migratory, and late, or intestinal. In an early phase A. quite often proceeds in the erased form. In other cases there is an expressed indisposition, cough develops dry or with expectoration; in a phlegm there can be an impurity of blood. Temperature is usually subfebrile, rises to 38 ° above less often; at some patients fever is absent. In lungs the centers of shortening of a percussion sound, dry and wet crepitant rattles are often noted. Sometimes — dry or exudative pleurisy. The liver and a spleen are occasionally increased. There can be urticaria. Radiological in lungs the so-called eosinophilic infiltrates which are followed by an eosinophilia of blood to 60 — 80% come to light. Total quantity of leukocytes is sometimes increased. ROE is more often normal. Infiltrates of lungs keep from several days to 2 — 3 weeks; sometimes, having disappeared, appear again.

Fig. 6. Obturatsionny intestinal impassability because of an ascaridosis (in loops of small bowels ascarids are visible).
Fig. 7. The loops of a small bowel containing balls of ascarids.

And. in an intestinal phase sometimes proceeds in the erased form. More often patients complain of the increased fatigue, a loss of appetite, nausea, vomiting, abdominal pains having sometimes skhvatkoobrazny character. Some patients have ponosa, or, on the contrary, locks, or their alternation. At 50% of patients gastric acidity up to an akhiliya goes down, and at 20% — increases. After successful deworming secretion of a stomach, as a rule, becomes normal. The rare dizenteriyepodobny, choleroid and reminding a typhoid syndromes are described, but the possibility of a combination in these cases of Ampere-second is not excluded by infectious diseases. At And. headaches, dizzinesses, increased fatigue are usual. It is observed anisocorias, nightmares, Menyer's syndrome, epileptiform spasms, a meningism. Arterial pressure at some patients decreases. Sometimes there are bronchitis, asthmatic suffocation. In blood it is frequent normo-or hypochromia anemia, an eosinophilia is changeable. The most frequent complications And. — obturatsionny (fig. 6 and 7) and spastic impassability of intestines; the first is caused by closing of its gleam with a ball of ascarids, the second — an enterospasm around an ascarid or about it. A heavy complication — penetration of ascarids into a gall bladder and bilious channels. At the same time there are attacks of acute terebrant pains in epigastriums and the right hypochondrium, vomiting. Often there is jaundice as a result of a cholangiohepatitis or obstruction by ascarids of the general bilious channel. Standard temperature or raised. The liver and a gall bladder are often increased. As a result of a consecutive bacterial infection emergence of a purulent cholangitis, abscess of a liver, peritonitis, sepsis is possible. It is described leading always to death so-called metastatic And. the right half of heart and a pulmonary trunk, caused by penetration of ascarids from a parenchyma of a liver in large branches of hepatic veins through their nekrotizirovanny wall. Penetration of ascarids into pancreat ducts leads to acute pancreatitis, in a worm-shaped shoot — to appendicitis. Ascarids can perforate intestines and a stomach in the field of operational seams and patholologically the changed sites of their walls. Cases of a perforation are described by ascarids of a gullet. Some patients have ascarids, climbing a gullet, reached a throat and from here crept in respiratory tracts, causing asphyxia. An exit of ascarids through a mouth puts to patients a mental injury. Ascarids were found in urinogenital bodies, by nasal cavities, the sleznonosovy channel, an acoustical pipe, a middle ear, pararenal cellulose.

And. burdens the course of dysentery, typhoid, scarlet fever, diphtheria, measles, trachoma, scrofulous keratoconjunctivites.

At the persons having frequent contact with ascarids the allergic phenomena — asthmatic suffocation, a small tortoiseshell, conjunctivitis, heartbeat quite often develop; allergic reorganization of an organism at some persons remains many years and after the termination of contact with ascarids.

The diagnosis

In an early phase A. it is distinguished on the basis of clinic of a disease, positive serological tests and at detection of larvae of ascarids in a phlegm. In an intestinal phase A. crucial importance has detection in Calais of eggs of ascarids which appear in 2 — 3 months after infection. Existence in intestines of one males comes to light radiological and trial purpose of protivogelmintny drugs.

Radiodiagnosis of an ascaridosis matters at not clear clinical displays of a disease and negative koprologichesky data, in particular in the presence in intestines only of one men's individuals of a parasite, and also for control of results of deworming. At the same time use a technique, usual for a research of a small bowel, with intake of a baric suspension. In the course of the research carry out dynamic overseeing by a passage of barium on a small bowel with performance of survey and aim pictures. For more careful and bystry studying of a small bowel throughout concerning estimated And. it is filled with a suspension of barium via the probe which is previously entered into an upper loop of a jejunum.

Fig. 8. Ascaridosis of intestines. Against the background of barium characteristic tape-like enlightenments in loops of a small bowel are visible. Roentgenograms.

In the presence of ascarids against the background of barium in a gleam of a small bowel the characteristic tape-like enlightenments caused by parasites (fig. 8, 1 and 2) are visible. Contours of these enlightenments accurate, the ends — pointed. Sometimes in the middle of a tape-like enlightenment the narrow longitudinal strip of the barium which is in a digestive tube of an ascarid is defined. Under the influence of a compression or a palpation of an ascarid are easily displaced, quite often begin to move, changing the situation in a gleam of a gut. Single ascarids are found in average and distal loops of a jejunum more often, and also in ileal. In places of the maximum accumulation of an ascarid sometimes keep within ranks in parallel each other. At a large number of parasites they can be found throughout all small bowel, and sometimes — in duodenal, thick, in a stomach and even in bilious ways. And. usually is followed by local dystonia and dyskinesia of intestines which degree of manifestation depends in many respects on duration of a disease, number and the sizes of ascarids. At the same time delay of a passage of barium, resistant spasms of a gut, a meteorism, and also reorganization of a relief of a mucous membrane (a thickening or flattening of folds) at the level of an arrangement of ascarids clearly is expressed. At multiple it is also long existing And. functional frustration extend to all digestive tract.

Forecast at uncomplicated And. favorable, at complicated — depending on a type of a complication.

Treatment

Specific treatment And. in an early phase does not exist. At a severe form of a disease appoint antihistaminic drugs. In an intestinal phase A. apply piperazin, Naftamonum, oxygen. Piperazin adipate and other salts of piperazin usually appoint 2 times in bucketed day between receptions at 1,5 — 2 o'clock within 2 days in a row in the following single doses: to children at the age of 1 year — 0,2 g, 2 — 3 years — 0,3 g, 4 — 6 years — 0,5 g, 7 — 9 years — 0,75 g, 10 — 14 years — 1,0 g, 15 years are also more senior — 1,5 — 2 g. Adults and children of school age can appoint piperazin once, giving a daily dose in one step. At children of preschool age this method is insufficiently effective. Training of the patient and a diet is not required. Laxative after reception of piperazin is given only at locks.

Naftamonum (alkopar) is appointed 1 — 2 day in a daily dose for adults and children 5 years — 5 g are more senior, children are 5 years old and more young — 2,5 g. All daily dose of drug is stirred in 50 ml of sugar syrup and drunk in one step. Drug is taken on an empty stomach for half an hour — one hour till a breakfast. Laxative is not appointed; diet usual.

Besides, for treatment And. apply oxygen which is entered into a stomach via the thin gastric or duodenal tube without olive on an empty stomach or in 3 — 4 hours after meal. A dose on a session to the adult — 1500 ml, to children up to 11 years — 100 ml for one year of life, to children and teenagers of 12 — 15 years — 1100 — 1250 ml. Gas is entered slowly on 200 — 250 bucketed ml 2 min. All procedure shall continue not less than 15 min. This treatment And. it is desirable to spend 2 days in a row. Laxative is appointed only at locks next day after the end of treatment. For a dosage of oxygen use the device from two communicating vessels, the device for imposing of pheumothorax adapted for this purpose by a double cylinder of Richardson. A control research a calla — in 2 — 4 weeks after treatment.

Prevention

Prevention is performed by means of a dignity. improvements of the inhabited places. Fertilizer of kitchen gardens sewage is allowed only after neutralization by their composting. The vegetables and fruit eaten by crude are washed and scalded boiled water. The helminths emitted at the patient boil or burn, excrements fill in with boiled water and maintain in the closed vessels of 40 min. In the intensive centers And., where a prevalence of the population of 30% and above, deworming (see) carry out 2 times a year to all population without continuous inspection. At decrease in a prevalence lower than 30% carry out treatment on the micro centers, i.e. all inhabitants where one patient is revealed at least And. At a prevalence And. in 3 — 5% treat only those in whom eggs of ascarids in Calais are found.

An ascaridosis at children

Children are surprised And. more often than adults that is explained by more frequent pollution of hands by the earth at underdevelopment of hygienic skills.

In the first, early, or migratory, a phase temperature is more often normal, sometimes subfebrile, seldom high. A condition of the child usually satisfactory, the febricula, a stethalgia, cough are sometimes noted. Bronchitis, pneumonia, pleurisy, eosinophilic infiltrates of a lung are possible. The skin rashes like small tortoiseshell or small bubbles on brushes and feet which are followed by an itch are less often observed. On site the burst bubbles the peeling of skin is possible. In blood the eosinophilia, ROE is quite often accelerated.

The second, late, or intestinal, a phase can proceed asymptomatically or with various clinical manifestations, usually heavier at children of early age. The dispeptic phenomena are noted: a loss of appetite, falling of weight, nausea in the mornings, vomiting, plentiful hypersalivation, frustration of a chair in the form of a lock, a diarrhea or their alternation. The most constant symptom is the abdominal pain, at most of children pristupoobrazny. Children of advanced age usually point to pains in a navel. Occasionally, in hard cases, the progressing enteritis or the coloenteritis which is followed by fever is observed is more rare — meningeal symptoms at which the lethal outcome is possible. Are known at And. children have convulsive twitchings, similar to choreic, hysterical or epileptiform attacks. The allergic phenomena are possible: pruritic rashes, attacks of bronchial asthma, asthmatic bronchitis. In blood the hemoglobin content is lowered, the eosinophilia, acceleration of ROE is noted. Children become irritable, whimsical, the uneasy dream, absent-mindedness, bystry fatigue are observed, memory and progress at school worsens. At a disease of the child of bacterial dysentery And. makes heavier its current and can promote transition of dysentery in hron, a form. Children's infections (diphtheria, scarlet fever, whooping cough) at accompanying And. proceed heavier and more often give complications.

Treatment And. at children it is carried out by the same ways, as well as at adults.


Bibliography: Biver P. K. Fight against the helminths which are transmitted through the soil, the lane with fr., M., 1962, bibliogr.; Vasilkova 3. G. Bases of a sanitary helminthology, M., 1950; Leukin E. C. The most important helminthoses of the person, M., 1967; The Multivolume guide to microbiology, clinic and epidemiology of infectious diseases, under the editorship of H. N. Zhukova-Verezhnikov, t. 9, page 543, M., 1968; Ovnatanyan K. T. Surgical complications of an ascaridosis, M., 1970, bibliogr.; Carpenters of H. H., Karnaukhov V. K. and And N and N and N and N. O. About one occupational disease of helminthologists, in book: Vopr. wedge. prof. Bol., under the editorship of E. M. Tareeva, page 49, M., 1964; Podjyapolskaya V. P. and Kapustin V. F. Helminthic diseases of the person, page 72, M., 1958; Podjyapolskaya V. P. is emenova N. E. Helminthoses at children, Mnogotomn. the guide to pediatrics, under the editorship of Yu. F. Dombrovskaya, t. 4, page 571, M., 1963, bibliogr.; Scriabin K. I. and Schultz P. - AA. C. Helminthoses of the person, the p. 2, M. — L., 1931; Smirnov G. G. Medical helminthology, page 26, L., 1959; Control of ascaria-sis, Wld Hlth Org. tecbn. Rep. Ser., No. 379, Geneva, 1967; Faust E. C. a. Russe IP. F. Craig and Faust’s clinical parasitology, Philadelphia, 1957, bibliogr.

Radiodiagnosis — Geselevich E. S. Znacheniye of X-ray inspection of digestive tract at an ascaridosis, Medical parazitol., t. 18, No. 2, page 115, 1949; Ovnatanyan K. T. To radiological diagnosis of an intestinal ascaridosis, in the same place, t. 30, No. 5, page 540, 1961, bibliogr.; Pas of N about in N. A., Gingold. 3. and Moskacheva K. A. Radiodiagnosis in pediatrics, page 400, M., 1972; The Reference book on a radiology and radiology, under the editorship of G. A. Zedgenidze, page 273, 380, M., 1972; Hanbabyanb.B. Radiological observations at an intestinal ascaridosis, Zhurn. ekspery. and wedge, medical, t. 6, No. 6, page 81, 1966, bibliogr.

H. N. Plotnikov; A. N. Kishkovsky (rents.), E. S. Leykina (etiology), R. N. Ryleyeva, M. Ya. Studenikin (ped.).

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