HELMINTHOSES

From Big Medical Encyclopedia

HELMINTHOSES (helminth [y) + - osis) — diseases of the person, the animals, plants called by helminths — helminths. Contain more than 150 nosological forms G.; at the same time there can be simultaneous infection with several types of helminths. The course of a disease variously (from subclinical to the hardest forms with a lethal outcome) depending on a type of the activator, intensity of an invasion and some other ekzo-and internal causes. Usually proceed chronically.

History

Some G. [an ascaridosis, an enterobiosis, a dracunculosis (parasitic worm), teniidoza] were known in an extreme antiquity. An invasion by ascarids and tapeworms it is mentioned in Ebers's Papyruses (16 century BC). Hippocrates entered the terms «Helminthos» and «Ascaridos». Ibn-Xing (1020) recommended to treat an ascaridosis a wormseed wormwood. M. Malpigi in 1697 for the first time described parasitizing of helminths (fastsiol) in a liver of the person. The item of S. of Pallas (1760) criticized the theory of self-generation of helminths, claiming that infection of people and animal G. occurs at receipt in their body of eggs of parasites through a mouth together with food and water. The first work on a medical helminthology belongs to Bremzer (J. Bremser, 1819). The helminthology gained further development in works in biology of trematodes of Stenstrup (I. Steenstrup, 1842), trichinellas — Gerbsta, Tsenker (G. Herbst, 1848; F. Zenker, 1860), an echinococcus — Zibolda (G. Siebold, 1852), a parasitic worm — A. P. Fedchenko (1869), vukhereriya — P. Maksona (1877), a wide tape-worm — - M. Brown (1883). In the middle of the last century were described as nosological forms of an ankilostomidoza [A. Dubini, 1838], an urinogenital schistosomatosis [Bilkharts (Th. Bilharz), 1851]. Grizinger (W. Griesinger, 1854) established etiol, a role of ankylostomas in development of a so-called Egyptian chlorosis. At the end of 19 — the beginning of 20 century are described a clonorchosis [J. McConnell, 1874], the Opisthorchosis (K. N. Vinogradov, 1891), a strongyloidosis [A. Normand, 1876], intestinal and Japanese Shistosomatoza.

S. P. Botkin (1884) established a causal relationship between parasitizing of a wide tape-worm and development in the patient of anemia. In experiences of autoinfection of Koino (S. Koino, 1922) established that larvae of ascarids, migrating on a small circle of blood circulation, cause the pulmonary syndrome later described by Leffler (W. Loffler, 1932).

I. I. Mechnikov (1901), R. Blanshar (1904), M. V. Veynberg (1907), K. I. Scriabin (1923) pointed to a role of helminths in transfer of a bacterial flora in a human body. The allergic nature of clinical manifestations of an acute phase G. was shown on the example of a trichinosis by V. P. Bazhenov (1935). It was established that at an invasion a wide tape-worm the endogenous avitaminosis of B12 which is the reason of anemia [G. F. Lang, develops 1940; Bonsdorff (V. Bonsdorff), 1948, 1951]. Since the beginning of 20 century at G. began to apply immunol, diagnostic methods. Talyaferro (W. Taliaferro, 1929), R. S. Schultz and N. P. Shikhobalova (from 1935 to 1940), Oliver-Gonsalez (J. Oliver-Gonzalez, 1946) laid the foundation for systematic studying of immunity at G.

Geographical distribution

G.'s Most (an ascaridosis, a trichuriasis, ankilostomidoza, filariases, Shistosomatoza, etc.) — - diseases are local which area considerably depends on an environment — climate, presence of intermediate and additional owners etc. Only the few G. (e.g., a hymenolepiasis, an enterobiosis) are not endemic. The prevalence of the population of G. is defined also by social factors — life and a profession, a dignity. a condition of the inhabited places, level of municipal services, level of the organization of health care etc.

G. among the population of tropical are especially various and eurysynusic: zones of Asia, Africa and South America that is connected with lack of sharp temperature variations, air humidities and soils in these areas; it favors to maturing of eggs and larvae of helminths, development of larval forms of biohelminths in an organism of water and land intermediate and additional owners, and also to development of maggots — carriers of filariases. The wide spread occurance of G. in a tropical zone is explained also by rather low economic level, the insufficient organization to lay down. - professional, the help to the population in developing countries. The hymenolepiasis and an enterobiosis are widespread everywhere.

An etiology

the Major G. of the person are caused by the helminths belonging to the classes Trematoda (flukes), Cestoda (tape-worms) and Nematoda (roundworms). According to it distinguish trematodoza (see), tsestodoza (see), nematodoses (see). Cases of parasitizing at the person of Annelida worms (annlides) and Acanthocephala — skrebn, or Acanthocephala are known (see. Akantotsefaleza ).

The epidemiology

the Source of infection of G. is the person, and at helminthozoonoses also house and wildings. Depending on factors of transfer of G. divide into two basic groups: geohelminthoses and biohelminthoses. Eggs or larvae of activators of geohelminthoses are allocated to patients with excrements in external environment where they ripen and become invasive. As factors of transfer serve the soil contaminated by larvae or eggs of geohelminths, water, food, toys, objects of use and a hand. The ascaridosis, a trichuriasis, ankilostomidoza, a strongyloidosis, etc. belong to geohelminthoses.

Activators of biohelminthoses, in addition to the final (definitivny) owner, need the development in intermediate, and sometimes and the additional owner in which organism larval stages of helminths (parasitize see. Hozyain of a parasite ). In an organism of definitivny owners biohelminths reach puberty. E.g., a definitivny owner of the activator of a teniarinkhoz — a bull tapeworm — is the person, the intermediate owner — cattle. The patient teniarinkhozy allocates with excrements of egg and the joints of a bull tapeworm containing a large number of mature eggs. At the animal who swallowed eggs of a bull tapeworm with a forage or water in muscles larvae — a cysticercus develop (Finns). The person catches teniarinkhozy at consumption of the crude or insufficiently thermally processed measly meat. The activator of a diphyllobotriasis — ^ a wide tape-worm, except definitivny owners — the person, a cat, a dog, etc., has owners intermediate (crustaceans Cyclops, etc.) and additional (fishes — a pike, a perch, a burbot, etc.). Infection with a diphyllobotriasis happens at consumption of the crude or insufficiently thermally processed fish or not salted caviar to larvae of a tape-worm. The teniosis, an opisthorchosis, a clonorchosis, a metagonimosis, a paragonimiasis, a fascioliasis, fastsiolopsidoz, a dicrocoeliosis, shistosomatoza, filariases, a trichinosis, etc. also belong to biohelminthoses. Of a trichinella it is characteristic that all stages of its development pass in one owner — the person, domestic and wild mammals.

For the activator of a hymenolepiasis — a dwarfish tapeworm — a definitivny and intermediate owner is the person: puberal helminths parasitize in a gleam of intestines, a larva — in fibers.

Which activators can parasitize both at the person, and at animals call helminthozoonoses. Trichinosis, Echinococcosis, alveococcosis, Opisthorchosis, clonorchosis, fascioliasis, the Japanese schistosomatosis, brugioz, etc. concern to them. Helminthozoonoses which exist and extend among wildings in nature regardless of the person and domestic animals, call prirodnoochagovy. Carry to similar G., e.g., an alveococcosis (an alveolar Echinococcosis), a trichinosis. The person catches an alveococcosis through the berries and edible herbs contaminated by excrements of the infested wild predators (a wolf, a fox, a polar fox, etc.), and infection with a trichinosis occurs at consumption of badly boiled thoroughly meat of wildings (a bear, a boar, a badger and marine mammals). However prirodnoochagovy G. can get into an environment of the person, forming constants or the temporary synanthropic (antropourgichesky) centers — the zoonotic centers connected on the origin with activity of the person.

The most characteristic example of such centers are the centers of a trichinosis where circulation of trichinellas happens between domestic animals (a pig, a dog, a cat) and house rodents.

See also Invasion .

The pathogeny

the Pathogeny is defined by a difficult complex of factors specific (for helminth of this look) and nonspecific (the general for all G.) character. Distinguish a pathogeny acute y hron, Phases. In an acute phase irrespective of a type of the activator there is the general allergic reaction of an organism of the owner to products of exchange of larval stages of helminths (see. Allergy ). This reaction is especially expressed in cases when larvae migrate on tissues of the owner. So, larvae of ascarids from invasive eggs, getting into intestines, are implemented into its wall and are brought by a blood-groove in a small circle of blood circulation. In lungs of a larva actively pass through a wall of alveoluses and on respiratory tracts get into a throat from where again get into intestines where the cycle of their development comes to an end. The migratory phase of an ascaridosis is followed by eosinophilic infiltrates, a pneumonitis of antigenic character, granulematozny (antigenic) hepatitis, skin rashes, an eosinophilia (see. Lefflera syndrome ).

The pulmonary syndrome arises also in an acute stage of trematodoz of a liver — an opisthorchosis, a clonorchosis, a fascioliasis at which larvae of helminths from a duodenum on the general bilious channel migrate directly in the intra hepatic bilious courses. The described syndromes arise also at shistosomatoza. Stereotype of the main clinical syndromes in an acute phase G. regardless of a type of the activator, its localization and ways of migration in an organism of the owner testifies to their nonspecific character. The hypereosinophilia of blood, quite often leukemoid character (leukocytes to 20 000 — 70 000 in 1 mkl, eosinophils to 80 — 90%), demonstrates existence of generalized anaphylactic reaction in an acute stage of G.; the fabric eosinophilia indicates the allergic nature of organ defeats. In genesis of system vasculites at G. of especially heavy current an important role is played by soluble immunocomplexes antigen — an antibody, i.e. immunopatol. reactions. The nonspecific nature of organ defeats at G. is confirmed by a possibility of reproduction of similar defeats at immunization of animals antigens of helminths.

At G. which activators repeatedly postpone live larvae napr, at a strongyloidosis, filariases, the all-allergic phenomena naturally arise also in hron, a phase of a disease. Urticaria, a hypereosinophilia of blood, anaphylactic reactions are especially characteristic of larvaceous (larval) G. at which the person is an intermediate owner, napr, for an echinococcosis, larva migrans (see). Plays an essential role in G.'s pathogeny disproteinoz and the heavy dystrophic processes developing as a result of massive antigenic impact of parasites on an organism of the owner (fatty dystrophy of a liver at a trichinosis, a system amyloidosis at an alveococcosis and a multiple echinococcosis of a liver, etc.). In addition to immunol, mechanisms, it is necessary to refer direct effect of the enzymes emitted by the migrating larvae to nonspecific influencing factors of helminths — hyaluronidases, collagenases, cholinesterases, peptidases, lipolytic enzymes.

In hron, a phase G. along with the sensibilizing impact of parasites on an organism an essential role is played by a mechanical factor, napr, disturbance of outflow of bile at placement of a cyst of an echinococcus or node of an alveokokk in portal fissures, an occlusal syndrome during the movement of tsistitserok in cerebral cavities, traumatizations of a mucous membrane of intestines by the fixing device of helminths. It is necessary to refer ability of a wide tape-worm to absorb from intestines of the owner B12 vitamin, at a krovososaniye — blood, oxygen and iron to specific influence of helminths that serves as the reason of development of pernitsiozopodobny anemia, and also loan as helminths of oxygen and iron in the course of oxidizing phosphorylation.

The course of a disease at G. depends on massiveness of an invasion, shtammovy features of parasites, the general condition of an organism of the owner, features of his profession defining quite often a way of infection of.

The burdening G.'s influence on the course of infections is caused by effect of antigens of helminths that promotes, on the one hand sensitization (see), and on the other hand, to suppression of formation of immunity.

Pathological anatomy

Patomorfol, changes in internals in an acute phase G. are characterized by proliferation of lymphoid elements, macrophages, plasmatic, mast cells, a granulomatosis, eosinophilic reaction, vasculites. At early lethal outcomes (2 — 3 weeks after infection) defeats, in later terms (4 — 6 weeks) — a granulomatosis or diffusion eosinophilic infiltration of the struck body (myocarditis, a pneumonitis, hepatitis, encephalitis), system vasculites, a trombogemorragichesky syndrome prevail hemorrhagic-alterativnye.

Immunity

G.'s Disease causes specific defense reactions of cellular and humoral character in the person and animals. Immunity (see) at G. it is shown by restriction of reproductive activity and removal from intestines of mature helminths (ascarids, trichinellas, etc.), suppression of viability, death and a resorption of fabric larval forms (trichinellas, an echinococcus, alveokokk), immunity to a superinvasion. Antibodies at G. are highly specific not only in relation to types, but also and stages of development of helminth of this look.

After deworming or spontaneous recovery specific antibodies disappear within 6 — 12 months

the Clinical picture

the Clinical picture — see articles according to names of helminthoses, e.g.: Akantotsefaleza , Alveococcosis , Hymenolepiasis , Clonorchosis , Metagonimosis , Strongyloidosis , Shistosomatoza etc.

the Diagnosis

the Diagnosis of helminthoses is made on the basis of a clinical picture of a disease, detection of eggs, larvae or mature helminths and their fragments in excrements, duodenal contents, a phlegm and data epidemiol, the anamnesis. The last is especially important for prirodnoochagovy G.' identification and for diagnosis of an early phase G. when the patient does not allocate some eggs or larvae of parasites yet. In an early phase G., and also at larvaceous G. (an echinococcosis, an alveococcosis, larva migrans) an important role is played immunol, by diagnostic methods — serol, reactions or allergy diagnostic tests with antigens of helminths (see. Helmintologic methods of a research ). Statement of diagnostic skin tests is simpler, than serol, reactions, however skin tests demand high purification of antigens of ballast substances.

At G. proceeding with the expressed anaphylactic reactions (Echinococcosis), badly purified antigens can cause heavy complications up to acute anaphylaxis (see). Significant assistance in G.'s recognition is given by X-ray inspection and use of radioisotopes, napr, scanning of a liver at an echinococcosis.

It must be kept in mind that G. can be an associated disease. Therefore at establishment of the diagnosis comprehensive inspection of the patient is necessary. A specification on G.'s recognition is given in the table «Short Clinicodiagnostic Characteristic of the Major Helminthoses».

Treatment

At G.'s treatment it is necessary to reduce side effect of anthelmintic means to a minimum; the choice of drug shall be carried out individually taking into account features pharmakol, effects of drug, a phase and weight of disease (see. Helminthicides ).

The most active remedies for nematodoses (a strongyloidosis, a trichinosis and some other) is thiabendazole and Mebendazolum. At an ascaridosis with success apply salts of piperazin, Naftamonum. The most effective remedies of treatment of an enterobiosis — pirviniya pamoat, Mebendazolum. At tsestodoza (a teniarinkhoza, a diphyllobotriasis, a hymenolepiasis) phenasal and its combinations with trikhlorofeny is most effective. At treatment of trematodoz — a paragonimiasis of lungs and a fascioliasis — use bitionol. At trematodoza of a liver with success apply also hloksit. At shistosomatoza along with drugs of trivalent antimony (antimonyl-sodium tartrate) appoint ambilkhar. Filariases treat the citrate of a ditrazin suppressing a mikrofilyariyemiya. Abroad apply to impact on mature filarias suramin. In treatment of an echinococcosis and alveococcosis the leading role belongs to surgical methods, chemotherapeutic means (Trypaflavinum, etc.) have limited use, however high chemotherapeutic activity is found in Mebendazolum. It is necessary to consider that efficiency of anthelmintic means concerning various stages of development of parasites is various. So, phenasal affects only mature stages of cestodes, hloksit on mature forms of trematodes, thiabendazole and Vermoxum — on larval and mature stages of nematodes. The drugs possessing larvicide action usually cause also more expressed nonspecific side effect (strengthening of signs of a sensitization of an organism in connection with death of larval forms of helminths). In an acute phase of a disease, and also in hron, a phase at the expressed organ pathology (e.g., a symptomatic ulcer of a duodenum at a strongyloidosis or an opisthorchosis) specific therapy can provoke strengthening of ulcer pains, bleeding of a mucous membrane of a stomach and intestines and even perforation of an ulcer. Therefore specific treatment in an early phase G. is carried out after subsiding of acute allergic manifestations against the background of the active desensibilizing therapy — purpose of antihistaminic drugs, novocaine, drugs of calcium. At the expressed general allergic reaction, organ defeats appoint steroid hormones. However it is necessary to remember that long hormonal therapy promotes a long current of an acute phase of a disease and development hron, damages of internals.

Specific treatment in hron, a phase G., proceeding with complications, is carried out after the active pathogenetic therapy directed to recovery of function of cardiovascular system, a liver, biliary tract, kidneys, elimination of anemia, scarring of stomach ulcers and intestines that improves portability of helminthicides and increases efficiency of deworming. In the presence of an active bacterial flora in bile or intestines it is also more reasonable to carry out the corresponding chemotherapy to dewormings (see). It is necessary to observe strictly instructions at administration of drugs, it is impossible to exceed dosages of drugs and to reduce intervals between cycles and courses of treatment. Increase in a dosage of anthelmintic means does not increase activity of therapy, and only promotes strengthening of by-effects.

About efficiency of deworming judge on the basis of results of a research of excrements, duodenal contents, phlegm, blood on eggs or larvae of helminths, by an otkhozhdeniye of parasites at defecation, to disappearance of painful symptoms, normalization of quantity of eosinophils of blood, in later terms (6 — 12 months) — by decrease in credits and lack of specific antibodies. Dead opistorkhis and klonorkhis after treatment hloksily it is possible to find often in duodenal contents during the sounding. Eggs of trematodes (opistorkhis, klonorkhis) after death of parasites can is long (up to 3 — 4 months) to be allocated from bilious channels in intestines.

During the deworming along with an extensive indicator of therapy (percent of the cured patients) also its intensive indicator (percent of the departed helminths) matters about what judge by decrease in number of eggs of helminths in excrements.

In uncomplicated cases treatment from G. provides a complete recovery of health. At G. proceeding with the expressed organ pathology, deworming promotes the termination of progressing of defeats (hron, gastritis, hron, hepatitis), to scarring of ulcers, disappearance of the general signs of a sensitization of an organism: asthmatic attacks, skin rashes and normalization of quantity of eosinophils of blood, etc.

Prevention

Increase in welfare of the population of the USSR, significant growth in improvement of the cities and villages, broad holding antihelminthic actions, increased for years of the Soviet power a dignity. - a gigabyte. the culture of the population, cultural development of livestock production, improvement of system vt. - a dignity. control led to falloff of incidence

of G. G. reveal at mass inspections of children's collectives (day nursery, kindergartens, schools), employees of the food industry and public catering and some other spheres of consumer services of the population, cattle breeders. Obligatory inspection on G. there undergo patients who are on hospitalization (see. Helmintologic methods of a research ). In the large cities and industrial centers specialized advisory receptions of sick G. and day hospitals are created. Planned mass treatment of sick G. is carried out in a preepidemic season taking into account G.'s epidemiology and local klimato-geographical conditions. Carrying out dewormings (see), especially mass, shall be followed by neutralization of excrements, the containing helminths and their egg. The large role in G.'s prevention is played by fight against larval forms of a parasite — the preimaginalny deworming preventing environmental pollution by eggs of helminths (see. Devastation ).

In prevention of biohelminthoses — a teniarinkhoza, a teniosis and a trichinosis — the leading role belongs vt. - a dignity. to the service providing the correct maintenance of the cattle, control of slaughter and examination of meat. By the Soviet legislation all carcasses of cattle and pigs before their start-up in sale or in production are checked for a cysticercosis, and carcasses of pigs and some wildings on a trichinosis. At detection of an intensive invasion by Finns or a trichinosis of ink burn or transfer to technical utilization. At a weak invasion Finns of ink neutralize (see. Veterinary sanitary inspection ).

Fight against G. is impossible without dignity. - a gleam. and educational work. The main task of this work — increase a dignity. - a gigabyte. skills of the population, an explanation of ways of fight since. Special attention should be paid to fight against the harmful household habits promoting infection with biohelminthoses (consumption of crude meat and fish). Educational work is especially effective in children's collectives with active participation of teachers in it.

At the Ministries of Health of the USSR and federal republics committees on fight against G. and the Interdepartmental commission on fight against a trichinosis are created. Organizational and methodical work on fight against G. departments carry out parazitol, a dignity. - epid, stations. The International commission on a trichinosis with the organizational center in the Polish People's Republic is created.

See also Helminthology , Gelmintofauna of the person , Infectious diseases .


Table. The short clinicodiagnostic characteristic of the major helminthoses

[at tabulation materials of numerous references are used. In this regard insignificant discrepancies with the data provided at the description of helminthoses in separate articles are in some cases possible. Eggs of some helminths — see tsvetn, the tab., Art. 17, fig. 1 (in the text of the table references to these drawings are given)]


  • Is possible as a complication at a teniosis of intestines

(autoinvasion) and as an independent disease during the entering of eggs of a pork tapeworm in a mouth of dirty hands, with water, etc.

    • the Echinococcosis all bodies and systems can be struck:

liver, lungs, abdominal cavity, brain, cardiac muscle, bones &of nbsp;     etc.; diagnosis of an echinococcosis of the most often found localizations is given.



Bibliography: Astafyev B. A. Sketches on the general pathology of helminthoses of the person, M., 1975; Kornyansky G. P., Vasin N. Ya. iepshteynp. B. Parasitic diseases of the central nervous system, M., 1968; A. I Moles. Experimental therapy of helminthoses, M., 1961, bibliogr.; To at l e r with about D. T. Immunitet's N to parasitic diseases, the lane with English, M., 1948, bibliogr.; The multivolume guide to microbiology, clinic and epidemiology of infectious diseases, under the editorship of H. N. Zhukova-Verezhni-kova, t. 9, M., 1968; Scriabin of K. I. Devastation in fight against helminthoses and other diseases of the person and animals, Frunze, 1947; Shikhobalo-v and N. P. Questions of immunity at helminthoses, M. — L., 1950, bibliogr.; it e, Helminthoses the general to the person and animals, M., 1955; Chemotherapy of helminthiasis, ed. by R. Cavier a. F. Hawking, v. 1, Oxford, 1973; Faust E. C. a. Russell P. F. Craig and Faust’s clinical parasitology, Philadelphia, 1957; Hunter G. W., Frye W. W. a. Swartzwel-d e of of Y. Page A manual of tropical medicine, Philadelphia, 1966; Manson’s tropical diseases, ed. by Ch. Wilcocks a. P. E. C. Man-son-Bahr, Baltimore, 1972.

H. H. Ozeretskobckaya; authors of tab. H. H. Carpenters, E. S. Leykina.

Яндекс.Метрика