Hookworm

As Hookworm diseases are called helminthiases a dochmiasis and a necatoriasis possessing the big resemblance of biology of originators, a pathogenesis and clinic and often meeting in common. Mainly gastrointestinal tract is amazed, often enough there is a hypochromia anaemia.

Aetiology. Hookworm disease originators - round helminths of family Ancylostomatidae: Ancylostomaduodenale (Dubini, 1843), A. braziliense (de Faria, 1910), Necator americanus (Stiles, 1902). Male L. duodenale in the length 8-11 mm and width - 0,4-0,5 mm, a female-accordingly of 10-13 and 0,4-0,6 mm. The head extremity of a body will bend in the dorsal party on which there is a stomatic capsule with four ankyroid ventral and two fineer pointed dorsal teeth. Eggs oval, with a thin, transparent, pallid cover. Their dimension 0,054-0,07 x 0,36-0,04 mm, in the central part of the postponed eggs are four balls of crushing. A. braziliense has a stomatic capsule with two pairs a ventral teeth of the unequal dimension. The male in length of 8,5 mm, a female-10,5 mm. At the human this helminth was rarely reaches sexual maturity, parasitizes mainly at dogs and cats. Ingrained in a skin of the human of larva A. braziliense cause a dermatitis and mostly perish. N. americanus has less educed capsule, than hookworms in which two acute cutting plates towards to which from the dorsal party two pairs a teeth act settle down. American hookworm eggs are similar to hookworm eggs.

Epidemiology. Hookworm diseases eurysynusic in tropical and subtropical regions, in ranges with a hot and wet climate, between 450 N and 30 ° S., especially in Southern and Central America, Asia and Africa. Development of larvas Anostostomatidae in an external environment is possible at temperature from 14 to 40 ° (optimum - 27-30 °) and high humidity of bedrock, only small part of larvas is capable to overwinter in deep layers of earth at insignificant droppings of temperature. In subtropical regions the bedrock is completely cleared of larvas, therefore infestation wears a seasonal nature, in tropical districts it can have all-the-year-round character, strengthening in a season of rains. A source of invasion A. duodenale and N. americanus sick humans, A braziliense - mainly dogs and cats are. Infestation by a dochmiasis descends through the polluted arms, vegetables, fruit, potherb, and a necatoriasis - at walking barefoot, lying on the earth.

Pathogenesis. The hookworm and an American hookworm are localised in a thin intestine, mainly in duodenal and lean intestines. Larvas of hookworms get to an organism of the master mainly through a mouth and educe in an intestine without migration. American hookworm larvas usually take root activly through a skin, inpour into vascular capillars, migrate on the big and small circles of a circulation. Having reached lungs, through pneumatic pathes, a larynx and a pharynx they get to an esophagus and an intestine where in 4-5 weeks educe in adults of helminths. Parasitizing in an intestine, helminths eat basically blood, putting to an intestine mucosa fine wounds by chitinous arms of a stomatic capsule. In head and cervical parts there are glands which excrete the special anticoagulants which cause a long bleeding. The intensive invasion, especially at children's and young age, can lead to a delay in physical and mental development, to attrition and a cachexia. Quite often in these cases the invasion comes to an end with a lethal outcome. Lifetime of helminths, possibly, 3-5 years, probably, more longly. The majority of Ancylostoma perishes in 1-2 years after penetration into a body of the human.

Symptoms and flow. In case of penetration of larvas of Ancylostoma through a skin the early clinical phenomena are bound to their migration on an organism. Brumpt (1952) has shown, that next day or in day after the first infestation the patient has an itch and on a skin there is an erythema with fine red papules. In 10 days these rashes disappear. At the second infestation immediately after drawing on a skin of larvas of hookworms the urticaria which in some hours dies away, being replaced by red papules in diameter pours out of 1-2 mm, the fields of a normal skin abjointed from each other. At the third and fourth infestation of the same person focal lesions become more and more serious and are accompanied by local edemas and vesiculation on a skin. In an early phase of hookworm diseases eosinophilic infiltrates in lungs and the vascular pneumonia proceeding with a fever and high (to 30-60 %) are described by a blood eosinophilia. Tracheites and laryngitis with hoarseness of a voice and even an aphonia are registered. In some cases these phenomena keep till 3 weeks.

In 8-30 days after infestation some persons have abdominal pains, vomiting, diarrhoeia and a febricula. Pains in the epigastric range, arising at many sick of hookworm diseases, remind pains at a duodenum peptic ulcer. They are caused by a duodenitis, including erosive, and a pylorospasm. In the beginning of disease of a pain have acute character, but in due course become less expressed.

Most typical feature of hookworm diseases is educing at an appreciable part of patients the hypochromia anaemia proceeding sometimes in very serious form. The patients, suffering an anaemia, complain of the general delicacy, a dyspnea, a sonitus, the raised mental and physical weariness, giddiness, blackout, weight loss, dropping, is rarer - appetite rising. They quite often eat clay, a lime, coal, ashes, a brick, a paper, lick metal subjects, salt, soap. At blood smear analysis find a microcythemia, a hypochromia and a polychromatophilia of erythrocytes. The quantity of reticulocytes is usually raised. The number of leucocytes is a little lowered. Temperature usually normal or subfebrile. Only at few patients it raises to 38 ° With and more. Gravity ancylostoma invasions depends on quantity of helminths and their species composition, duration of experience of parasites, quality of a food of the patient.

Diagnosis and the differential diagnosis. Recognition of hookworm diseases is based on the account clinical and datas of laboratory, the core is feces analysis on eggs of Ancylostoma. Excrements or duodenal contents are investigated for the purpose of revealing of eggs of Ancylostoma by a method of a native smear on the big glass which is looked through under the binocular microscope, and also by a flotation method. Thus upholding proceeds only 10-20 minutes since later the number of eggs in Membranula considerably decreases.