Hookworm ( hookworm and necatoriasis ) - Causes, Symptoms and Treatment .MF .
hookworm disease affecting up to 30% of the world's population, and are fairly widespread in countries with hot climates.
Hookworm - it geohelminthiasis (eggs ripen in the external environment in the soil), including diseases caused by nematodes of the family Ancylostomae Looss, which include hookworm and necatoriasis with a similar clinical picture.
Geographical distribution of hookworm diseases due to the presence of endemic foci mainly subtropical and tropical countries - South Asia, Africa, Central and South America, Australia, where it undergoes the invasion to 45-50% of the local population.Periodically ancylostomiasis found in temperate countries (Italy, Serbia, and others).Of the neighboring countries in the epidemic reports featured Georgia, Azerbaijan, Turkmenistan, Kazakhstan, Uzbekistan.In Russia, it is mainly the southern regions - Krasnodar and others.
causes of hookworm diseases
Pathogens: roundworms (nematodes so-called) of the family Ancylostomae Looss and include: Ancylostoma
Necator americanus (American krivogolovka).
mature individuals hookworm
This obligate human parasites (parasitic only in humans).This pale pink roundworms with curved front end.Dimensions hookworms - 11 mm male, 14 mm female.American hookworm sizes - 8 mm male, 10 mm female.At the head end has oral sucker to attach to the intestinal wall.Oral sucker hookworms contains chitin teeth in the amount of 6 pieces, and the American hookworm - two chitin inserts.
Oral sucker worm
The tail end has a sex bag (bursa).Eggs and American hookworm hookworms are practically indistinguishable from each other, with an oval-shaped colorless coating.Their size varies from 34-39 to 56-66 microns.The fresh eggs can be identified in a number of blastomeres of 4-8 pieces.
source of infection is a sick person, is excreted in the faeces helminth eggs.There are experimental data about infection of dogs, cats and monkeys.The adult worm lives in the small intestine of man, attaching oral sucker.Daily mature fertile females can allocate up to 30 000 eggs depending on the species of parasite.Lifespan hookworm helminth to 8 years, American hookworm - up to 15 years.
mechanism hookworm infection through fecal-oral, and at necatoriasis - perkutantny (percutaneous).Modes of transmission - water, food, contact.helminth transmission factors for hookworm - a contaminated soil particles with the larvae of worms hand, vegetable and fruit crops, various greens, berries.When necatoriasis infection occurs when walking barefoot on the earth, rest in the earth, digging and other forms of leisure and work associated with direct contact from the soil larvae with human skin.In connection with this are at risk for infestation: children, often running around barefoot, agricultural workers, gardeners, gardeners, employees of mining pits, where the high temperature and humidity.
susceptibility of the population to high hookworm.
development cycle. with faeces into the environment are allocated helminth eggs, of which 24-48 hours under favorable conditions (t = 27-30 °, high humidity of 70-80% for hookworm, 80-100% for hookworms, free access of oxygen) come alivelarvae that live in the soil.However, they are not invasive.Under such favorable conditions for 7-10 days before the infective larvae mature stage, and they are movable.Dates viability of the larvae in the upper layers of soil up to 8 weeks in countries with tropical climates.If the conditions are uncomfortable for the larvae (temperate climate), the deadlines are extended (slows metabolism).
In the human body get the fecal-oral (most hookworm) and perkutantnym or transdermal (mostly American hookworm) by.In the intestine, hookworm develop to sexual maturity, which occurs within 4-5 weeks.At the American hookworm - larvae penetrate into the blood vessels, and then fall into the pulmonary circulation, are in the lung (alveoli, bronchi, trachea, nasopharynx) - this process is called "migration of the larvae," and then the larvae are swallowed and mature in the intestine.The entire process of development of mature individuals of American hookworm up to 8-10 weeks.If American hookworm initially penetrates through the mouth, then through the mucosa of the oropharynx larva enters the bloodstream.Mature individuals of parasites in the gut and 12perstnoy in the upper small intestine.Fertilized females lay 30,000 eggs (hookworm) and 9000 (American hookworm).
Helminths - hematophagous (penetrate the intestinal mucosa, secrete a substance with anticoagulant properties and are fed with blood flowing from wounds).Living up to 5 years, hookworm, American hookworm - up to 15 years.
Pathogenic action of American hookworm hookworms and on the human body
1) there is a toxic and allergic reactions in the early phase of the disease (rash, bronchitis, eosinophils reach up to 60% in the blood), as well as the appearance of skin dermatitis at the site of the introduction of larvae.The duration of the manifestations may be 1-2 weeks.
2) in chronic phase or intestinal parasitosis appears iron deficiency anemia due to vascular damage, splash anticoagulants, bleeding.Blood loss depends on the degree of infestation.May occur folate deficiency, hypoalbuminemia or decrease serum albumin (which may be associated with blood loss or, malabsorption or amino acids in the gut, or protein deficiency in the diet).During the day, hookworm can consume up to 0.35 ml of blood, American hookworm to 0.05 ml.
3) There is a mechanical damage of the intestinal wall by mature individuals in violation of motor and secretory functions of the gastrointestinal tract.
Symptoms of hookworm diseases
The incubation period (the period from the moment of entering the larvae into the human body to the onset of symptoms) is 30 to 60 days.The disease may be asymptomatic, but still identify several features.
in early (acute) phase there is a common allergic reaction to the waste products and the introduction of larvae.In places the introduction of a phenomenon dermatitis.The patient has severe itching, polymorphous (diverse) skin rash, swelling, erythema (redness).Perhaps elements of secondary infection due to itching and scratching.Dermatoses last up to 10 days.In this phase, you can observe the changes in the state, due to the migration of the larvae, namely, changes in the respiratory - cough, asthma attacks, pneumonia;X-ray - eosinophilic inflammatory infiltrates, accompanied by fever and a high eosinophilia in the blood (up to 30-60%).
necatoriasis, manifestations on the skin
chronic phase (30-60 days after infestation) characterized by two pathological conditions: the development of anemia and lesions of the digestive system.
hypochromic iron deficiency anemia has character.With the increase in the degree of severity of anemia appear subjective symptoms: general weakness, fatigue, dizziness, tinnitus.Objectively: pale skin, sometimes peripheral edema, hypotension (decreased blood pressure), tachycardia (increased heart rate), systolic murmur on auscultation of heart sounds, expanding borders of the heart.The ECG - myocardial.
From digestive disorders in patients recorded: loss of appetite, nausea until aversion to food, abdominal pain (pain associated with duodenitis, periduodenitom, eyuitom - inflammatory changes in the intestinal wall).It may be diarrhea or constipation.X-ray - a violation of the motor function of the gastrointestinal tract.
In the chronic phase, changes are observed in the nervous system (irritability, sleep disturbance, fatigue, women - the menstrual cycle).
The general analysis of blood: decrease in the number of red blood cells, decrease in hemoglobin (2-3 g%), p / n 0.3-0.5, microcytosis, Anisocytosis, poikilocytosis increase in reticulocytes.When eosinophilia (in various degrees) and anemia and leukopenia observed Dysproteinemia (decreased albumin).
favorable prognosis for hookworm.With timely diagnosis and treatment recovery occurs.In rare severe cases may occur severe disease and poor outcome.
Diagnosis of hookworm diseases
diagnosis of hookworm disease is exposed on the basis of the following criteria:
1) careful collection of epidemiological history (health violation, visiting houses and gardens and food without proper sanitization of the hands and the products, the possibility of contact with the ground, certain professions, members of therisk - agricultural workers, miners, etc.);
2) clinical symptoms specific to a particular phase of helminthiasis;
3) changes in general blood test (eosinophilia up to 30-60%, decrease in red blood cells and hemoglobin, color index, reticulocytosis and others), protein spectrum disorders - a decrease of albumin serum;
4) changes on X-rays (changes in the lungs - eosinophilic infiltrates, hypotension and intestinal dysmotility with fecal stagnation phenomena);
5) koproovoskopiya - detection of helminth eggs in feces and macroscopic (adult analysis of the parasite), and identification of parasites is only possible after a discharge of deworming and adults, since it is impossible to distinguish between them in the balls.
Treatment of hookworm diseases
Etiotropic treatment appointed the doctor and carried out under the supervision of the state of the patient's blood counts. drugs have contraindications and side effects! Treatment usually performed on an outpatient basis, but if severe - in the hospital.
1) the drug of choice - pyrantel (gelmintoks, kombantrin) 10-12 mg / kg / day during meals
course of 2-3 days, which is determined by the physician.
2) naftamon once: for children up to 5 years - 2-2.5 g, for children older than 5 years - 5 g Mix with warm sugar syrup
fasting for 1-2 hours before breakfast.
3) levamisole (dekaris) - Children up to 14 years - 2.5 mg / kg over 14 years and adults - 150 mg dose.
4) Vermoxum (mebendazole) - 100 mg (1 tablet) 2 cut per day for 3 days..
Pathogenetic and symptomatic treatment implies the appointment of iron supplementation,
folic acid, vitamin B12, sedatives, antihistamines and others.According to the testimony of a transfusion of blood products.
monitoring the effectiveness of therapy is carried out not earlier than cherez3-4 weeks after the treatment, the study of feces 3hkratno held at intervals of 4 weeks.Clinical examination of patients with hookworm
held annually for 4 years, and patients necatoriasis - annually for 7 years.
prevention of hookworm diseases
1) Compliance with the rules of personal hygiene (washing hands after using the toilet and before eating, washing the feet when the gardening work, careful handling of vegetables, fruits, berries before eating).
2) Timely detection of hookworm disease symptoms, medical examination and deworming.
3) Sanitary cleaning environmental objects and mines from filth.Small soil areas suspected to be contaminated with larvae of hookworms and American hookworm treated with common salt and boiling water.
4) The annual medical examination of risk groups for hookworm disease (employees of mining enterprises, agricultural workers and others).
infectious disease doctor Bykov NI