What is Necatorosis?
Necatorosis – helminthiasis from the group of ankylostomidosis, caused by Necator americanus, parasitizing in the small intestine; proceeds with dyspeptic phenomena, signs of allergy and the development of hypochromic anemia: distributed in tropical and subtropical zones.
Causes of Necatorosis
The causative agent of necatoria – necator (Necator americanus), parasitic in the small intestine of a person, often in the duodenum. A necator does not have teeth in the oral capsule, instead it has two cutting plates. Eggs of both helminths are oval.
Necator americanus is registered in Asia, Africa and America.
Pathogenesis during Necatorosis
The life cycle begins with the eggs in the soil along with faeces. The development of larvae is possible at a temperature of 14-40°C (optimum temperature of 28-30°C) and high soil moisture.
After 7-10 days, the larvae take the form of a filarial with a cylindrical esophagus and become infectious. Larvae actively move in the soil in horizontal and vertical directions. When a person’s skin is in contact with the soil, the larvae, attracted by body heat, actively penetrate the host’s body through the skin.
Infection occurs with the active introduction of the larvae through the skin or if they are swallowed by contaminated vegetables, fruits, and water. The larvae migrate through the large and small circles of blood circulation, lasting 7-10 days.
With saliva, the larvae are ingested by the host and enter the duodenum, where their further development to the mature stage occurs. The larvae they produce come out with feces. 8-10 weeks after the infection, the sexually mature helminth eggs are secreted from the body of the sick person. A sick person is not an immediate danger to others, because at the time of the release from the body the eggs do not possess an invasive ability. It is necessary ripening helminth eggs in the soil. The lifespan of a necator reaches up to 15 years.
During migration, the larvae cause toxic and allergic phenomena. Adult hematophagous worms. When fixing to the intestinal mucosa, they injure tissues, lead to the formation of hemorrhage, erosion, cause bleeding, anemization, maintain the state of allergy, dyskinesia of the gastrointestinal tract and dyspepsia.
Symptoms of Nekatorosis
The incubation period of the disease lasts 40-60 days. In most cases, the disease is asymptomatic. With more severe course of symptoms depends on the method of penetration of the parasites into the body. When penetrating through the skin, itching and burning of the skin, various kinds of rash (erythematous, papular, vesicular, pustular) occur, which may persist for several months. Massive invasion leads to swelling of the limbs. During the migration of larvae through the respiratory tract may develop catarrhal phenomena, shortness of breath, wheezing, possible development of bronchitis, pleurisy, pneumonia. At a later stage, when it enters the gastrointestinal tract, duodenitis develops with heartburn, lack of or increased appetite, sometimes taste distortion (desire to eat, for example, clay), nausea, vomiting, pain in the epigastric and hepatic regions, often accompanied by diarrhea.
The most characteristic manifestation of the disease is hypochromic iron deficiency anemia. It is attached to the walls of the intestinal mucosa by the teeth. At the place of fixation of the helminth, erosion and ulcers up to 2 cm in diameter occur, and long-term intestinal bleeding may occur, which cause the development of iron deficiency anemia. Blood protein decreases (hypoalbuminemia).
The central nervous system is affected, lethargy, mental retardation and physical development appear.
Diagnosis of Necatorosis
The diagnosis is confirmed by the detection of eggs in the feces and occasionally in the duodenal contents.
In cases of severe anemia (hemoglobin below 67 g / l), iron preparations and red blood cell transfusions are used. Worm-cleaning is carried out with naphtamon, combantrin or levamisole. Naftamon is prescribed on an empty stomach for 2-5 days. Single dose for adults 5 g. To eliminate the bitter taste and nausea, the drug is best given in 50 ml of warm sugar syrup. Kombantrin (Pyrantel) is prescribed in a daily dose of 10 mg / kg in two doses after meals, and levamisole (decaris) in a daily dose of 2.5 mg / kg in one dose. Treatment with these drugs lasts 3 days. Efficiency about 80%.
In the foci of hookworms should not walk barefoot and lie on the ground without litter. It is necessary to thoroughly wash and scald fruits, vegetables, and berries with boiling water before eating them; you should not drink unboiled water.