Ancylostomiases

Ancylostomiases

 

(hookworm diseases), helminthic diseases caused by parasitization of the intestine in man with the roundworms Ancylostomatidae. Ancylostoma duodenale causes ancylostomiasis; Necator americanus causes necatoriasis. Hookworm diseases are widespread in the tropical and subtropical zones of the terrestrial globe, between 45°N lat. and 30°S lat., especially in South and Central America, Asia, and Africa. In the USSR, necatoriasis has been recorded in the Georgian SSR, Azerbaijan SSR, along the Black Sea coast of Krasnodar Krai, and in certain settlements of the Kirghiz and Kazakh SSR’s. Ancylostomiasis is found only in the south of the Turkmen SSR and in the Bukhara Oblast of the Uzbek SSR. A person suffering from hookworm disease, who discharges the eggs of Ancylostomatidae in the feces, serves as the source of infection. Infestation occurs when virulent (those capable of causing infection) larvae of Ancylostomatidae enter the body; optimal temperature of the external environment for development of larvae from eggs is 30°-32°C. Infection with hookworm disease occurs principally through contamination of hands, vegetables, fruits, berries, and greens with soil containing larvae of ancylostomes; infection with necatoriasis may be caused by going barefoot or lying on the ground, since the larvae of nectors penetrate the body of man mainly through the skin. Having entered the body, the larvae move along the bloodstream to the lung capillaries, exit through the bronchi, and enter the buccal cavity via the trachea; after being swallowed, the larvae develop into sexually mature parasites in the intestine. Necators may live in a human from ten to 15 years; ancylostomes, from four to five years.

Ancylostomatidae attach themselves to the mucous membrane of the small intestine and, wounding it, feed on the effluent blood. Prolonged intestinal hemorrhages may occur as a result, which cause the development of iron-deficiency anemia in the patient. Hookworm disease is manifested by heartburn, vomiting, absence of or increase in appetite, sometimes taste perversion, and pains in the epigastrium and the liver. Diagnosis of hookworm disease is made on the basis of clinical examination and discovery of the eggs of Ancylostomatidae in the patient’s stool. Treatment is chemotherapeutic (Naftamon, or Alcopar and thiabendazole); usually, complete recovery is made. Prophylaxis consists in protecting the soil from fecal contamination and rendering sewage harmless. On small parcels of land, the soil is treated with rapidly boiling water or common salt to destroy the larvae. It is suggested that the soil be treated with by-products of petroleum refining (petroleum growth stimulant).

REFERENCES

Pod”iapol’skaia, V. P., and V. F. Kapustin. Glistnye bolezni cheloveka, 3rd ed. Moscow, 1958.
Leikina, E. S. Vazhneishie gel’mintozy cheloveka [3rd ed.]. Moscow, 1967.
Maruashvili, G. M. “Problema likvidatsii ankilostomidozov ν SSSR.” Meditsinskaia parazitologiia i parazitarnye bolezni, 1967, no. 2. Pages 131–38.

A. I. KROTOV