Ancylostomiasis is defined as the condition of infestation of the human intestine by hookworms. The common hookworms that infect humans are Ancylostoma duodenale and Necator americanus. These parasites feed on blood from the host's intestinal walls.
Ancylostomiasis is prevalent in tropical and subtropical areas, and affects around 1/5th of the world population. Hookworms are responsible for 50,000 - 60,000 deaths every year.
· Hookworm disease
· Miner's anemia
· Tunnel disease
· Brickmaker's anemia
· Egyptian chlorosis
· Tropical Anemia
The causative organisms may present with or cause the following:
- Classic hookworm disease: Caused by Ancylostoma duodenale,Necator americanus and rarely Ancylostoma ceylanicum
- Cutaneous larva migrans: Caused by larvae of Ancylostoma braziliense and Ancylostoma caninum. This causes skin rash and intense itching
- Eosinophilic enteritis: caused by Ancylostoma caninum (dog hookworm). It presents with abdominal pain, and the patient has no blood loss.
CAUSES & RISK FACTORS
The causative organisms are theancylostoma hookworms, Ancylostoma duodenale, Necator americanus, rarelyAncylostoma ceylanicum (normally infests cats and dogs); and Ancylostoma brazilienseand Ancylostoma caninum that causes cutaneous larva migrans.
The infection is seen commonly inindividuals who walk barefoot in areas where defecation is done outdoors in thesoil.
Life Cycle: The larvae of thehookworm penetrate through the skin, enter the bloodstream and are carried tothe lungs. From the lungs they travel through the airways and are swalloweddown the food pipe into the intestines, where they develop into adult worms. Inthe intestines, they attach to the intestinal wall with their sharp hooks andfeed on blood. Some of these adult worms and larvae are then excreted in the feces.
The larvae of the dog or cathookworm, however, are unable to penetrate through the skin and migrate justbelow the skin producing creeping eruptions or wavy snake-like markings, knownas cutaneous larva migrans.
SYMPTOMS & SIGNS
- Blood in the stool (due to intestinal bleeding)
- Pain and discomfort in abdomen
- Blood in the sputum.
- Local intense itching in the skin
TESTS & DIAGNOSIS
- Complete blood count (CBC)
- Stool sample: For ova and parasites examination under the microscope.
- D-Xylose absorption test.
- Mebendazole, Albendazole or pyrantel pamoate, to kill the organism. These drugs are given for 1-3days
- Iron supplements, if the patient has anemia
- Thiabendazoleointment, is used in case of Cutaneous larva migrans.
- People should avoid defecation outside and should use proper sewage disposal system.
- Avoid walking barefoot in areas where hookworm infection is widespread, and in areas where the soil may be contaminated with human feces.
Complete recovery is seen with treatment.
A 5 year old boy living in a rural area of Uttar Pradesh presents with pain in the abdomen and fatigue. On asking, the mother gave a history of blood in the sputum and that the child usually plays barefoot outdoors. On examination, the child had severe anaemia. His stool sample showed occult blood and ova and parasites of the hookworm, Ancylostoma duodenale. The child was prescribed Albendazole 400 mg once orally.
REFERENCES & INTERNET LINKS
Hookworm infection. N Engl J Med. 2004 Aug 19; 351(8):799-807
Caumes, E., J. Carriere, A. Datry, P. Gaxotte, M. Danis, and M. Gentilini. 1993. A randomized trial of ivermectin versus albendazole for the treatment of cutaneous larva migrans. Am. J. Trop. Med. Hyg. 49: 641 – 644.