Ancylostoma duodenale

Synonyms

4

Overview

Ancylostoma duodenale is one of two parasitic hookworms which can cause serious infections in human intestines - Hookworms feed on the blood of the host. Severe infections can cause chronic blood loss and related anemia.

Human infection with A duodenale is estimated to affect approximately one fourth of the world's population. Infection is most prevalent in tropical and subtropical zones, roughly between the latitudes of 45°N and 30°S. Hookworm infection occurs only in isolated temperate areas.

Infection is endemic in most developing countries. However, even in endemic regions, infection is usually confined to rural areas, especially where human feces are used as fertilizer or where sanitation is inadequate. In developed countries, infection is most commonly encountered in travelers, immigrants, and adoptees from developing countries.

A duodenale is the predominant species in the Mediterranean region, in northern regions of India and China, and in North Africa.

A light infection causes abdominal pain, loss of appetite and geophagy. Heavy infection causes severe protein deficiency or iron deficiency anemia. Protein deficiency may lead to dry skin, edema and potbelly, while iron deficiency anemia might result in mental dullness and heart failure.

Symptoms

  • Itching rash at the infection site
  • Fever
  • Coughing
  • Respiratory and gastrointestinal issues
  • Iron-deficiency anemia 
  • Intestinal bleeding 
  • Itching 

Causes

The worm larvae can survive for up to a month in the soil. If a host touches the contaminated area, the larva enters through its skin. It then moves to the circulatory system and is carried to the lungs.

The larva will exit the lungs, entering the alveoli and traveling up the tracheal tree. The host will eventually cough up the larva and swallow it. The larva will pass through the digestive tract to the small intestine, where it will grow into an adult.

Prevention

Do not walk barefoot or contact the soil with bare hands in areas where hookworm is common or where there may be fecal contamination of the soil. Improvement in sanitation measures in developing countries is necessary for prevention of infection.

Diagnosis

Diagnosis can be determined by looking for hookworm eggs in a recently collected stool sample. Blood tests for anemia and nutritional deficiencies, particularly iron, can help to confirm the diagnosis.

Prognosis

Complete recovery occurs if treatment is given before serious complications develop. The infection is easily eradicated with treatment.

Treatment

Anti-parasitic drugs such as Albendazole are the medication of choice for treating the infection.

Some of the other medications used in the treatment of Ancylostoma duodenale include:

  • Mebendazole
  • Vermox
  • Revapol
  • Vermicol
  • Vermidil
  • Vermin

Symptoms and complications of anemia are treated as they arise. The doctor will likely recommend increasing the amount of protein in your diet.

Resources

  • CDC
  • MedlinePlus
  • eHow
  • emedicine
  • NIH