Strongyloidiasis is an infection caused by the roundworm Strongyloides stercoralis (S. stercoralis).

S. stercoralis is a roundworm that is fairly common in warm, moist areas. Rarely, it can be found as far north as Canada.

People catch the infection when they come in contact with soil contaminated with the worms.

The tiny worm is barely visible to the naked eye. Young roundworms can move through a person's skin and into the bloodstream to the lungs and airways. As the worms grow older, they bury themselves in the walls of the intestines. Later, they produce eggs in the intestines. Areas where the worms go through the skin may become red and painful.

The rate of this infection is low in the United States. Most of the disease seen in North America is brought by travelers who have visited or lived in South America and Africa.

Most of the time, there are no symptoms.

Symptoms that may occur include:

• Red hive-like areas near the anus
• Abdominal pain (upper abdomen)
• Vomiting
• Diarrhea
• Cough
• Unintentional weight loss
• Rash

The following tests may be done:

• White blood cell count
• Stool sample exam to check for S. stercoralis
• Duodenal aspiration
• Blood antigen test for S. stercoralis
• Sputum culture

The goal of treatment is to eliminate the worms with anti-worm medications such as ivermectin, albendazole, mebendazole, or thiabendazole.

Full recovery with eradication of parasites is expected with adequate treatment. Sometimes treatment needs to be repeated.

Infections that are widespread often have a poor prognosis, especially in patients with weakened immune systems.

• Acute pulmonary eosinophilia (Loeffler's syndrome)
• Malabsorption
• Disseminated strongyloidiasis, especially in patients with HIV or an otherwise compromised immune system

Call for an appointment with your health care provider if symptoms of strongyloidiasis are present.

Good personal hygiene can reduce the risk of strongyloidiasis. Adequate public health services and sanitary facilities provide good control of infection.