Tropical Sprue

What Is It?

Tropical sprue is a digestive problem that occurs in the tropics and subtropics. People with tropical sprue do not absorb nutrients properly, especially vitamin B12 and folic acid.

Normal small intestines have fingerlike projections called villi that provide more surface area for nutrients to be absorbed. In people with tropical sprue, these villi are flattened, making absorption difficult.

Tropical sprue affects about 1 of every 1 million people and occurs from about 30 degrees north of the equator to 30 degrees south of it. It is more common in certain countries, including India, Haiti, Cuba, Puerto Rico and the Dominican Republic. It is rare or absent in Africa, the Bahamas and Jamaica. The condition afflicts residents of the affected countries as well as travelers, though usually it affects only travelers who stay for 6 months or longer.

The cause of tropical sprue has not been identified, but it is probably a combination of factors, including infection and poor nutrition, that act together to damage the lining of the small intestine, making it less able to absorb nutrients.

Symptoms

Diarrhea is the main symptom of tropical sprue. People who eat a lot of fatty foods may get more severe diarrhea than those on diets low in fat. Other symptoms include cramps, nausea, weight loss, gas and indigestion.

Diagnosis

Diagnosis of tropical sprue can be complicated, because many conditions have similar symptoms. Your physician will order stool and blood tests to check for other causes of diarrhea. If these are negative and you have lived in the tropics for a long period, then tropical sprue is a potential cause for your illness. Your doctor may do a biopsy, in which small piece of tissue is removed from your small bowel to be examined under a microscope. To do this procedure, your doctor will need to examine your stomach and small intestines through a small tube that is passed through your mouth and esophagus. There is no one test that can confirm the diagnosis, but it is likely you have tropical sprue if the tissue removed during the biopsy appears similar to tissue from other people who have had the disease.

Certain blood tests also can give an indication that you might have tropical sprue. Because the disease blocks certain vitamins and minerals from being absorbed, you may have low levels of albumin, calcium or vitamins D, A, K and E. You also may have anemia due to vitamin B12 and folate deficiencies. Anemia is a low level of red blood cells. In addition, stool specimens may demonstrate an excess amount of fat.

Expected Duration

Once treatment has started, most people are relieved of symptoms within weeks.

Prevention

Other than avoiding tropical climates, there are no known ways to prevent tropical sprue.

Treatment

Treatment is usually 3 to 6 months of antibiotics and folic acid (also called folate) supplements. People with vitamin B12 deficiency will receive vitamin supplements as well.

When To Call A Professional

Contact your doctor if you have diarrhea that does not respond to over-the-counter treatments. If you have lived in a tropical country for at least a few months, you may have developed tropical sprue. Once you are undergoing treatment for tropical sprue, contact your doctor's office if the condition does not respond after several weeks.

Prognosis

The outlook for tropical sprue in travelers is usually excellent. In about 20% of tropical residents who have tropical sprue, the disease comes back after treatment.

Additional Info

Centers for Disease Control and Prevention (CDC)

National Center for Infectious Diseases

Division of Bacterial and Mycotic Diseases

11600 Clifton Road

Atlanta, Georgia 30333

http://www.cdc.gov/ncidod/dbmd