Dracunculiasis…yes, the worm hanging out of peoples’ feet

Dracunculus medinensis

Dracunculus medinensis

This is a very notorious human parasite with a long history.  Also known as the “Guinea worm” or simply “the worm that hangs out of peoples’ feet, Dracunculus is also believed to be the “serpent” that winds around the staff of Hippocrates and predecessor of the caduceus.  This illness is still around, thousands of years after Hippocrates, and can still cause problems for both locals and travelers in endemic areas. 

BASICS:

This is the nematode that protrudes out of people’s feet or lower limbs. Ingestion of copepods in contaminated water is the main way to get it. When the people with the Guinea worm hanging out of their foot walk in water, the worm releases eggs. Symptoms include a large blister on the foot or leg when the pregnant female is ready to burst through the skin and begin to shed eggs, along with itching and nausea/vomiting.

LOCATION:

Sub-Saharan Africa

TRANSMISSION and INCUBATION:

Acquired by drinking water infected with copepods. Incubation time from ingestion to symptoms is approximately one year.

Filtration straws at work

Filtration straws at work

PREVENTION:

 

Adequate pore filtration of water (100 micrometer strain), education to stay out of water if infected

TREATMENT:

Prevention of secondary infection at blister site, tetanus prophylaxis and an attempt at gentle/long term/very slow extraction is best. Albendazole, DEC, etc. are ineffective.  Care must be taken to avoid breaking the worm off, inside the body, as this can result in a secondary infection.

LIFE CYCLE:

A large global health burden, frequently entire villages are infected and still are drinking contaminated water. Adequate instruction on filtration is all that is required to prevent this. The infected person walks in still, fresh water and the pregnant female worm release her eggs. From there, they are ingested by a copepod (small crustacean). This copepod is then swimming in the water an unsuspecting person drinks. Ingestion of the copepod and the developing larvae it carries lead to the stomach. Once there, the larvae penetrate the stomach/duodenal wall and migrate through the body. After the male and female mate, the pregnant female goes to the lowest part of the body because it will be closest to water. Then she breaks through the skin and lays eggs when in the infected person wades in water.

REMOVAL:

Removal of the guinea worm is a hotly debated topic. Some advocate a surgical attempt to remove the entire female worm from the blister, before she penetrates the skin. However, if she has already pierced the skin, it won’t work. Use of a toothpick or other small stick to “wrap” the worm around (like winding thread on a spool) is also used. As the head of the worm protrudes, simply wrap the worm on the stick and tape the stick to the leg. This prevents the worm from retreating back into the body after laying eggs. Then, slowly, each day, wind a bit more of the worm on the stick. Caution must be used to avoid breaking the worm or tearing it in half, while winding.

Travelers to endemic areas should routinely filter their drinking water if it comes from a questionable source, especially in rural areas.  Of course, hikers and off-road athletes taking water from lakes, streams, etc. should also get in the habit of water filtration.

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One Response

  1. Yuck!

    My travel mate in Laos had a worm in her foot and the doctor recommended leaving it inside. Eventually meds killed it but we would watch its progress every day and wonder which way it was going to eat next. 🙂 Here’s a pic!

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