Water for Life 13
Worm infections
Some worms and other parasites (tiny animals) that live in surface water can get into
people’s intestines and cause diseases. The larger ones can be seen, but most cannot.
Stepping into or washing with contaminated water, drinking this water, or eating
uncooked shellfish or plants can pass these worms and parasites to people.
To prevent worm infections
• Reduce contact with contaminated water.
• Keep animal waste out of water.
• Use toilets and wash hands after use.
• Cook food well and protect food from germs.
• Trim fingernails and wash hands often.
• Wear shoes to prevent worms from entering through the feet.
• Settle, filter, and disinfect drinking water.
Guinea Worm
Guinea worm is a long, thin worm that lives under the skin and makes a painful sore on
the body. The worm, which looks like a white thread, can be over a meter long. Guinea
worm is found in parts of Africa, India, and the Middle East.
Signs of guinea worm:
• A painful swelling develops on the ankle, leg, or elsewhere on the body.
• After a few days to a week a blister forms which soon bursts open and forms a
sore. This often happens when standing in water or bathing. The end of a white
thread-like guinea worm can be seen poking out of the sore. The worm works its
way out of the body over the next week.
• If the sore gets dirty and infected or if the worm is broken by trying to pull it
out, the pain and swelling spread and walking becomes impossible.
Guinea worm is spread from person to person like this:
1. Infected person with
open sore wades
into a water hole.
The worm pokes out
of the sore and lays
eggs in the water.
2. Tiny water‑fleas eat
the worm eggs.
3. Another person drinks
the water. The fleas,
with the worm eggs,
are swallowed.
4. Some of the eggs
develop slowly into
worms under the skin.
After a year, a sore
forms when a worm
breaks through the skin
to lay eggs.
To treat guinea worms see a health worker or a general health book like Where There is
No Doctor. In addition, measures should be taken to prevent new contact with worms.
To prevent guinea worms see page 23, Steps to safer water holes and page 39, Cloth filters.