Frequently Asked Questions about worms
Schistosomiasis
- Schistosomes are worms.
- There are 5 species of schistosomes which infect humans (see table below).
1. What are schistosomes?
2. How do I get schistososmiasis?
- A person infected with urinary schistosomaisis will have parasite eggs in their urine.
- A person infected with intestinal schistosomaisis will have parasite eggs in their faeces.
- In areas where there is no proper latrine system, freshwater sources around the village become contaminated with faeces or urine containing the worm eggs.
- In the water the eggs hatch and then they must find a particular type of snail.
- The snail acts like a mini photocopier and releases thousands of infective larvae.
- When people come in contact with the water, these larvae penetrate the skin.
- Children who spend a lot of time playing and swimming in the water are particularly vulnerable, as are fishermen and women carrying out household chores like washing.
3. How do I avoid getting schistosomiasis?
- Avoid swimming or other contact with fresh water lakes, rivers, or irrigation channels in areas where schistosomiasis is known to be transmitted (see Geographical distribution).
4. What are the symptoms of schistosomiasis?
- Urinary Schistosomaisis: If you have been in an area where urinary schistosomiasis is transmitted, and then you see blood in your urine, treat for schistosomiasis first of all.
- Intestinal Schistosomaisis: The symptoms for intestinal schistosomiasis are much more nonspecific and can be caused by other diseases as well: they include diarrhoea, lethargy and tiredness, abdominal pain or discomfort, and blood in the faeces.
5. If I think I have schistosomiasis, how do I treat it?
- There is only one drug for the treatment of schistosomiasis, which is called praziquantel.
- The dose is calculated according to your weight (see table below).
- Children under 5 years are unlikely to have much contact with water and are therefore unlikely to be heavily infected. From the age of about 6 years onwards, children learn to swim and play in water and as a result are much more at risk.
6. If I am pregnant, is it safe to take the drugs to treat schistosomiasis?
- Yes, the drug is extremely safe and WHO recommends that if you have schistosomiasis, you should be treated, even if you are pregnant.
- As a general precaution, WHO recommendations state that all drugs should be taken after the first trimester.