Schistosomiasis is caused by tiny worms that live in untreated fresh water like rivers, lakes and ponds.
You cannot see the worms, so they may be in the water even if it looks clean.
If water containing the worms gets on your skin (for example, while swimming, washing or walking in water), they can burrow into your skin and get into your body.
The worms that cause schistosomiasis are found in tropical and sub-tropical parts of the world like:
- most of Africa
- the Middle East
- southern and south-east Asia
- some parts of South America and the Caribbean
You cannot get schistosomiasis from rain drops, sea water, or swimming pools treated with chlorine.
Check before you travel
You can get health advice for a country you're travelling to on the TravelHealthPro website
There's no vaccine for schistosomiasis, but there are things you can do to help avoid it if you're travelling to an area where there's a risk of getting it.
Do
only drink bottled, filtered or cooled boiled water – the worms that cause schistosomiasis could burrow into your lips or mouth if you drink unclean water
ask where you're staying if the water used for washing is safe – use cooled boiled water if you're not sure
wear protective clothing (such as boots or waders, or long-sleeve shirts and gloves) if you need to enter fresh water
Don't
do not swim, walk, drink from or wash in lakes, rivers, ponds or other bodies of fresh water
Schistosomiasis often does not cause any symptoms at all, or may only cause symptoms weeks, months or years after infection.
If you do get symptoms of schistosomiasis, they include:
- an itchy, bumpy rash or prickly, stinging feeling on skin that was in the water ("swimmer's itch")
- a high temperature (fever)
- headaches, tummy ache, muscle aches and joint pain
- feeling tired
- a cough
- diarrhoea – this may have blood in it
- blood in your pee
- blisters, sores or bleeding from your vagina, or pain when having sex
If you get a rash, it usually appears within a few days of having been in the water.
The other symptoms can start at any time after infection, but usually happen 2 to 12 weeks later.
You cannot see the worms that cause schistosomiasis.
If you have found worms or worm eggs in your poo, or have a worm-shaped rash, see advice about worms in humans.
See a GP if:
You travelled to an area with schistosomiasis and:
- fresh water from a lake, river or pond got on your skin or in your mouth
- have a rash
- feel unwell
Tell anyone you speak to about your travel.
Schistosomiasis can cause serious long-term problems if it's not treated.
If there's a chance you could have schistosomiasis, a doctor will ask you questions about your symptoms and where you've travelled.
If they think you may have the infection, they may refer you to a specialist.
You may need to give samples of your pee and poo, and have a blood test.
Schistosomiasis is treated by taking tablets to kill the worms that cause the infection.
You may also be given steroid medicine to reduce the side effects of your body fighting the infection.
You normally will only need to be treated once, but you may be given more medicine if your symptoms do not get better.
