HEALTH CONDITION

Schistosomiasis (bilharzia)

Schistosomiasis, also called bilharzia, is an infection caused by tiny worms that live in ponds, lakes and rivers. It's not found in the UK, but there's a risk of catching it in some parts of the world.

Check if you're at risk of schistosomiasis

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.

How to avoid schistosomiasis while travelling

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

Symptoms of schistosomiasis

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.

What happens at your appointment

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.

Treatment for schistosomiasis

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.

Source: NHS, last reviewed 17 July 2025. Contains public sector information licensed under the Open Government Licence v3.0.

This page is general information and is not medical advice. It does not replace a registered doctor, and it is not a prescription or a recommendation to use any medicine or test. Prices are listed prices and may change. Always follow the advice of your doctor or pharmacist.