Bilharzia - Preventing schistosomiasis

There is no vaccine for schistosomiasis, but scientists are working on developing one that will prevent the parasite completing its life cycle in humans.

If you are planning to visit an infected area, it is a good idea to take waterproof trousers and boots with you just in case you have to cross a stream or river.

If you are unsure whether the country you are visiting is known to have a problem with schistosomiasis, check the National Travel Health Network and Centre (NaTHNaC) website.

While you are away

Avoid swimming in fresh water (ponds, lakes and rivers) when visiting areas where schistosomiasis is widespread. This includes popular holiday spots such as Lake Malawi. Only swim in chlorinated swimming pools or safe sea water.

Always boil or filter water using a travel kettle or a portable water filter before drinking it to kill any harmful parasites, bacteria and viruses.

If you have to cross a river or go into a lake in contaminated areas, aim for clear patches of water with no vegetation and dry yourself as soon as you get out. Try to cross rivers upstream from villages and wear waterproof shoes or boots if possible.

You should not rely on assurances from hotels, tourist boards or similar that a particular stretch of water is safe. There have been reports of these sorts of organisations downplaying the risks of exposure when in fact the risk was very high.

What to avoid

Medication that is advertised to treat schistosomiasis is widely available over the counter in most African countries, but buying it is not usually recommended.

These types of medication are often either fake, substandard, or not given at the correct dosage. In addition, they are only effective once the worms have matured, so taking medication a few days after possible exposure to the schistosomes parasites will not be effective.

What you can do

There is some evidence that applying 50% DEET (diethyltoluamide) insect repellent immediately after contact with infected water kills the invading cercaria in the skin. Tests to exclude infection should still be undertaken after your return to this country.

When to seek medical advice

If you develop symptoms that could be the result of schistosomiasis while on holiday or travelling, you should seek medical advice.

While schistosomiasis is not especially serious in people who are otherwise healthy, it does share symptoms with more serious tropical conditions such as malaria. 

It is important to get the diagnosis confirmed (or ruled out) by a doctor with experience of treating the condition.

Read more about healthcare abroad.

If you are concerned that you may have been exposed to the parasites when travelling, contact your GP. They should be able to refer you for a stool sample. This would normally be carried out at a hospital or somewhere where doctors have experience of diagnosing and treating tropical diseases.