Europe travel warning as tropical disease spreads where 'worms move through your blood' and 'lay eggs' - virus and symptoms explained

Schistosomiasis, also known as bilharzia, has been spreading rapidly due to climate change, according to new research from KU Leuven University. The disease is caused by a parasitic flatworm. Warming conditions have made southern Europe a more hospitable environment for the freshwater snails which carry the parasite.

The disease is the second most prevalent infectious disease on the planet after malaria, with more than 200 million reported cases each year. Patients contract the infection through exposure to contaminated rivers, lakes, and ponds.

Scientists are looking into the temperature tolerances of the freshwater snails as waters in southern Europe warm up. A team from KU Leuven, the Royal Museum for Central Africa and the University of Copenhagen have conducted the research. Tim Maes, a biologist at KU Leuven, said: "We find that these snails can easily adapt to new conditions...they can thus easily colonise new regions like Europe."

Spain, Portugal, France, Italy and Greece will predominantly have climates promoting the survival of the snail in the next 100 years, according to predictive climate models. Since 2013, Schistosomiasis has been found on the French island of Corsica and more recently Almeria, in Spain.

According to the NHS, you often don't have any symptoms when you first become infected with schistosomiasis, but the parasite can remain in the body for many years and cause damage to organs such as the bladder, kidneys and liver. Once in your body, the worms move through your blood to areas such as the liver and bowel.

After a few weeks, the worms start to lay eggs. Some eggs remain inside the body and are attacked by the immune system, while some are passed out in the person's urine or poo. Without treatment, the worms can keep laying eggs for several years.

You probably won't notice that you've been infected, although occasionally people get small, itchy red bumps on their skin for a few days where the worms burrowed in. After a few weeks, some people develop:

• a high temperature (fever)
• an itchy, red, blotchy and raised rash
• a cough
• diarrhoea
• muscle and joint pain
• tummy pain
• a general sense of feeling unwell