Bilharzia and the 'fluke' discovery
European and African researchers are working together to improve treatments against a parasitic disease known as Bilharzia. Yet an unexpected discovery has shown that the parasite may hold the secret to preventing allergies in humans.
Bilharzia is a tropical disease that causes thousands of cases of anemia each year. The symptoms include stomach pains and the presence of blood in urine. Over a longer period of time it can also lead to infertility and even to cancer of the bladder. Places of residency for the worm that causes the disease include many rivers in Gabon, in Central Africa, where much research towards an efficient treatment is being done.
Larvae living in aquatic snails can penetrate the skin and move to a human host, where they grow and reproduce. The eggs leave the body through urine and eventually end up back in the river. The new born larvae infest snails and the cycle begins once again.
For many years researchers have been studying Bilharzia. However, it was recently discovered that those who had suffered worm infections at an early age develop remarkably fewer allergies compared to people who had never been infected. So researchers are now not only trying to treat the disease but also investigate how it can be used to prevent allergies.
At the Albert Schweitzer Hospital in Gabon scientists are looking at bilharzia larvae in aquatic snails. It is believed that once the larvae and worms have a human host they activate hormones that cause protective immune reactions to allergies. The scientists want to identify and extract the molecules from the worms that are responsible for these immune reactions.
Research to find these molecules is also being conducted at the Institute of Tropical Medicine at the Tuebingen University in Germany. They have a partial understanding of how the immune system reacts to these molecules, but its exact identity remains illusive. Scientists have shown the effects on mice, which have developed a protection against allergies. This will help to pin-point the sought-after molecule.
Meanwhile a quick and effective treatment against the disease is still a top priority. In rural areas of Gabon 80-100% of the children have the disease. But through the cooperation of European and African researchers it may also be possible to gain something positive from the water-dwelling parasite.