Hard to Swallow...

On the whole, people tend to have very mixed feelings about worms. While earthworms are almost universally loved - especially by gardeners and young children - and regarded as beneficial and harbingers of a healthy ecosystem, parasitic worms - whether found in humans or animals - are viewed with disgust and seen as something to be purged at the earliest opportunity before further damage is caused to the host.

But it now emerges that this view may be erroneous. For example, researchers at the University of Strathclyde in Scotland have found that secretions from a parasitic worm, called a filarial nematode, have an anti-inflammatory effect. This discovery, they believe, could one day relieve the pain of rheumatoid arthritis and similar conditions. The worm may also be able to help with autoimmune diseases: it is carried by millions of people living in the tropics, where the incidence of autoimmune disease is relatively low. Apparently the worm secretes a molecule called ES-62 that enables it to survive inside the host; however, the worm does not appear to have any visible impact on humans except to reduce inflammation. 'We hope to produce a derivative of the worm's anti-inflammatory molecule and use it as the basis for a drug,' said Professor William Harnett, who led the study. 'It still seems ironic, however, that a parasitic worm, which lives off humans may also provide a means to relieve suffering for millions of people.'

Even the humble tapeworm could turn out to be much maligned. Ligula intestinalis, a tapeworm found in freshwater carp, contains a chemical that seems to make all fish infertile. Researchers from Keele University say this could form the basis of a contraceptive for humans that both men and women could use. However, they do not yet know what the chemical is, and stress that any Pill is years away. Professor Chris Arme, of the Centre for Applied Etymology and Parasitology at Keele, says the tapeworm contraceptive may yet come to occupy a place in our medicine cupboards.