Why feeling disgust can be good for us
By Philippa Roxby Health reporter, BBC News

The facial expression for disgust is universal. We can all picture the contorted, horrified face which communicates a feeling of revulsion and loathing.

Spiders, slimy creatures, mucus and faeces can all provoke this feeling. Our reaction is to distance ourselves from the cause.

As a result, feelings of disgust help us to avoid, or at the very least recognise, the things that make us feel this way - and for a very good reason, psychologists say.

When it comes to infectious diseases, disgust has evolved to help us steer clear of sick people, dirty water, vomit, body fluids and all the other stuff that makes us react "Yuck."

In a paper published in Philosophical Transactions for the Royal Society B, Dr Val Curtis, from the London School of Hygiene and Tropical Medicine, argues that avoidance behaviour is essential to prevent the spread of all the major current and recent infectious diseases which present a threat to humans.

Diarrhoeal diseases, respiratory tract infections, malaria, measles, HIV, tuberculosis and parasitic worms can all be avoided by thinking about aspects of hygiene, Dr Curtis says.