How to beat colds and flu this winter

How often you fall ill can be down to the luck of the draw but diet, sleep and exercise also help, says Jonathan deBurca Butler.

AGNES Munyiva is a prostitute. Over the course of the last 30 years has had (unprotected) sex with more than 2,000 men in a slum in the Kenyan capital Nairobi.

And yet in a country with a HIV positive rate of about 7%, she has not got infected.