生活艰难，韩国老人走上卖淫之路(2)

Inside those bags the Bacchus Ladies carry is the source of a hidden epidemic: a special injection supposed to help older men achieve erections - delivered directly into the vein. Dr Lee confirms that the needles aren't disposed of afterwards, but used again - 10 or 20 times.

The results, she says, can be seen in one local survey, which found that almost 40% of the men tested had a sexually transmitted disease despite the fact that some of the most common diseases weren't included in the test. With most sex education classes aimed at teenagers, this has the makings of a real problem. Some local governments have now begun offering sex education clinics especially for seniors.

Hidden in a dingy warren of alleyways in central Seoul, is the place where these lonely journeys end - the narrow corridors of a "love motel" and one of the grey rooms which open off them.

Inside, a large bed takes up most of the space, its thin mattress and single pillow hardly inviting a long night's sleep. On the bed-head is a sticker: for room service press zero; for pornography press three; and if you want the electric blanket, you'll find the wire on the far side of the bed.

So here you have food, sex, and even a little warmth all at the touch of a button. If only it were that simple outside the motel room, in South Korea's rich, hi-tech society.

But for the grandparents who built its fearsome economy, food is expensive, sex is cheap, and human warmth rarely available at any price.