While taking photographs at the Hong Kong-Shenzhen border this year, Jack Picone met a truck driver who had three mobile phones: one for his wife, one for himself and one for his mistress. He was complaining about the size of his phone bill. It was a poignant moment for the award-winning Australian photographer, and one that highlights a vast problem of cross-border trafficking into Hong Kong - not in drugs, but in HIV and Aids. Studies have shown truck drivers and others who engage in unprotected sex on the mainland are bringing the virus back to the city. 'HIV is a totally transportable virus,' says Picone. 'Borders won't stop it and therefore truck drivers are potentially a conduit for bringing it here en masse.' Picone's images of drivers waiting at the mainland crossing are the latest addition to the 250-odd pictures in Positive Lives, a startling exhibition that has been travelling the world for more than a decade and opened in Hong Kong's Central Library yesterday. In January Picone worked with local organisation Aids Concern to examine the cross-border traffic between Hong Kong and the mainland and its effect on HIV/Aids rates in the territory. The links were clear. About 60 per cent of Hong Kong men attending government sexual health clinics reported having had sexual contact on the mainland, while more than 30 per cent admitted never using a condom with a casual partner, Aids Concern says. The findings are supported by those of the Hong Kong Coalition of Aids Service Organisations, an umbrella body covering 11 Aids groups, which interviewed 261 cross-border drivers in 2001. It found 50 per cent of the drivers had visited prostitutes on the mainland in the previous six months and half of those admitted they did not always use a condom. Official figures put the number of mainland HIV infections from 840,000 to one million, but experts say the problem is far greater. In comparison, 2,244 people in Hong Kong had been diagnosed HIV positive between 1985 and the end of last year, with 669 cases of full-blown Aids. North of the border, the spread of the disease was initially fuelled by intravenous drug use and contaminated blood transfusions, but today, the role of sex as a means of transmission is growing. 'Hong Kong has a low HIV rate right now, but they say China is a bomb waiting to explode and that could have a huge impact here,' says Picone. With the Chinese economy going from strength to strength, truck drivers are earning more and can therefore afford to visit sex workers or even keep a mistress on the mainland, he says. Aids Concern's Margaret Pang, who works with the drivers on the border and who accompanied Picone on his project, says her group is 'not necessarily there to change the truck drivers behaviour, but to adapt their behaviour by getting them to use condoms and practise safer sex'. Picone came to admire Aids Concern's work after watching Pang give presentations in rest stops and cafes. 'It's rudimentary but effective,' he says. 'The groups of men I saw all picked up condoms. The demonstrations were humorous. The men laughed and you could see it was working. What Aids Concern and organisations like it are doing is a good thing. They're getting in at ground level before it really becomes a big problem.' Picone admits it was difficult taking the photographs because, not surprisingly, few of the truck drivers wanted to be identified. Nonetheless, Pang says the images are important. 'Pictures have a strong impact,' she says. 'If they get more people thinking about Aids prevention then they will help.' Positive Lives also features pictures from Thailand, Japan, Malaysia and Australia and shows how HIV-positive people and their carers live with the devastating condition. In the lead-up to the 15th international Aids conference, to be held in Bangkok in July, it is a timely reminder of the potential devastation the epidemic could wreak in Asia. Says Picone: 'If just one person seeing the pictures thinks twice about what they're doing, then I believe it was worth taking them. I think HIV/Aids is the biggest issue facing our society.' Positive Lives is at the Hong Kong Central Library, Causeway Bay, until May 24. Admission free. Inquiries: HK Aids Foundation, tel: 2560 8528.