Mechai warns that an estimated 250,000 Thais are unaware they are carrying the HIV virus. ''They are not going for testing and they are having sex around the place,'' he says. ''Getting them to be tested should be a priority.''

Mechai calls on the Prime Minister, Yingluck Shinawatra, to take charge immediately of a campaign blitz on sex.

''The Prime Minister could stand up and declare there is again a problem that is sending Thais to early graves,'' he says. ''The campaign should involve everyone, from religious institutions to schools and businesses.''

There were few things Mechai has not done to erase the stigma of talking about sex in Buddhist Thailand, first in the 1970s when Thailand's population growth needed reining in and then in the 1990s when HIV was spreading rapidly.

There were condom-blowing contests, police handing out condoms in traffic, taxi drivers playing cassettes urging customers going to red-light areas to have safe sex. Millions of condoms were handed out free, monks blessed batches of condoms and farmers painted illustrations of condoms on their cows.

''Raising sex matters like this is nothing to be ashamed of. I was made when my mother and father had sex. Where did you come from?'' he says.

Mechai says a new campaign needs to include AIDS messages on radio, television and ATM screens as well as putting complimentary condoms in hotel rooms.

A Ministry of Health campaign centred on a ''zero new infections'' slogan has had little impact, he says. ''Nobody in government is pushing this. It's pathetic. If you stopped advertising Coca-Cola people would stop drinking it. We have to do the same … talk condoms, condoms and condoms.''

Mechai, a former minister who was educated at Geelong Grammar and Melbourne University where he studied economics, uses profits from his five-star hotel resort to fund an adjacent model farm and school for 200 poor students.

Mechai, 73, says many young people don't think enough about safe sex and contraception. ''We now have one of the highest rates of teenage pregnancies in the world. We used to have one of the lowest,'' he says. ''Young Thais don't realise how easy it is to become infected with HIV. They allow their erections to rule their lives rather than their brains.''

World Aids Day was marked on the streets of Pattaya earlier this month with a parade of bands, vintage cars and sex workers, some of them transgender people or ''lady boys'', several wearing little more than body paint and holding signs such as ''getting to zero'' and ''free condoms and lubricants''. Lew, a 30 year-old transsexual, says some of Pattaya's 5000 transgender sex workers do not use condoms regularly.

''There is more that can be done to make people more aware about HIV,'' she says.

As multi-coloured condoms were handed to spectators in the city with Asia's biggest brothel area, Mechai said such one-off events needed to be followed by an all-year-round campaign.

Alongkot, the 57-year-old monk who has been caring for HIV suffers since 1992 when most of his compatriots still shunned them, says anti-retroviral drugs now allow AIDS victims to live longer and stay at home to be looked after by their families.

Thailand has pioneered the widespread distribution of the medicines. But many AIDS sufferers still come to Alongkot's Wat Phra Baht Nam Phu temple, on a parched hillside near the town of Lopburi, to die.

Thai students are encouraged to go there to be made aware of the risk of the disease.

In a single-storey ward, men lie on beds in nappies, women stare unmoving at walls while others curl up, lost in pain and torpor.

Nearby in the sprawling complex, thousands of teenagers each week are led into a museum where dozens of mummified corpses of AIDS patients are displayed in cabinets, two of them children who were infected by their mothers.

Max, 42, a worker at the temple who is HIV-positive, says most teenagers who file past the haunting images feel sad. ''They change their behaviour for one or two months but then they go back to their own ways.''