Contrary to the widely-held belief that HIV/AIDS is fuelled by poverty, a surprising and authoritative new study reveals that the epidemic in Asia is being driven by wealthy men, often after having unprotected sex with prostitutes.

“Clients of sex workers account for most HIV cases in Asia. Typically they are wealthy men,” said Ross McLeod, an economist, presenting the findings of a joint study commissioned by the Asian Development Bank and UNAIDS at an international conference on AIDS in Colombo, Sri Lanka.

Turning generally held academic belief on its head, the multi-nation study finds that HIV does not necessarily spread under conditions of poverty.

“It’s wealthy men who pass on the virus. In Cambodia 12 per cent of the richest men passed on the virus,” McLeod told the 8th International Conference on AIDS in Asia and the Pacific (ICAAP).

“Poverty does not seem to increase the risk of infection in the first place. But AIDS increases the risk of poverty,” added Jacques Jeugmans of the ADB. McLeod said infection among wealthy Asian women is also on the rise, adding: “Seventy per cent of cases in Asia are male, but this is beginning to change.”

A number of UN health experts said the majority of HIV-positive women in the region are married women who have only had sex with their husbands — leading them to conclude that these women contracted the virus through no fault of their own  from husbands who had had unprotected sex outside marriage.

The study seems to pinpoint men who have sex with multiple partners, including sex workers, but do not use condoms. Well-known Indian epidemiologist Swarup Sarkar, regional director of UNAIDS for South Asia, said that although the joint ADB-UNAIDS study was an ongoing project, it already held out major policy implications for the way HIV/AIDS ought to be tackled in Asia.

For instance, one important new finding is about the way the virus has spread in countries — it usually started among injecting drug users in the 1990s, moved on to sex workers, from there to male clients and their faithful wives.

Homosexuals and other men who have sex with men were infected well before the epidemic took root among the general population. “Therefore, early intervention among IDUs is essential,” said Sarkar, pointing out that Bangladesh, Malaysia and Pakistan are now at the stage where they could benefit from making such an intervention, whereas the priority group for Cambodia would be sex workers.

“But resource allocation is disproportionate,” said Sarkar. Whereas “condoms and clean needles avert most infections,” money from a US fund for AIDS (known as PEPFAR and the largest such aid line in the world) was going into programs to promote abstinence and faithfulness.

And instead of intervention, many countries in the region — including India and Sri Lanka— instead criminalize sex workers, drug users and gays and lesbians.