``This rate of infection, of 7 adults per 1,000, is more than in any other country in the world except South Africa,'' says the report. India's epidemic is highly diverse, the report says, while some states show almost no HIV infection, others have reached HIV prevalence rates of 2 per cent and above.

In parts of the North-East, especially Manipur, widespread injecting drug use provided an easy early entry point for HIV. In Manipur, the prevalence of HIV infection among injecting drug users shot up from virtually nothing in 1988 to over 70 per cent just four years later, and it has remained at these high levels ever since. ``Predictably, since almost all injecting drug users in the state are men, HIV then spread to their wives and girlfriends through unprotected sex,'' the reports says. Around 2.2 per cent of the pregnant women in Manipur tested positive for HIV in 1999. In other states, even higher levels of HIV infection have been recorded in pregnant women.

Most cases of infection appear to have been acquired from husbands who have been infected in turn by sex workers, themselves part of a longer chain of transmission.

``By the mid-90s, a quarter or more of the sex workers, in cities like New Delhi, Hyderabad, Mumbai, Madurai, Pune, Triupati and Vellore, tested positive for HIV,'' the report says. In Mumbai, the prevalence of HIV infection among sex workers reached 71 per cent in 1997.

The report says that state governments have launched preventive programmes to reduce high-risk sex, and there is evidence that in some states the programmes are resulting in safer behaviour. ``If the current prevention efforts can be scaled up and sustained, India may be able to bring down the rates of HIV infection in particularly exposed groups and avert widespread heterosexual epidemic,'' the report says.

In comparison with Africa, the general rates of infection in Asia are low. The prevalence among 15 to 49 year-olds exceeds 1 per cent only in three countries-Cambodia, Myanmar and Thailand; in other countries, the prevalence rate is often far lower. In Indonesia, the world's fourth most populous country, fewer than 5 people in 10,000 are living with HIV. In the Philippines, the rate of infection is only slightly higher, at 7 per 10,000.

Many other countries in Asia have yet to see a significant spread of HIV, despite evidence that many men regularly have sex outside of marriage. It may be just a matter of time before infections reach a critical level in populations with the highest risk behaviour and begin to spread more widely, the report says.