The United Nations’ top AIDS scientists plan to acknowledge this week that they have long overestimated both the size and the course of the epidemic, which they now believe has been slowing for nearly a decade.

Revised figures in the latest UN Aids annual report released on Monday cut an estimate for total infections to 32.7 million from the 39.5 million cases given in the agency’s 2006 report.

The UN report stated that the number of people in India estimated to be living with HIV/Aids has been more than halved to 2.5 million due to better statistics and evidence gathering.

In Asia, there are now 4.9 million cases, up from 440,000 last year. Indonesia has the fastest growing HIV prevalence on the continent, while the number of infections in Vietnam has more than doubled between 2000 and 2005.

Having millions fewer people with a lethal contagious disease is good news. Some researchers, however, contend that persistent overestimates in the widely quoted U.N. reports have long skewed funding decisions and obscured potential lessons about how to slow the spread of HIV. Critics have also said that U.N. officials overstated the extent of the epidemic to help gather political and financial support for combating AIDS.

Unprotected sex is the main factor behind the spread of the virus, with contaminated drug injecting equipment also playing a key role, the report said.