The joint Indian and Canadian team say the figures show safe sex awareness campaigns can have a dramatic impact.
The Lancet study tracked HIV infection rates among young women attending pregnancy clinics, and young men attending sex disease clinics.
More than five million people are living with HIV in India, 75% of them in the southern states.
Male use of female sex workers is a main reason for the spread of HIV in these areas – this subsequently puts wives in a vulnerable position.
Source: BBC News
