A UNAIDS and World Health Organization (WHO) study has found that "poor knowledge of HIV" especially "among homosexual groups," male prostitution, and unsafe drug abuse practices are main drivers of HIV propagation. The study observed patterns of spread of HIV in Delhi, Mumbai, and Chennai and drew largely from data of state-run National AIDS Control
The authors of UNAIDS/WHO 2006 AIDS Epidemic Update point out that even in high-tech cities like Bangalore, "three out of four men have sex with men" are not aware of "how the virus is transmitted" and "a large proportion of them engage in unprotected sex." They differed from NACO guesstimates of infected population of 5.2 million and say that there may be 5.7 million infected people that may include about 5.2 million adults in the age group 15-49.
The study also finds there has been very little research on the role of sex between men and especially male prostitutes who have sex with men for money. HIV prevalence among homosexuals in Chennai is 6.8% and 9.6% in Mumbai and conclude that a "substantial proportion of men who have sex with other men also sell sex." A recent study in Andhra Pradesh (AP) found that one in four homosexuals have sex for money.