HIV/AIDS in India: an overview of the Indian epidemic.

The first cases of HIV infection in India were detected in 1986 among female sex workers in Chennai. A rapid increase followed in many states. The current national prevalence is about 0.26% compared with a global average of 0.2%, but the figure in most high-risk groups including female sex workers is much higher (up to 7%). New HIV infections reached a peak in 1998 and have since declined by 60%, although the total number of HIV-positive persons remains stable at 2.1 million, largely probably due to the increased life expectancy following antiretroviral therapy. The Indian epidemic is characterized by low levels in the general population and elevated concentrations among high-risk groups. Transmission is mainly heterosexually driven, with differential burdens across the states. The four main drivers of HIV infection in India differ in order from those elsewhere in the world and are commercial sex work, general heterosexual intercourse, injecting drug use and unprotected anal sex between men who have sex with men. There are distinct differences from state to state in the prevalence of HIV, with some around the national norm of 0.21% but others with over 1% infected. India has embarked on a targeted HIV prevention strategy in recent years which is strongly associated with a fall in infection rate in both low- and high-risk groups.