PIP: With a population of almost 1 billion people and an estimated 4 million people infected with HIV, India is thought to be the country with the largest number of HIV-infected people in the world. According to UNAIDS, HIV is firmly embedded in India's general population and rapidly spreading into rural areas previously thought to be relatively spared from the epidemic. Almost 500,000 people are infected in Tamil Nadu and the infection rate is 3 times higher in villages than in cities. According to the National AIDS Control Organization, the rate of HIV infection among attendees of STD clinics in Mumbai increased from 23% to 36% in 1 year, and 51% of prostitutes in Mumbai and 55.8% of IV drug users in Manipur are infected. It is estimated that AIDS will cost India US$11 billion cumulatively by 2000, 5% of the country's gross domestic product. Negotiations are underway for the World Bank to loan India $200 million with which to combat HIV/AIDS. Since antiretroviral therapy is too expensive for most Indians, vaccine research must be accelerated in India. HIV infection in India is mainly of HIV-1 subtype C, although subtypes A and B, along with some new recombinant subtypes, have also been reported. HIV-2 has been reported sporadically.