The epidemiology of AIDS in the Vellore region, Southern India

To describe the epidemiology of patients with AIDS in Vellore region, Southern India. Sixty-one patients with AIDS were diagnosed and treated between July 1987 and June 1992. Information on their demographic characteristics and probable modes of acquiring HIV infection was collected at interviews with them and their spouses. There was a progressive increase in the number of patients seen over the 5 years. The mean ages of the 51 men and the 10 women were 33 and 29 years, respectively. Of the 44 patients from our district (population, 5 million), 28 were from Vellore town and 10 from rural areas. Forty-seven (92%) men had frequently used prostitutes. Of the women, four were prostitutes, one had had multiple sex partners and five had not had extramarital sexual contact. One man and one woman had no other risk factor except blood transfusion. Thirty-one (51%) patients had died by August 1992. The AIDS epidemic in this region is in its early ascending phase, with a doubling time of approximately 1 year. Most men with AIDS were infected by heterosexual contact with prostitutes, while some women were prostitutes themselves. Together with the male-to-female ratio of 5:1, these results suggest that the male population at risk has sex with a much smaller population of female prostitutes, constituting the major chain of transmission. HIV infection is occurring in both urban and rural populations.