Prevalence and risk factors of HIV-1 and HIV-2 infection in urban and rural areas in Tamil Nadu, India.

We aim to study the factors associated with the prevalence of HIV-1 and HIV-2 infection in the urban and rural areas of Tamil Nadu, India. The population of Tamil Nadu is approximately 60 million. Between April 94 and March 95, 992 samples from 5 representative urban centres and 1071 samples from 5 representative rural centres were collected and studied. A questionnaire was administered privately and it preceded collection of each sample. Samples were screened using ELISA and antibodies to HIV-1 and HIV-2 were confirmed using Western blot. The study was anonymous and unlinked. The prevalence of HIV infection in urban and rural areas was 7.2% (95% CI=6.1 to 8.31%); HIV-1 antibodies were found in 7.4% (95% CI=5.8 to 9.2%) of urban and 7.0% (95% CI=5.6 to 8.7%) of rural population; HIV-2 antibodies were found in 0.8% of urban and 0.3% of rural population. Heterosexual transmission, more so among those with multiple partner sex, was the main mode; higher prevalence of HIV infection among divorced/single individuals both in urban (21.1%) and rural (26.1%) was found. HIV infection among housewives stood at 4.1% (urban) and 3.8% (rural). The strength of association between STDs and HIV was observed to be greater in rural subjects (OR=8.89; 95% CI=5.11 to 15.57) than in urban subjects (OR=1.9; 95% CI=1.14 to 3.18). The prevalence of condom use was found to be less than 2% in the study subjects. HIV-2 is not as widely prevalent in Tamil Nadu as HIV-1. In our study the most common risk factors for HIV infection that emerged were (a) having multiple sexual partners, and (b) history of STDs or Venereal Disease Research Laboratory (VDRL) reactivity. Mobility of individuals between urban and rural areas has furthered the dissemination of HIV infection. Low condom usage among study subjects questions the effectiveness of the existing AIDS awareness and education programme. The study indicates the importance of placing equal emphasis on HIV prevention in rural India. HIV infection among housewives in urban and rural areas is indicative of gender inequalities and the importance of empowering women to prevent infection from spouse.