Is HIV prevalence declining in southern India? Evidence from two rounds of general population surveys in Bagalkot District, Karnataka.

OBJECTIVES

To assess the levels and trends in the prevalence of HIV and sexually transmitted infections in the general population in Bagalkot district using 2 cross-sectional surveys undertaken in 2003 and 2009.

METHODS

In both surveys, a target sample of 6600 adult males and females was selected systematically from a sample of 10 rural villages and 20 urban blocks in 3 of the 6 talukas (subdistrict units) in the district. Urine and blood samples were collected from all consenting participants for HIV and sexually transmitted infection testing. Changes in HIV prevalence in age subgroups were determined by logistic regression, taking into account the survey design.

RESULTS

HIV prevalence fell not significantly from 3.2% to 2.5% during the 6-year study period. It decreased significantly (P = 0.023) among persons aged 15 to 24 years, from 2.4% in 2003 (95% confidence interval [95% CI]: 1.2-3.7) to 1.3% in 2009 (95% CI: 0.6 -2.0). However, among males aged 35 and above, HIV prevalence increased significantly (P = 0.008), from 3.0% (95% CI: 1.1-4.8) to 4.2% (95% CI: 1.8-6.6), a level similar to that found in the younger age-group in 2003.

CONCLUSIONS

We observed a significant decline in HIV prevalence among people aged 15 to 24 years, where HIV prevalence more closely reflects incidence. The increase in HIV prevalence among older males may have been because of the aging of a cohort of men among whom HIV prevalence was highest in the 2003 survey. It may also have in part reflected increased survival, as a result of the scaling up of antiretroviral treatment programs throughout the district and state.