[Estimated number of HIV-infected individuals aged 15-49 years in Brazil, 1998].

This study estimates the number of HIV-infected individuals from 15 to 49 years of age in Brazil in 1998 based on sentinel population studies in pregnant women, with a selection bias in the sample. A principal components procedure was used to group 44 counties in homogeneous 13 clusters. Two indicators were constructed for each cluster: a) the logarithm of the accumulated AIDS incidence rate among women from 15 to 34 years of age (1996) and b) the logarithm of the growth ratio for the mean AIDS incidence rate for women from 15 to 34 years of age for the period from 1990-1992 to 1993-1996. Taking the log of the proportion of HIV-infected pregnant women as the dependent variable and the two above-mentioned indicators as the independent variables, a regression line was fitted to the aggregate data. Estimation of the model's parameters allowed us to calculate the proportion of infected individuals by macro-region, by age (15-34 and 35-49 years) and gender. The point estimate was 536 thousand HIV-infected adults with a 68% CI (470.689 - 603.305).