The feminization of the AIDS Brazilian epidemics is over
1University of São Paulo, Mathematics, São Paulo, Brazil, 2GIV (Group for LIfe Incentive), São Paulo, Brazil, 3ABIA (Interdisciplinary Brazilian AIDS Association, Rio de Janeiro, Brazil, 4RNP+ (Brazilian Network of PWHIV/AIDS), São Paulo, Brazil
Background: From 1995 on, scientific publications and the National AIDS Epidemiological Bulletin pointed out the existence of a feminization phase in the Brazilian epidemics. Here we calculate and compare the annual AIDS incidence rates for men and women for the years 1984-2006.
Methods: We used the data of the National System of Notification (SINAN, consulted online 12/09/2009) for the AIDS cases and the estimates of the Brazilian population divided according to sex by Brazilian Institute of Geography and Statistics (IBGE). We calculated the annual incidence rate for men (IM) and women (IW), and the relative risk (RR=IM/IW) for the population of 15 (RR15) or more years and 20 (RR20) and more years of age. We considered the years 1984-2006. We adjusted curves by minimum squares through Excel program.
Results: The best fit curves were constant plus exponentials with negative exponents. The constants we considered were the minimum levels of RR20 and RR15, reached in 2005. They correspond to 1,71 masculine cases for each feminine case for people over 20 years and 1,67 cases for people over 15 years. In our case, RR20=1,71+exp(3,58-0,28T) and RR15=1,67+exp(3,58-0,29T) where T=year-1984.
Conclusions: The initial rapid decay of both RR is followed by a rapid stabilization, shown by the consequent nice fit of the curves for the last years and the small increase in relative risks for 2006. Thus, we can state that the feminization phase is over at present. In Brazil, AIDS incidence was always and still remains higher in men than in women.
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