Revista de SIDA e investigación clínica

Estimation of the HIV Incidence and of the Number of People Living With HIV/AIDS in Brazil, 2012

Abstract

Celia Landmann Szwarcwald, Ana Roberta Pati Pascom and Paulo Roberto de Souza Junior

Introduction: In this study, statistical techniques were applied to reconstruct the historical HIV infection curve using all available surveillance data sources in Brazil, including AIDS reported cases, HIV incident cases in recent years, and AIDS deaths. Using this model, we estimated the HIV incidence and the number of people living with HIV/ AIDS (PLWHA) in Brazil, 2012.

Methods: To estimate HIV incidence in the period 2005-2012, we used a new method based on a CD4 count depletion model. From SISCEL information, we estimated the time lag between HIV infection and the date of first CD4 count for each treatment-naïve HIV infected case aged 15 years or older. To estimate the HIV incidence in past years, we used an extended back calculation method. Then, we used the back-calculating estimates of HIV incidence from AIDS reported cases together with the estimates of HIV incidence in recent years (2005-2012) to reconstruct the HIV incidence curve, in Brazil. To calculate the total prevalence in the middle of 2012, we used the accumulated incident cases and the total number of deaths up to the middle of year 2012.

Results: By midyear 2012, 672959 AIDS cases have been reported, and from those, 336391 were alive. In the middle of 2012, the prevalence was 715003 and the prevalence rate 3.7 per 1000 population. The number of HIV cases infected in 2012 of 47573 represents 6.6% of the total prevalence, with an incidence rate of 24.5 per 100,000 populations. The number of prevalent cases with no CD4 count in the middle of 2012 was 240333, or 33.6% of the total number of PLWHA.

Discussion: Currently, the Ministry of Health adopted the new policy of offering immediate treatment to those diagnosed with HIV and new challenges have to be faced. In this study, we estimated that around 715,000 people live with HIV/AIDS in Brazil, from which one third do not have a CD4 count, and is not benefiting from the new policy. As patients who belatedly starting therapy have lower survival, consume more resources, and reduce the chances of therapy success, policies to eliminate structural barriers to HIV testing are essential in Brazil.