[The knowledge of the aged about HIV/AIDS: epidemiologic study in Vale do Rio dos Sinos, Rio Grande do Sul, Brazil].

The objective of this study was to assess the knowledge about HIV/AIDS in participants of companionship groups in the Vale do Sinos, Rio Grande do Sul, Brazil. It was a prospective cross-sectional study in a sample of 510 individuals, 17% males and 82.5% females aged between 60 and 90 years. We used the Questionnaire on HIV for the Old Aged, which comprises the general characteristics of the participants and questions concerning HIV/AIDS, organized into the elements 'concept', 'transmission', 'prevention', 'vulnerability', and 'treatment'. Nearly half of the participants (48.4 %) reported having studied 4 to 7 years and the monthly income of 52.2% was of 1 to 3 minimum wages. In the dimensions concept and transmission, 49.4% had no idea about the asymptomatic phase of the infection, and 41.4% believed HIV could be transmitted by a mosquito bite. With regard to prevention and vulnerability, 25.5% did not know about the female condom and 36.9% considered AIDS a disease confined to men who have sex with men, sex workers, and injection-drug users. Regarding antiretroviral treatment, 12.2% ignored its existence. Elderly people in companionship groups have important misconceptions about HIV/AIDS, which can increase their risk of infection. There is a need for public health programs directed to this population in order to prevent or decrease the risk of HIV transmission.