Characteristics and behaviors in a sample of patients unaware of their infection until AIDS diagnosis in Italy: a cross-sectional study.

The objective of this study was to define the sociodemographic and behavioral characteristics of people unaware of being HIV-positive at AIDS diagnosis. A multi-center cross-sectional study was conducted in 11 Italian centers of infectious diseases, recruited on a voluntary basis. Each center enrolled individuals diagnosed with AIDS aged ≥ 18 years from May 2003 to December 2005. The patients were classified into two groups on the basis of the amount of time that elapsed from diagnosis of HIV infection to AIDS diagnosis. "Late testers" were defined as those with a time period of ≤ 6 months between first HIV positive test and AIDS diagnosis. In order to evaluate the factors independently associated with being a late tester, a multivariate logistic regression model was performed. The McNemar χ(2) test was used to analyze behavioral changes before and after HIV diagnosis. During the study period, 245 patients were enrolled; of these, 51.8% were late testers. The variables independently associated with being a late testers were as follows: being employed; having acquired the infection through sexual contacts; having taken the HIV test because they didn't feel well; having at least one symptom or illness among those indicating infection; and not having had paid sex within the 12 months prior to HIV diagnosis. Before and after HIV diagnosis a significant increase in safe-sex behaviors was observed among individuals with no delay in diagnosis. However, the proportion of people who continue not to use condoms is still high. This study seems to indicate that sexual transmission is often associated with late testing. Individuals enrolled seem to have a low perception of risk, they do not undergo HIV testing, and consequently miss the opportunity of early diagnosis.