Increasing proportion of late testers among AIDS cases in Italy, 1996-2002.

In recent years, the proportion of individuals who are unaware of being infected with HIV when diagnosed with AIDS (defined as 'late testers') has dramatically increased in several European countries, including Italy. We evaluated the extent and determinants of late testing and its impact in terms of AIDS-defining illnesses among AIDS cases reported to the Italian National AIDS Registry since 1996. Late testers were defined as those persons whose first positive HIV test result was within six months of the AIDS diagnosis. Late testers were more likely to be heterosexual contacts or MSWM, as opposed to IDUs. They were also more likely to come from low prevalence areas of Italy or from foreign countries. At AIDS diagnosis, late testers were less likely to be undergoing HAART or prophylaxis against PCP/toxoplasmosis, compared to non-late testers. The mean CD4 cell count at AIDS diagnosis was significantly lower among late testers. PCP, toxoplasmosis and Kaposi's sarcoma were more frequently diagnosed as an AIDS-defining illness in late testers, who also had a significantly higher risk of presenting with multiple concomitant AIDS-defining illnesses. In conclusion, late testing results in missed opportunities for preventing and treating HIV infection, leading to an increased risk of developing preventable opportunistic infections and death.