How many people are living with undiagnosed HIV infection? An estimate for Italy, based on surveillance data

Abstract

The estimate of people in Italy with undiagnosed HIV in 2012 was in a plausible range of 12,000-18,000 cases, corresponding to 11-13% of the overall prevalence. The method is straightforward to implement only requiring annual information from the HIV surveillance system about CD4⁺ cell count and clinical stage at HIV diagnosis. Thus, it could be used to monitor if a certain prevention initiative lead to the reduction of the undiagnosed HIV population over time. It can also be easily implemented in other countries collecting the same basic information from the HIV surveillance system.