Epidemiology of human immunodeficiency virus (HIV) infection in a tertiary care hospital in Northern Italy

Introduction: HIV infection is one of the major public health issues involving 36.7 million people. This study aims to assess HIV infection prevalence among Italians and foreigners in the area of Parma (Northern Italy), comparing 2009 vs 2015. Material and Methods: sera from 9866 (2009) and 9401 (2015) subjects attending the University Hospital of Parma were analyzed with VIDAS HIV DUO (BioMérieux) and ARCHITECT HIV Ag/Ab Combo (Abbott) assays. HIV-positivity was confirmed with HIV BLOT 2.2 (MP Biomedicals), New Lav Blot II (BioRad), and VIDAS HIV p24 (BioMérieux) assays. Plasma from 920 (2009) and 987 (2015) HIV-positive individuals were subjected to HIV-1 RNA quantization with COBAS Ampliprep/COBAS Taqman HIV-1 assay (Roche); 825 (2009) and 926 (2015) subjects were diagnosed HIV-positive before the examined years. The study included 10653 (2009) and 10320 (2015) subjects with sera and plasma, calculating them once. Results: of the 9866 subjects (63.1% females, 36.9% males) examined in 2009, 124 (1.25%) were seropositive (1.24%: HIV-1; 0.01%: HIV-2), and of the 9401 subjects (60.9% females, 37% males, 2.1% anonymous) examined in 2015, 80 (0.85%). The seroprevalence related to residents was 0.028% (124/437308) in 2009 and 0.018% (80/446987) in 2015. Including seropositive previously diagnosed, it was 8.91% (825+124=949 subjects: 72.1% Italians, 27.9% foreigners, 60% males, 40% females) in 2009 and 9.75% (926+80=1.006 subjects: 69.5% Italians, 29.8% foreigners, 61.5% males, 37.8% females, 0.7% anonymous) in 2015, and 0.22% related to residents in both years. The seroprevalence of Italians related to Italian residents was 0.18% (684/387161; 699/387084) in both years, while that of foreigners related to foreign residents 0.53% (265/50147) in 2009 and 0.50% (300/59903) in 2015. Among Italians prevailed males (2009: 67.5%; 2015: 70.5%) of median age of 46 (2009) and 50 (2015) years, while among foreigners females (2009: 59.6%; 2015: 58%) of median age of 34 (2009) and 39 (2015) years. Discussion and Conclusions: HIV prevalence diminished in 2015 vs 2009, while including seropositive diagnosed before it increased. Seropositive were mostly Italian males at an advanced age, while among foreigners young females prevailed. These results evidence an increase in the number of people living with HIV. Moreover, migratory flows from endemic regions increase the risks of HIV infection circulation. These findings are in agreement with global data, that focus on increased late diagnoses and prolonged survival of seropositive, following the use of highly active antiretroviral therapy. Epidemiological analyses contribute to estimate the disease burden associated with HIV infection, reinforcing the need of a continuous surveillance to optimize its prediction and control.