Bloodstream infections in patients living with HIV infection in the recent cART era: did something change?”.

Background: In the modern combined antiretroviral therapy (cART) era, non-AIDS defining infections are becoming an increasing cause of hospitalization of people living with HIV (PLWHIV). The present study aims to investigate the current epidemiology and clinical characteristics of bloodstream infections (BSI) in HIV-positive patients. Material and Methods: Retrospective multicentre study conducted in 2008-2015, enrolling all PLWHIV>18 years who developed a BSI. Results: A total of 114 episodes of BSI were recorded in 75 PLWHIV, followed for a mean period of 2.7 ± 2.6 years. All patients were hospitalized. Forty-six episodes (40%) were nosocomial, with significantly longer hospital stay compared to community-acquired episodes (59, Q34-110, median days, p<0.0001). The majority of patients PLWHIV included in the study were male (73.3%), previous intravenous drug users (58.7%), co-infected with HCV or HBV (60.0%) and in CDC stage C (58.7%). Gram-positive (G+) pathogens caused 46.5% of BSI, followed by Gram-negative (G-), 42.1%, and fungi (F), 11.4%. G- were prevalent among community-acquired BSI (48.5% vs 32.6%), while G+ were more frequent in nosocomial infections (48% vs 46%). Despite numbers are low, F were more often seen in hospitalized patients (9 of 13 episodes, p=0.03). The most frequently isolated pathogen was E.coli (18%), followed by Streptococcus spp (15%) and S. aureus (12%). Candida spp and coagulase negative staphylococci were the two most frequent pathogens found in nosocomial BSI (17% each), while E.coli was prevalent in community-acquired BSI (27%). Median CD4+ count (cells/mm3) was 165 (62-278) in the global population, varying from 226 (102-299) in G-, 161 (61-256) in G+ and 62 (35-175) in F BSI (p = 0.03 for trend). Mortality was 7% within the first two weeks, 13% within 30 days, 24% within 6 months and 38% within 1 year. The higher mortality was found in fungal BSI: 23% within 30 days (vs 13% in G- and 11.3% in G+), 46.1% within 6 months (vs 21% in G- and 21% in G+) and 62% at 1 year (vs 35% in G- and 34% in G+). At the last available follow-up, the overall crude mortality was 76%. Median time to death from BSI was 231 days (43-438). Fungal etiology, number of previous episodes of BSI, advanced CDC stage and older age resulted significantly associated with higher mortality in univariable model. Only advanced CDC stage and older age remained in the multivariable model (HR 1.0 95%CI 1.0-1.1, p=0.01 and HR 3.7, 95%CI 1.5-9.1, p=0.005). Conclusions: The study found high frequency of nosocomial episodes and a higher than expected frequency of G- as etiology of community-acquired BSI, with E.coli as main causative agent overall. For the first time Candida spp. has been found to be the most frequent cause of nosocomial BSI in PLWHIV. Older age and advanced HIV stage are the main factors correlated to mortality in our population.