2265. The Changing Landscape of AIDS Defining CNS Infections in S. Alberta, Canada Over 30 Years

BACKGROUND: The incidence of AIDS defining CNS infections declined significantly with HAART; however, the longitudinal change in factors and effects of disease has not been well described. We characterized the changing incidence and outcomes in AIDS defining CNS infections over the past 30 years in the geographically defined, well-characterized southern Alberta HIV Cohort (SAC). METHODS: All episodes of cytomegalovirus (CMV) retinitis, progressive multifocal leukoencephalopathy (PML), toxoplasma encephalitis (TE) and cryptococcal meningitis (CM) between January 1, 1987 and January 1, 2017 were identified from the SAC database. Mycobacterium Tuberculosis CNS infections were excluded due to <5 cases. CD4 most proximal to CNS infection and the length of survival to date of death or January 1, 2017 were determined. We compared incidence and outcomes before and after implementation of highly active antiretroviral therapy (HAART), defined as January 1, 1997. RESULTS: Of the 3,633 patients followed at SAC between January 1, 1987 and December 31, 2016, with 27,776 years of follow-up, 256 cases of AIDS defining CNS infections occurred in 241 individuals including; 150 episodes of CMV retinitis, 50 of TE, 21 of CM and 35 of PML. Two or more concurrent CNS infections were identified in 30 cases. Pre-HAART, the overall incidence rate of CNS infections was 40.5/1,000 patient-years (163 cases), declining to 6.5/1,000 patient-years (53 cases) from 1997 to 2007 and to 3.1/1,000 patient-years (48 cases) after 2007 (Figure 1). CNS infection occurred an average of 52 months (SD: ±49.1 months) following HIV diagnosis. Of note, 14% of CM, 26% of PML and 32% of TE cases were diagnosed within 3 months of HIV. The median CD4 count at diagnosis of CMV retinitis was 19 /mm(3), PML 29 /mm(3), CM 60 /mm(3) and TE 77 /mm(3). Pre-HAART 5-year all-cause mortality for AIDS defining CNS infections was 88.0%; with post-HAART decreasing to 38.7% (Figure 2). Of people who died, survival pre-HAART was 10.4 months and post-HAART was 18.5 months. [Image: see text] [Image: see text] CONCLUSION: With the widespread use of HAART, the incidence of AIDS defining CNS infections decreased more than tenfold leading to a significant decline in all-cause mortality. The survival differences and legacy from functional impairment is currently under further examination. DISCLOSURES: All authors: No reported disclosures.