1502. Disseminated Mycobacterium-avium complex in People with HIV in México City: a Single-center, 23 year (1999-2022) Retrospective Cohort Study

Abstract Background Despite universal access to combined antiretroviral therapy (ART) in Mexico since 2005, people with HIV (PWH) still present with late-stage complications due to delayed diagnosis and/or entry into care. Among these complications, disseminated Mycobacterium-avium complex infection (DMAC) remains a concerning issue given its high mortality and diagnostic challenges. Therefore, we aimed to describe the clinical and microbiological characteristics and outcomes of PWH with DMAC in a tertiary care center in Mexico City over a period of 23 years. Methods In this retrospective study, we reviewed all records of PWH attending our hospital from 1999-2022. We included adult PWH with any positive extra-pulmonary MAC-culture. We developed a standardized case report form and recorded sociodemographic, clinical, and microbiological characteristics. We followed patients until microbiological cure or death. Results We included 37 PWH diagnosed with DMAC infection, of whom 34 (92%) were men. Overall, 4 (11%) were diagnosed with DMAC before 2005 and 33 (89%) after 2005. The median age was 34 years (IQR 27-36 years). Following HIV diagnosis, mean time to diagnosis of DMAC was 14.2 months (IQR 1.6-11.3 months). At DMAC diagnosis, 12 (32%) patients were on ART and 25 (68%) were ART naïve. Fever was the most common presenting symptom, affecting 32 patients (86%). Mean time to microbiological diagnosis was 34 days. The most common sites for culture isolation were blood (76%) and bone marrow (70%). Anemia occurred in 34 patients (92%), followed by leukopenia in 23 (62%) and pancytopenia in 9 (24%). All patients required hospitalization, with 32 (86%) receiving DMAC-specific treatment and 5 (14%) dying before treatment initiation. Thirty-four patients (92%) received a clarithromycin-based regimen, 15 (41%) of patients developed IRIS. Overall mortality during follow-up was 51%, with 79% deaths occurring within the first year after DMAC diagnosis. Conclusion Despite universal ART access, DMAC remains a high-mortality AIDS-defining illness in Mexico City. Efforts must be made to promote HIV testing, early diagnosis, and entry into care. Disclosures All Authors: No reported disclosures