Risk Factors for Infective Endocarditis and Serious Injection Related Infections Among People Who Inject Drugs in Los Angeles, CA and Denver, CO

Background: Injection drug use-related infective endocarditis (IDU-IE) and bacterial infections have grown in the United States, but little is known about risk factors for these infections in community samples of people who inject drugs (PWID). Methods: During 2021-22, PWID were recruited from community settings and surveyed for history of IDU-IE, serious injection related symptoms (SIRI) and untreated infection symptoms in the last 3 months. We used bivariate analysis and multiple logistic regression to examine factors associated with these outcomes. Results: Among participants (n = 472), 7 % reported ever having IDU-IE, 14 % reported having SIRI symptoms and 20 % reported untreated infection symptoms in the last 3 months. Ever having IDU-IE was associated with HCV (adjusted odds ratio [AOR]=8.37; 95% confidence interval [CI]=2.46, 28.49), prior MRSA infection (AOR=5.37; 95 % CI=2.44, 11.80), identifying as female and/or gender minority person (AOR=3.14; 95 % CI=1.42, 6.95). SIRI symptoms were associated with greater material hardship (compared to low; AOR=2.47; 95% CI=1.17, 5.22), fentanyl use (AOR=2.15; 95% CI=1.01, 4.61), sharing filter/cotton (AOR=1.93; 95% CI=1.10, 3.39), and licking needle prior to injection (AOR=1.85; 95% CI=1.02, 3.36). Untreated infection symptoms were associated with poor quality sleep (AOR=2.04; 95 % CI=1.21, 3.43), any mental health diagnoses (AOR=2.01; 95% CI=3.56), any chronic pain (AOR=1.89; 95% CI=1.14, 3.11), sharing filters (AOR=1.81; 95% CI=1.10, 2.98), and prior MRSA infection (AOR=1.75; 95% CI=1.04, 2.97). Conclusion: Risk factors identified include treatable co-morbidities (i.e., HCV & MRSA history, mental health, pain, opioid use), modifiable health behaviors (i.e., equipment sharing, needle-licking), and addressable structural conditions (material hardship, housing).