1211. Increasing Incidence of Invasive Methicillin-Resistant and Methicillin-Sensitive S. aureus Infections Among Persons Who Inject Drugs, 2014–2017

Abstract

BackgroundIn 2011, persons who inject drugs (PWID) were estimated to be 2.6% of the US population 13 years of age and older. Infectious endocarditis (IE) and hepatitis C infections among PWID are increasing. We describe trends in invasive Staphylococcus aureus (iSA) infections among PWID.MethodsPopulation-based surveillance for invasive (from normally sterile site) methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) has been conducted in Monroe County, NY (2010 Census population: 744,344) as part of the CDC’s Emerging Infections Program since September 2014. Cases are county residents with an iSA infection; iSA incidence was calculated as cases/100,000 census population.ResultsDuring September 2014–August 2017, 1,460 iSA cases were identified; 150 (10%) in PWID. The incidence of PWID-associated iSA doubled among 18–49 year olds during years 1–3 (Table 1). The proportion of cases occurring in PWID increased among both MRSA (7% to 20%) and MSSA (6% to 11%). PWID were significantly younger (P < 0.0001) than noninjection drug users, and more often White (P = 0.003) and non-Hispanic (p = 0.004). Among PWID with iSA, 45% had IE. Almost all PWID with iSA used other illicit drugs (n = 112, 91% of 123 unique cases); 89% (110) were smokers, and 46% (56) had chronic liver disease. PWID with iSA had a longer mean length of stay (26 days [SD 22] vs. 21 [37], P = 0.01); PWID with MRSA were more likely to have septic shock (22% vs. 8%, P = 0.03) and pneumonia (9% vs. 1%, P = 0.04) when compared with PWID with MSSA. Among iSA, a history of recurrent skin abscess/boil (24% vs. 8%, P = 0.02) was more common in PWID with MRSA; fewer PWID with MRSA were obese (2% vs. 15%, p = 0.02).ConclusionThe increasing incidence of invasive MRSA/MSSA among PWID, frequently accompanied by concurrent chronic liver disease, polysubstance use, and need for extended hospital stays, poses an increasing challenge to the public health and clinical communities. This highlights the critical need to prevent worsening of the epidemic of injection drug use and provide comprehensive treatment for individuals engaging in highest risk drug-related behaviors.Table 1. Incidence (per 100,000 County Residents) of PWID-Associated iSA by Age GroupYear18–49 Years50–64 Years65–84 YearsTotal1 (September 1, 2014–August 31, 2015)7.15.41.24.32 (September 1, 2015–August 1, 2016)13.95.41.27.33 (September 1, 2016–August 31, 2017)16.45.43.55.6Disclosures All authors: No reported disclosures.