2049. National Trends in Infections caused by Pseudomonas aeruginosa and Carbapenem Resistant Pseudomonas aeruginosa, 2017 – 2020

Abstract Background Pseudomonas aeruginosa is an opportunistic pathogen commonly found in the environment, including water and plumbing, which may serve as a reservoir of spread. We examined P. aeruginosa and carbapenem resistant P. aeruginosa (CRPA) rates and trends in recent years. Methods We assessed rates of P. aeruginosa using microbiology data from over 265 hospitals in the Premier Healthcare Database from January 2017 – December 2020. We identified a cohort of inpatients with any clinical culture yielding an isolate of P. aeruginosa with accompanying susceptibility testing results. Any isolate with at least 1 resistant result to imipenem, meropenem, or doripenem was considered CRPA. Cases were defined as community-onset (CO) when the culture was obtained immediately preceding admission or within the first 3 days of hospitalization, and hospital-onset (HO) when the culture was obtained on day 4 or later. Using monthly hospital level data we modeled cases per discharge, controlling for hospital characteristics, month of discharge, proportion of patients in specific age groups, and proportion of male patients. We developed weights using a raking procedure to match the American Hospital Association distribution for acute care hospitals to produce national estimates. Weighted multivariable logistic regression models were used to estimate national trends in rates per 10,000 discharges. Results Weighted rates of overall, HO, and CO P. aeruginosa and CRPA are shown in Figure 1. From 2019 – 2020, P. aeruginosa adjusted rates increased 7% (p=0.037) (Figure 2). HO P. aeruginosa rates declined 15% from 2017 – 2018 (p=0.014), however HO rates increased 29% in 2020 compared with 2019 (p< .0001). HO CRPA rates did not change during 2018 – 2019 compared with 2017, however HO rates increased 44% in 2020 compared with 2019 (p=0.001). Figure 1.Weighted Rates per 10,000 discharges, 2017 – 2020Figure 2.Pseudomonas aeruginosa and Carbapenem Resistant Pseudomonas aeruginosa Non-Linear Trend Comparisons, 2017 – 2020*Indicates statistical significance at p<0.05. Conclusion We observed an increase in the overall rate of P. aeruginosa in 2020 compared with 2019, driven by an increase in HO P. aeruginosa rates. HO CRPA rates also increased. Further evaluation of drivers of increasing HO P. aeruginosa infections is warranted, including exploration of the hypothesis that pandemic-associated changes in water use and management, such as intermittent closure and reopening of hospital units, may have increased exposure to water harboring P. aeruginosa. Disclosures All Authors: No reported disclosures.