Trends in Incidence and Epidemiology of Methicillin-Resistant <i>Staphylococcus aureus</i> Bacteremia, Six Emerging Infections Program Surveillance Sites, 2005–2022

Abstract

Abstract Background The impact of the coronavirus disease 2019 (COVID-19) pandemic on methicillin-resistant Staphylococcus aureus (MRSA) bacteremia incidence compared with prepandemic trends is unknown. Methods Active laboratory- and population-based surveillance identified incident MRSA blood isolates among surveillance area residents in 6 continuously reporting sites during 2005–2022. Annual incidence per 100 000 census population was stratified by epidemiologic classification (hospital-onset, community-associated, health care–associated community-onset). Joinpoint with Poisson regression was used to determine incidence trend segments and annual percent change (APC; 2005–2019) and predicted incidence (2020–2022). Recent COVID-19 was a positive severe acute respiratory syndrome coronavirus 2 viral test ≤30 days before incident MRSA culture. Results Overall declines in MRSA bacteremia incidence during 2005–2016 (APC, –7.1; P &amp;lt; .001) reversed during 2016–2019 (APC, +5.9; P &amp;lt; .001). Hospital-onset incidence did not change significantly during 2014–2019 (APC, –1.5; P = .32), but during 2020–2022 it was higher than during 2016–2019 and significantly higher than predicted in 2021. Health care–associated community-onset incidence increased during 2017–2019 (APC, +8.4; P &amp;lt; .001); 2021 incidence was the lowest observed during 2005–2022, although it was not significantly lower than predicted. Community-associated incidence was increasing prepandemic (APC, +8.4; P &amp;lt; .001), but during 2020–2022 it was lower than predicted. During 2020–2022, the proportion of cases with recent COVID-19 was highest among hospital-onset infections (18%–22%); 2021 hospital-onset incidence excluding these cases fell within the predicted range. Conclusions Previous declines in MRSA bacteremia incidence had ended before the COVID-19 pandemic. During 2020–2022, patients with recent COVID-19 contributed substantially to increases in hospital-onset MRSA bacteremia, suggesting a need for robust infection prevention in this population. Reversal of prepandemic increases in health care–associated community-onset and community-associated infections during the pandemic could be related to COVID-19 mitigation measures.