Trends in Incidence and Epidemiology of Methicillin-Resistant <i>Staphylococcus aureus</i> Bacteremia, Six Emerging Infections Program Surveillance Sites, 2005–2022
Holly M. Biggs, Rongxia Li, Kelly A. Jackson, Joelle Nadle, Susan Petit, Susan M. Ray, Ruth Lynfield, Kathryn Como‐Sabetti, Ghinwa Dumyati, Anita Gellert, Marissa Walsh, William Schaffner, James Baggs, Isaac See
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 &lt; .001) reversed during 2016–2019 (APC, +5.9; P &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 &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 &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.