A comprehensive study by the Centers for Disease Control and Prevention (CDC) has revealed critical insights into the fluctuation of hospital-acquired infections over the past decade, with specific focus on the pandemic years. The most notable finding was an initial reduction in such infections followed by a resurgence during the early pandemic phase (2020-2021). The research also identified variations amongst different pathogens; some remained stable, others decreased, and a particular group experienced an increase.
Zooming into the microscopic world with a magnification of 9560X, researchers visualized clumps of methicillin-resistant Staphylococcus aureus (MRSA) — a depiction that underscores the criticality of antimicrobial resistance in healthcare settings. The decade-long investigation by the CDC tracked antimicrobial resistance trends in hospitals from 2012 to 2019, and it documented an unsettling rise during the acute COVID-19 pandemic years. Interestingly, one group of pathogens marked a distinct increase over this period, while others manifested stable or decreasing trends.
The study primarily focused on six types of pathogens: MRSA; vancomycin-resistant Enterococcus spp (VRE); extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella spp (excluding Klebsiella aerogenes) suggestive of extended-spectrum β-lactamase production, or ESCR-EK; carbapenem-resistant Enterobacterales (CRE); carbapenem-resistant Acinetobacter spp, or CRAsp; and multidrug-resistant (MDR) Pseudomonas aeruginosa. These pathogens, identified by CDC and the World Health Organization as high priorities, were the primary focus, and the findings were published in JAMA Network Open.
Researchers found that resistance for MRSA, VRE, CRE, CRAsp, and MDR P aeruginosa remained stable or decreased from 2012 to 2022, with one significant exception. In nonsterile body sites, hospital-onset E coli and Klebsiella spp — specifically, ESCR-EK cases — increased from 12.2% in 2012 to 19.7% in 2022. The increase was steeper in normally sterile body sites, where the figures jumped from 17.5% to 24.5%.
The researchers found regional and species-related differences as well as variations based on sex and age. For example, hospital-onset MRSA, CRE, CRAsp, and MDR P aeruginosa infections were more common among males and within the 55-74 age group. There were differences in hospital-onset CRE rates, too — while rates decreased for CR K pneumoniae from 2012 to 2022, those for CR E cloacae complex and E coli did not.
The study, a cohort analysis evaluating data from 2012 to 2022, factored in variables such as inpatient hospitalizations, clinical cultures, and facility-level characteristics. It only considered hospital months when at least one culture with microbial growth and antimicrobial susceptibility testing (AST) was reported.
The investigators found that resistance rates for MRSA, VRE, CRE, CRAsp, and MDR P aeruginosa were mostly stable or decreased during the 10-year timespan, but incidents of ESCR-EK infections in nonsterile and sterile body sites significantly increased. The researchers also reported an increase in average patient stays per hospitalization from 2020 to 2022, which potentially resulted in inflating hospital-associated infections.
The pandemic-precipitated rise in hospital-onset resistant cases underpins the urgent need for ongoing and adaptable infection prevention measures. The CDC concludes that more strategies are needed, especially in an atmosphere of an aging US population with increasing rates of chronic illnesses and less acute patients being managed in outpatient care.
In summary, this study underscores the importance of steadfast infection prevention in hospitals, particularly during significant healthcare crises like the COVID-19 pandemic. The researchers call for prevention efforts capable of maintaining effectiveness despite substantial strain on health care systems and workers.