CDC Finds Good News on Hospital-Associated Infections

Americans were less likely to have a healthcare-associated infection (HAI) in 2023 than in 2015, though reducing surgical-site infections and non-ventilator-associated pneumonia in hospitals remained a challenge, CDC survey findings suggested.

Among roughly 200 U.S. hospitals, the proportion of patients with at least one HAI on any given day dropped from 3.2% to 2.6%, according to Nora Chea, MD, of the CDC’s Division of Healthcare Quality Promotion in Atlanta, and colleagues.

In the 151 hospitals with data for both years, adjusted analyses found that patients were 27% less likely to have an HAI in 2023 (risk ratio 0.73, 95% CI 0.63-0.85), the researchers detailed in the New England Journal of Medicine.

The drop from 2015 to 2023 was driven primarily by declines in:

• Clostridioides difficile infections: 0.54% vs 0.22%, respectively
• Central catheter-associated bloodstream infections: 0.30% vs 0.16%
• Catheter-associated urinary tract infections: 0.20% vs 0.09%

Despite the improvements, an estimated 471,555 U.S. hospital patients still had at least one HAI in 2023, with an estimated 518,000 HAIs overall.

“The reduction in prevalence provides evidence of continued success of prevention strategies,” Chea and colleagues wrote. However, “additional interventions focusing on prevention of surgical-site infections and health care-associated infections that are not associated with devices or procedures are recommended to further reduce the risk of healthcare-associated infections in hospitals.”

Of note, pneumonia remained the most common HAI in both surveys, Chea and colleagues noted, highlighting the continued need to find and implement effective prevention strategies.

Most HAIs weren’t linked with a procedure or device in either year, as observed with 60.2% of HAIs in 2015 and 61.3% of those in 2023. Similarly, a majority of pneumonia cases were non-ventilator-associated: 64.5% in 2015 and 65.7% in 2023. The overall percentage of hospital patients with non-ventilator-associated HAI pneumonia slid from 0.58% in 2015 to 0.49% in 2023.

“A major challenge to evaluating prevention measures and tracking progress in reducing non-ventilator-associated pneumonia is the lack of a surveillance definition based on data elements that are readily retrievable from electronic health records. Recent work to develop such a definition provides a foundation for a potential national digital quality measure in the future,” the study authors noted.

The survey included data from the CDC’s Emerging Infections Program, drawing from hospitals in 10 states. Hospitals selected one survey day from May 1 to Sept. 30, 2023, to randomly choose patients from a hospital’s morning census.

The 2023 survey included 13,653 patients across 218 U.S. hospitals. Those data were compared with 12,299 patients across 199 hospitalized captured in a 2015 survey.

More than half of patients in 2015 and 2023 were age 45 or older (65.2% and 71.6%, respectively), with mean hospital stays of 5 days and 6 days, respectively. Most patients in the 2023 survey were white (62.8%), in a ward (73.5%), and in a medium or large hospital (68.4%).

Researchers identified HAIs using definitions from the CDC’s National Healthcare Safety Network (NHSN).

Between the surveys, there were drops in device-related bloodstream infections (from 73% in 2015 to 47% in 2023) and in the incidence of device-related urinary tract infections (62% in 2015 and 34% in 2025).

However, the percentage of patients with surgical-site HAIs rose between 2015 and 2023, from 0.56% to 0.59%. Despite better prevention guidelines and surgical techniques, bringing down those rates remains challenging, Chea and team said.

More than half of HAI pathogens identified in the 2023 survey (51%) were either Staphylococcus aureus, Escherichia coli, or C. difficile. While C. difficile was the most commonly identified pathogen in 2015 (accounting for 15.5% of all HAIs), its prevalence in 2023 dropped by more than half (to 7.7% of all HAIs). By 2023, S. aureus was the most common pathogen, accounting for 13.8% of HAIs.

The C. difficile drop was likely due to hospitals using more two-step testing for such infections, Chea’s group said, which delivers a higher specificity than one-step tests. Hospitals also may have been more judicious in their C. difficile testing, avoiding patients without diarrhea, for example.

Study limitations included changes over time in NHSN definitions of HAI. The results also may not be generalizable to all U.S. hospitals.