New data published last week by federal and state health officials show US hospitals are making progress in cutting healthcare-associated infections (HAIs).

The data, based on surveys of US hospitals in 10 states, show that one in every 38 hospital patients had at least one HAI on any given day in 2023, compared with one in 31 patients in 2015 and one in 25 in 2011. The findings were published in the New England Journal of Medicine.

HAIs can cause severe illness and sometimes be deadly for hospital patients. Treating these infections costs hospitals billions of dollars a year. The reduction is a promising sign coming on the heels of a significant spike in HAIs during the first two years of the COVID-19 pandemic.

“This is good news for patient safety and healthcare quality—we're thankful for the public health and healthcare partners that helped drive this progress,” Shelley Magill, MD, study co-author and acting deputy director for science and program with the Centers for Disease Control and Prevention’s (CDC’s) Division of Healthcare Quality Promotion, said in an agency press release.

HAIs come in many forms but are often a byproduct of the bacterial pathogens that lurk in hospitals, the invasive devices that can be contaminated with those pathogens, and patient procedures. They include surgical-site infections (SSIs), ventilator-associated pneumonia (VAP), central line–associated bloodstream infections (CLABSIs), and catheter-associated urinary tract infections (CAUTIs). 

Another common HAI, Clostridioides difficile infection (CDI), occurs when hospital patients are treated with antibiotics for another infection. The antibiotics disrupt the balance of bacteria in the gut, leading to the proliferation of C difficile, which infects the colon and causes severe diarrhea.

The CDC and the Centers for Medicare & Medicaid Services (CMS) have prioritized HAI reduction over the past two decades. In 2005, the CDC established the National Healthcare Safety Network (NHSN), which tracks HAIs at 25,000 US healthcare facilities. 

CMS in 2015 introduced a program to incentivize hospitals to reduce HAIs by reducing reimbursement payments to hospitals that rank in the worst-performing quartile on HAIs and other hospital-acquired conditions.

This is good news for patient safety and healthcare quality—we're thankful for the public health and healthcare partners that helped drive this progress.

Those efforts were bearing fruit until 2020, when the COVID pandemic hit and HAIs surged in US hospitals, fueled by an influx of severely ill COVID patients, staffing shortages, and disruptions to standard infection prevention and control (IPC) practices. Higher HAI rates continued through 2021.

To track HAI rates in 2023, researchers from the CDC and state public health departments conducted point-prevalence surveys from May through September at hospitals from 10 states in the CDC’s Emerging Infections Program, or EIP (California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee). Each site recruited up to 25 hospitals, for a total of 218. 

EIP staff identified HAIs from patient medical records using NHSN definitions. The results were compared with a similar survey conducted at EIP sites in 2015.

Overall, 355 (2.6%) of 13,653 patients in US hospitals in 2023 had at least one HAI on any given day, compared with 394 (3.2%) of 12,299 patients in 2015. Among the 151 hospitals that participated in both surveys, after adjustments were made for other factors, patients in 2023 were 27% less likely to have an HAI than patients in 2015.

The study authors said the reduction in HAIs occurred even though patients in the 2023 survey were older and had longer hospital stays than those in the 2015 survey. “Both factors that would be expected to increase, not decrease, the presence of healthcare-associated infections,” they wrote.

Minnesota state epidemiologist and study coauthor Ruth Lynfield, MD, said it was encouraging to see the HAI reductions after the pandemic-related increases observed in 2020 and 2021.

“As hospitals recovered from the challenges of the pandemic, infection prevention programs, staffing, and routine quality improvement efforts were re-established and strengthened,” Lynfield told CIDRAP News. “All of these contributed to the reduction in HAIs.”

The biggest contributors to the lower prevalence of HAIs in 2023 were reductions in CDI, CLABSIs, and CAUTIs. The authors suggest the CDI reductions could be related to more hospitals adopting a two-step testing process that’s better at identifying true CDI cases, along with more judicious diagnostic testing and improved antimicrobial stewardship and IPC. Implementation of established strategies to reduce device-associated infections may have played a role in fewer CAUTIs and CLABSIs, they add.

But the study still estimated that 518,000 HAIs occurred at US hospitals in 2023, and rates of pneumonia and SSIs did not change much from the 2015 survey. Furthermore, 61% of the HAIs in 2023 were not associated with medical devices or procedures. 

As hospitals recovered from the challenges of the pandemic, infection prevention programs, staffing, and routine quality improvement efforts were re-established and strengthened.

Lynfield said these types of HAIs—which include non–ventilator-associated pneumonia, gastrointestinal infections, and skin and soft tissue infections—can be more challenging to prevent than device- or procedure-associated HAIs.

“They are more varied, with different underlying mechanisms and risk factors, so there is no single prevention strategy that can be applied,” she explained. “In contrast, many device- and procedure-associated infections can be prevented through well-defined, evidence-based bundles that target specific risk factors.”

Lynfield added that hospitals would benefit from more data on the most effective strategies for preventing HAIs that aren’t linked to devices or procedures.

CMS administrator Mehmet Oz, MD, hailed the drop in HAIs but said more needs to be done. 

“No patient should leave the hospital sicker than when they arrived,” Oz said. “Progress so far is promising, but preventable harm across our healthcare system must continue to decline.”