Healthcare-associated infections (HAI) in acute care hospitals soared during the COVID-19 pandemic in 2020, potentially erasing years of progress in combating these infections, researchers said.

Significant increases in the national standardized infection ratios for central line-associated bloodstream infections, catheter-associated urinary tract infections, ventilator-associated events, and methicillin-resistant Staphylococcus aureus (MRSA) bacteremia were noted in 2020 over 2019, reported Lindsey Weiner-Lastinger, MPH, of the CDC, and colleagues.

Notably, central line-associated bloodstream infections had the largest increases, though ventilator-associated events also saw significant increases throughout 2020, which was unsurprising given the number of COVID patients requiring critical care, the authors wrote in Infection Control & Hospital Epidemiology.

A number of factors contributed to these increases, including more patients requiring the use of catheters and ventilators, as well as challenges with staffing and supply within hospitals, the team noted.

“COVID-19 created a perfect storm for antibiotic resistance and healthcare-associated infections in healthcare settings,” said Arjun Srinivasan, MD, associate director of Healthcare-Associated Infection Prevention Programs at the CDC, in a statement. “This information emphasizes the importance of building stronger, deeper, and broader infection control resources throughout healthcare that will not only improve our ability to protect patients in future pandemics, but will also improve patient care every day.”

From 2015 to 2019, “significant, consistent reductions” were seen in the incidence of central line-associated bloodstream infections, catheter-associated urinary tract infections, and Clostridioides difficile infection (CDI) laboratory-identified events, noted Weiner-Lastinger and colleagues, with some declines in MRSA bacteremia laboratory-identified events since 2010.

To gauge the impact of the pandemic on HAI incidence, the authors examined quarterly data from CDC’s National Healthcare Safety Network (NHSN), described as the largest HAI surveillance system in the U.S., and used by nearly all U.S. hospitals to report HAIs. Infections occurring in 2019 and 2020 were included, as were those reported to the NHSN Patient Safety Component as of April 1, 2021.

The largest year-to-year increases were in central line-associated bloodstream infections, for which incidence rose 46%-47% in the third and fourth quarter of 2020 over 2019. Ventilator-associated events rose 45% in the fourth quarter of 2020, while laboratory-identified MRSA bacteremia events were up 34% in the fourth quarter.

Not surprisingly, both urinary catheter and central line usage were higher from the second to fourth quarter of 2020, while ventilator use was higher in all four quarters, the authors said.

However, not all infections increased during the pandemic. An accompanying editorial by Tara Palmore, MD, and David Henderson, MD, both of the NIH Clinical Center in Bethesda, Maryland, noted that rates of surgical site infections and CDI did not increase during 2020.

“We hypothesize that surgical-site infection prevention relies on ingrained practices in antimicrobial stewardship, the preoperative arena, and the operating room, which were not as directly affected by the diversion of hospital infection control resources toward COVID-19,” they wrote.

Palmore and Henderson also speculated that a drop in outpatient antimicrobial prescriptions could have played a role in the lower rate of CDI.

Limitations included the fact that data from the fourth quarter of 2020 may have been incomplete, as well as the fact that the analysis was restricted to hospitals reporting in 2019 and 2020, so those opening new units in 2020 were not included. In addition, incidence of HAIs was only explored in hospitals, not critical access or long-term care facilities.

A press release from the CDC said that these results emphasize the need for hospitals to continue to reinforce infection prevention and control practices and continually monitor and review HAI surveillance data.

“CDC will continue to invest in healthcare infection prevention, training for all healthcare providers, and ensuring healthcare facilities and partners in state and local health departments have actionable data to ensure that individuals who need healthcare during the pandemic and beyond are able to receive safe care,” the release stated.