A recent study has shed light on the ongoing challenge of antimicrobial resistance (AMR) in the US.
Despite strides made in combatting AMR since its peak during the COVID-19 pandemic, hospital-acquired AMR infections remain significantly above pre-pandemic levels.
Led by Dr Christina Yek from the US National Institute of Allergy and Infectious Diseases (NIAID), the study analysed AMR infection rates before, during, and after the COVID-19 pandemic across 120 US hospitals.
The study, presented at this year’s ESCMID Global Congress, emphasised the persistence of hospital-onset infections, particularly those caused by gram-negative resistant organisms.
The findings underscore the urgent need for action to identify the drivers and solutions for difficult-to-treat gram-negative AMR.
AMR is estimated to cause at least 35,000 deaths annually in the US and 1.27 million worldwide, indicating the gravity of the issue.
Pre-pandemic trends
A US Centers for Disease Control and Prevention report in 2022 revealed alarming rises in AMR infections across US hospitals during the initial year of the COVID-19 pandemic.
Resistant hospital-related infections surged by 15% between 2019 and 2020, yet the key drivers and lasting effects remained unexplored.
Investigating the rise of AMR infections
Researchers analysed trends in AMR incidence in adults across the 120 hospitals before (Jan 2018–Dec 2019), during (March 2020–Feb 2022), and after the pandemic (March–Dec 2022).
They examined culture-confirmed infections by six pathogens, distinguishing between community-acquired and hospital-acquired infections.
These included methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended-spectrum cephalosporin-resistant Enterobacterales (ECR), carbapenem-resistant Enterobacterales (CRE), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CR-PA).
During the pandemic, the prevalence of AMR infections increased by 6.3%, primarily driven by a significant rise in hospital-acquired resistant infections.
Notably, gram-negative pathogen infections, resistant to multiple drugs and increasingly resistant to most antibiotics, surged by almost 20% compared to pre-pandemic levels.
Specific increases
The most substantial increases were observed in hospital-acquired infections resistant to carbapenems, vital antibiotics for severe infections. Infections caused by CRAB increased by 151%, CRE by 62%, and CR-PA by 54% during the pandemic.
Conversely, community-acquired MRSA infections declined by 10% and 19% during and after the pandemic, respectively. This trend, predating the pandemic, might have been bolstered by reduced societal mobility and interactions due to pandemic restrictions.
Impact of COVID-19 patient surges
Hospitals experiencing surges in severely ill COVID-19 patients during the pandemic witnessed the largest increases in hospital-acquired AMR infections.
Larger hospitals with higher bed capacity had more than double the odds of AMR infections compared to smaller ones.
While overall AMR incidence nearly returned to pre-pandemic rates post-pandemic, hospital-acquired AMR infections remained 13% above pre-pandemic levels in December 2022.
The persistence of gram-negative pathogen infections resistant to first-line antibiotics remains a concern.
The study’s findings underscore the ongoing challenge of combating AMR, particularly in hospital settings.
Addressing the persistence of hospital-acquired AMR infections, especially those caused by gram-negative organisms, requires concerted efforts in surveillance, infection control, and antibiotic stewardship.
