SUPERBUGSStudy Highlights Community Spread of Superbugs

Published 3 August 2022

New US surveillance data indicate that infections caused by multidrug-resistant bacterial pathogens are moving beyond the healthcare setting.

New US surveillance data indicate that infections caused by multidrug-resistant bacterial pathogens are moving beyond the healthcare setting.

In a study published last week in the American Journal of Infection Control, researchers with the Centers for Disease Control and Prevention (CDC) and eight US public health departments reported that 1 in 10 infections caused by carbapenem-resistant Enterobacterales (CRE) were community-associated, occurring in patients without the known healthcare risks—like hospitalization or stays in long-term care facilities—typically associated with CRE infections. Most were found in white women with urinary tract infections (UTIs).

Furthermore, molecular analysis of samples from those infections identified the presence of an enzyme that makes bacteria resistant to multiple classes of antibiotics and is carried on mobile genetic elements that are easily shared with other bacteria.

The findings are concerning because CRE infections are resistant to most antibiotics and are considered a major public health threat by the CDC. And while CRE are already a major target of hospital infection prevention and control efforts, the worry is that once they’re established in the community and in a broader population, it will likely be more difficult to control them.

CRE cause difficult-to-treat infections and have the potential to spread rapidly, including outside of the healthcare setting, where most cases currently occur…and some Enterobacterales are common causes of infection that occur in the community already,” CDC epidemiologist and lead study author Sandra Bulens, MPH, told CIDRAP News. “So there’s a real potential for these organisms to spread into the community.”

CRE Are Spreading into a Broader Population
To get a baseline understanding of the incidence of community-associated CRE (CA-CRE) cases compared with healthcare-associated CRE (HCA-CRE) cases, and some of the associated risk factors, Bulens and her colleagues analyzed laboratory- and population-based surveillance data collected from eight sites in Georgia, Minnesota, Oregon, Colorado, New Mexico, Maryland, New York, and Tennessee from 2012 through 2015. The total population under surveillance in 2015 was approximately 15.2 million.