Key factors in screening for extended-spectrum beta-lactamase (ESBL)-producing bacteria and carbapenemase-producing organism (CPO): A narrative synthesis of current evidence

Abstract

Background and aim Extended-spectrum beta-lactamases (ESBLs) are enzymes produced by gram-negative bacteria that inhibit the effect of the most common types of betalactam antibiotics. Carbapenemase-producing organisms (CPO) possess mechanisms that also make them resistant to broad-spectrum betalactams. These bacteria are significant in the context of infection prevention and control (IPC) measures in healthcare due to its resistance mechanisms, high disease burden and limited treatment options. National prevention guidelines in Norway and Denmark were updated in 2015 and 2018, respectiveely. In 2023, the Norwegian Institute of Public Health (NIPH) and the Statens Serum Institut (SSI) decided to collaborate on proposals for new national recommendations for screening targeting resistant microbes of special significance to healthcare. We conducted literature reviews to update screening recommendations for resistant microbes in healthcare. This literature review is part of a series of reviews aimed at providing evidence to support this process. Methods We systematically searched five databases for systematic reviews and primary literature from the Nordic countries and the Netherlands. Inclusion criteria included whether outcomes were duration of colonisation, risk of transmission, prevalence of ESBL-producing bacteria and CPO among different patient populations and in different settings, or individual factors associated with ESBL/CPO- colonisation or infection. We excluded studies on treatment, management, laboratory methods, drug resistance, and environmental screening. We did not to include a discussion section in this report, as the interpretation of the results will be addressed in a more comprehensive assessment, which will incorporate all evidence syntheses along with other considerations. Results We found 437 systematic reviews and 52 primary studies to be relevant. Assessments of duration of colonisation and long-time carriage remain challenging based on identified studies, but there might be a trend that persistent colonisation decreases over time. Evidence on risk of infection/ colonisation with ESBL-producing bacteria and CPO after exposure is limited to a few settings in the systematic reviews found. The exposure may increase the risk of transmission, but the evidence is scarce. Studies on prevalence in different setting showed a relatively high prevalence of resistance in countries outside the Nordic region, especially in Southeast Asia and Africa. Studies on asylum seekers and refugees found a colonisation rate of multidrug-resistant bacteria up to 45%. Associated factors with ESBL/CPO colonisation were travel to countries outside Europe and medical travel. Other associated factors were prior antibiotic use, surgery, mechanical ventilation and catheter use. Conclusion This overview showed that persistent ESBL/CPO colonization can decrease over time. Documentation on the risk of transmission remains inconclusive. Important associated factors for ESBL/CPO colonization include travel to countries outside of Europe, medical travel, use of antibiotics, surgery, respiratory therapy, and catheter use. The studies also showed a high prevalence of colonization among asylum seekers and refugees.