Effects of screening strategies to detect carbapenem-resistant gram-negative bacteria: A systematic review

Objective: This systematic review aims to summarize the evidence on the effects of screening strategies to detect carbapenem-resistant gram-negative bacteria (Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa).Methods: Eligible studies were randomized trials, non-randomized controlled trials, controlled before-after studies, and interrupted time series. We conducted searches in CENTRAL, PUBMED, Embase, Epistemonikos, and in multiple databases available in the Virtual Health Library (LILACS, Scielo, WHO IBECS, and PAHO IBECS). All the searches covered the period until 4 June 2021. No date or language restrictions were applied. Two reviewers independently evaluated potentially eligible studies according to predefined selection crite-ria, and extracted data on study characteristics, methods, outcomes, and risk of bias, using a predesigned standardized form. When possible, we intended to conduct meta-analyses using a random-effect model. We assessed the certainty of the evidence (CoE) and summarized the results using the GRADE approach.Results: Our search strategy yielded 57,451 references. No randomized trials were identified. Sixteen studies (one controlled before-after study and 15 interrupted time series) met our inclusion criteria and were included in the review. Most studies were conducted in tertiary care general hospitals from the United States, Europe, and Asia. Eleven studies included adult patients hospitalized in general wards and intensive care units, one was carried out in a neonatal intensive care unit, two in hematology or oncology units, and one in a solid organ transplantation department. Eleven studies were conducted in the setting of an outbreak. Regarding the detection strategy used, all studies included screening strategies for high-risk patients at the moment of admission and 7 studies reported a contact surveillance strategy. Most studies were conducted in settings where infection prevention and control measures were concomitantly installed or reinforced. Data were not suitable for meta-analysis, so the results were presented as a narrative synthesis. Most studies showed a decline in the prevalence of both infection and colonization rates after the implementation of a pol-icy of active surveillance, but the CoE is low. Screening strategies may result in little to no difference in the risk of all-cause mortality and the length of hospital stay.Conclusions: Existing evidence may favor the use of surveillance culture to carbapenem-resistant gram -neg-ative bacteria, but its quality is poor, so solid conclusions cannot be drawn. Well-conducted randomized trials or high-quality quasi-experimental studies are needed to improve the certainty of the existing evidence. These studies should assess the effect of the addition of screening strategies as a single intervention and mea-sure clinically important outcomes such as infection, length of hospital stay, and mortality.(c) 2022 The Author(s). Published by Elsevier Inc. on behalf of Association for Professionals in Infection Control and Epidemiology, Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Automated summary

This systematic review aims to summarize the evidence on the effects of screening strategies to detect carbapenem-resistant gram-negative bacteria. The review found that there was a decline in the prevalence of infection and colonization rates after the implementation of active surveillance, but the quality of the evidence was low. Screening strategies may not have a significant impact on all-cause mortality risk and length of hospital stay. More high-quality studies are needed to improve the certainty of the existing evidence.