Discussion
infection, gram-negative, CRPA
INFECTION
This pragmatic, cluster-randomized, cross-over study showed that active surveillance testing to identify patients colonized with CRGNB was associated with non-statistically significant decrease in the acquisition of CRGNB in clinical specimens.Early detection of patients colonized or infected with CRGNB is important for implementing timely interventions to prevent subsequent spread. However, active surveillance testing is a complicated and resource-intensive intervention that has the potential for several adverse consequences, including reduced contact between healthcare workers and patients due to contact precautions [The incidence of CRGNB acquisition was higher in the period 1 (before COVID-19 pandemic) than in period 2 (after COVID-19 pandemic). The lower acquisition rate in period 2 may be associated with additional infection prevention measure to respond COVID-19 pandemic, especially universal donning of gown and glove. Previous cluster randomized study showed that universal glove and gown use was associated with decrease in acquisition of antibiotic-resistant gram-negative bacteria, although it was not statistically significant [In our subgroup analysis, the CRGNB acquisition rate was higher in the intervention period than in the control period in MICU1 and SICU2. Although a CPE outbreak occurred in SICU2, there was no outbreak of CRGNB in MICU1, and the reason for this unanticipated finding is unclear. It may be a seasonal effect, or more enhanced environmental cleaning might have been performed during the control period due to the COVID-19 pandemic, which occurred in the latter 6-month period (Additional file The acquisition rates of CRPA, CRAB, and CRE did not differ between the intervention and control periods. Because this trial was designed to identify the effectiveness of reducing the total CRGNB acquisition rate, further study is needed to identify the effectiveness of active surveillance testing for each organisms.Our study has some limitations. First, it was a single-center study with a low prevalence of CRGNB. A multicenter study with variable prevalences of CRGNB is warranted to generalize our findings. Despite this limitation, well-monitored infection control practices and policies to minimize unmeasured confounding factors by different centers during the study period is a strength of our study. Second, as this study was not blinded, the difference in the number of clinical specimens submitted to the laboratory may be present, and this may have affected the chance to detect CRGNB. However, the number of clinical specimen was not different between intervention and control periods in mITT analysis. Third, we did not perform surveillance testing during the control period, which may have biased our findings. However, we performed a pragmatic trial that reflects actual clinical practices, and we evaluated the outcomes of CRGNB acquisition in clinical specimens. Fourth, data regarding immunosuppressant use was absent. Use of immunosuppressant is associated with exposure to antimicrobials and acquisition of MDR gram-negative organism [