Risk factors for colonization by carbapenemase-producing bacteria in Spanish long-term care facilities: a multicentre point-prevalence study

Background The emergence of carbapenemase-producing bacteria (CPB) has become a major public health concern. Long-term care facilities (LTCF) are potential reservoirs for multidrug-resistant micro-organisms (MDRO). However, data on CPB is limited. The study aims to determine the prevalence of MDRO and risk factors for CPB colonization among residents of LTCFs. Methods A point-prevalence study was conducted at 14 LTCFs in Tenerife (Spain) between October 2020 and May 2021. Nasal and rectal swabs were cultured for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), carbapenemase-producing Enterobacterales, MDR Acinetobacter baumannii (MDR-Ab) and MDR Pseudomonas aeruginosa . Antimicrobial susceptibility testing and molecular detection of resistance genes were performed. Risk factors for colonization by carbapenemase-producing bacteria (CPB) were determined by univariate and multivariate analysis. Results A total of 760 LTCF residents were recruited. The prevalence of colonization by CPB was 9.3% (n = 71) with the following distribution: 35 (49.3%) K. pneumoniae , 26 (36.6%) MDR-Ab, 17 (23.9%) E. coli , and 1 (1.4%) C. koseri . In addition, the prevalence of colonization by MRSA was 28.1% (n = 215) and only one case of VRE was isolated. Multivariate analysis identified male sex (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.86–3.11; P = 0.01), having a high health requirement (OR, 6.32; 95% CI, 1.91–20.92; P = 0.003) and previous hospitalization (OR, 3.60; 95% CI, 1.59–8.15 P = 0.002) as independent risk factors for CPB rectal carriage. Conclusions LTCFs are an important reservoir for MDRO, including CPB. We have identified some predictors of colonization by CPB, which enable a more targeted management of high-risk residents. Antimicrobial stewardship programmes and infection control preventive measures are needed to stop acquisition and transmission of MDRO.