Molecular epidemiology and risk factors for extended-spectrum β-lactamase-producing Enterobacterales in long-term care residents

Objectives: We aimed to assess the burden of extended-spectrum β-lactamase
(ESBL)-producing Enterobacterales in Swiss long-term care facilities
(LTCFs) to describe the molecular epidemiology, describe the
intra-institutional and regional clusters of resistant pathogens, and
identify independent institution- and resident-level factors associated
with colonization. Design: Cross-sectional study. Setting and
participants: From August to October 2019, we performed a point prevalence
study among residents from 16 LTCFs in Western and Eastern Switzerland (8
per region). Methods: Residents underwent screening for ESBL-producing
Enterobacterales (ESBL-E); whole-genome sequencing (WGS) was performed. We
gathered institution-level (eg, number of beds, staff-resident ratio,
alcoholic hand rub consumption) and resident-level [eg, anthropometric
data, time in facility, dependency, health care exposure, antibiotic
treatment, proton-pump inhibitor (PPI) use] characteristics. Factors
associated with colonization were identified using a generalized linear
model. Results: Among 1185 eligible residents, 606 (51%) consented to the
study. ESBL-E prevalence was 11.6% (70/606), ranging from 1.9% to 33.3%
between institutions, with a median of 12.5% in the West and 6.9% in the
East (P = .03). Among 59 Escherichia coli (from 58 residents), multilocus
sequence type (ST) 131 was most common (n = 43/59, 73%), predominantly its
subclone H30R1 (n = 37/43, 86%). WGS data identified multiple
intra-institutional and regional clusters. Independent risk factors for
ESBL carriage were previous ESBL colonization [adjusted odds ratio (aOR)
23.5, 95% confidence interval (CI) 6.6–83.8, P < .001), male gender
(aOR 2.6, 95% CI 1.5–4.6, P = .002), and use of PPIs (aOR 2.2, 95% CI
1.2–3.8, P = .01). Conclusions and implications: Overall ESBL-E prevalence
in Swiss LTCF residents is low. Yet, we identified several clusters of
residents with identical pathogens within the same institution. This
implies that particularly affected institutions might benefit from
targeted infection control interventions. PPI use was the only modifiable
factor associated with carriage of ESBL producers. This study adds to the
growing list of adverse outcomes associated with PPIs, calling for action
to restrict their use in the long-term care setting.