Effectiveness of annual influenza campaigns and vaccination in reducing influenza burden in nursing homes of Canton Vaud in Switzerland.

BACKGROUND: Influenza infections pose significant risks for nursing home (NH) residents. Our aim was to evaluate the impact of the cantonal influenza campaign, and influenza vaccination coverage of residents and healthcare workers (HCWs) on influenza burden in NHs in a context of enhanced infection prevention and control measures (IPC) during the SARS-CoV-2 pandemic. METHODS: We extracted data from epidemic reports provided by our unit to NHs over two consecutive winter seasons (2021-22 and 2022-23) and used linear regression to assess the impact of resident and HCW vaccination coverage, and participation in the campaign, on residents' cumulative influenza incidence and mortality. RESULTS: Thirty-six NHs reported 155 influenza cases and 21 deaths during the two winter seasons corresponding to 6.2% of infected residents and a case fatality ratio of 13.5%. Median vaccination coverage was 83% for residents, 25.8% for HCWs, while 87% of NHs participated in the campaign. Resident vaccination was significantly associated with a decrease in odds of death (odds ratio (OR) 0.96, 95% confidence interval (CI): 0.93-0.99). There was no significant effect of HCW vaccination coverage on resident infections and deaths. Campaign participation was associated with decreased odds of infection and death among residents (OR: 0.17, 95% CI: 0.06-0.47 and OR: 0.06, 95% CI: 0.02-0.17 respectively). CONCLUSION: Our analysis suggests that in a context of reinforced IPC measures, influenza still represents a significant burden for NH residents. The most effective measures in decreasing resident influenza burden in NHs was participation in the cantonal influenza vaccination campaign and resident vaccination.

Molecular Epidemiology and Risk Factors for Extended-Spectrum ß-Lactamase-Producing Enterobacterales in Long-Term Care Residents.

OBJECTIVES: We aimed to assess the burden of extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales in Swiss long-term care facilities (LTCFs) to describe the molecular epidemiology, describe the intrainstitutional 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 intrainstitutional 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.