Immunovirological and environmental screening reveals actionable risk factors for fatal COVID-19 during post-vaccination nursing home outbreaks.

Coronavirus Disease 2019 (COVID-19) vaccination has resulted in excellent protection against fatal disease, including in older adults. However, risk factors for post-vaccination fatal COVID-19 are largely unknown. We comprehensively studied three large nursing home outbreaks (20-35% fatal cases among residents) by combining severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) aerosol monitoring, whole-genome phylogenetic analysis and immunovirological profiling of nasal mucosa by digital nCounter transcriptomics. Phylogenetic investigations indicated that each outbreak stemmed from a single introduction event, although with different variants (Delta, Gamma and Mu). SARS-CoV-2 was detected in aerosol samples up to 52 d after the initial infection. Combining demographic, immune and viral parameters, the best predictive models for mortality comprised IFNB1 or age, viral ORF7a and ACE2 receptor transcripts. Comparison with published pre-vaccine fatal COVID-19 transcriptomic and genomic signatures uncovered a unique IRF3 low/IRF7 high immune signature in post-vaccine fatal COVID-19 outbreaks. A multi-layered strategy, including environmental sampling, immunomonitoring and early antiviral therapy, should be considered to prevent post-vaccination COVID-19 mortality in nursing homes.

Infection prevention and control challenges in Flemish homecare nursing: a pilot study.

Home nursing is evolving towards more invasive care. Nevertheless, no national data are available on the prevalence of HAI in this setting. The aim of this pilot study is to explore the Flemish home care setting as a first step toward a national surveillance program. A survey, focused on patient characteristics and HAI, was conducted between 7 May and 20 July 2018 on 711 Flemish patients. Most of the patients (74%) are 65 years or older and half of them had a form of comorbidity. Assisting with personal hygiene and wound care were the most frequent services delivered by home care nurses. A comparison of the prevalence of infections diagnosed by a physician or applying uniform criteria (ECDC), revealed a similar prevalence of skin and soft tissue infections (9% vs. 8.5%) and urinary tract infections (4% vs. 4.5%). A positive MDRO-screening was found in 6% of the patients. This pilot study is a first step towards a standardized national surveillance in home care to collect information on the prevalence of HAI and it reveals several interesting facts and study pitfalls for this setting.